ANÁLISIS COMPARATIVO DE ELEMENTOS DEL TREN DE...

ANÁLISIS COMPARATIVO DE ELEMENTOS DEL TREN DE POTENCIA DE VEHÍCULOS ELECTRICOS DE CLASE M Y N

SEPTIEMBRE 2019

Elena Irene Jaimez Farnham

DIRECTOR DEL TRABAJO FIN DE GRADO:

José María López Martínez

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TRABAJO FIN DE GRADO PARA

LA OBTENCIÓN DEL TÍTULO DE

GRADUADO EN INGENIERÍA EN

TECNOLOGÍAS INDUSTRIALES

Resumen ejecutivo

Una de las cuestiones que ha adquirido más relevancia en las últimas décadas se encuentra en la necesidad de reducir nuestras emisiones de gases de efecto invernadero. Y siendo el sector transportes uno de los principales emisores a nivel mundial, la reducción de la contaminación producida por este sector se presenta como un factor crucial para este fin.

Es precisamente por ello que los órganos gubernamentales y administrativos están tomando medidas restrictivas a nivel mundial, y no sólo con el control del tránsito de vehículos convencionales de combustión, sino que también con la inversión en nuevas tecnologías para sustituir a este tipo de vehículos.

La movilidad eléctrica ha demostrado ser una de las apuestas más exitosas de las nuevas tecnologías que han estado siendo desarrolladas, de manera que los vehículos eléctricos ya se han abierto camino en el mercado automovilístico. Y aunque solamente el 2’2% de la población de vehículos son eléctricos, esta cifra parece que continuará aumentando en los próximos años.

La transición hacia una movilidad eléctrica resulta especialmente desafiante en el ámbito de vehículos de medio y alto tonelaje. Uno de los mayores retos que conlleva este cambio es minimizar el peso de las baterías, ya que, aunque sea una característica deseada para cualquier tipo de vehículo, es especialmente necesario tener baterías con altas densidades de energía para poder desplazar vehículos de elevados pesos brutos, y a la vez con un peso bajo para poder alcanzar autonomías medianamente altas. Además, los vehículos de medio y alto tonelaje son precisamente los responsables de la mayoría de las emisiones procedentes del sector transportes (aproximadamente un 40% de su total), y por ello esta transición es necesaria.

El instituto PEM (Production Engineering of E-mobility Components) de la Universidad Técnica de Aquisgrán, en el cual se ha realizado este trabajo, se encarga de la investigación y desarrollo de la producción de elementos de vehículos eléctricos, y actualmente cuentan con el proyecto “Life” para vehículos pesados, precisamente para evaluar las mejores técnicas aplicables a la industria automovilística para alto tonelaje.

Puesto que el mercado de vehículos eléctricos es relativamente nuevo, las compañías que fabrican este tipo de productos disponen de una cierta libertad para su diseño y su desarrollo. Pero esta falta de directrices en la producción conlleva que los fabricantes también tengan que aportar grandes labores investigativas previas, además de complicar el proceso de producción y de aumentar sus costes. Por este motivo es necesario establecer una serie de estándares en el mercado de vehículos eléctricos. Esta determinación favorecerá una maduración tecnológica más rápida y óptima en este sector, lo que a su vez permitirá acelerar la transición hacia una movilidad con un mayor porcentaje de vehículos eléctricos

La Comisión Europea tiene establecidas mediante la ley comunitaria cuatro grandes categorías en las que clasifica todos los tipos de vehículos de carretera. Este agrupamiento es imprescindible para mantener una competitividad en la industria automovilística, posibilitando a los fabricantes obtener un beneficio del mercado interior de la Unión Europea y a su vez, exportar sus productos a países que se encuentran fuera de la Unión.

Estas categorías impuestas por la Comisión Europea permanecen inalteradas de cara a la sustitución de los vehículos de motores de combustión por medios de

transportes más limpios. Por tanto, la introducción de trenes de potencia eléctricos en nuestros vehículos solamente implica un cambio en la tecnología empleada, y el concepto de movilidad integrado por los vehículos convencionales permanece inalterado.

En este trabajo se han analizado los componentes de los trenes de potencia de los vehículos eléctricos de batería de las clases M y N, respectivamente correspondientes a aquellos vehículos motorizados de al menos cuatro ruedas destinados al transporte de pasajeros y a los vehículos motorizados de al menos cuatro ruedas con la función del transporte de mercancías. Dentro de cada una de estas clases se han diferenciado también las categorías limitadas por pesos brutos. De esta forma, en la categoría M encontramos M1 (peso bruto inferior a 3,5 toneladas), M2 (peso bruto entre 3,5 y 5 toneladas) y M3 (peso bruto superior a 5 toneladas), y en la categoría N encontraremos N1 (peso bruto inferior a 3,5 toneladas), N2 (peso bruto entre 3,5 y 12 toneladas) y N3 (peso bruto superior a 12 toneladas).

El tren de potencia de un vehículo se corresponde con el circuito que sigue la energía en éste, desde la entrada de la energía, su traspaso hasta la llegada al motor, y saliendo finalmente en forma de energía mecánica por los ejes motrices de éste. En el caso de un vehículo eléctrico, los componentes que integran su tren de potencia son el sistema de carga, la batería, el conversor DC/DC o DC/AC, el motor eléctrico y la transmisión.

De los cinco elementos nombrados en el párrafo anterior, son la batería y el motor eléctrico los dos componentes más relevantes y, por tanto, este trabajo se ha centrado en obtener un mayor número de datos de estos dos elementos.

La batería es el componente encargado de recibir energía en forma de corriente continua durante su carga y acumularla como energía electroquímica. Durante su descarga esta energía es expulsada también como corriente continua. Los datos más relevantes para analizar de la batería son el tipo de tecnología empleada para sus celdas, el tiempo de carga y los distintos métodos posibles para ello, y la capacidad de la batería. Este último dato es el que determina la energía máxima que es capaz de acumular el paquete de baterías que está integrado en el vehículo y, por tanto, la distancia máxima que puede recorrer el vehículo sin necesidad de ser recargado.

El motor eléctrico transforma la energía eléctrica que recibe en forma de corriente continua o corriente alterna (dependiendo del tipo de motor del que se trate) en energía mecánica, empleada para mover las ruedas motrices. En el motor los datos de mayor relevancia serán el tipo de motor empleado, y los respectivos máximos de potencia y torque. Estos dos últimos parámetros serán buenos indicadores de rendimiento, y su comparación entre distintos modelos permitirá comprobar la existencia de algún tipo de correlación.

El análisis comparativo (o “benchmarking” en inglés) permite comparar distintos procesos y rendimientos parametrizados que se utilizan en la práctica industrial, de forma que es posible analizar cuáles son las mejores prácticas del sector y cuáles son las compañías que las están desarrollando. Es particularmente interesante en la industria automovilística y ha tenido siempre un cierto énfasis en las labores investigativas de las distintas empresas.

Este proyecto incluye un total de 167 de los que se han obtenido una serie de datos reunidos en tablas Excel y se han podido comparar entre ellos, tanto por categorías individuales como en conjunto total. Puesto que no todos los datos estaban

disponibles, se han representado gráficamente aquellos datos con mayor accesibilidad, que a la vez son de los más característicos para su correspondiente elemento del tren de potencia. La visualización gráfica permite apreciar con mayor facilidad las diferencias entre estos valores para los distintos modelos incluidos en el trabajo.

El análisis comparativo también ha podido reflejar las diferencias entre las distintas categorías de vehículos, demostrando un escaso número de modelos en ciertas categorías, como en las M2 y N3. Además, los vehículos destinados al transporte de pasajeros presentan un desarrollo mucho más extenso que aquellos empleados para el transporte de bienes. Los coches eléctricos de baterías (categoría M1) han empezado a alcanzar una madurez tecnológica que les está permitiendo empezar a competir en el mercado con vehículos convencionales de gasolina. A su vez, los autobuses eléctricos han estado aumentando con el fin de mejorar la calidad del aire en zonas urbanas.

Los alcances registrados para todos los vehículos de todas las clases presentan valores superiores a 100 km en una sola carga de batería. Sin embargo, por encima de este valor, las autonomías varían en un espectro muy amplio, llegando hasta los 450 km en una carga para algunos de los modelos de Tesla. Esto demuestra la inexistencia de una dirección determinada en los valores de todas las categorías.

La capacidad de las baterías también ha demostrado presentar índices muy dispersos para las seis categorías incluidas. Los valores oscilan entre los 20 kWh para algunos vehículos de clase M1, con alcances y pesos relativamente bajos, hasta los 500 kWh para algunos vehículos de clase M3, que tienen que transportar pesos elevados y a la vez obtener una autonomía lo suficientemente elevada.

Además de lo mencionado en los últimos dos párrafos, la esperada correspondencia entre autonomía sí se ha podio observar con una ligera correlación, de forma que, para lograr obtener mayores autonomías, es necesaria una mayor capacidad de energía en la batería. Y también hemos notado como para algunos vehículos de alto tonelaje y alta capacidad, la autonomía es relativamente baja debido a la carga que tienen que llevar. Aún así, hay también muchos modelos que se salen de estas relaciones, de forma que hay vehículos con bajas autonomías, bajas capacidades y a la vez bajos tonelajes, a la vez que vehículos con altas autonomías, altas capacidades y altos tonelajes. Estos dos aspectos dificultan también la definición de una tenencia específica para los paquetes de batería en los vehículos eléctricos de batería.

Respecto a las características del motor, tanto potencia máxima alcanzada como par máximo presentan valores dentro de un rango muy amplio. Aunque para potencia máxima el rango es relativamente más estrecho que para otros valores, sigue siendo relativamente más estrecho que para el resto de los valores. Sin embargo, el torque máximo sí presenta una gran variación de unos modelos a otros dentro de una misma categoría. Esto ocurre especialmente en vehículos que funcionalmente llevan cargas muy pesadas, y tienen la posibilidad de obtener un alto torque total mediante el empleo de varios motores de pares más bajos, o mediante la inserción de un solo motor que proporcione un par muy elevado.

En los sistemas de carga también disponemos de un gran espectro de posibilidades. A pesar de existir ya una serie de tipos y métodos de carga, la capacidad de la batería y su habilidad para ser recargada todavía no ha alcanzado por completo sus niveles de desarrollo. En consecuencia, se pueden obtener tiempos de carga muy dispares con métodos de corriente continua o de corriente alterna y con capacidades de

baterías muy diferentes, de forma que tampoco es posible observar ningún tipo de directriz para estos valores.

Todos estos resultados nos permiten declarar que hay una clara ausencia de estándares en los vehículos eléctricos de carretera. Aunque este hecho produce por una parte una situación ventajosa, ya que las compañías son otorgadas la libertad de diseñar y fabricar vehículos eléctricos con la tecnología que ellos mismos desarrollan y encuentran más apropiada. Sin embargo, por otra parte, esto también complica la distribución de este tipo de vehículos en el mercado público, ya que la existencia de unas diferencias tan notables en un mismo producto complica su capacidad de venta.

Es por esta razón que la evolución tecnológica del vehículo eléctrico poco a poco tendrá que ir tomando forma para estabilizar este tipo de producto en el mercado. El alcance que ofrecen los vehículos convencionales de combustión es uno de los principales retos a los que se enfrentan los vehículos

Aunque es importante tener en cuenta que los vehículos convencionales de combustión han sido desarrollados e investigados a lo largo de todo el siglo XX. Y considerando que los avances tecnológicos están teniendo lugar con un índice de frecuencia mucho más alto, estas progresiones pueden acaecer en los próximos años.

Actualmente el progreso de los vehículos eléctricos está apuntando hacia la asequibilidad del producto ofrecido por este sector. Puesto que el mercado de la electro-movilidad es tan reciente y no ha experimentado una fuerte demanda, los precios de estos vehículos no son competitivos comparados con aquellos de los vehículos de combustión.

La necesidad de promover la investigación en electro-movilidad es crucial para solventar el problema de las emisiones producidas por el sector transportes. Desafortunadamente, nuestras emisiones globales tienen que ser reducidas drásticamente en los próximos años para poder conservar nuestro planeta tal y como lo conocemos. Por ello, no solo es el sector transporte el que tiene que trabajar en el desarrollo de nuevas tecnologías, sino que todos los sectores de sociedad tienen que intervenir. La situación de concienciación y toma de acción ha mejorado en los últimos años, y están avanzando incluso más rápido hoy día, pero aún hay mucho por hacer.

Palabras clave: vehículo eléctrico, directriz, desarrollo, capacidad de batería, autonomía, potencia máxima suministrada por motor, par máximo suministrado por el motor

Presupuesto: 5.296,99 euros

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1. Sumario del trabajo

Introducción y teoría del vehículo eléctrico

La necesidad de reducir nuestras emisiones de gases de efecto invernadero ha sido una cuestión muy relevante a lo largo de las últimas décadas. Y recientemente, esta situación ha desencadenado una insistente demanda por parte de la población hacia los organismos políticos a nivel mundial para que tomen medidas de forma eminente.

En este contexto de necesidad de reducir nuestras emisiones, las regulaciones impuestas globalmente han comenzado a presentar un carácter mucho más estricto en todas las áreas. El sector transportes, aunque se trata del cuarto mayor emisor de gases de efecto invernadero a nivel mundial, es el primer emisor en Estados Unidos y el segundo de Europa. Por tanto, la reducción de emisiones de este sector es crucial.

Las medidas restrictivas tomadas en los últimos años están teniendo un impacto más notable sobre el tránsito de vehículos en las grandes ciudades. Esto es debido a que los parámetros de calidad del aire están alcanzando niveles preocupantes de cara a la salud ciudadana. Con ello, no sólo se está restringiendo la circulación por la ciudad, sino que además se está invirtiendo en nuevas tecnologías de transporte público para disminuir las emisiones procedentes de este tipo de vehículos.

La sustitución de los vehículos de combustión interna ha desatado la aparición de numerosas alternativas tecnológicas, como el gas natural licuado (GNL), biodiesel o las pilas de combustible de propano. Aunque son los vehículos híbridos y eléctricos los que han tomado un papel más relevante en el desarrollo de un transporte limpio en carretera. Actualmente sólo el 2’2% de los automóviles destinados al transporte de pasajeros son eléctricos, pero esta cifra aumentará en los próximos años.

Adentrándonos más en los valores de las emisiones en el sector transporte, es destacable el hecho de que la población de camiones solamente suma el 9% del número total de vehículos en Europa, pero sus emisiones son responsables de casi el 40% de las emisiones totales debidas al transporte por carretera. Además de este aspecto, se prevé que la población de camiones sobrepasará el doble de las cifras actuales, lo que conllevaría un incremento drástico de las emisiones producidas por este sector.

Puesto que la electrificación de los medios de transporte ha demostrado ser la solución más exitosa en los últimos años, muchas compañías han empezado a invertir en la investigación y desarrollo de la electrificación de transporte pesado y semipesado. Esta transición supone un gran desafío para la industria automovilística, pero indudablemente se trata de un área que se tiene que promover.

La relativa novedad del sector de vehículos eléctricos implica que las compañías que están fomentando este tipo de productos disponen de una cierta libertad para su diseño y desarrollo. Pero esta falta de directrices en la producción conlleva que los fabricantes también tengan que aportar grandes labores investigativas previas, además de complicar el proceso de producción y de aumentar sus costes.

Por este motivo es necesario establecer una serie de estándares en el mercado de vehículos eléctricos. Esta determinación favorecerá una maduración tecnológica más rápida y óptima en este sector, lo que a su vez permitirá acelerar la transición hacia una movilidad eléctrica.

Se conoce como vehículo eléctrico aquel que cuenta con uno o varios motores eléctricos (también llamados motores de tracción) para su propulsión. Hay un amplio rango de posibilidades de fuentes de energía que pueden ser utilizadas para alimentar al motor

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eléctrico, dentro de las cuales podemos distinguir dos categorías. Por una parte, las fuentes de energía contenidas en el vehículo, como las baterías o los generadores, que reciben electricidad de por medio de conversión de combustible o por paneles solares. Por otra parte, encontramos las fuentes no-contenidas en el vehículo, como los sistemas de catenaria, mediante las cuales los vehículos emplean sistemas de colección de corriente externas para alimentar el motor.

Recientemente la noción de movilidad eléctrica ha adoptado una nueva forma, pudiendo referirse también a todos los medios de transporte alternativos de carretera que están basados en medios de propulsión eléctrica. Por tanto, es posible encontrar ambas definiciones en fuentes de información distintas, siendo esta última la más popular de las dos. Pero realmente podemos encontrar vehículos de impulsión eléctrica en todas las áreas de movilidad, existiendo distintos tipos de ellos tanto para vehículos de suelo, aire, mar e incluso vehículos espaciales de propulsión eléctrica.

La primera aparición de los vehículos eléctricos se remonta hace mediados del siglo XIX, inicialmente mediante el uso de corriente continua y posteriormente evolucionando hacia sistemas de corriente alterna. Los sistemas de electrificación ferroviaria y los vehículos eléctricos de carretera fueron los primeros en surgir, y por tanto son los que tienen un mayor recorrido histórico y de desarrollo.

La locomotora eléctrica ha experimentado una de las mayores extensiones en el ámbito ferroviario, siendo hoy día prácticamente todos los vehículos de este sector eléctricos. Europa cuenta con un amplio sistema de transporte por tren, muchos de los cuales son de alta velocidad. También muchas ciudades presentan memorables sistemas de metro subterráneo, como Nueva York o Londres, y otros sistemas de tranvía, como Muni Metro en San Francisco o la red de tranvía en Lisboa. Este tipo de sistemas son muy eficaces para mejorar los niveles de calidad del aire en los centros de grandes ciudades, aunque inicialmente no hubieran sido diseñados para este fin.

A diferencia de lo ocurrido con el desarrollo del sistema ferroviario eléctrico, el transporte eléctrico en carretea sí ha experimentado su extensión en los últimos años debido a la necesidad de reducir la contaminación. No obstante, los primeros coches eléctricos surgieron a finales del siglo XIX, pero se vieron rápidamente eclipsados con la aparición de los vehículos de motor de combustión interna. Es por ello que los coches alimentados con diésel o gasolina han contado con cien años de estudio y mejora, que los ha llevado a la situación tan extendida que tienen ahora.

Fue a principios del siglo XXI cuando distintos fabricantes de coches empezaron a sacar sus primeros conceptos de vehículos eléctricos y hacer algunos de ellos ponibles en el mercado. La aparición de la compañía Tesla, Inc. en 2003 desencadenó una situación de competencia entre los fabricantes, de tal forma que empezaron a verse más modelos eléctricos disponibles en el mercado.

Actualmente sólo uno de cada 250 coches en la carretera es eléctrico, a pesar de haber alcanzado un récord de ventas en 2018 con dos millones de vehículos vendidos. Se espera que estas cifras aumenten en los próximos años, pero la transición hacia el empleo de este tipo de vehículos viene acompañada de una serie de desafíos que también habrá que afrontar.

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Situación tecnológica

La Comisión Europea tiene establecidas mediante la ley comunitaria cuatro grandes categorías en las que clasifica todos los tipos de vehículos de carretera. Este agrupamiento es imprescindible para mantener una competitividad en la industria automovilística. Las categorías organizan los vehículos en grupos con un objetivo regulador, el cual posibilita a los fabricantes obtener un beneficio del mercado interior de la Unión Europea y a su vez, exportar sus productos a países que se encuentran fuera de la Unión. Todos estos aspectos pertenecen a la llamada armonización técnica de los productos de la UE.

Estos cuatro grupos definidos por el marco europeo son las categorías M, N, L y T. La categoría M engloba a aquellos vehículos motorizados de al menos cuatro ruedas destinados al transporte de pasajeros. La categoría N abarca a los vehículos motorizados de al menos cuatro ruedas con la función del transporte de mercancías. Finalmente, las categorías L y T incluyen respectivamente a los vehículos motorizados de menos de cuatro ruedas y a los vehículos motorizados, de ruedas o de oruga para agricultura o forestación.

Estas categorías impuestas por la Comisión Europea permanecen inalteradas de cara a la sustitución de los vehículos de motores de combustión por medios de transportes más limpios. Por tanto, la introducción de trenes de potencia eléctricos en nuestros vehículos solamente implica un cambio en la tecnología empleada, y el concepto de movilidad integrado por los vehículos convencionales permanece inalterado.

Considerando una clasificación de los vehículos desde un punto de vista tecnológico, dentro del tipo de vehículos eléctricos podemos diferenciar los siguientes tres grupos, dependiendo del de las distintas fuentes de energía con las que cuentan.

En primer lugar, encontramos el vehículo híbrido. Este tipo de automóvil fue de los primeros que salió al mercado consiguiendo un número de ventas más alto. Se caracterizan por recibir la energía para su movimiento de al menos dos fuentes de energía distintas y, por tanto, tiene integrados al menos dos trenes de potencia distintos. La combinación más frecuente en estos vehículos es la de el motor de combustión interna con componentes eléctricos. Es por esta razón que comúnmente se conoce a estos vehículos solamente por combinar estas dos fuentes de energía.

Dependiendo de la disposición del tren de potencia de los vehículos híbridos, podemos encontrar principalmente tres configuraciones distintas de sus elementos. Los híbridos-serie disponen las fuentes de energía de forma seguida, tal que el motor de combustión está conectado al motor eléctrico, y no hay conexión mecánica entre el motor de combustión y las ruedas motrices. Los híbridos-paralelo tienen tanto el motor eléctrico como el de combustión interna conectados a las ruedas motrices, lo que permite utilizar ambos mecanismos simultáneamente o por separado. Por último, los híbridos de potencia dividida presentan una mayor complejidad que las otras dos configuraciones, integrando una mezcla de estas dos, pero obteniendo finalmente una mayor eficiencia.

En segundo lugar, encontramos los vehículos eléctricos de alcance extendido, o EREV por sus siglas en inglés “Extended Range Electric Vehicle”. Dispone también de un motor de combustión interna y de un sistema eléctrico, pero no se trata explícitamente de uno de los vehículos híbridos descritos anteriormente por el tipo de acoplamiento de los elementos en el tren de potencia.

Por último, los vehículos eléctricos de batería, en cuyo tren de potencia sólo hay una fuente de potencia que alimenta al motor eléctrico, que son baterías recargables. Este tipo de configuración es el estudiado en este trabajo.

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A continuación, se presentará un breve resumen de los componentes que integran el

tren de potencia de un vehículo eléctrico y su funcionamiento. Esto nos permitirá comprender mejor la selección de los elementos que incluiremos en el análisis comparativo posterior.

Siguiendo el orden según el flujo de energía desde la toma de corriente hasta la salida de par por la transmisión en el eje hacia la rueda, podemos diferenciar cinco elementos principales que participan en el proceso. Éstos se presentan en la imagen inferior con su función principal.

Figura 1: Diagrama de bloques del tren de potencia de un vehículo eléctrico de batería

El sistema de carga empleado para la recarga de la batería de un vehículo eléctrico es uno de los aspectos más investigados en el funcionamiento de vehículos eléctricos de batería. Esto se debe a la necesidad de obtener tiempos de carga lo más bajos posibles para poder competir en el mercado automovilístico con los vehículos convencionales de combustión, los cuales cuentan con una recarga de combustible muy rápida. A pesar de ello, los sistemas de carga están relativamente normalizados y existen distintos estándares establecidos por la SAE (“Society of Automotive Engineers” de sus siglas en inglés) en Estados Unidos y por Comisión Electrotécnica Internacional. Esta homologación, aunque sí es ventajosa para el desarrollo de la creación de sistemas de carga, no termina de suponer una ventaja excesivamente notable para la fabricación de las baterías, ya que, al ser las capacidades de éstas muy variables, los sistemas para recargarlas también varían mucho de un modelo de vehículo a otro.

Cabe mencionar que el sistema de carga puede o no ser considerado un elemento del tren de potencia dependiendo de la función que cumplen. Los sistemas de carga de corriente alterna, o “off-board charging”, se encargan de alimentar la entrada de carga del vehículo con corriente alterna, la cual es posteriormente transformada en corriente continua por el sistema de carga de corriente continua, o “on-board charging”. Este último también es capaz de recargar la batería con corriente continua directamente aportada mediante el método de carga rápida (“fast-charging” en inglés). De estos dos sistemas, el sistema de “on-board charging” es el que se puede considerar parte del tren de potencia, ya que es el que se encuentra integrado en el vehículo. Este componente del tren de potencia no será abordado con más detalle debido a su relativa complejidad y extensión.

Las baterías presentes en los vehículos eléctricos son del tipo secundarias, esto es, a diferencia de las primarias, pueden ser cargadas y descargadas repetidas veces con el tiempo. La unidad básica del paquete de baterías con el que cuenta un vehículo eléctrico es la celda. Las celdas de batería pueden presentar distintas configuraciones según su disposición en serie y paralelo. La configuración más común para los paquetes en vehículos eléctricos es la división en módulos. Las celdas de baterías se disponen en serie (formando una serie de baterías), y cada serie puede ser conectada posteriormente como módulo

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individual. Esta conexión permite obtener un mayor voltaje, potencia, energía y corriente, al igual que un tiempo de vida más largo.

El tipo de celda empleado puede ser principalmente de dos tipos. Por una parte, existen los condensadores de doble capa, los cuales funcionan mediante un principio electroquímico que les permite alcanzar altas densidades de energía y potencia. Por otra parte, están las celdas electroquímicas, en los que hay una variación de energía debida a una reacción química, la cual es desencadenada por un intercambio de cargas eléctricas. Dentro de este tipo de celdas, las más comunes son las celdas de plomo, ion-litio y sodio-níquel-cloro (también llamadas ZEBRA).

Las celdas ion-litio son las que han demostrado presentar unas propiedades más adecuadas para las aplicaciones en vehículos eléctricos, concretamente aquellas celdas que disponen de un ánodo no metálico y un electrolito líquido. Estas baterías presentan unas propiedades eléctricas excelentes, y presentan un rango de densidades energéticas muy amplio, dependiendo de su construcción. Además, presentan una alta seguridad, sobre todo los sistemas de litio-hierro-fosfato, que son cada vez más empleados para su uso como material catódico precisamente debida a esta propiedad. El largo tiempo de vida que pueden alcanzar estas celdas también es una característica ventajosa de su funcionamiento.

El inversor o el variador de frecuencia es el dispositivo encargado de controlar la corriente de entrada al motor eléctrico mediante la transformación de la corriente continua proporcionado por la batería. Esta corriente de salido puede ser alterna o continua, dependiendo del tipo de motor del que se disponga.

Estos vehículos disponen de máquinas eléctricas, que según las condiciones pueden funcionar como motor eléctrico o como generador. El primer caso de funcionamiento consiste en la obtención de energía mecánica a partir de la energía eléctrica que le es suministrada a la máquina. El proceso de funcionamiento del generador es el inverso al del motor, en el que la energía mecánica es transformada en corriente eléctrica, la cual permite recargar la batería. La operación de una máquina eléctrica es producida por la interacción de una corriente eléctrica que fluye por los bobinados y el campo magnético que se le induce.

Se pueden distinguir principalmente dos tipos de motores eléctricos en función del tipo de corriente que se les suministra. Por una parte, se disponen de motores de corriente alterna, normalmente trifásicos y con 240 V de tensión de operación. Las dos configuraciones más empleadas en vehículos eléctricos de este tipo de motores son motores de inducción (asíncronos), y los motores síncronos de imanes permanentes. Por otra parte, encontramos motores de corriente continua, que suelen operar entre tensiones entre los 100 y los 200 V. Los principales tipos son el motor de corriente continua con escobillas, y el motor de corriente continua sin escobillas, en el último de los cuales encontramos también el motor paso a paso sin escobillas.

De los subtipos mencionados anteriormente los tres más empleados en el mercado del vehículo eléctrico con el motor de inducción, el motor síncrono de imanes permanentes y el motor de corriente continua sin escobillas. La principal ventaja de este último tipo de motores es que su velocidad puede ser controlada en un rango muy grande. Sin embargo, los motores de corriente alterna son conocidos por tener un funcionamiento más suave por terrenos más robustos, además de ofrecer una aceleración muy alta. Estas dos características hacen que los motores de inducción y los motores síncronos de imanes permanentes sean los más utilizados de entre los tres.

Otra de las ventajas que presentan los vehículos eléctricos es la integración de una transmisión directa, o lo que es lo mismo, cuentan con una sola marcha para variar el par suministrado al eje motriz del vehículo. Esto permite que la transmisión sea más eficiente que

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en los vehículos de motor de combustión, que, al tener un mayor número de niveles de transmisión, experimentan mayores pérdidas desde la salida del par del motor hasta las ruedas motrices.

Análisis comparativo

El término de análisis comparativo consiste en la comparación de distintos procesos y rendimientos parametrizados que se utilizan en la práctica industrial. Con ello es posible analizar cuáles son las mejores prácticas del sector y cuáles son las compañías que las están desarrollando. Es particularmente interesante en la industria automovilística y ha tenido siempre un cierto énfasis en las labores investigativas de las distintas empresas.

Los vehículos incluidos en este proyecto son los vehículos eléctricos de batería (o BEVs por sus siglas en inglés de “Battery Electric Vehicles”), no incluyendo el resto de los vehículos eléctricos por exceder las requeridas dimensiones del trabajo. Dentro de este tipo de configuración clasificaremos los vehículos de clase M y N establecidos por el marco europeo, ya que son las categorías con mayores poblaciones de vehículos eléctricos en el mercado. Diferenciaremos además las tres categorías dentro de cada una de ellas, clasificando finalmente los vehículos en clase M1, M2, M3, N1, N2 y N3.

Se han reunido datos de un total de 167 vehículos entre las seis categorías, obteniendo una mayor variedad de datos de los elementos batería y motor eléctrico que del resto de los elementos que constituyen el tren de potencia mencionados anteriormente. Muchos de los datos no estaban disponibles para todos los vehículos debido a su relativa novedad en el mercado y falta de información suministrada por los fabricantes. Aún así, se han podido obtener unas conclusiones claras de los datos acumulados, las cuales serán presentadas al final de este sumario.

Los vehículos de la categoría M1 comprende los vehículos destinados al transporte de personas con menos de nueve pasajeros (ocho asientos más el conductor) y con un peso bruto de menos de 3,5 toneladas. En esta categoría la población de vehículos es relativamente grande, y los distintos prototipos cuentan con años modelo entre 2018 y 2019. Las autonomías (o alcances máximos que pueden alcanzar en una sola carga) varían entre los 100 km para los modelos e.GO Life y los 482 km para el Tesla Roadster 3.0.

Prácticamente todas las baterías que contienen estos vehículos son de ion-litio, algunas de las cuales especifican un empleo de polímero. Las capacidades de los paquetes de baterías, que son la máxima energía capaz de ser almacenada en un paquete de celdas, varían entre los 14,5 kWh para el modelo e.GO Life 20 y 100 kWh para el Tesla Model X, con tiempos de carga muy variables.

Todos los motores son de corriente alterna, de los cuales la mayoría son síncronos de imanes permanentes. Las potencias máximas que pueden alcanzar varían entre un mínimo de 20 kWh para el modelo e.GO Life 20 y un máximo de 285 kWh en el eje trasero del Tesla Model S de autonomía estándar. Las velocidades máximas alcanzadas por los motores son las correspondientes a las potencias máximas, y se encuentran entre las 4800 rpm en el motor síncrono de imanes permanentes del BMW i3, y la velocidad máxima del Volkswagen e-up! con 12000 rpm. Los torques máximos de salida de los motores varían entre los 130 Nm y los 450 Nm para los respectivos Smart Electric Drive y para el BYD e6 en el eje trasero.

Además de estas características, todos cuentan con un frenado regenerativo (en el que la máquina eléctrica funciona como generador y recarga la batería) y con una reductora de una única marcha.

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Los vehículos pertenecientes a la clase M2 son aquellos destinados al transporte de personas con una capacidad para más de nueve pasajeros, y un peso bruto entre 3,5 y 5 toneladas. En esta categoría sólo se ha encontrado un vehículo con datos disponibles, y, aunque seguramente haya más vehículos en la categoría, se ha visto un claro déficit de producción en este grupo.

En la categoría M3 se encuentran los vehículos destinados al transporte de personas con una capacidad de más de nueve pasajeros y pesos brutos por encima de las 5 toneladas. Es apreciable el número de vehículos tan alto que hay en esta categoría. Una de las razones es la imposición de medidas restrictivas en las grandes ciudades para reducir emisiones y el intento de mejorar esta reducción en el sector del transporte público. Muchas ciudades han empezado a introducir flotas de autobuses que emplean métodos alternativos de propulsión. Varios vehículos presentan años modelo más antiguos que los vistos en la categoría M1, teniendo el modelo de autobús Solaris Trollino 12 un año modelo de 2005. El número de pasajeros es también relevante en este tipo de vehículos, y es influyente en el peso bruto y las dimensiones del vehículo.

Las autonomías presentan valores más variables que en el resto de las categorías, debido a la posibilidad de recarga de las baterías por medio de catenarias. Por ello encontramos datos con valores entre los 15 km y los 362,102 km para los modelos Belkommunmash E433 y Xcelsior CHARGE 40’ respectivamente. Las capacidades que emplean sus baterías también son muy variables, presentando valores bajos para los vehículos con condensadores de doble capa, y valores más altos para baterías de ion-litio.

La mayoría de los motores eléctricos de esta categoría son también síncronos de imanes permanentes, y presentan valores de potencia máxima muy variables, entre 55,2 kW y 240 kW para los motores de los modelos Gulliver y TODA BGT-N2D respectivamente. Los torques máximos de salida presentan rangos mucho más amplios que en el resto de las categorías, con un valor mínimo para los modelos de BYD con 350 Nm y máximo para el modelo Linkker 12+LE con 7800 Nm.

La categoría N1 incluye a aquellos vehículos destinados al transporte de mercancías con un peso bruto inferior a las 3,5 toneladas. Son vehículos más recientes, presentando el vehículo eléctrico el año modelo más antiguo en el año 2016. Las autonomías varían entre los 175 km y 257 km, con un valor excepcionalmente alto para el modelo VW e-Transporter de 400 km.

Las baterías son todas de ion-litio (muchas de ellas específicamente de LiFePO4), excepto la batería del modelo IVECO Daily 35 S que utiliza el tipo de batería ZEBRA. Las capacidades que presentan varían entre los 20 kWh, el mínimo valor dado para el modelo StreetScooter WORK, y los 76,6 kWh, el máximo valor observado para el modelo VW e-Transporter. Los motores eléctricos son todos síncronos de corriente alterna, algunos de los cuales han especificado ser de imanes permanentes. Los valores de potencia máxima están entre los 44 kW y los 92 kW, los pares máximos de salida del motor están entre los 200 Nm y los 320 Nm.

En la categoría N2 encontramos vehículos destinados al transporte de bienes que tienen un peso bruto entre 3,5 y 12 toneladas. La electrificación de este tipo de vehículos ha sido interesante también para reducir la contaminación en las ciudades, y por tanto podemos encontrar un mayor número de vehículos en este grupo.

Las autonomías varían entre los 100 km y los 250 km, que son el valor mínimo y máximo observado para los modelos Fuso eCanter y BYD de clase 5 respectivamente. Hay un valor excepcionalmente alto para el modelo eM2 Daimler, que tiene 370 km de autonomía. Las baterías vuelven a ser prácticamente todas de ion-litio (y particularmente de elemento

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catódico LiFePO4) con una excepción de batería ZEBRA en el modelo IVECO Daily 50 C. Los valores de las capacidades de las baterías varían entre los 35,8 kWh y los 325 kWh.

Los motores son todos síncronos de imanes permanentes, y sus potencias máximas varían entre los 90 kW y los 353 kW. Los torques de salida también presentan valores variables entre los 290 Nm y los 1800 Nm.

La categoría de N3 esta constituida por los vehículos destinados al transporte de bienes con un peso bruto superior a las 12 toneladas. La fabricación de vehículos pesados eléctricos presenta una serie de dificultades que han producido un desarrollo menor en la tecnología de estos vehículos, y por esta razón encontramos un número tan reducido de modelos.

Sus autonomías han conseguido mantener niveles relativamente altos para el peso de estos vehículos, teniendo valores entre los 128,7 km y los 300 km. Los tipos de baterías que se han podido registrar son de ion-litio, y las capacidades presentan valores entre 120 kWh y 435 kWh, siendo este último valor correspondiente al modelo chino BYD clase 8.

Los motores están todos alimentados por corriente alterna, dos de los cuales son síncronos híbridos y el resto asíncronos trifásicos. Las potencias máximas varían entre los 125 kW y los 360 kW, y los pares máximos varían entre los 205 Nm y los 3000 Nm.

Objetivo del estudio

Como se ha mencionado previamente al principio del sumario, el propósito del análisis comparativo en este trabajo es el de la identificación de la existencia de algún tipo de correlación entre los datos mencionados en el apartado anterior. Para facilitar esta identificación, representaremos los datos en gráficos de Excel, para poder entender la presencia o no de alguna relación entre los datos de una forma visual.

Los valores escogidos para representarse en los gráficos son la autonomía del vehículo, la capacidad del paquete de baterías, la potencia máxima que puede alcanzar el motor y el par máximo de salida del motor. Los dos primeros datos son buenos medidores del funcionamiento adecuando del paquete de baterías, y los dos últimos parametrizan el rendimiento del motor eléctrico. Estos dos elementos son los que, como se indicó anteriormente, tendrán una mayor influencia sobre el resultado de rendimiento total del vehículo.

A nivel de batería, hemos visto como la gran mayoría de las celdas utilizadas en los paquetes son de ion-litio, muchas de las cuales se han identificado con material catódico LiFePO4. En los motores eléctricos hemos visto una mayoría de funcionamiento de corriente alterna, de los cuales la mayoría eran síncronos de imanes permanentes, seguidos con un número no demasiado inferior de motores asíncronos de inducción.

En la autonomía de los distintos vehículos observamos valores superiores a 100 km para prácticamente todos los vehículos de todas las categorías. Presentan algunas excepciones en los vehículos de clase M3, que disponen de condensadores de doble capa como batería y se van recargando mediante un sistema de catenaria a lo largo del recorrido del vehículo, cuyos valores se han representado de forma distintiva en la respectiva gráfica. Pero el resto de vehículos que no disponen de este sistema de carga, presentan todos unas autonomías muy variadas en los distintos vehículos de una misma clase. Por tanto, podemos afirmar que no hay ningún tipo de tendencia definida para este parámetro. Las gráficas correspondientes a las autonomías de las seis clases se pueden encontrar en el trabajo

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original en la figura 5-1 para la categoría M1, la figura 5-5 para la categoría M3, la figura 5-9 para la categoría N1, la figura 5-13 para la categoría N2 y la figura 5-17 para la categoría N3.

Además de lo mencionado en el último párrafo, la autonomía viene parcialmente condicionada por la capacidad de la batería. Para este parámetro también aparecen valores registrados muy variables, con un rango de variabilidad muy amplio. Este aspecto también puede en parte justificarse por la baja autonomía que presentan los vehículos, aunque evidentemente influyen una gran cantidad de variables. Y como se mencionó en el apartado anterior, los vehículos de la clase M3 que presentan condensadores de doble capa, aparecen marcados en su respectivo gráfico. de capacidad. Pero podemos establecer que tampoco se observa ninguna correlación evaluable en este parámetro. Las gráficas correspondientes a las capacidades de los paquetes de baterías de las seis clases se pueden encontrar en el trabajo original en la figura 5-2 para la categoría M1, la figura 5-6 para la categoría M3, la figura 5-10 para la categoría N1, la figura 5-14 para la categoría N2 y la figura 5-18 para la categoría N3.

La potencia máxima sí presenta un rango de variabilidad parcialmente más estrecho que aquellos de la capacidad y autonomía, pero sigue habiendo diferencias de 150 kW entre el valor más alto y más bajo entre los motores de la misma clase. Además, no hay ninguna relación aparente entre los valores que son más altos y entre los que son más bajos. Por esta razón tampoco podemos asegurar ningún estándar seguido para este parámetro de los motores eléctricos. Las gráficas correspondientes a las potencias máximas alcanzables en los motores de las seis clases se pueden encontrar en el trabajo original en la figura 5-3 para la categoría M1, la figura 5-7 para la categoría M3, la figura 5-11 para la categoría N1, la figura 5-15 para la categoría N2 y la figura 5-19 para la categoría N3.

El par máximo de salida del motor es el valor que presenta una mayor variabilidad, en especial en los vehículos pesados. Esto se debe a que este tipo de vehículos con un peso tan elevado, necesitan valores de par muy altos para poder desplazarlos. Y este torque tan elevado puede conseguirse o por el empleo de varios motores que sumen un par elevado, o el empleo de pocos o un motor que tengan un valor muy elevado. Como consecuencia de ello, también descartamos la existencia de cualquier tipo de tendencia en este parámetro de los motores eléctricos. Las gráficas correspondientes al par máximo de salida del motor de las seis clases se pueden encontrar en el trabajo original en la figura 5-4 para la categoría M1, la figura 5-8 para la categoría M3, la figura 5-12 para la categoría N1, la figura 5-16 para la categoría N2 y la figura 5-20 para la categoría N3.

Además de estos parámetros, hemos podido realizar las siguientes observaciones respecto al conjunto completo de vehículos estudiados.

Comparando los valores de peso bruto con su respectiva autonomía en los vehículos de clase M y clase N por separado, podemos observar cómo hay una ligera relación entre el alcance y el peso: a mayor peso de vehículo, menor es la autonomía que tiene. Esto sí demuestra como el peso del vehículo limita el alcance máximo que puede tener y, por tanto, la capacidad máxima de la batería. Sin embargo, hay un gran número de vehículos que no cumplen específicamente esta correlación, presentando un bajo alcance para un bajo peso bruto de vehículo, al igual que otros vehículos de un alcance más elevado con un alto peso bruto de vehículo. Por esta razón tampoco podemos confirmar una correlación exacta entre estos dos valores. Las gráficas mencionadas se corresponden a la figura 5-21 para la comparación del peso bruto con su alcance para los vehículos de clase M, y a la figura 5-22 para la comparación de peso bruto con su alcance para los vehículos de clase N, ambas figuras referidas al trabajo original.

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Además del contraste anterior, también se han comparado los valores de las capacidades de los paquetes de baterías con las respectivas autonomías de los vehículos. Este análisis ha demostrado que tampoco podemos asegurar con completa certeza la relación entre capacidad de paquete de batería. En el diagrama de puntos disperso representado con los vehículos de las seis clases, que se puede encontrar en la figura 5-23 del trabajo original, se puede observar que no se cumple la relación de mayor alcance para mayor capacidad de batería ni aun teniendo en cuenta los pesos de los vehículos. Hay varios puntos correspondientes a vehículos de clase M3 que presentan capacidades y autonomías muy altas, al igual que hay vehículos de N1 y M1 que presentan bajas autonomías con valores muy bajos de capacidad, rompiendo cualquier tipo de posible relación exacta que podría ser esperada.

Resultados y conclusiones

Como resultado de los análisis acumulados anteriormente, podemos afirmar que, indiscutiblemente, el actual mercado del vehículo eléctrico carece de cualquier tendencia o estandarización. Los valores tan dispersos obtenidos para los datos representados en los gráficos de todas las categorías de vehículos demuestran que no hay ninguna directriz impuesta.

Los vehículos destinados al transporte de pasajeros presentan un desarrollo más avanzado que aquellos destinados al transporte de mercancías. Los coches eléctricos han empezado a alcanzar una potenciada madurez tecnológica para ser capaces de competir en el mercado con los automóviles de gasolina convencionales. Al mismo tiempo, los autobuses eléctricos han estado acentuando su crecimiento en varias ciudades para mejorar la calidad del aire en zonas urbanas.

Como se ha señalado en el apartado anterior de este sumario, no hay ninguna relación existente entre los valores de autonomía, capacidad de los paquetes de baterías, potencia máxima alcanzada por el motor y par máximo saliente del motor, ni entre los modelos de una misma categoría, ni entre los modelos de las distintas seis categorías. La correlación entre la capacidad de los paquetes de baterías y la autonomía de los vehículos, al tampoco presentarse con suficiente claridad, dificulta la posibilidad de definir una tendencia específica para la capacidad de los paquetes de las baterías de vehículos eléctricos.

Todos estos resultados nos permiten declarar que hay una clara ausencia de estándares en los vehículos eléctricos de carretera. Aunque este hecho produce por una parte una situación ventajosa, ya que las compañías son otorgadas la libertad de diseñar y fabricar vehículos eléctricos con la tecnología que ellos mismos desarrollan y encuentran más apropiada. Sin embargo, por otra parte, esto también complica la distribución de este tipo de vehículos en el mercado público, ya que la existencia de unas diferencias tan notables en un mismo producto complica su capacidad de venta.

Indudablemente, el alcance que pueden ofrecer los vehículos eléctricos de baterías es una de las mayores inquietudes, debido a la necesidad de competir con los vehículos convencionales de combustión que se encuentran en el mercado. Como se ha mencionado anteriormente, los valores mostrados por todos los vehículos superan los 100 km en una carga completa de batería. Pero este valor aún no es comparable a la autonomía asegurada por un vehículo con un motor de combustión interna, que normalmente (salvo en modelos excepcionales) suele encontrarse entre los 300 y los 400 km por cada tanque llenado. Asimismo, la posibilidad de distinguir entre vehículos de corto alcance y vehículos de largo alcance es posible en vehículos de propulsión convencionales, la cual es una particularidad que aún tiene que ser desarrollada en la tecnología de baterías.

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Con respecto a los motores eléctricos, su operación también es fundamental para el funcionamiento del vehículo. Estos motores ya tienen integrados una ventaja sobre los motores de combustión interna produciendo el par máximo desde su arranque. También disponen de la habilidad de cubrir un extenso rango de potencias, velocidades y pares con una construcción simple y relativamente sencilla. El único detrimento que presentan es en la cantidad de energía con la que son alimentados, lo que nos devuelve a las limitaciones que suponen las baterías para este tipo de vehículos, y la necesidad de progresar en el funcionamiento adecuado de la tecnología de este ámbito.

Más aún, los motores que se fabrican con una serie de directrices y valores regulados sin duda podrán contribuir a incrementar su productividad y su habilidad de ser introducidos en el sector transportes. Por esta razón, aunque las baterías constituyen el principal aspecto en el que se tiene que trabajar en el área de electro-movilidad, los motores eléctricos también juegan un papel fundamental para incrementar el rendimiento total de los vehículos eléctricos.

Considerando todos estos aspectos que han sido mencionados, podemos asegurar que con un mayor acrecimiento tecnológico de los diferentes elementos que integran el tren de potencia de los vehículos eléctricos, conllevará con seguridad un incremento de la demanda de estos vehículos y, por tanto, su producción e implementación en la sociedad.

Pronóstico

Todos los elementos considerados en la sección anterior podrán ser mejorados en los próximos años. Los vehículos convencionales de combustión han sido desarrollados e investigados a lo largo de todo el siglo XX. Y considerando que los avances tecnológicos están teniendo lugar con un índice de frecuencia mucho más alto, estas progresiones pueden acaecer en los próximos años.

Actualmente el progreso de los vehículos eléctricos está apuntando hacia la asequibilidad del producto ofrecido por este sector. Puesto que el mercado de la electro-movilidad es tan reciente y no ha experimentado una fuerte demanda, los precios de estos vehículos no son competitivos comparados con aquellos de los vehículos de combustión. No solo el proceso de fabricación de los vehículos eléctricos sigue siendo muy costoso, sino que además este producto no presenta una ventaja destacable sobre vehículos convencionales desde el punto de vista del consumidor, a nivel de comodidad de éste. Como consecuencia de ello, ha sido complicado alcanzar una alta demanda en un plazo de tiempo tan corto. Aún así, la investigación y las mejoras que están teniendo lugar en el sector contribuirán a hacer la electro-movilidad más asequible para todos.

La investigación que actualmente se está llevando a cabo en la tecnología de baterías presenta un aspecto muy positivo para el futuro de la electro-movilidad. Es seguramente el aspecto que tiene que ser más trabajado, para poder reducir su peso sin reducir su capacidad de almacenar energía. Las baterías de ion-litio parecen ser la tecnología de celda más ventajosa hasta ahora, pero teniendo en cuenta la cantidad de investigación que están presentando otros sistemas de almacenamiento de energía, es complicado asegurar la existencia de una sola tecnología que domine este sector.

La producción de baterías en grandes cantidades conllevará una serie de problemas que también tendrán que ser solucionados en el futuro. Por ejemplo, la contaminación de la extracción de litio y la escasez de los recursos que proporcionan los materiales para la fabricación de las baterías son algunos de estos problemas. Añadido a esto, la habilidad o no de reciclar las baterías después de que hayan alcanzado su tiempo de vida es también una preocupación importante.

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Otro aspecto destacable en la transición a movilidad eléctrica es el aumento de la demanda eléctrica de la red. Sin embargo, este factor no supondría un problema con una transición simultánea hacia energías renovables. Por tanto, aunque la inserción de vehículos eléctricos en sí supondrá una mejora en la contaminación local, sólo supondrá beneficiosa a un nivel global con un enfoque hacia una progresiva mezcla energética más limpia.

Y aunque esta transición venga con unas confrontaciones, es importante tener en cuenta que la ingeniería ha sido desarrollada para esto. A lo largo de la historia, el ser humano ha desarrollado continuamente diversos productos para mejorar muestra calidad de vida y aumentar nuestra comodidad, resolviendo problemas de nuestras vidas cotidianas. Este es precisamente el caso del automóvil, inventado para poder recorrer distancias más largas de una forma más cómoda. En los últimos años, la toma de conciencia de que teníamos que reducir nuestras emisiones también ha supuesto un problema que hay que resolver. Constituyendo la contaminación debida al sector transportes como un problema, los vehículos eléctricos son una posible solución, y actualmente una de las más exitosas. Y aunque el progreso de vehículos eléctricos conlleve una serie de problemas, la situación de contaminación aérea con la que hay que lidiar en estos instantes podrá ser solucionada. Y en los próximos años, los problemas que vayan surgiendo también irán siendo solucionados por la ingeniería.

La necesidad de promover la investigación en electro-movilidad es crucial para solventar el problema de las emisiones producidas por el sector transportes. Desafortunadamente, nuestras emisiones globales tienen que ser reducidas drásticamente en los próximos años para poder conservar nuestro planeta tal y como lo conocemos. Por ello, no solo es el sector transporte el que tiene que trabajar en el desarrollo de nuevas tecnologías, sino que todos los sectores de sociedad tienen que intervenir. La situación de concienciación y toma de acción ha mejorado en los últimos años, y están avanzando incluso más rápido hoy día, pero aún hay mucho por hacer.

13

2. Diagrama de Gantt

El Trabajo Fin de Grado para alumnos internacionales en la Facultad de Ingeniería Mecánica de la Universidad Técnica de Aquisgrán tiene una duración de diez semanas, con un valor total de 15 créditos ECTS. El primer día tiene lugar una presentación introductoria para comenzar oficialmente con el trabajo, y se calculan las diez semanas a partir de éste. La distribución del trabajo desde el día de la presentación, el 13 de junio de 2019, hasta el día de la entrega, 22 de agosto de 2019, se puede ver en el diagrama de Gantt de la figura inferior.

Figura 2: Diagrama de Gantt

3. Presupuesto

Puesto que se trata de un trabajo teórico y de recopilación de datos, no conlleva ningún gasto adicional de simulación y material. Por tanto, sólo tendremos que considerar los gastos de las licencias de los productos Office, los costes de los medios utilizados para contactar con las distintas empresas y las horas empleadas para llevar a cabo el trabajo.

Considerando que un crédito ECTS equivale a 25 horas de trabajo, y que en Alemania el sueldo medio de un ingeniero junior es de 14 euros/hora, el sueldo aproximado para un trabajo de 15 créditos sería de 5.250 euros.

Tabla 1: Estimación de presupuesto

Actividad del presupuesto Cantidad requerida

Licencias de productos Office 36,99

Gastos de contacto con compañías 10,00

Sueldo del trabajador 5.250,00

Presupuesto total 5.296,99

This thesis was presented at the Chair of Production Engineering of

E-Mobility Components (PEM) at RWTH Aachen.

Bachelor Thesis

Name: Elena Irene Jaimez Farnham

Matr.-No.: 399780

Title: Benchmarking of powertrain elements of M

and N class electric vehicles

Supervising assistant: Rahul Pandey, M.Sc.

1. Examiner: Prof. Dr.-Ing. Achim Kampker

2. Examiner: Dr.-Ing. Dipl.-Wirt-Ing. Heiner Hans Heimes

Aachen, 22nd August 2019

The contents and the result of this thesis are for internal use only. All copyrights remain

with RWTH Aachen. This thesis or parts of it are not to be transferred to a third party

without the express authorization of the supervising professor.

I Table of Contents

i

I Table of Contents I Table of Contents ......................................................................................................... i

II List of Symbols and Abbreviations ............................................................................iii

III List of Figures ..............................................................................................................iv

IV List of Tables ..............................................................................................................vii

1 Motivation..................................................................................................................... 8

2 Theory of electro-mobility ..........................................................................................10

2.1 Definition of electro-mobility ............................................................................................................... 10

2.2 Historical overview ................................................................................................................................... 12

2.3 Current status .............................................................................................................................................. 15

3 State of technology ....................................................................................................18

3.1 Vehicle classification................................................................................................................................. 18

3.1.1 Road transport classification ...................................................................................................... 18

3.1.2 Type of electric vehicles ............................................................................................................... 19

3.2 Technology in BEVs ................................................................................................................................... 23

3.2.1 Charging systems ............................................................................................................................. 23

3.2.2 Batteries .............................................................................................................................................. 25

3.2.3 Inverter ................................................................................................................................................ 33

3.2.4 Motors .................................................................................................................................................. 33

3.2.5 Drivetrain elements ........................................................................................................................ 36

4 Benchmarking .............................................................................................................37

4.1 M1 ..................................................................................................................................................................... 39

4.2 M2 ..................................................................................................................................................................... 40

4.3 M3 ..................................................................................................................................................................... 41

4.4 N1 ..................................................................................................................................................................... 42

4.5 N2 ..................................................................................................................................................................... 43

4.6 N3 ..................................................................................................................................................................... 44

5 Scope of research .......................................................................................................46

5.1 M1 class observations .............................................................................................................................. 46

5.2 M3 class observations .............................................................................................................................. 49

5.3 N1 class observations ............................................................................................................................... 53



5.6 Common observations ............................................................................................................................. 61

6 Results and conclusion ..............................................................................................64

7 Outlook ........................................................................................................................66

8 Bibliography ................................................................................................................67

I Table of Contents

ii

V Annexed

Annexed I: Excel sheet of collected data from M1 class vehicles

Annexed II: Excel sheet of collected data from M2 class vehicles

Annexed III: Excel sheet of collected data from M3 class vehicles

Annexed IV: Excel sheet of collected data from N1 class vehicles

Annexed V: Excel sheet of collected data from N2 class vehicles

Annexed VI: Excel sheet of collected data from N3 class vehicles

II List of Symbols and Abbreviations

iii

II List of Symbols and Abbreviations

symbol unit description

abbreviation description

OEM Original Equipment Manufacturer

BEV Battery Electric Vehicle

GHG Greenhouse Gas

HEV Hybrid Electric Vehicle

PHEV Plug-in Hybrid Electric Vehicle

EREV Extended Range Electric Vehicle

EV Electric vehicle

LEV Low-emission vehicle

AC Alternate current

DC Direct current

IC Internal combustion

CARB California Air Resource Board

VRLA Valve-regulates lead-acid

AGM Absorbed glass material

BMS Batter Management System

SEI Solid Electrolyte Interface

III List of Figures

iv

III List of Figures

Figure 1-1: European Environment Agency transport emissions and target emissions

comparison1 ................................................................................................................... 8

Figure 1-2: Global vehicle stock, distance traveled, and life-cycle road transport greenhouse

gas emissions by vehicle type in 2015 ........................................................................... 9

Figure 1-3: Projected global freight activity and life-cycle greenhouse gas emissions from

2015 to 20508 ................................................................................................................ 9

Figure 2-1: European high-speed railway system25 ..............................................................15

Figure 2-2: Plug-in EV shares of US vehicle market .............................................................16

Figure 2-3: Total number of electric cars registered in Germany from 2008 to 2018 .............16

Figure 3-1: Serial hybrid, Fisker – Karma32 ...........................................................................20

Figure 3-2: Parallel hybrid, Mercedes-Benz S 500 Plug-in Hybrid32 ......................................20

Figure 3-3: Power Split Hybrid, Chevrolet Volt 232 ................................................................21

Figure 3-4: Drive train elements in EREV with possible coupling in between engine and drive

axle33 ............................................................................................................................22

Figure 3-5: Block diagram of power transfer in an EV powertrain .........................................23

Figure 3-6: Series connection ...............................................................................................25

Figure 3-7: Parallel connection on cell level ..........................................................................26

Figure 3-8: String-wise parallel connection ...........................................................................26

Abbildung 3-9: Individual modular strings .............................................................................26

FIgure 3-10: Schematics of supercapacitor ..........................................................................28

Figure 3-11: Equivalent circuit of supercapacitor32 ................................................................28

Figure 3-12: Schematic of lead-acid battery41 .......................................................................29

Figure 3-13: Schematics of Lithium-Ion battery.....................................................................31

Figure 3-14: Lithium-Ion cell classification ............................................................................31

III List of Figures

v

Figure 3-15: Cell designs of round, prismatic and pouch-bag cell design (in order form left to

right)40 ...........................................................................................................................32

Figure 3-16: ZEBRA cell set-up40..........................................................................................33

Figure 3-17: Rotor squirrel-cage (to the left) and stator (to the right) of an electric inductive

motor48 ..........................................................................................................................34

Figure 5-1: Ranges (km) of M1 vehicles ...............................................................................46

Figure 5-2: Capacity of battery pack (kWh) of M1 vehicles ...................................................47

Figure 5-3: Maximal Torque (Nm) for M1 vehicles motors ....................................................47

Figure 5-4: Maximal power (kW) and respective maximal speed (rpm) .................................48

Figure 5-5: Ranges (km) of M3 vehicles ...............................................................................49

Figure 5-6: Battery pack capacity (kWh) ...............................................................................50

Figure 5-7: Maximal power output (kW) ................................................................................51

Figure 5-8: Maximal torque output (Nm) ...............................................................................52

Figure 5-9: Ranges ..............................................................................................................53

Figure 5-10: Capacities ........................................................................................................53

Figure 5-11: Maximal Power .................................................................................................54

Figure 5-12: Maximum torque ...............................................................................................55

Figure 5-13: Ranges .............................................................................................................56

Figure 5-14: Capacities ........................................................................................................56

Figure 5-15: Maximal Power (kW) ........................................................................................57

Figure 5-16: Max. Torque (Nm) ............................................................................................58

Figure 5-17: Ranges (km) .....................................................................................................59

Figure 5-18: Battery pack capacities (kWh) ..........................................................................59

Figure 5-19: Maximal Power (kW) ........................................................................................60

III List of Figures

vi

Figure 5-20: Maximal Torque (Nm) .......................................................................................60

Figure 5-21: Gross weight (tonnes) – Range (km), M class vehicles ....................................61

Figure 5-22: Gross weight (tonnes) – Range (km), N class vehicles .....................................62

Figure 5-23: Battery pack capacity (kWh) – Range (km) .......................................................63

IV List of Tables

vii

IV List of Tables

Table 3-1: Requirements on batteries for selected unconventional drive trains ....................27

8

1 Motivation

The need to reduce our global greenhouse gas emissions has been a relevant issue dur-ing the last couple of decades and it has recently acquired an even more powerful drive as people all over the globe demand political organizations to act on this matter.

In this context of requirement to reduce emissions, regulations worldwide have developed into being much stricter. The European Union has set the target of reducing transportation GHG emissions by 60% and maritime GHG emissions by 40% until 2050 compared to their 1990 levels1.The transportation sector, although as fourth highest emitter at a global scale, has been accounted to be the second most GHG emitting sector in Europe in 20182 and the first most polluting in the United States3. Therefore, the reduction of emissions in this sector is crucial.

Figure 1-1: European Environment Agency transport emissions and target emissions compari-

son1

Restrictive measures for transportation in the main urban areas have been one of the most highlighted actions to tackle air pollution in big cities. These restrictions are triggered not only by the unreasonably high temperatures that have been being registered, but also because of the decline of air quality to the point in which some air parameters are reaching worrisome values for human health. Some of these restrictions imply limiting car’s transit in downtown areas or requiring a payment or license to do so. Public transportation has also seen changes in this area, as the emissions proceeding from buses are also being regulated in interurban areas, also by limiting their transit and by using new technologies4.

1 Cf. EEA - European Environmental Agency 2018. 2 Cf. Eurostat - European Comission, 2018. 3 Cf. EPA - United States Environmental Protection Agency, 2017. 4 Cf. Harris, 2019.

9

Many solutions to conventional combustion engines have been emerging in this time, such as liquefied compressed natural gas, biodiesel or propane or fuel cells5. But electric and hybrid vehicles have indisputably played the main role in the development of clean road transportation over the past two decades. Although data has shown that currently only 2,2% of worldwide passenger cars are plug-in electric6, it is sure that the numbers will rise.

Passenger electric vehicles have started to gain an acceleration in the automotive mar-ket, as well as the development of electric city buses has also experimented an important impulse. This is due to the fact that reducing local emissions in cities is also seeing a critical situation.

Elaborating more in transport emissions, although trucks only add up to 9% of the total European vehicle population, their GHG emissions account almost 40% of the total transport emissions. In addition to this aspect, it is also expected for the truck population to overpass the double of their current number. That would imply that emissions from this specific source can also increase drastically7.

Figure 1-2: Global vehicle stock, distance traveled, and life-cycle road transport greenhouse gas emissions by vehicle type in 20158

Figure 1-3: Projected global freight activity and life-cycle greenhouse gas emissions from 2015 to 20508

As mentioned previously, electrification of vehicles currently seems to be the most pros-perous solution. It is therefore that many companies have started to invest in development and investigation of electrifying heavy- and medium-duty vehicles as well. Although its fulfillment is challenging, there is no doubt in that it must be worked on.

Since the electric vehicle sector is relatively new, companies that are currently working on this type of products are freely designing and developing them. This lack of guidelines implies that the manufacturers still need to make great investigation efforts prior to the product design.

This is the reason there is a need to set standards in the electric vehicle market. With this purpose, it will be easier to enable a faster and more optimal development of products in the sector.

5 Cf. Taylor III 2013. 6 Cf. Deloitte Center for Energy Solutions . 7 Cf. Moultak et al. 2017. 8 Cf. Hausfather, 2018.

10

2 Theory of electro-mobility

2.1 Definition of electro-mobility An electric vehicle (EV) is propelled by one or many electric motors, also called traction

motors. There is a wide range of technologies that can be used as energy sources to power the electric motor. The power sources can be self-contained in the vehicle, like batteries, elec-tric generators that receive their electricity from fuel conversion or solar panels. There are also off-vehicle sources from which electric vehicles can receive electricity through a collector sys-tem9.

More recently the notion of electro-mobility has adopted a new form, and it can refer to all alternative road transportation systems which are based on electrically propelled vehicles10, from motorcycles to cars and buses and trucks. It is, therefore, possible to find both definitions in different literature sources, being the most recent definition the most popular among the two of them.

EVs can be found in all mobility areas, and therefore we find different types of them for ground, airborne and seaborne vehicles, as well as electrically powered spacecraft.

Ground vehicles

The automobile sector at the same types counts with different ways of vehicle mounting, which will be discussed in further depth in section three of “State of technol-ogy”.

Rail borne electric vehicles were one of the first types of EVs to be conceived. They can be supplied with power from two main sources. On one hand from a stationary source, for instance, a third rail or an overhead wire, or on the other hand from re-chargeable energy storage systems, such as batteries or mining locomotives which are powered by supercapacitors11.

At the same time, there are three differentiating characteristics in the design of electric locomotive systems. First, the type of electrical power that is used to supply the vehicle, AC or DC. Second, which has been mentioned in the previous paragraph, is the method of either storing or collecting the power. And third and finally, the method applied to connect the traction motors to the driving wheels11.

The emergence of electrified bicycles and stand-up scooters has also been no-ticeable lately. The so-called e-bikes, for example, are bicycles that are integrated with an electric motor and can accordingly, be used for propulsion. The speeds and powers these types of vehicles can reach cover a very extensive range.

Another markable area to adopt electric transportation has been in mobility aid devices. Here we can include electric wheelchairs and mobility scooters, which are supplied with rechargeable energy storage systems (rechargeable batteries), and even though there are also gasoline-powered scooters, these are quickly being replaced by electric designs12.

9 Cf. Faiz et al. 1996. 10 Cf. Sandén et al. 2014. 11 Cf. Duffy, 2003. 12 Cf. Leonard, 2017.

11

The last ground EV worthy to mention are space rovers, which have been used in different space exploration programs on the Moon and Mars. For example, Mars Pathfinder Exploration Rover is solar-powered. They count with a maximized area for the solar cells that collect the sun’s energy, which is used to recharge the battery13.

Airborne electric vehicles

These types of EVs have counted with a high number of experimentation pro-jects since the start of the development of aircraft systems. The electric motor of the aircraft can be supplied by various methods, such as solar cells, ultracapacitors or fuel cells. There is currently still a lot of research that is taking place in this field.

Seaborne electric vehicles

Electric boats had high popularity at the beginning of the XX century until com-

bustion engines started to take over in the market. At the end of the XX century, the interest of this type of marine transportation increased, due to the pursue of usage of clean energy sources. An example in this matter is the use of solar cells, which have provided motorboats and infinite range. Diesel engines have also been replaced by electric motors in sail boats14. Submarines can also be equipped with batteries, which are recharged through different methods on the surface, and that power the electric motor used for propulsion.

Electrically powered spacecraft

The electric energy is used to vary the speed of the spacecraft. The power sources that can be used for this matter are batteries, solar panels, and nuclear power15.

13 Cf. NASA . 14 Cf. Oceanvolt . 15 Cf. NASA 2008.

12

2.2 Historical overview

The emergence of EVs can be traced back to the mid-XIX century, starting off with DC power systems and evolving later into AC power systems. Within the types of EVs mentioned in the previous section, railway electric vehicles and road electric vehicles are the ones that have experimented a higher development throughout the last 150 years. Therefore, a brief historical description of the evolution of these two systems will be presented in the following. In addition to this, the current situation of both technologies will also be discussed in the next subsection.

Electric railways historical aspects

The railway system was the first mobility sector in transitioning locomotives to an electric design. The first known electric locomotive was constructed in Scotland in 1837 by the chemist Robert Davidson. It used a galvanic cell as an energy source and is therefore at the same time the first battery-electric locomotive. Later, the same chemist developed another larger locomotive (this one integrated two motors), which were di-rectly driven reluctance motors (presenting one gear stage).

It was not until 1879 when Werner von Siemens proved an electric railway in Berlin, which was functioned with a 150 V DC, 2’2 kW, bipolar motor at a maximum speed of 12 km/h. Two years later Siemens Halske marked the introduction of the first passenger electric railway by one in Lichterfelde. Electric locomotive systems were being preferred due to their higher efficiencies compared to those of steam or diesel locomotives and to the lack of combustion in the operation process16.

In 1883 the Volk’s Electric Railway was opened in Brighton, which is still opera-tional today and is consequently the oldest operational electric railway in the world17. During this same year the first tram line in the world powered by an overhead line in regular service started to function. It was located near Vienna in Austria and was known as the Mölding and Hinterbrühl Tram18.

The first AC electric locomotive was designed by Charles Brown in Zürich in 1891. He had observed that three-phase motors had a higher power-to-weight ratio than DC motors and were also easier to manufacture and maintain. Electric traction for the entire line was first introduced in Italy in 1902. Later in 1918 Kandó developed the rotary phase converter, which enabled electric locomotives to use three-phase motors that were sup-plied electrically through a single overhead wire. They carried the simple industrial fre-quency of 50 Hz single phase AC of the high voltage national networks19.

After World War II the French National Railway Company (SNCF from Société nationale des chemins de fer français) had assessed the industrial-frequency AC line routed through the Höllental Valley. The company then accepted the performance of AC locomotives as developed enough to allow its installation and to be able to apply it in all kinds of terrain19. This was a very influential step towards the usage of AC locomotives all around Europe.

Many European lines were electrified during the 1960s since the electric locomo-tive system was extensively developed from the 1920s onwards. In this same decade,

16 Cf. Oura et al. 1998. 17 Cf. Volk's Electric Railway Association, 2019. 18 Cf. Mödlinger Stadtverkehrsmuseum . 19 Cf. Duffy, 2003.

13

locomotives that could reach up to 200 km/h were implemented in France and Germany. Later in the 1980s the high-speed lines development launched this electrification even further.

As improvements kept appearing, the introduction of electronic control systems led to the standardization starting in the 1990s of the asynchronous three-phase motors fed through GTO-inverters. This enabled the use of lighter and more powerful motors that had a better fitting in the locomotive’s structure.

Electric automotive historical aspects

At the end of the XIX century the first modern vehicle was developed by Karl Benz, based on an internal-combustion engine20. These first vehicles were noisy and polluting, as well as complicated to start and unreliable.

At the same time, Nikola Tesla was developing which would end up being the modern electric technologies by partnering with George Westinghouse and disputing with Thomas Edison over direct-current (DC) power system to establish himself with the leadership with his alternate-current (AC) approach. These innovations led to the emergence of the first battery electric vehicles (BEVs) in the 1890s, which were energized by lead-acid batteries and motorized with DC power systems. In contrast to the ICE (internal combustion engine) vehicles of the moment, EVs did not have any starting problems and no tailpipe emissions. In these times the low range of BEVs was not a relevant problem since a proper road system had not yet been developed.

For these reasons, in 1900 the sales of electric vehicles and gasoline vehicles were proportionate in quantity, but over the next ten years EV sales were to collapse. During this same time, EVs did not have the same popularity in Europe as they had in the United States. Germany and France owned companies, such as Daimler, Benz, Renault, and Peugeot, that were world leaders in developing internal combustion engines.

The further improvement of gasoline vehicles in the next two decades finally led to a non-competing situation between BEVs and ICE vehicles. The main factor to trigger the high growth of gasoline engines was the mass-production system implemented by Henry Ford to produce the Ford Model T, which resulted in a major drop in the sales price of this type of product. The second factor to increase gasoline vehicle sales was the invention and introduction of the electric ignition and start, needing to have the car’s engine started by a manual crank until then. In addition to this, the BEVs started to show a low distance range in comparison to gasoline vehicles, which together with the high prices these vehi-cles were showing, ended with the electric vehicle market.

During the next years, gasoline vehicles were continued to be further developed, as well as the diesel engine, which was introduced into the market in 1922. This engine pre-sented a higher efficiency in its compression-ignition stage compared to the efficiency of the spark-ignition stage that took place in the ICE fueled by gasoline. Since it presented a high-torque-at-low-speed curve characteristic, it became very attractive for the medium- and heavy-duty vehicles worldwide21.

Already in the early XX century, the environmental costs of the internal combustion engine vehicles started to make themselves noticeable. The pollution and “smog” (term that comes from the words smoke and fog) in the area of Southern California, which was urbanizing at a very high speed, became worrisome for many scientists. Although different

20 Cf. Daimler, 2019 21 Cf. John G. Hayes, John G. et al. 2017.

14

engineers had tried to diminish the problem with catalytic converters throughout the cen-tury, it was not until 1973 when the first production catalytic converter was created. This also led to a continuous development of the product, which made and has made today’s exhaust gases up to 98 percent cleaner in terms of nitrogen dioxide as they were in the 1970s22.

Despite these innovations to reduce emissions in gasoline vehicles, the air quality was still a major concern in many large cities. Many cases of chronical respiratory diseases that appeared in California in the 80s and 90s were accounted to the squalid air quality in the area of Los Angeles in Southern California23.

General Motors (GM) developed an all-electric car at the end of the 1980s. It was prompted on one hand by the successful “Sunraycer” solar-powered electric car, designed for the Solar Challenge (a 3000 km race across Australia), and on the other hand, due to the severity urban pollution had reached in many cities in the United States21.

This initial prototype BEV later became to be known as the GM EV1, which GM com-mitted to mass-produce. It was developed and produced in Southern California and Mich-igan and debuted in 1996 presenting revolutionary features to which we can give credit of many of today’s innovations. And this automobile appeared in a moment in which the Cal-ifornia Air Resource Board (CARB) had just adopted the Low-Emission Vehicle (LEV) Pro-gram standards, to continue trying to recede the pollution problem23.

Some models of the EV1 were leased throughout California but within a few years they were recollected by GM, without giving the customer’s the option to purchase them. Simultaneously other electric vehicles, such as Ford Th!Nks, Ranger Electric puck-ups, Honda EVs or Toyotas RAV4s were also being collected by their respective production companies23.

Unfortunately, these events led to the final situation of practically the disappearance of any possible EV commercialization. This vanishing of electric vehicles was triggered not only by the automobile companies, who were being pressured by oil companies to not have these products become popular, but also by the decrease in gasoline’s price in that time as well as the lack of government support21.

At the beginning of the 2000s, some pioneers of GM’s EV1 started to develop some concept EVs, although the only markable feature of these automobiles was that they in-cluded a high number of computer laptop Li-ion cells for the storage of the main battery. This provided the vehicle with a higher efficiency and performance due to its more viable range21.

In 2003 the company Tesla, Inc. was founded in Silicon Valley and introduced their first vehicle in 2007, the Tesla Roadster. This company pursued the commercialization of electric automobiles and became the first company to mass-market EVs characterized with Li-ion cells21. This emergence led to a new perspective on road electro-mobility and started to create a new sector of competitiveness in the area of electric automobiles. In the next years, companies such as Nissan and Toyota started to introduce their own products into the market. These vehicles will be discussed in further depth in the next chapters of this project.

22 Cf. Hevesi, 2008. 23 Cf. Chris Paine, 2006.

15

2.3 Current status

Electric locomotive systems Electric trains and fast speed trains have been widely implemented in today’s mobility

systems. Europe counts with a wide railway system, which includes many high-speed sys-tems. Some of the most notable are AGV Italo in Italy, which is the fastest high-speed train in Europe, Siemens Velaro E/AVS 103 in Spain, which covers the transit Madrid-Barcelona, or Talgo T350 in Spain or ICE 3 in Germany24.

Figure 2-1: European high-speed railway system25

City trams and underground railways are another one of the major applications of elec-

tric locomotives. Some cities count with famous tram systems, such as San Francisco’s Muni Metro or Lisbon’s tramway network, as well as other cities, which have memorable underground railways such as New York’s or London’s underground. Although some of these systems have been operating for over a century, they still play a very important role in urban mobility.

It is important to note that these systems, although they have not been designed and

implemented with the purpose of reducing climate change, they are very effective for re-ducing local air pollution in major cities.

24 Cf. Railway Technology, 2013.

16

Road electric vehicles

The EV market has been drastically increasing over the last years and all indicates it will keep rising. 2’2 percent of today’s vehicles worldwide are electric, having reached a record last year of approximately two million sells, although this implies that only one in 250 cars that are on the road are electric25.

Figure 2-2: Plug-in EV shares of US vehicle market26

Figure 2-3: Total number of electric cars registered in Germany from 2008 to 201827

25 Cf. Coren, 2019. 26 Cf. Deloitte, 2017. 27 Cf. Statista Company, 2019.

17

But this transition to EVs comes with a series of challenges which will also have to be faced and worked out in an appropriate way.

As we have been able to see in the historical overview, electric vehicles have finally been developed to be able to start solving our polluting situation. On one hand, and es-pecially, to reduce local emissions in the large urban areas, and on the other hand to progressively move towards the reduction of global warming. But to achieve this last one the transition towards electromobility indispensably must come accompanied by an en-ergy transition towards renewables. This aspect can be approached as an opportunity for the renewable energy sector to also take an impulse28.

In the following, we will discuss in further depth the technology behind the current BEVs we can find on the market.

28 Cf. International Renewable Energy Agency (IRENA), 2017.

18

3 State of technology

3.1 Vehicle classification

3.1.1 Road transport classification

The categorization of vehicles stands the same for all vehicles in the European Union. This classification is fundamental in order to maintain competitiveness in the automotive in-dustry. The categories arrange the vehicles in groups with a regulatory purpose, which enables the manufacturers to receive benefit from the Single Market system of the EU and to export their products to countries which are outside of the European Union29.

The reason for which vehicle categories play such an important role is due to their belonging to a well-functioning type-approval system. The type-approval system or technical harmonization allows manufacturers to profit from the options available in the internal market of the EU. And meanwhile in the context the United Nations Economic Commission for Europe (UNECE) they are offered a market beyond European boundaries in which to take place in30.

The main categories of vehicles are30:

Category M: power-driven vehicles which have at least four wheels and are used for transport of passengers.

Category M1: Not comprising more than eight seats plus the driver’s seat, also called passenger vehicles.

Category M2: Comprising more than eight seats plus the driver’s seat and with a maximum weight that does not overpass 5 tonnes.

Category M3: Comprising more than eight seats plus the driver’s seat and with a maximum weight that overpasses 5 tonnes.

Category N: power-driven vehicles which have at least four wheels and used for transport of goods.

Category N1: Maximum weight that does not exceed 3.5 tonnes. Category N2: Maximum weight that exceeds 3.5 tonnes but that does not

exceed 12 tonnes. Category N3: Maximum weight that exceeds 12 tonnes.

Category L: Motor vehicles with less than four wheels.

Category L1: two-wheeled vehicle with maximum speed not exceeding 50

km/h, and cylinder capacity lower than 50 cm3 in case of using ICE. Category L2: asymmetrically arranged three-wheeled vehicle with maximum

speed of 50 km/h. Category L3: two-wheeled vehicle with maximum speed exceeding 50 km/h,

and cylinder capacity higher than 50 cm3 in case of using ICE. Category L4: asymmetrically arranged three-wheeled vehicle with maximum

speed exceeding 50 km/h. Category L5: symmetrically arranged three-wheeled vehicle (according to

the longitudinal vehicle axis).

29 Cf. European Comission, 2007. 30 Cf. UNECE 2017.

19

Category L6: four-wheeled vehicle with a curb weight not exceeding 350 kg and does not exceed 45 km/h.

Category L7: four-wheeled vehicle with a curb weight not exceeding 400 kg.

Category T: Motorized, wheeled or tracked agricultural or forestry vehicle.

With the transition of conventional transport systems to cleaner solutions the vehicle categorization remains the same. Therefore, the introduction of electric powertrain systems in vehicles only implies a change of the technology in use, but the mobility concept of conven-tional motorized vehicles remains the same.

3.1.2 Type of electric vehicles

Within EVs in the automobile field we can classify the different types of vehicles within the next groups, depending on the different energy sources they count with.

Hybrid electric vehicles

Hybrid vehicles represent the electric vehicle technology which was first released into the market with a successful outcome. A hybrid propulsion system receives energy to generate its motion through at least two different power sources. Therefore, and by its definition, it en-gages two different powertrains. Following this concept, the most abundant combination of energy sources and for which the HEV is commonly known integrates an ICE and electric components31.

The electric component use implies the use of a rechargeable battery. The possible ways in which the battery can be recharged differentiate another type of hybrid vehicle inside this category. Plug-in hybrid electric vehicles (PHEV) offer the option of connecting the battery to the power grid. Other hybrid vehicles recharge the battery while the electric motor is working as a generator or through regenerative braking. This last process, also known as recuperation, implies that the electric motor is also working as a generator while the vehicle is braking, pro-ducing electricity that can be stored in the battery.32

For this type of vehicle, it is very important to have a well-defined operating strategy, that oversees defining all temporal and logical operations that need to take place. Consequently, it defines which process has to take place at which point in time32.

Depending on the disposition of a hybrid vehicle’s powertrain, we can find within this category three different dispositions: parallel hybrid, serial hybrid and power-split hybrid.

31 Cf. Prof. Dr.-Ing. Lutz Eckstein, 2015.

20

o Serial hybrids

Figure 3-1: Serial hybrid, Fisker – Karma31

Serial hybrids present energy converters connected in series. The combustion en-gine in connected to the electric motor and it has no mechanical connection to the driving wheels. The generator is driven by the ICE and it is possible to desensitize this last one, having a smooth transient behavior. This helps the engine operate very close to its best efficiency31.

o Parallel hybrid

Both the combustion engine and the electric motor are mechanically connected to the drive wheels. This system is more complex than the previous, since many gear-boxes, clutches or freewheels are required. For this case it is possible to have both drives can be used individually or at the same time. Depending on the necessary per-formance of the vehicle, it is possible to design both motors relatively small31.

Figure 3-2: Parallel hybrid, Mercedes-Benz S 500 Plug-in Hybrid31

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o Power split hybrid

This variant of a hybrid powertrain has a very high complexity. It integrates a mixture between the parallel and the serial configuration. Part of the combustion engine’s power is directly transmitted to the drive wheels and the rest of it is transmitted to a planetary gear and two electric machines, which are responsible for transferring this power to the drive wheels. Generally electric batteries are used for the electric storage. One of the greatest advantages this configuration offers is the possibility to operate the combus-tion engine on a fuel consumption optimized curve. This way the operating point can be changed throughout the curve, achieving a higher efficiency31.

Figure 3-3: Power Split Hybrid, Chevrolet Volt 231

Electric range extended vehicle

These vehicles offer the possibility of recharging the battery when it has reached a high discharge state through the next system: electric energy is generated with specific set-up of the combustion engine and the generator, which enables the recharging of the battery. With this, the total range of the vehicle can be extended32.

This type of vehicle can be used as a transition technology from the conventional com-bustion engine vehicles and battery electric vehicles, which still have a smaller range in comparison to the range of and ICE vehicle33.

The difference in between an HEV and an EREV lays within the coupling of the power-train elements, as it is shown in figure 3-4.

32 Cf. P. Spichartz 2015.

22

Figure 3-4: Drive train elements in EREV with possible coupling in between engine and drive

axle33

Battery electric vehicles

Battery electric vehicles (BEV) convert chemical energy from the metal’s ions or ox-ides33 which is stored in rechargeable battery packs. These batteries are electrically charged when connected to the power grid.

Due to the fact that the research of all these types of vehicles exceeds the dimensions of this project, the focus of this thesis is centered in BEV and, consequently, this configura-tion will be explained in further depth in the following subchapter.

33 Cf. Schmidt-Rohr 2018.

23

3.2 Technology in BEVs To simplify the understanding of the following benchmarking research, this section will

provide an overview of the elements which will be analyzed in the different types of vehicles, with the parts that integrate each element as well as their purpose and performance.

The powertrain elements will be explained in order accordingly to the power flow from the intake of electricity in the plug-in of the vehicle to the output of the resulting torque throughout the drivetrain. Therefore, the components to be determined will be:

Charging port (on-board charging) Energy storage Power converter Electric motor Drivetrain elements

Figure 3-5: Block diagram of power transfer in an EV powertrain

Considering these elements, we will focus in more depth on the energy storage systems and electric motor characteristics, since they represent the two most variable and determining ele-ments in the powertrain of electric vehicles.

3.2.1 Charging systems

The charging of the vehicle’s battery consists in the obtention of electric power, nor-mally from the electric grid, to enable its storage as electro-chemical energy. The different charging techniques and the time required to fully charge the battery are one of the most im-portant aspects that are being held in research. This is caused by the very quick fuel recharge that conventional gasoline vehicles count with. In order to compete with them in the automobile market, not only are EVs going to need to improve the range they operate with, but also their recharging time.

It is worthy to mention that the charging systems do not have to necessarily be consid-ered part of the powertrain of an EV. In this case all charging systems will be explained for completing the understanding of how these vehicles function. The following three main charg-ing systems will be defined, as well as the current charging standards presented by the regu-lations.

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AC charging or off-board charging

Off-board charging refers to charging the EV’s battery pack from the electric grid, which supplies AC power to the vehicle. It is then transformed into DC power through the on-board charging system. This system is mainly in charge of three different aspects34:

Conversion of the AC power obtained from the grid into DC power that can be used to charge the battery.

Current flow control which enters the battery by managing the DC output from the charging.

Communicator of the vehicle’s off-vehicle equipment The so-called bi-directional chargers also allow the transfer of

electric power to the grid.

DC charging or on-board charging

This type of charger connects the battery directly to the charger, without the use of the on-board charging system. It is necessary for there to be a very sturdy con-nection between the vehicle and the off-board charger. These are high power chargers that are very heavy, and consequently cannot be installed in the vehicle.

Charging standards

According to the US based SAE (Society of Automotive Engineers)35:

o Level 1: standard of 120 V AC. o Level 2: 240 V AC. o Level 3 AC: 208-240 V. o Level 3 DC: 208-600 V output and 0-1000 V input. o DC charging: up to 500 V for passenger cars. Can vary for other types

of vehicles, reaching up to 1000 V.

According to the International Electrotechnical Commission36:

o Mode 1: single or three-phase slow charge form regular socket. o Mode 2: slow regular socket charge from regular socket with specific

protection arrangement. o Mode 3: specific EV multi-pin socket with control and protection func-

tions with fast or slow charge. o Mode 4: special charging technology for fast charging such as

CHAdeMO.

Three connection cases37:

o Case A: charger connected to mains, which is usually attached to the charger, associated with modes 1 and 2.

o Case B: on- board vehicle charger with mains supply cable, detachable form both supply and vehicle, associated with mode 3.

o Case C: charging station with DC supply to the vehicle, associated with mode 4.

34 Cf. Neil Johnson 2014. 35 Cf. SAE International 2018. 36 Cf. IEC 2018/19. 37 Cf. ISO Standards, 2013.

25

Three plug types38:

o Type 1: single-phase vehicle coupler SAE J1772 specifications o Type 2: single- and three- phase vehicle coupler VDE-AR-E 2623-2-2 o Type 3: single- and three- phase vehicle coupler with safety shutters EV

Plug Alliance. o Type 4: fast charging applications.

Combined Charging System (CCS): additional Combo 1 and Combo 2 connector style inlets. As Type 1 and Type 2 but with extra connectors to connect to high voltage charging stations.

The previously mentioned systems will not be engaged with in further detail in this project, due to the extensiveness of this area.

3.2.2 Batteries

An electric battery is a storage system that accumulates electrochemical energy and con-verts it into electrical energy. In the automotive industry, the batteries used in the powertrain are the so-called secondary batteries. These can be repeatedly charged and discharged over time. On the contrary, primary batteries cannot be recharged again after they have been dis-charged21.

The battery cell is the basic battery unit. Many of these are arranged in the battery pack in a certain way, depending on the energy storage, the pack voltage and the battery pack power that wants to be achieved, which will all also have an impact on the reliance of the pack. There are mainly four types of arrangements of cells inside a battery pack38:

Series connection As shown in the figure, this connection consists of having all cells connected in series. Mainly this type of connection has the objective of or increasing the battery pack voltage as well as its power, alt-hough this derives into a larger cell unbal-ancing and no redundancy. Redundancy refers to a specific battery architecture based on cell repetition, that contributes to avoid the previously mentioned problem of voltage cell unbalance39. This type of arrangement is not commonly used for electric vehicle battery pack pre-cisely because of the unbalancing aspect.

38 Cf. Orion Battery Management Systems. 39 Cf. Manenti et al. 2011.

Figure 3-6: Series connection

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Parallel connection on cell level It consists of having different cells con-nected on a string in parallel, which are then connected in series between each other. This type of arrangement usually presents low voltages and high powers in the battery pack, and high redundancy. It also presents a low battery management system (BMS) efforts and unequal cur-rents among the cells.

This arrangement is also not commonly used in EVs, since a relatively high voltage is also required.

String-wise parallel connection

The cells are arranged in series on each string, and the strings are then connected in parallel. This connection allows high volt-ages and high powers in the battery pack, as well as high redundancy, low BMS ef-forts and unequal current among cells.

This type of connection is more common among electric vehicles since it offers the three positive aspects mentioned before (all except the high BMS efforts).

Individual modular strings

This type of connection presents the cell con-nected in series on each string, which can later be connected as individual modules. It is characterized by presenting low voltages and low powers in the battery pack, high re-dundancy, but high flexibility on type and age of cells. It also requires high BMS efforts39.

This arrangement is also commonly used in EV batteries, since working with modules makes the manufacturing more comfortable.

Figure 3-7: Parallel connection on cell level

Figure 3-8: String-wise parallel connection

Figure 3-9: Individual modular strings

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From these possible battery packing options, the modular design is the most common arrangement in the automotive industry for EVs40. This allows the battery pack to offer a higher voltage, power, energy and current, as well as a higher lifetime21.

Although we are focusing on the technology of BEVs, it is worthy to mention that the connection of the batteries will also depend on the type of EV, since each category of EVs has a different requirement of voltage, power, and energy content. These characteristics will also, influence the type of cell chemistry chosen to arrange the battery pack. It is therefore that the structure of the powertrain makes the demands of the batteries have very extreme differences. In the following table some unconventional types of drivetrains have been inserted, to compare the values necessary for the batteries of each one.

Table 3-1: Requirements on batteries for selected unconventional drive trains41

Vehicle concept Characteristics Voltage Energy con-

tent Power Technology

Micro hybrid Star-stop function,

limited regenera-

tive brake,

booster

12 V 0.6 – 1.2

kWh 2 kW

Lead-acid, lead acid

+ supercapacitors

Smooth hybrid Start-stop func-

tion, regenerative

braking, booster

36 - 150 V 1 kWh 5 – 20 kW

(Power optimized)

lead acid, NiMH, Li-

Ion

Complete hybrid Start-stop func-

tion, regenerative

braking, all elec-

tric drive

200 – 400

V 1 kWh 30 – 50 kW Energy optimized

Plug-in hybrid As a complete hy-

brid but with

longer all electric

range

200 – 400

V 5 – 10 kWh 30 – 70 kW

Li-Ion (energy/power

optimized)

Electro vehicle Regenerative

brake, all-electric

drive

200 – 400

V 10 – 30 kWh 30 – 70 kW

NiMH Li-Ion (energy

optimized)

Fuel cell vehicle As complete hy-

brid but larger all

electric range

200 – 400

V 1 kWh 30 – 50 kW

NiMH Li-Ion (power

optimized)

It is clearly observed that a higher driving range with the electric drive of the powertrain, higher voltages, powers, and energies are required. This will imply that the connection to achieve these higher values will be different than those which are maintained lower.

We can distinguish two main types of rechargeable batteries:

40 Cf. Sauer, 2019. 41 Cf. Prof. Dr.-Ing. Lutz Eckstein .

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Electrochemical Double Layer Capacitors or Supercaps

The electrochemical principle of this type of batteries allows them to achieve very high energy and power densities. The functioning principle of this cell consists of the forming of double layers in between the firm electrode, which works as an electron conductor, and the liquid electrolyte, which works as an ion conductor. These double layers can be charged and discharged reversibly, and they are formed by the charge carriers of the electrolytic solution by adsorption at the surface of the electrode.

FIgure 3-10: Schematics of supercapacitor

With this principle and the addition of smooth conductive surfaces, it is possible to achieve specific capacities of up to 25 µF/cm2. By increasing the surface of the capacitor or by intro-ducing the use of special electrode materials (such as carbon fibers or structured polymers) that increase the electrically effective surface with a small geometric surface, we can increase the capacity of the cell42.

A simple equivalent circuit of the supercapacitor can be represented as in figure 3-1141.

Figure 3-11: Equivalent circuit of supercapacitor41

Rs represents the equivalent series resistance or inner resistance. It is possible to achieve low values by using a set-up of the so-called “sandwich”-structures based on bipolar electrodes that have the function of the anode of a cell and the cathode of the continuous cell at the same time, having the separator the function of avoiding the contact between the two cells.

42 Cf. Jayathu 2015.

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C stands for the capacity of the supercapacitor.

L represents the equivalent inductance, which can usually be neglected.

Rp acts as the equivalent parallel resistance, also known simply as parallel resistance and is a product of the self-discharge.

Some other positive aspects that this type of cell has are presenting a relatively good life-time (calendric and cycle/energy throughput), and well as presenting a good charging at high currents, and therefore a good acceptance for fast charging. It also has a wide temperature range, low maintenance efforts, and high efficiencies. In contrast to this, supercaps have the negative aspect of having a very complex and high cost-effective recycling processes, which decreases its ability to be produced at minimal costs with the best quality42.

Electrochemical cell

The exchange of electrical charges is the process that triggers a chemical reaction. This process comes accompanied by an energy variation, noticeable through the heat release (ex-othermal reaction) or heat absorption (endothermic reaction). In electrochemical cells, these variations are straightly transformed into electric energy, which can, therefore, be used for storing this energy to use it later41.

There are three main electrochemical storage systems used in the automotive industry, which will be explained in the following.

o Lead Acid battery

Figure 3-12: Schematic of lead-acid battery41

The electric energy flows through the external circuit while ions flow in the electrolyte. The chemical reaction which leads to the obtaining of electric energy takes place at the solid electrolyte interface. One of the noticeable features of this type of cell is that the electrolyte is the reactant.

The electrochemical reaction that takes place in these batteries is accompanied by a side reaction. It consists of the dissociation of water into hydrogen (negative electrode) and oxygen (positive electrode). If these gasses are not recombined in a further reaction, this water is lost from the battery. The mechanism applied to control the side reactions is known as valve-regulation, and therefore, the so-called valve-regulated lead-acid batteries (VRLA). These avoid the movement of the electrolyte

30

inside the container, retaining the hydrogen near the plates, and therefore having them already available to re-combine while the battery is being charged.

In the VRLA we can differentiate two types of technologies:

Absorbed glass material (AGM) batteries: the electrolyte is belted in highly porous glass material. This type of technology can improve its lifetime by applying pressure on active materials.

Gel batteries: gel material is created from the sulfuric acid by the addi-tion of SO2

From a broad point of view, AGM lead-acid batteries present better properties than gel batteries, having the first one’s low manufacturing costs, better high current capabilities and longer lifetime due to the better contact of active materials. The disadvantage they present is that they only have the possibility to be used in bat-teries with grid plates.

This type of battery cell is almost perfectly suitable for stationary standby appli-cations, being relatively inexpensive and optimal for starter batteries. Recent re-search has proven a high potential for further development of lifetime and electrical performance in an application for micro and mild hybrid vehicles. They present a disadvantage due to their weight in the area of mobile applications43.

o Lithium Ion cell

Lithium Ion batteries present a different functioning pattern to that of the lead-acid battery. In this case the ions of lithium are fixed in the electrode and are re-leased as positive ions during the charging of the cell. This way the ions travel through the electrolyte without having any type of chemical bond. Once the ions reach the anode, they combine themselves with the carbon electrode resulting in lithiated carbon 19.

The electrolyte consists of a highly conductive lithium salt that eases the move-ment of the lithium ions towards the anode19. The solid electrolyte interface (SEI) forms as a consequence of the decomposition materials associating with the elec-trolyte of the battery. It has a very important function in high-performance batteries, since it is in charge of preventing any further electrolyte decomposition in order to maintain the cycling ability. Therefore, the SEI must have good adherent properties with electrode material, high electronic insulation characteristics as well as a proper conductivity of lithium ions44. On the anode interface, the SEI is formed in the first charging process, and it is the most noticeable aging factor of li-Ion batteries44. On the cathode interface it is also possible to have a SEI created during the first five charge-discharge cycles. But the cathodic SEI has been less researched since the layer that is formed is much thinner and less influential in the functioning process than the SEI formed on the anode, which has a lower reaction possibility with the environment since it is mainly formed by organic compounds.

43 Cf. Pavlov 2017. 44 Cf. Forge Nano, 2018.

31

Figure 3-13: Schematics of Lithium-Ion battery45

Lithium ion batteries can be classified attending to the material from which the anode and the electrolyte are made from, classifying the anode in metallic or non-me-tallic and the electrolyte in liquid or polymer45, as shown in figure 3-14.

Figure 3-14: Lithium-Ion cell classification

In EV and HEV applications, Li-Ion-Liquid batteries are most commonly used, although Li-Ion-Polymer have recently proved to be advantageous. This type of battery provides a higher specific energy, counting with a high conductive semisolid polymer as electrolyte (gel-type material)46.

The cell design of these batteries can be classified in three groups, which will be chosen according to the characteristics to obtain for each specific case:45

Round cell type: they count with many years of experience in their de-signing as well as a high lifetime, but in contrast they have a complex cooling system.

Pouch-bag cell: they provide good cooling characteristics and high en-ergy density, although they arise the problem related to the tightness of the cell.

45 Cf. Laboratory for Energy Storage and Conversion (LESC), UCSD. 46 Cf. Scrosati et al. 2013.

32

Prismatic cell: they supply the battery pack with high volumetric energy densities and combine different aspects from both round cells and pouch-bag cells.

Figure 3-15: Cell designs of round, prismatic and pouch-bag cell design (in order form left to right)41

One other important aspect to mention about Li-Ion batteries is the effect lithium plating has on its performance. This phenomenon if produced when the battery either works at low temperatures, is subjected to high currents or is overcharged. It consists in the formation of metallic lithium in the SEI during charging, which limits the charging-discharging process, having an important effect on the battery’s lifetime and safety47.

The use of LiFePO4 has been proven to be a suitable active material option in Li-Ion batteries. Its characterized for having a high stability and, therefore, good safety properties. Due to this, they have been being implemented in electromobility sector47.

So far Lithium-Ion systems have proven to be a very good option for EV applications due to their excellent electrical properties. Safety is currently the major concern of this type of battery, although a sustainable production in the future might also suppose an issue. The lifetime of these batteries is another aspect needed to develop to fully inte-grate this type of battery for electromobility applications40.

o ZEBRA-Cell/Sodium-Nickel-Chloride

This battery type is particularly suitable for EV applications, due to its high-power density, which exceeds in almost three times the power density of a lead-acid battery. ZEBRA stands for “Zeolite Battery Research Africa Project”, since it was developed by the Council for Scientific and Industrial Research in Pretoria (South Africa)41.

47 Cf. Winter et al. 2007.

33

Figure 3-16: ZEBRA cell set-up40

These batteries have an internal operating temperature in between 270 oC and 350 oC and they belong to the group of high temperature systems. They can operate at a minimum temperature of 157 oC, and above it the electro-chemical reactions are induced by the melting of the electrolyte41. The reaction consists in the transformation of sodium-chloride and sulfur into sodium and sulfur-chloride during the charging process, and this reaction takes place re-versibly during discharging.

3.2.3 Inverter

Frequency converters or inverters control the input current of the electric motor by transforming the DC provided by the battery’s output terminal. With this they manage the speed and torque that it provided by the motor.

The DC power supplied by the battery is conducted into the variable frequency drive system, which consists of three components: an AC motor, main drive controller assembly and drive/operator interface. In a brief explanation, this power is filtered and transformed into AC power with a frequency that can be varied. The motor is then supplied with this AC power.

In the case of having an EV with a DC motor, the DC power supplied by the battery needs no transformation. These motors are supplied with a DC motor controller, which regulate through electronics the power they deliver to the motor21.

3.2.4 Motors

Electric vehicles use electric machines to convert electric energy into mechanical en-ergy in order to propel the vehicle, although they can also work reversibly as generators. In this functioning mode mechanical energy is transformed into electric energy, which can then be used to charge the battery (as occurs while regenerative braking). The operation of the electric motor is produced by the interaction of the electric current that flows through the wire windings and the magnetic field that is induced in it48.

48 Cf. Drury 2001.

34

The basic parts of any electric motor are shown in the figure below

Figure 3-17: Rotor squirrel-cage (to the right) and stator (to the left) of an electric inductive mo-

tor48

Rotor: part of the motor which is in movement and turns the shaft to transmit the me-chanical power.

Stator: part of the motor which is stationary. It is made from thin metal sheets to reduce energy losses, which are called laminations.

Windings: wires that are coiled around the magnetic core to form the magnetic poles when current flows through the wiring.

Air gap: distance between the stator and the rotor, which is minimized in order to not affect excessively the performance of the motor.

Bearings: supports that sustain the rotor to allow it to rotate around its axis.

Electric motors can be classified attending to the form of power they are supplied with:

AC electric motors

AC electric motors are powered by alternating current, usually consisting of three-phase motors that can be operated at 240V. As previously mentioned, they can also work as a gen-erator. In accordance to road performance, AC motors are considered to run more smoothly through rougher terrains as well as to offer a higher acceleration. Due to these two facts, they are very popularly applied in the automobile industry.

The two main AC motors used in the automotive industry are Induction Motors and Perma-nent Magnetic Synchronous Motors. Although only these two are being explained in this sec-tion, it is also possible to find other types of motors un the AC category, such as Reluctance Synchronous Motors or Hysteresis Synchronous Motors.

35

o Induction Motor (Asynchronous)

The functioning principle lies in the inductance of a magnetic flux in the rotor by the magnetic field of the stator’s windings. This produces the rotating torque in the rotor as well as in the shaft, which impulses the vehicle49.

In this case the rotating magnetic field and the rotor have different rotating speeds, having the magnetic field a higher speed than the rotor. This difference of speeds is the so-called slip of the motor50.

According to how the input power is supplied, induction motors can be classified as well into single-phased or three-phased. Three-phase induction motors have the advantage of being self-starting. Although the functioning principle in both types is very similar, there are some differences in the controlling mechanism49.

o Permanent Magnetic Synchronous Motor

These motors are characterized by having zero slip under normal operating condi-tions, this means that the rotor and the magnetic field have the same rotating speed.

They use permanent magnets that are embedded in the steel rotor to create a mag-netic field that remains constant. For this reason, they are not self-started and there-fore, need a variable-frequency power source to start51.

DC electric motors

DC electric motors are powered by direct current, usually by running approximately in be-tween 100 and 200V. Their speed can be controlled over a wide range, which can be achieved by changing the current input in the windings.

Mainly three types of DC motors are used in electric vehicles, which are brushed, brushless and inside this category, brushless stepper motors.

o Brushed DC motor

These motors directly the DC power provided to the motor and use an internal com-mutator (in order to change the direction of the current with a certain frequency), stationary magnets (which can be either permanent or electromagnetic), and elec-tromagnets50.

They can be controlled by either changing the voltage or the intensity of the mag-netic field. The torque and speed that characterize the motor can be changed in order to provide different functioning states50.

o Brushless DC motor

In this case a motor controller converts the direct current into alternate current, which simplifies the task of transferring the power received by the motor to the spin-ning rotor. They have one or more permanent magnets in the rotor and electromag-nets in the stator.

49 Cf. Wadibhasme et al. 2017. 50 Cf. Veganzones, 2017. 51 Cf. Krishnan 2009.

36

The motor controller can detect the position of the rotor through sensors, and there-fore the ability to control timing and phase, in order to optimize torque, regulate speed, or control power.

Stepper motors are included within this category, with the particularity of dividing a full rotation into several equal steps. Therefore, the position of the motor can be held a certain point or move to a certain point without the need of using a sensor to do so51.

3.2.5 Drivetrain elements

Generally, the drivetrain in EV only consists in one-single-stage automatic gear, which is connected directly from the motor to the driving axle. This one-stage gear can have a large range of gear transmission ratios, but in a passenger EV it is usually around a value of 9.

Some vehicles present a two-stage gear transmission, but the single-gear is much more common due to its simplicity to manage.

This is a clear positive aspect of the drivetrain of an EV compared to that of a conventional gasoline vehicle. Having one-gear-stage transmission the losses are much lower than in pre-senting multiple gear stages.

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4 Benchmarking Benchmarking is a term used in the business practice that consists in the comparison of

different processes and performance metrics that are used in the industry. With this, it is pos-sible to analyze which are the best practices in this sector and which are the companies that are developing them52.

Usually the benchmarking utilized a specific indicator to carry out the comparison, which results in a measurement of performance that can later be compared to the performances of other units52. The execution of benchmarking in the automotive industry has been an attractive practice for many years and has an important focus of the company’s research.

As mentioned previously in the third chapter of this project, the categories for vehicle clas-sification have been maintained in the transition to clean transportation technologies.

This project contains the benchmarking of BEVs that are on the market on the following cate-gories53:

Category M: vehicles carrying passengers o M1: passenger cars, that can only carry up to eight seats plus the driver’s seat. o M2: with a maximum mass not exceeding 5 tonnes. o M3: with a maximum mass exceeding 5 tonnes.

Category N: vehicles carrying goods o N1: Light Commercial Vehicles (LCV), with a maximum mass not exceeding 3.5

tonnes (also pick-up trucks) o N2: with a maximum weight in between 3.5 tonnes and 12 tonnes. o N3: with a maximum weight exceeding 12 tonnes.

The equivalent with the carrying of goods vehicle classification in the United States is presented in the following since many vehicles from the American market have also been taking into consideration54:

N1: includes class 1 (0 – 2.721 tonnes) and part of class 2 (2.721 - 4.536 tonnes)

N2: includes part of class 2 (2.721 - 4.536 tonnes), class 3 (4.536 – 6.35 tonnes), class 4 (6.35 – 7.257 tonnes), class 5 (7.257 - 8.845 tonnes), class 6 (8.845 – 11.793) and part of class 7 (11.793 – 14.968 tonnes)

N3: includes class 7 (11.793 – 14.968 tonnes) and class 8 (over 14.968 tonnes)

The data that has been searched for in this benchmarking practice was focused on the powertrain elements of these EVs, and particularly with more detail in the battery and motor’s specifications. This is because these elements are the ones that present a wider production possibility and with it, can impact the total vehicle’s performance in a more noticeable way. Charging systems, as we mentioned previously in chapter three, are currently one of the most researched topics in electro-mobility (despite their standardization) and cover a broad field to also include in this project. On the other hand, inverters and commuters are powertrain ele-ments that do not present many differences from one design to another.

The specifications that have been searched for are consequently related to battery, mo-tor, drivetrain, as well as general specifications of the vehicle, which will help understand the performance of the individual elements of each type of BEV.

52 Cf. Fifer Robert M. 1989. 53 Cf. European Comission . 54 Cf. NTEA - Association for the Work Truck Industry .

38

As for battery specifications, the main values and characteristics that have been taken into consideration for standardizing this component are:

Battery manufacturer Cell type Battery pack capacity AC and DC charging systems: respective charging power and charging time have been

considered. In case of having different charging possibilities for each type of current mode, the highest charging power value has been considered and, therefore, the fast-est charging rate.

Cooling system

Regarding the motor, the specifications that have been focused on are:

Electric motor manufacturer Type of motor Number of motors Nominal and maximal power Nominal and maximal torque Maximal speed Operating voltage and required current Presence or not of regenerative braking

Other mechanical components have been taken into consideration, not including many details on the drivetrain due to its simplicity in electrically driven vehicles. These elements are:

Gear shifting levels Drivetrain ratio Front braking system Rear braking system

As for general aspects of the vehicle the following values and characteristics have been in-cluded:

Model year Gross weight Curb weight: Range: it is important to remark for this value that it can vary a lot depending on the

test that has been performed to study it. Due to this, the type of test the range has been studied with is also marked as a note in the excel sheet (every time in was available).

Maximum speed Acceleration

These values have been recollected in an Excel table on different sheets, one for each vehicle category. Some of the general aspects vary from one vehicle category to another. This is because of the differences in the vehicle applications, since different values become more relevant depending on the functionality of the vehicle. Therefore, for example, knowing the number of passengers is relevant for M3 and M2 categories, and having knowledge of the curb weight and gross weight are important for all “transport of goods” vehicles to be able to deter-mine the range of payload the vehicle is able to withstand.

Not all the values that were target of the research were able to be registered since not all the data was available from all the vehicles. All data that has not been referenced has been collected by information provided by the different companies through contacting or with inter-viewing material.

The vehicles that have been included in this project are vehicles which are on the market, considering those which are available to be bought and have already been sold. Therefore, concept vehicles or vehicles which can be ordered but still have not been seen on the roads have not been introduced.

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4.1 M1 This category presents a very large population of BEV models, since light-duty vehicles

represent 59% of the global vehicle stock55. The automotive market also has created a higher competitiveness in this area. After the foundation of Tesla in 2006, the rest of the companies started to develop their own EVs to be left behind in this likely outcome of the transport industry.

Some of the available models that were found in this category were Renault Zoe R110, Chevrolet Bolt EV, Tesla Model S, Jaguar I-Pace, e.Go, BMW i3 or Nissan Leaf.

General aspects

Approximately all vehicles have their last model released in 2018 or 2019. Some of these vehicles actually have their first release in this year, but many others have been renewing the same model for many years, as has happened with Nissan Leaf, which was first released into the market in 2010, or even Tesla’s Model S, first released in 2012. Therefore, the manufacturers keep updating and improving their models, to be able to maintain them in the competitive market for a longer time.

The curb weight of passenger vehicles reflects up to a certain extent how heavy the battery pack of the vehicle is, since it is the heaviest component of the powertrain. It reaches minimum values from 1,21 tonnes in e.GO Life models and 1,229 in Volkswagen e-up!, to maximum values of 2,46 tonnes in NIO models. Tesla S model, for example, also has a relatively high curb weight, of 2,163 tonnes.

The gross weight of the vehicles matches de range which is allowed by the regulations for this type of vehicle. We can observe minimum values for the same models as we ob-served minimum values for curb weight, with a minimum of 1,53 tonnes for Volkswagen e-up! followed by 1,6 tonnes for the e.GO Life models. The highest value is reached by the Audi e-tron 55 quattro with a value of 3,13 tonnes.

Vehicle ranges also present very disperse values. Tesla Roadster 3.0 shows the high-est value of 482 km in one charge, and e.GO Life 20 the lowest value with 100 km.

As for highest speed that can be reached by the vehicle we can detect a lowest value for the e.GO Life 20 of 112 km/h, and a highest value for Tesla Model S Standard Range, with a maximum speed of 225 km/h.

Energy storage

Regarding the battery of the electric vehicle, it is observed that all batteries packs are manufactured with Li-Ion cell chemistry. Some of the data that has been collected specifi-cally mentioned the use of polymer Li-Ion batteries, such as Kia Soul and all Hyundai mod-els.

For battery capacities we can observe minimum values for the three e.GO Life models (with a lowest of 14,5 kWh for the e.GO Life 20) and for Volkswagen e-up!. The highest value is reached by Tesla Model X battery, with a value of 100 kWh, followed by 95 kWh battery of Audi e-tron 55 quattro.

The AC power charging for the passenger electric vehicles has a minimum value of 6,6 kW for the Nissan Leaf SL Plus model, which provides a 10-hour and 20-minute charging duration for 100% battery charge. The fastest charging rate is reached by the Renault Zoe with 22 kW charging power and a duration of 2 hours and 5 minutes.

The DC power charging of passenger electric vehicles usually can have a value of either 50 kW or 100 kW. In our researched data the minimum charging power value is for Volkswagen e-up! with 40 kW and a duration of 28 minutes for 80% charge. The maximum value is of 150 kW for Audi e-tron 55 quattro with a duration of 31 minutes for 80% charge.

55 Cf. Hausfather 2018.

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Electric motor

As for the type of electric motor used by the different automotive manufacturers, it is seen that they are all AC motors. Out of these, the majority are AC induction and the rest are Permanent Magnetic Synchronous Motors. Most of the models have only one driving axle and therefore, only one electric motor, but some models integrate one motor per axle, both on rear and front, such as Tesla Model S and Audi e-tron 55 quattro.

Maximum power output from the motors are registered to have a minimum value for the e.GO Life 20 model of 20 kW and a maximum value for Tesla Model S Standard Range of 285 kW on its rear axle. The maximum speed (rpm) is given for the correspondent max-imum power output. Not all these values were able to be collected, but from the available data, the minimum value of rpm is in the BMW i3 motor with 4800 rpm, and the maximum value for the motor of Volkswagen e-up! with 12000 rpm.

Maximum torque motor output can be seen in BYD e6, with a value of 450 Nm for the rear axle motor, and minimum value in Smart Electric Drive with 130 Nm.

From the vehicles that had this data available, they were all provided with regenerative braking. The vehicles that have two driving axles offer regenerative braking in at least one of the motors.

Mechanical components

All models have a single-speed reduction, and drivetrain ratio values that vary from 7,05 in the Chevrolet Bolt EV model to 9,665 in the BMW i3 model. As for brakes, most vehicles use ventilated discs in at least one of their axles. Some vehicles use plain discs brakes instead, on both axles or only on the rear axle, and the exception of the Volkswagen e-up! using drum brakes in the rear axle.

4.2 M2 This category contains vehicles that have a total gross weight lower than 5 tonnes and

capacity for more than eight passengers plus the driver. Besides the research that was per-formed, there was only one vehicle found that fitted this category, since most of the vehicles for transporting passengers exceeded 5 tonnes. Although there are surely more, this part of the automotive sector clearly has a lack of design and production. Therefore, we can find a gap in the electric vehicle market when we refer to this class of vehicles.

The vehicle that has been registered is the Zenith Electric Passenger Van. Its gross weight is just below the limit, with 5,558 tonnes, has a length of 6,35 m and has a capacity of 16 passengers. It has a range of up to 217,261 km and a maximum speed of 96,56 km/h.

The cell type is Lithium-Ion-Phosphate, with possible capacities of 51’8 kWh, 62’1 kWh or 70 kWh. The motor is Permanent Magnetic Synchronous and has a maximum power of 135 kW for a speed of 10000 rpm. The maximum torque is 320 Nm.

No further data has been able to be collected from other mechanical components.

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4.3 M3 The M3 class vehicles, assigned to the transport of passengers and with a gross weight

that surpasses 5 tonnes, present a high development in the EV market. Since reducing local pollution in large urban areas has been a worrisome issue for the last years, the investments have been more noticeable in this area. Therefore, many cities already count with fleets of electric buses (BEV, PHEV or HEV). Previous reports have already identified and classified the elements of the vehicles that can be found in this sector.

Although we have only included battery electric vehicle, it is noticeable how there is a great variety inside this electric vehicle category. With this, we find buses that are constantly supplied with power from the grid through an overhead catenary, and others that have a dou-ble-layer-capacitor as storage system. These aspects will be discussed in the following56.

General aspects

Some of the vehicles that we can find in this category have been manufactured very recently, as most electric vehicles that we were able to find in the M1 category. But we also find model years from over a decade ago. An example of this last case are the Solaris Trollino 18/18.75 model and the Solaris Trollino 12 model, which have been manufactured in 2005. This reflects on how the pollution in cities has been trying to be addressed for a relatively long period of time now.

The total passenger capacity is an important aspect of these types of vehicles, although this aspect is more related to the designed dimensions of the vehicle. Therefore, we are able to find buses that have maximum passenger capacity of up to 221 passengers for the LighTram Trolley BGGT-N2D with an accordingly gross weight of 39,4 tonnes and a length 24,72 m. On the other hand, as the vehicle with least passenger capacity there is the Gul-liver model, with 20 passengers, and a gross weight of 6,3 tonnes and 5,3 m length.

As for vehicle range we can find diverse values, since the charging methods and tech-nologies that are applied vary quite a lot from one another. Therefore, we can find minimal ranges of 15 km for Belkommunmash E433 model with the use of a supercapacitor, and maximal ranges for Xcelsior CHARGE 40' with 362,102 km with the use of Li-Ion battery.

The maximal speed of these vehicles does not surpass 100 km/h, having Thomas Saf-T-Liner C2 the highest speed with 104,607 km/h. This is mainly because these vehicles are usually designed for city transport and, therefore, are not in the need of reaching very high speeds.

Energy storage system

As we have mentioned before, the type of cells used for these vehicles are very diverse. As for electrochemical cells, most of them are Lithium-based systems, such as Li-Ion-Phosphate, Lithium-Titanate or NMC, but we also find models that apply ZEBRA type, such as the Gulliver model. There are also models that integrate Supercapacitors, like Chariot models, that have Graphene ultracapacitors, or the previously mentioned Belkommun-mash E433.

The capacities for the batteries of these vehicles also have very diverse values. Alt-hough here we had to keep in mind that, even though we have included all powered electric buses in this category, not all of them are BEV. Instead, there are many that are powered through an overhead catenary, and the batteries integrated in these vehicles require a much lower capacity. Some examples of these vehicles are Belkommunmash E433 with 34 kWh in the ultracpacitor, or the Gulliver model 59.02 kWh of capacity.

The charging systems for these vehicles was not clearly defined in the available infor-mation. It is worthy to mention that many of them present overhead catenary charging

56 Cf. UITP, the International Association of Public Transport 2018.

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systems. These systems have been implemented in different cities for public transporta-tion, since it is efficient and practical when the vehicle always drives the same short-dis-tance route.

Electric motor

The types of electric motors of the vehicles in this category are very diverse. The two main types of motors that are observed are still AC synchronous and Permanent Magnetic Synchronous. In addition to these two types, we can also find Permanent Electromagnetic motors, as well as more specific aspects, as wheel-hub motors (which means that the mo-tor is integrated in the wheel connection of the riving axles).

Maximal power that can be provide by the motor have minimum values such as for Gulliver model with 55,2 kW, and maximal values such as for TOSA BGT-N2D with 240 kW.

The torque produced by the motors of the different models presents very different val-ues in this class of vehicles, due to the difference of weights in between vehicles in the same class. Higher values than in M1 category can be seen, since the weight of the vehi-cles is much larger. The lowest value observed for an individual motor is for BYD models, with 350 Nm, and the highest value is in Linkker 12+LE with 7800 Nm.


No further information has been obtained for the mechanical elements of drivetrain or braking system.

4.4 N1 Light duty vehicles for the transport of goods have also been a target for the electric vehicle market for the past few years. They have many different applications in the industry, since they are very versatile vehicles that can be used for completing a large variety of tasks.

General aspects

The models that are currently on the market have all been released after 2016, or that have their last model year after 2016. They have not seen such a high development as passenger electric vehicle, but there are also many concept vehicles that have not been included in this report, but that will seek their way into the market in the next years.

The weights of these vehicles are all under 3,5 tonnes, as is market by the normative of the vehicle categories. The highest weight can be seen for the IVECO Daily 35 S van with a gross weight of 3,5 tonnes, and the lowest weight for Citroen Berlingo Electric, StreetScooter WORK models with 2,18 tonnes.

The ranges they present present diverse values. They generally revolve around 175 km, seeing a minimum range of 100 km for the StreetScooter WORK 20 kW and maximum value of 257 km for VW eCaddy. There is one very noticeable high value for the VW e-Transporter with a range of 400 km, which marks the exception in the values that have been previously mentioned.

The maximum speed reached by the recorded vehicles have values close to 100 km/h, showing StreetScooter WORK the lowest value with 85 km/h, and VW eCaddy the highest value with 160 km/h.

These vehicles present accelerations that are slightly lower than those of the vehicles in the same weight range for transport of passengers. The highest acceleration is seen for the VW eCaddy, that can go from 0 to 100 km/h in 13 s. The lowest acceleration is observed by LDV EV80, that can go from 0 to 100 km/h in 24 s.

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Energy storage system

Practically all batteries are lithium ion cells. There is only one exception in IVECO Daily 35 S, which uses a ZEBRA battery (NaNiCl2). In Li-Ion batteries we can observe one model that specifies the use of a LiFePO4 in their cells.

The capacities take diverse values. They are in between 20 kWh, the minimum value seen in the StreetScooter WORK, and 76,6 kWh, the maximum value observed in the VW e-Transporter.

The data of the charging systems for these vehicles is not that clearly defined as for M1 vehicles. The specifications that have been able to be recorded show that AC charging times can go from 4 hours with a charging power of 6,6 kW in the 24 kWh battery of the Nissan e-NV200, to up to 10 hours with a charging power of 7,2 kW in the 38,8 kWh battery of the VW eCaddy.

DC charging is also implemented in these vehicles, with minimum charging times of 30 minutes in Citroen Berlingo Electric and Peugeot Partner Electric, both of which use 40 kW DC charging power. The highest DC charging time is observed in the VW e-Transporter with 1 hour and 38 minutes with 40 kW charging power.

Electric motor

As for type of motor, all the models in this category present AC synchronous motor. Some of them have specified the use a Permanent Magnetic Synchronous Motors, such as the Citroen Berlingo Electric or the StreetScooter WORK models.

The maximal power at which the motors of the vehicles can operate have values in between 44 kW for the Renault Kangoo EV model, and 92 kW in the motor of the LDV EV80 model.

The maximal torque also varies less in this category compared to values reached in other, but still has values that go from 200 Nm in the Citroen Berlingo Electric, Peugeot Partner Electric and StreetScooter WORK models.


All vehicles that have this data available are integrated with a single-speed reduction, and present gear transmission ratios that go from 9,3 to 13.

Braking systems of these vehicles usually consist discs, and in some cases the use of drum brakes is also seen, as in the StreetScooter WORK models.

4.5 N2 Medium-duty vehicles for transport of goods has more models than the previous cate-

gory. These vehicles are often used for city logistics and delivery applications. These activities usually take place in the cities. Therefore, their electrification is also interesting in order to undertake the problematics of pollution in large cities.

General aspects

The vehicles in this category are also relatively recent. The earliest model year we can observe is of 2017. There are also vehicles from 2018 and other from which the model year was not available. But different concept vehicles have been announced to start production in 2019.

The N2 category presents a wide range of possible weights, which is also reflected in the electric vehicle sector. The lowest gross weight for the vehicles in this category is of 4,05 tonnes of the StreetScooter WORK XL, and the highest of 12 tonnes of the Newton Truck and eM2 Daimler.

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The ranges of the vehicles in this category show values that vary in between 100 km and 249,45 km, corresponding to Fuso eCanter and BYD Class 5 truck respectively. There is an exception in this range corresponding to the eM2 Daimler model, which reaches a range of 370 km.

Speeds also have values that are near to 100 km/h. The lowest speed that can be reached is 80 km/h by the Fuso eCanter and ORTEN E75 models, and the highest value is observed in Chanje V8100 model with 130 km/h.

Acceleration values are not so important in this category, as well as the heavier vehicles in the M class categories.

Energy Storage System

Most vehicles present again lithium-ion systems, and specifically LiFePO4 as cathode material. There is one exception in the IVECO Daily 50 C, which uses a ZEBRA battery instead of Lithium-Ion.

The capacities of these vehicles also present very different values, and generally higher than the previous N1 category. The lowest value is observed for the VW eCrafter with 35,8 kWh, and the highest value is seen in the eM2 Daimler model with 325 kWh.

As well as for the other categories, both AC charging and DC charging times reach higher values than N1 class vehicles. This is due to the higher capacities of the batteries, which will take more time to charge using the same charging powers as for lower capacity batteries. The fastest charging with AC recorded in this category is a four-hour charge with 22 kW charging power for the ORTEN E75’s battery, and the fastest charging for DC is observed for VW eCrafter battery of 45 minutes.

Electric Motor

All vehicles with this information available presented Permanent Magentic Synchro-nous Motors.

The values of maximal power reached by the motor are recorded in between a minimal value of 90 kW, found in the motor of ORTEN E75 model, and a maximal value of 353 kW, correspondent to the eM2 Daimler model.

Maximal torque reached by the electric motor presents much higher values for this cat-egory. We can still observe relatively low values, such as for VW eCrafter with 290 Nm as a minimal value for the category. Although the maximal value is reached at 1800 Nm by BYD Class 6 Step Van, BYD Class 6 Refuse Truck and BYD Class 6 Truck.


The recorded braking systems use discs brakes, some of them specifying air discs or hy-draulic discs. No information was provided regarding the transmission of these vehicles.

4.6 N3 Vehicles in this category are noticeably scarcer than in the previously accounted, although

the market gap is not as big as in the M2 class vehicles. These are one of the most complicated vehicle categories to work with regarding the combination of weight and vehicle range. This aspect will be explained in more depth in the next chapter.

General aspects

Although the number of vehicles is not that large, the available vehicles present various model years, some much earlier than in other categories. EFORCE EF18 has model of 2013. They currently have a new available model of the same design but is still has not been purchased by any buyer.

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Gross weight of the vehicles in this category also cover a very wide range. Therefore, we have vehicles with a minimal value of 18 tonnes, as in EFORCE EF18 model, and also vehicles with maximal values of 47 tonnes, such as the BYD Class 8 Refuse Truck.

Heavy-duty vehicles are aiming for higher ranges, but still seen with very different val-ues. Therefore, we can see ranges vary from 128,7 km in Motiv ERV Class 8 model up to 300 km in the models of EFORCE EF18 and Volvo FL electric.

Maximal speeds are approximately also around 100 km/h, with a minimum of 80 km/h for Motiv ERV Class 8 model and maximum of 104,607 km/h for the BYD Class 8 Day Cab and BYD Class 8 Refuse Truck.

Energy Storage System

The three storage systems that are stated in the table correspond to lithium-ion batter-ies. The battery of the EFORCE EF18 model specifically has LiFePO4 cathode, and the Mercedes-Benz eActros model has a Niquel-Manganese-Cobalt cathode.

As for battery pack capacity we are able to see much higher values as in the previous categories. The lowest value corresponds to the EFORCE EF18 model, with a value of 120 kWh, and the highest value is in the BYD Class 8 Day Cab battery pack.

The charging times also increase for this category, as the battery pack capacity also has increased. In this case we can find a minimum AC charging time of three hours with the BYD class 8 Terminal Tractor and Day Cab. In DC charging we have minimal charging time of one hour, in the EFROCE EF18 model with 350 kW charging power, and in the Volvo FL electric with 150 kW charging power.

Electric Motor

Two types motors have been registered for heavy-duty EVs, a Hybrid Synchronous Motor for the EFORCE EF18 and an AC three-phase asynchronous motor for the Mer-cedes-Benz eActros.

Maximal power provided by the electric motor varies for the different models. For the lowest value we have the Mercedes-Benz eActros with 125 kW, and the highest value for the BYD Class 8 Day Cab with 360 kW.

Maximal torque provided from the motors also differs significantly from one model to another. EFORCE EF18 presents the lowest value with 305 Nm and the highest value if provided by the Motiv ERV Class 8 with 3000 Nm.

The rotating speed achieved by the motor is recorded for EFORCE EF18 model with a maximum value of 2500 rpm, and the maximum for the model Mercedes-Benz eActros with 8250 rpm.


In gear shifting levels, a single-speed reduction was recorded for the EFORCE EF18 model, while a two-gear stage is given in the Volvo FL electric.

BYD models use air drums as baking systems, except the BYD Class 8 Day Cab, which uses air discs for the front braking and air drums for the rear braking.

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5 Scope of research In the following we are going to evaluate the results that we have mentioned in the previ-

ous chapter. The values that will to be compared in each category are range (km), battery pack capacity (kWh), maximal motor power (kW) and maximal motor torque (Nm). These values are a good indicator of the performance of the vehicle and are therefore available data for practi-cally all the vehicles we have included in the project.

Initially we will contemplate these values for the individual vehicle categories. Subse-quently, some data from the different categories will be compared between one another. The purpose of these comparisons will not only be to evaluate the possible existing trends, but also to understand the development that the market has already followed.

The data obtained has been presented in Excel graphs in order to facilitate the compre-hension of these contrasts in a visual manner. Bar graphs have been used for the values of the individual categories and disperse graphs have been used for assembling the data of all the different categories.

5.1 M1 class observations

Range, maximal distance to travel on one charge

Figure 5-1: Ranges (km) of M1 vehicles

The figure shows a large variety of range values for the different vehicle passenger cars. Although we can say that all vehicles are designed to travel over 100 km on one charge, no pattern in between the different models can be noted. There is also no distinction in between long-range vehicles and short-range vehicles, having instead all vehicles very different range values in between 100 km and 482 km.

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Battery pack capacity (total energy that can be stored in the battery)

Figure 5-2: Capacity of battery pack (kWh) of M1 vehicles

The values for battery pack capacity, or maximum energy the battery can store, present large contrasts between themselves. Therefore, there is also no established value for this pa-rameter of BEVs.

Maximal torque output from the electric motor

Figure 5-3: Maximal Torque (Nm) for M1 vehicles motors

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We can see in the graph that all the maximum torque values for the different models are all very spread in the range we have mentioned in the previous chapter. The lowest value for the Smart Electric Drive is the lowest with 130 Nm, which is justified for its low gross weight. But the contrast is very noticeable in comparison with the BYD e6 with 450 Nm. And even though the differences are somewhat smaller than for other recorded values, we are not able to define any determined followed value.

Maximal power output from the electric motor

Figure 5-4: Maximal power (kW) and respective maximal speed (rpm)

The graph shows how the values of maximal power output from the motor vary from one model to another. In between the minimum value of 20 kW and the maximum of 285 kW, the powers are reached inconstantly. Therefore, there is no type of correlation that we can observe for this characteristic.

As for maximal speed reached by the motor when it is operating at its maximal power also has very different values. Depending on the motor, the maximum speed values for maximal power are different for motors that have the same maximal power. Accordingly, these values can also take very different values.

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5.2 M3 class observations


Figure 5-5: Ranges (km) of M3 vehicles

As mentioned in the previous chapter, ranges of this type of vehicle take such different values due to the different charging methods they present. The highest values are over 350 km in one charge, and most of the vehicles have ranges in between 150 and 200 km. The lowest values correspond to vehicles with overhead charging systems. The vehicles that present the possibility of overhead charging are have the bars in orange, while the blue bars of the diagram only offer plug-in charging. All these factors make us conclude that the vehicles in this category have no defined standards either.

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Battery pack capacity (total energy that can be stored in the battery)

Battery pack capacity for M3 class vehicles presents very divergent values. The capacity of the vehicles with the possibility of overhead charging is represented in orange in the graph, and the rest of the vehicles in blue. With this represented data, we can also assure there is no guideline to be followed for this characteristic for M3 vehicles.

Figure 5-6: Battery pack capacity (kWh)

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The maximal power output of the motors of these vehicles have a slightly more reduced variety as for other categories, with values that commonly are in between 100 kW and 200 kW. But we still count with many exceptions, as it is seen in the graph, and not any observed trend for this value.

Figure 5-7: Maximal power output (kW)

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The values recorded for maximal torque present very different values, since the required torque for heavier vehicles is higher. To achieve a total higher torque in the vehicle, it is possible to choose in between using more motors, or using a motor with a higher torque. This factor contributes to the diversity of the maximal torque values that haven been noted. There is no observed common aspect for this characteristic value.

Figure 5-8: Maximal torque output (Nm)

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5.3 N1 class observations


Figure 5-9: Ranges

The case seen in the las two mentioned categories is repeated for N1 class vehicles as well. Range values are averagely in between 100 km and 250 km, which has a large variety in it, and with an exceptionally high value of 400 km. Therefore, there are no observed standards.

Battery pack capacities (total energy that can be stored in the battery)

Figure 5-10: Capacities

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As we have previously mentioned for capacities of M1 and M3 categories, finding no guidelines in range will imply a lack of guidelines in capacity. For this reason, there is no presented stand-ard for capacity in N1 vehicles.


Figure 5-11: Maximal Power

For this category we are able to see values that vary in a 50 kW range. Although this range is somewhat smaller, there is still no observed correlation in between the different values.

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Figure 5-12: Maximum torque

Maximum output torque values of these vehicles also have a relatively smaller range in which they vary in. We can observe in the graph torque in between 200 Nm and approximately 350 Nm. But as in the previous categories, no defined trend can be seen.

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5.4 N2 class observations


Figure 5-13: Ranges

In this category, all vehicles also present ranges over 100 km and usually under 250 km (with one exception of over 350 km). But values are too diverse to assure any existence of correlation here as well.


Figure 5-14: Capacities

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The lack of guidelines in battery capacity can also be noticed in this category. There is a distance of over 200 kWh in between the lowest and highest battery pack capacity.

Maximal power output from the motor

Figure 5-15: Maximal Power (kW)

We can observe very different values in maximum output power of motor, and as in the previous categories, there are no followed trends to be defined.

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Maximal torque output from the motor

Figure 5-16: Max. Torque (Nm)

We can observe how having higher weights imply the use of motors with higher torques. But as well as in the previous cases, the values present large variations from one another, having a lack of trends also for this characteristic in this category.

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5.5 N3 class observations This category only has seven vehicles recorded in it. For this first reason, it is hard to define trends when the development of the vehicles is still very scarce and recent.


Figure 5-17: Ranges (km)

Ranges are relatively higher than in the previous categories, but we are still able to see a significant difference of more than 150 km in between the highest and lowest value.


Figure 5-18: Battery pack capacities (kWh)

Battery pack capacity also presents scattered values, with over 200 kWh difference be-tween the highest and lowest value. Consequently, we cannot appreciate any guidelines for this value in the M3 category.

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Figure 5-19: Maximal Power (kW)

Four of the vehicles have values that do not overpass 200 kW, and the other three vehicles have values over this power. With these diverse values, we can also assure there are no seen guidelines for this parameter of the electric motors in this category.


Figure 5-20: Maximal Torque (Nm)

The maximal torque values for heavy-duty vehicles is where the lack of standardization is more significant, as it is seen in the graph. Therefore, the lack of trend for this characteristic value is also present in the N3 class.

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5.6 Common observations

Figure 5-21: Gross weight (tonnes) – Range (km), M class vehicles

Comparing the gross weight of all vehicles of the M class with their respective range on one charge (km), we can observe a clear correlation between range and weight: the higher the weight of the vehicle, the lower the range. This reflects how the range and, therefore, the capacity of the battery, is limited by the maximal permissible weight of the vehicle.

Despite this correlation between weight and range, the previous affirmation is not strictly true either. As it is shown in the graph, there are models that present lower ranges despite having very low gross weights, and even some models that have higher ranges with higher gross weights as those with lower gross weights.

The previously mentioned market gap in the M2 class can be observed in the section of weights right before reaching 5 tonnes (in between 3,5 and 5 tonnes). It is also worthy to mention that this vehicle category has a very limited weight range, which also limits the number of passengers these vehicles can transport. These reasons make the M2 class have a lower possibility of including a large number of vehicles.

On the other hand, M3 class includes a very large range of gross weights, which is translated into having a large number of vehicles. Not only this aspect is relevant for the nu-merous vehicles in the category, but also the previously mentioned need of reducing local pollution in big cities. These two aspects contribute to having M3 as the category with a greater number of vehicles of this project.

M1 vehicles not only are lighter in order to achieve higher ranges, but they also present the need of having high ranges in order to compete with conventional combustion engine ve-hicles. With these two aspects, there are also a considerable number of vehicles in this cate-gory.

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As it is reflected in the graph, the slight correlation that we were able to appreciate in the M class vehicles is not present for the N class. All points in the graph are very disperse, which implies that we find high and low ranges for vehicles with high and low gross weights.

The main problem for this class is the need to reach high ranges with a high payload added to them. The addressing of this problem has been a reason for which innovation in this sector has taken a longer time to appear. With this, the lack of experience and development is reflected in the graph, with very diverse characteristic ranges for not many vehicles.

Another issue that specially concerns these vehicles is the weight of the batteries. Since the purpose of these vehicles is the transport of goods, the need of having a high payload available is crucial. But in order to increase the range of these vehicles, batteries with higher capacities are required, and, therefore, with higher weights. Finding the balance in between the weight of these two elements is one the main challenges that the electric-heavy-duty vehi-cle manufacturers have to face.

It is also worthy to mention that the data recollected for the ranges of the six vehicle categories do not all correspond to the same range test cycles. Most of the vehicles present values corresponding to the New European Driving Cycle (NEDC) or the EPA Federal Test Procedure. The conditions of the different tests vary from one to another and it is for this reason that we must acknowledge that the values represented in this project and the lack of correlation between the data is an approximation.

Figure 5-22: Gross weight (tonnes) – Range (km), N class vehicles

63

The comparison of the total battery pack capacity with the range of the vehicles in all six categories included in the project is also interesting to analyze. The total amount of energy the battery is able to store has previously mentioned to be related with the range in the way that the higher the stored energy, the higher the range. Observing all vehicles in the graph, this tendency is not that noticeable.

Many vehicles with high capacities present relatively low ranges, as well as there are vehicles with relatively low capacities that have much higher ranges. The graph does not take into account the weight of the vehicles, but the correlation expected was still not as evident as expected.

This aspect proves how the battery pack technology does not follow a specific trend either when considering them in the electric vehicle market. Therefore, the need of research and development specifically in this sector is crucial.

Figure 5-23: Battery pack capacity (kWh) – Range (km)

64

6 Results and conclusion Analyzing the results accumulated during the research, the current battery electric vehicle

market indisputably lacks a trend and standardization. The scattered values obtained for the data represented in the graphs of all vehicle categories prove that there are no set guidelines.

Vehicles meant for transport of passengers present a higher development than those for transport of goods. Electric cars have started to reach an enhanced technical maturity to be able to compete in the market with conventional gasoline cars. At the same time electric buses have been on the rise in many cities to improve air quality in urban areas. This is reflected in the number of vehicles registered for the M categories compared to those registered for the N categories.

In the classes that were included, practically all vehicles are capable of ensuring ranges that are above 100 km in one charge. But above this value the numbers differ in a very wide spectrum, reaching ranges of up to 450 km in one charge for some Tesla models. This fact justifies the non-existence of a determined shift for this value in any of the categories.

Battery pack capacity also follows undetermined rates in all six categories. The possible values they can reach go from 20 kWh in M1 class vehicles, which have low weights and low ranges, and up to 500 kWh in the case of some M3 class vehicles, which have to transport large amounts of weight and at the same time reach sufficient range.

The expected correspondence between range and capacity has been able to slightly be observed from the values we have registered, as for achieving higher ranges it is necessary to aim for higher battery capacities. In this comparison we have also seen many vehicles that for high battery capacities present lower ranges due to the weight they are loaded with. But there are also many models that present exceptions in both mentioned aspects. On one hand, vehicles showing low range with a low capacity and at the same time a low gross weight, and on the other hand, vehicles showing high range and high capacity for carrying heavy loads. These last two aspects also complicate the definition of a specific tendency for the battery pack capacity of BEVs.

The maximal power provided by the electric motors also takes very diverse values in all categories. The distance between these values is slightly less prominent as for the correspond-ing to range and battery pack capacity, of about 100 kW of average difference. But the values are still too divergent to ensure any kind of followed guideline. The corresponding maximal speeds reached by the motor in the condition of maximal power also present drastic contrasts from one model to another, being able to apply the same conclusion to this value.

The maximal torque attained by the electric motor of the different vehicles is also one of the values that experiments most noticeable variances. This specially occurs in vehicles which functionally carry large loads and have the option of obtaining a large total torque value by adding the individual torques of different motors, or by using a smaller number of motors with larger torque values.

Regarding charging systems, we have been able to also see a wide range of possibilities. Although there has already been a series of set charging types and methods, the battery’s capacity and ability to charge at very high charging rates has still not reached its full develop-ment. Consequently, very different charging times for DC charging and AC charging can be achieved with a large spectrum of battery pack capacities, not being able to observe any trend in this area as well.

With all these results, we can state that there is an absence of standards in the road electric vehicle market. Although this fact also provides an advantageous situation, as compa-nies are granted the liberty of designing and manufacturing electric vehicles with the technol-ogy that they develop themselves and find more suitable. Nevertheless, this complicates the distribution of these types of vehicles in the public market, since the existence of such notice-able differences in one same product complicates its selling capability.

65

Undoubtably, the range that battery electric vehicles can offer is one of the major con-cerns, due to the need to compete with the ICE vehicles that are on the market. As we have previously mentioned, values for practically all vehicles are over 100 km in one charge. But this value is still not comparable to the ensured range provided by a combustion engine, which usually is in between 300 and 400 km per fueling tank. Furthermore, the possibility of distin-guishing between short-range vehicles and long-range vehicles is also possible in convention-ally propelled vehicles, which is a feature that still needs an extensive development in battery technology of BEVs.

As for electric motors, their operation is also essential for the performance of the vehicle. These motors already integrate an advantage over ICE by producing the maximum torque from the stating of the vehicles. They also present the ability to reach a very high range of powers, speeds and torques with a simple construction and a relatively light design. The only detriment they show is the amount of energy they are supplied with, which brings us back to the limits that batteries suppose for these vehicles, and the need of a progression in well-functioning batteries.

Moreover, motors which are manufactured with a set of guidelines and regulated values will certainly contribute to increase their productivity and their ability to be introduced into the mobility sector. For this reason, even though batteries are the main aspect to work on in elec-tromobility, electric motors must also be taken into account to increase the overall performance of BEVs.

Considering all of these aspects that have been mentioned, we can assure that by a fur-ther technological growth of the different elements that integrate the powertrain in an electric vehicle will definitely lead to an increase in the demand of these vehicles, and therefore, their production and implementation into society.

66

7 Outlook All the considered elements in the previous chapter will be able to be improved within the

coming years. Conventional combustion engine vehicles have been developed and re-searched for the last century. And considering that technological improvements can nowadays occur at a much higher rate, these progressions can take place in the near future.

Presently, the electric vehicle progress is also aiming towards the affordability of the prod-ucts offered in this sector. Since the market that constitutes EVs is so recent and has not experimented a high demand, the prices of these vehicles are uncompetitive compared to the prices of ICE automobiles. Not only is the manufacturing process of EVs still very costly, but the product does not present a remarkable advantage over conventional gasoline vehicles from the consumer’s point of view, as far as comfort is concerned. Consequently, it has been complicated to reach a high demand in such a short amount of time. Nevertheless, the re-search and improvements that are taking place in this area will contribute to make electromo-bility more affordable for everyone.

The investigation that is currently taking place in battery technology looks very positive for the future of electromobility. It is surely the aspect that has to be worked on the most, in order to reduce their weight without decreasing their capacity. Lithium-ion batteries seem to be the battery technology with the most success, but accounting the amount of investigation that is being held in other energy storage systems, it is difficult to ensure the use of one and only battery cell technology to dominate the battery pack sector for EVs.

Production of batteries in large quantities will convey a series of problems that will also have to be addressed in the future. For example, the pollution of the extraction of lithium and the scarcity of resources that provide materials for battery manufacturing are some of these problems. In addition to these, the ability or not to recycle the batteries after they have reached their lifetime is also an important concern.

Another meaningful aspect in the transition to electromobility is the increase of the demand of electricity from the grid. This aspect however will not suppose a problem by transitioning to renewable energy sources. Therefore, being electromobility itself a solution to decreasing local pollution, the change will only suppose a benefit at a global scale through an accompanied shift towards a clean energy mix.

But even though the introduction of electric vehicles at a large scale in our society shows to come with other threatening confrontations, it is important to keep in mind that, after all, that is the reason engineering was established. Throughout history, humans have continuously developed products to improve our lifestyle and increase our comfort, solving problems of our day-to-day life. This is the case of cars, which were invented in order to travel longer distances in a more comfortable and faster way. In the most recent years, the sudden realization that we need to decrease our emissions has also been a problem that needed to be solved. Constitut-ing pollution caused by the transportation sector a problem to solve, electric vehicles are a possible solution to it, and currently one of the most successful. Even though the progression of this product will also lead to other complications, the situation that has to be dealt with now will be improved. And in the coming years, these new appearing problems will also continue to have a solution.

The need of promoting investigation in electro-mobility is crucial in order to undertake the problem of transportation emissions. Unfortunately, our global emissions must be reduced drastically in the next years to conserve our planet as we know it. For this, not only the trans-portation industry has to work on their development of new technologies, but all sectors and society in general must intervene. The awareness situation and taking action in the matter have certainly improved in the past years and are advancing even faster today, but there is still a lot of work to be done.

67

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M1 (under 3.5t)

MODEL Nissan Leaf SL Plus BMW i3 42 kWh Kia Soul Audi e-tron 55 quattro Chevrolet Bolt EV

GENERAL ASPECTSPropulsion system BEV BEV BEV BEV BEVModel year 2019 2019 2019 2019 2019Gross weight (t) 2,155 1,715 1,96 3,13 2,047Curb weight (t) 1,729 1,345 1,506 2,49 1,625Range (km) 346 246,2 178,6 328,3 383Maximum speed (km/h) 157 150 145 200 145Acceleration (km/h in s) From 0 to 100 in 7,3 From 0 to 100 in 7,2 From 0 to 100 in 11,5 From 0 to 100 in 6,6 From 80 to 120 in 4,5ENERGY STORAGE

Battery manufacturerAutomotive Energy Supply Corporation (AESC)

Samsung SDI SK Innovation - LG Chem

Cell type Li-Ion Li-Ion Li-Ion Polymer (NMC) Li-Ion Li-IonCapacity (kWh) 62 42,2 31,8 95 60

AC Type of charger / Interface Wall box / Type 1 (J Plug)Wallbox / Type 2 (SAE

J3068)Normal AC / -

Mode 3 charging cable / Type 2 (CCS2)

Wallbox / Type 1 (CCS1)

AC Charging power (kW) (max. Permissible) 6,6 11 6,6 11 7,8

AC Charging time (hh:mm) 10:20 3:50 4:38 8:38 8:20

DC Type of charger / Interface Fast charging / Type 4 (CHAdeMO)Fast charging / Type 2

(CCS2)Fast charging / Type 4 (CHAdeMO) Fast charging / Type 2 (CCS2) Fast charging / Type 1 (CSS1)

DC Charging power (kW) 70 50 50 150 80DC Charging time (% charged in hh:mm) 0:30 0:44 0:20 0:31 0:36

Cooling system Air convection (active)Water-based coolant

circulationAir convection

Indirect, aluminium sections separate from cell space

Water-based cooling circulation

MOTORElectric motor manufacturer Nissan BMW Kia Motors (Not 100% sure) - -

Type of motor AC Synchronous (EM57) AC Synchronous (PMSM) AC Synchronous (PMSM)AC induction (front) /

synchronous (rear)AC Synchronous (PMSM)

Number of motors 1 1 1 2 (Front and rear) 1 (front)Maximal power (kW) 160 125 81 140 150Maximal torque (Nm) 340 250 285 314 360Maximal speed (rpm) 5800 4800 8000 0 0Operating voltage (V) 360 - 360 - -Regenerative braking Yes Yes Yes - Yes

MECHANICAL COMPONENTSGear Shifting levels Single-speed reduction Single-speed reduction Single-speed reduction Single-speed reduction Single-speed reductionDrivetrain ratio 8,193 9,665 8,206 9,205 7,05Front breaking system Ventilated discs Ventilated discs Ventilated discs Ventilated discs Ventilated discsRear breaking system Ventilated discs Ventilated discs Ventilated discs Ventilated discs Discs

Renault Zoe R110 e.GO Life 60 e.GO Life 40 e.GO Life 20Hyundai IONIQ Electric 28

kWhHyundai KONA Electric 64

kWhHyundai KONA Electric 39

kWh

BEV BEV BEV BEV BEV BEV BEV2018 2019 2019 2019 2019 2019 20191,954 1,6 1,6 1,6 1,88 2,17 2,02

1,5 1,21 1,21 1,15 1,42 1,685 1,535300 145 113 100 200 415 289135 142 123 112 165 167 155

From 0 to 100 in 11,4 From 0 to 50 in 3,4 From 0 to 50 in 4,7 From 0 to 50 in 7,7 0 to 100 in 9,9 0 to 100 in 7,6 0 to 100 in 9,7

Renalut aand LG Chem - - - LG Chem (NCM 622) LG Chem (NMC 622) LG Chem (NMC 622)

Li-Ion Li-Ion Li-Ion Li-Ion Li-Ion Polymer Li-Ion Polymer Li-Ion Polymer45,61 23,5 17,5 14,5 28 64 39,2

Wallbox / Type 2 (SAE J3068)

e.Go Wallbox / - e.Go Wallbox / - e.Go Wallbox / -POD Point Wallbox / Type 2

(CCS2)POD Point Wallbox / Type 2

(CCS2)POD Point Wallbox / Type 2

(CCS2)

22 11 11 11 7 7,2 7,2

2:05 6:21 4:44 3:55 4:16 8:54 5:27

-Fast charging / Type 2 (SAE

J3068)Fast charging / Type 2 (SAE

J3068)Fast charging / Type 2 (SAE

J3068)Public CCS / Type 2 (CCS2) Public CCS / Type 2 (CCS2) Public CCS / Type 2 (CCS2)

- 50 50 50 100 100 100- 0:28 0:21 0:18 0:14 0:39 0:24

Air convection - - - Air convectionWater-based coolant

circulationWater-based coolant

circulation

Renault (R110 Model) Bosch Bosch Bosch - Siemens Siemens

AC Synchronous (PMSM) - - - AC Synchronous (PMSM) AC Synchronous (PMSM) AC Synchronous (PMSM)

1 1 1 1 1 1 180 60 40 20 88 150 100

225 0 0 0 295 395 39510980 0 0 0 6000 0 0

- 230 230 230 - - -Yes - - - Yes Yes Yes

Single-speed reduction Single-speed reduction Single-speed reduction Single-speed reduction Single-speed reduction Single-speed reduction Single-speed reduction- - - - 7,412 7,981 -

Ventilated discs Discs Discs Discs Ventilated discs Ventilated discs Ventilated discsDrums Discs Discs Discs Discs Discs Discs

Jaguar I-Pace KIA e-Niro 64 KIA e-Niro 39 NIO ES6 Standard 70 kWh NIO ES8 84 kWh NIO ES8 70 kWh Peugeot e-208 GT

BEV BEV BEV BEV BEV BEV BEV2019 2019 2019 2019 2019 2019 20192,67 2,23 2,08 0 0 0 02,14 1,748 1,667 - 2,46 2,46 1,5

376,6 384 289 420 425 355 450200 167 155 200 200 200 150

0 to 100 in 4,8 0 to 100 in 7,8 0 to 100 in 9,5 0 to 100 in 5,6 0 to 100 in 4,4 0 to 100 in 4,4 0 to 100 in 8,1

LG Chem (LGX N2.1) SK Innovation SK Innovation CATL (NCM811) CATL (NCM811) CATL (NCM811) -

Li-Ion Li-Ion Polymer Li-Ion Polymer Li-Ion Li-Ion Li-Ion -90 64 39,2 70 84 70 50

Wallbox / - EVSE cable / Type 1 (CCS1)Home charging station (3-

phase) / Type 2 (J3068)AC charging / Type 2 (J3068) AC charging / Type 2 (J3068) AC charging / Type 2 (J3068) Wallbox / Type 2 (CCS2)

7,4 7,2 22 7 7 7 11

12:51 8:54 5:27 10:30 12:00 10:30 4:33

Fast charging / - Public CCS / Type 1 (CCS1) Public CCS / Type 2 (J3068) Fast charging / - Fast charging / - Fast charging / - Fast charging / Type 2 (CCS2)

100 100 100 90 90 90 1000:43 0:29 0:19 0:47 0:45 0:47 0:24

Water-based coolant circulation






-

Jaguar (EV400) - - - - - -

AC Synchronous (PMSM) AC Synchronous (PMSM) AC Synchronous (PMSM) AC induction AC induction AC induction -

2 1 1 2 (Front and rear) 2 (Front and rear) 2 (Front and rear) 2147 150 100 160 240 240 100348 395 395 305 420 420 260

0 8000 8000 0 0 0 0- 356 327 - - - -

Yes Yes Yes Yes Yes Yes Yes (second motor)

Single-speed reduction Single-speed reduction Single-speed reduction Single-speed reduction Single-speed reduction Single-speed reduction Single-speed reduction9,04 8,206 8,206 - - - -

Ventilated discs Ventilated discs Ventilated discs Ventilated discs Ventilated discs Ventilated discs DiscsVentilated discs Discs Discs Ventilated discs Ventilated discs Ventilated discs Discs

Volkswagen e-up!Tesla Model S Standard

RangeTesla Model 3 Standard

RangeTesla Model X 100D Tesla Roadster 3.0 Volkswagen e-Golf SE BYD e6

BEV BEV BEV BEV BEV BEV BEV2019 2019 2019 2018 2016 2019 20171,53 0 0 3,079 1,485 2,02 2,794

1,229 2,163 1,645 2,459 1,237 1,615 2,419141 436,5 354 475 482 300 400130 225 209 250 201 150 140

0 to 100 in 12,4 0 to 100 in 4,4 10 to 100 in 5,9 0 to 100 in 4,9 0 to 96,56 in 3,7 0 to 100 in 9,6 0 to 96,56 in 7,69

Panasonic-Sanyo Panasonic Tesla and Panasonic Panasonic Panasonic Samsung SDI BYD

Li-Ion Li-Ion Li-Ion Li-Ion Li-Ion Li-Ion Li-Ion (LiFePO4)18,4 72,5 62 100 80 35,8 80

Wallbox / Type 2 (J3068)Wall Connector / Tesla

charging inletWall Connector / Tesla



charging inletWall box / Type 2 -

7,2 11,5 11,5 17,28 16,8 7,2 -

2:36 8:42 5:39 5:47 8:00 4:55 -Fast charging charging / Type

2 (CCS2)Supercharger / Tesla

charging inletSupercharger / Tesla

charging inletSupercharger / Tesla charging

inlet- CCS fast charging / Type 1 -

40 120 120 145 - 50 -0:28 0:40 0:30 0:40 - 0:34 -

-Water based coolant

circulationWater based coolant

circulationWater based coolant

circulation- Passive cooling -

Volkswagen Tesla Tesla Tesla Tesla Volkswagen -

AC Synchronous (PMSM) AC induction (both) Switched reluctance AC induction/asynchronous AC induction/asynchronous PMSM AC Synchronous Brushless

- - 1 2 1 1 -60 285 202 193 215 100 90

210 440 0 330 400 290 45012000 6850 0 6800 4400 12000 0

- 320 (both) 370 320 - - -Yes Yes (rear) / - (front) - Yes - Yes Yes

Single-speed reduction Single-speed reduction Single-speed reduction Single-speed reduction Single-speed reduction Single-speed reduction- 9,34 9 9,325 8,2752 3,61

Ventilated discs Ventilated discs Ventilated discs Ventilated discs Ventilated discs Ventilated discs DiscsDrums Ventilated discs Ventilated discs Ventilated discs Ventilated discs Discs Discs

i-MiEV Smart electric drive Renault Fluence ZE

BEV BEV BEV2019 2017 2011

1,1 0,985 1,543150 145 185130 125 135

0 to 100 in 15,9 0 to 100 in 11,5 0 to 100 in 13

Li-Ion Li-Ion Li-Ion16 17,6 22

3-phase 32A / Type 1 3-phase 32A / Type 2 -

22 22 -

4:42 4:30 -

CHAdeMO - -

100 - -0:21 - -

Water cooling - -

-

PMSM PMSM PMSM

1 - -47 55 70

196 130 2260 0 11000- - -

Yes

Single-speed reduction

Hydraulic discsDrums

M2 (over 3.5t and under 5t)MODEL Zenith Electric Passenger VanGENERAL ASPECTSPropulsion system BEVYear release 2018Gross weight (t) 4,558Vehicle length (m) 6,35Maximum number of passengers 16Range (km) 217,261Maximum speed (km/h) 96,56Acceleration (km/h in s) -ENERGY STORAGEBattery manufacturer -Cell type Li-Ion (LiFePO4)Capacity (kWh) 70Voltage range (V) -Charging power (kW) -Charging time (h) -Type of charger -On board charging -Portable charging -Cooling system -MOTORElectric motor manufacturer UQM, PowerPhase Pro 135Type of motor AC Synchronous (PMSM)Number of motors -Nominal power (kW) 80Maximal power (kW) 135Nominal torque (Nm) -Maximal torque (Nm) 320Speed (rpm) 10000Operating voltage (V) -Required current (A) -Cooling system -

M3 (over 5 t)MODEL ABB TOSA flash-charging AVASS Metro Bus SeriesGENERAL ASPECTSPropulsion system BEV BEVYear release 2018 -Total Passengers Capacity 133 70Vehicle lenght (m) 18,75 12Gross weight (t) 0 18Range (km) 0 300Maximum speed (km/h) - 80Acceleration (km/h in s) - 0 to 50 in less than 18 sENERGY STORAGEBattery manufacturer - -Cell type - Li-Ion (LiFePO4)Capacity (kWh) 0 259Voltage range (V) - -Charging power (kW) 600 -Charging time (h) 20 sType of charger Flash chargingMOTORElectric motor manufacturer - -Type of motor -Number of motors - -Nominal power (kW) - -Maximal power (kW) 0 200Nominal torque (Nm) - -Maximal torque (Nm) 0 2400Speed (rpm) - -Cooling system - -MECHANICAL COMPONENTSGear shifting levels - -Front braking system - -Rear braking system - -

AVASS Touring Coach Series Belkommunmash E433 Bluebus 6m (Bolloré) ZEUS BredaMenarini

BEV BEV BEV BEV- - - -

39 153 22 -9,45 18,735 6 5,914,5 28 6,17 0250 15 120 12080 70 50 -

0 to 50 in less than 15 s - - -

- - BlueSolutions -Li-Ion (Polymer) Supercapacitor Lithium metal polymer Li-Ion

167 34 90 0- 420 - 600 - -- - - -

8

- - - -AC Synchronous (PMSM) - AC Asynchronous AC Asynchronous

- - - -- - - -

200 0 0 0- - - -

2400 0 0 0- - - -- - - -

- - - -- - - -- - - -

BONLUCK JXK6105E EBUS22 (BS&CS) Ekova Oréos 4X Oréos 2X

BEV BEV BEV BEV BEV- - - 2010 2010

45 - 90 22 4910,76 - 11,98 9 713,3 0 18 0 0318 - 0 150 150

- - - 90 90- - - - -

- - - - -- Li-Ion (LiFePO4) Li-Ion NMC NMC0 130 265 0 0

Pack voltage of 528 - - - -- - 43 (DC) / 22 (AC) - -

- - Ziehl Abegg Motors - -- - AC Synchronous - -- - 2 - -- - 113 - -0 0 155 0 0- - - - -0 0 0 0 0- - - - -- - Liquid cooling - -

- - - - -- - - - -- - - - -

Mercedes-Benz eCitaro Xcelsior CHARGE 35' Xcelsior CHARGE 40'

BEV BEV BEV2018 2019 2019

80 67 8212 11,05 12,5

19,5 0 0150 313,82 362,102

- - -- - -

AKASOL XALT Energy and A123 Systems XALT Energy and A123 SystemsLi-Ion Li-Ion Li-Ion243 388 466

- - -- - -

On-Route / Plug-In

- Siemens (ELFA2 electric drive syst.) Siemens (ELFA2 electric drive syst.)- DC motor (PEM) DC motor (PEM)2 - -- - -

125 160 160- - -

485 1400 1400- - -- - -

- Single-speed reduction Single-speed reduction- - -- - -

Xcelsior CHARGE 60' LFSe Novabus Gulliver Thomas Saf-T-Liner C2

BEV BEV BEV BEV2019 2018 2008 2018130 112 20

18,54 12,2 5,30 0 6,3 0

281,635 0 130 160- - 33 104,607- - From 1 to 50 in 1 s From 0 to 96,56 in 45 s

XALT Energy and A123 Systems Volvo (high voltage) ZEBRA (ML3P/418) -Li-Ion Li-Ion ZEBRA (NaNiCl) -620 0 59,02 155

- - - -- - - -

0:05 8 h for 100% Under 8 h (4 to 6 fot nominal charge)Overhead pantograph charging AC charging AC charging

Siemens (ELFA2 electric drive syst.) TM4 Sumo HD electric powertrain Eta Systems -DC motor (PEM) - - -

- - - -- - 27,2 -

210 230 55,2 234,895- - - -

2000 2700 0 0- - - -- - - -

Single-speed reduction Single-speed reduction - -- Disc brakes - -- Disc brakes - -

Wuzhoulong FDG6113EVG Wuzhoulong FDG6751EVG Wuzhoulong FDG6801EVG

BEV BEV BEV

94 69 9011,49 7,495 7,95

18 10,8 12,50 0 0

69 69 69- - -

OPTIMUM Battery Co. Dongguan New Energy Power Technology Co. Guangdong Power Technology Co., Ltd.Li-Ion (LiFePO4) Li-Ion (LiFePO4) Li-Ion (LiFePO4)

0 103,68 0- - -- - -

Dalian Tianyuan Electric Motor Corp. Shanghai Dajun Power Control Technology Co., Ltd. Dalian Tianyuan Electric Motor Corp.- AC Synchronous (PMSM) AC Synchronous (PMSM)- 4 -- 48 -

90 100 136- - -0 0 0- - -- - -

- - -- - -

Disc brakes - -

Wuzhoulong WZL6100EVG Proterra Catalyst E2 BYD ADL Enviro200EV

BEV BEV BEV2017 2016 (Europe)

100 117 9010,49 12,192 1216,5 17,713 18,6

0 0 25075 - 70- - -

Guangdong Power Technology Co. - BYDLi-Ion (LiFePO4) Li-Ion Li-Ion / LiFePO4

0 660 324- - -- - 80

4Manual charging

Dongfang Electric Group Dongfeng Motor Co., Ltd. BYDAC Asynchronous (Induction) Permanent magnetic Traction Motor -

- - -- - -

100 0 180- - -0 0 700

2000 - -2000 - -

- 2 -- Disc brakes -- Disc brakes -

BYD ADL Enviro200EV APTIS APTIS Bluebus 12m (Bolloré)With heating and AC(electric) With heating and AC

BEV BEV BEV BEV2017 (Europe) 2017 2017 2016

78 77 77 9710,8 12 12 1218,6 0 0 20250 200 120 18070 70 70 70- - - -

BYD Fiamm Fiamm BLueSolutionsLi-Ion / LiFePO4 Sodium Nickel Sodium Nickel Lithium metal polymer

307 346 346 240- - - -

80 NC NC 504 From 7 to 8 From 7 to 8 05-ene

Manual charging NC NC Manual

BYD Alston Alston Siemens- AC Synchronous (PMSM) AC Synchronous (PMSM) AC Synchronous (PMSM)- - - -- - - -

180 180 180 160- 970 970 -

700 0 0 2500- 970 970 -- 970 970 -

- - - -- - - -- - - -

Sileo S10 Sileo S12 Sileo S18 Sileo S24 BYD 12m China BYD 12m Overseas

BEV BEV BEV BEV BEV BEV2015 2015 2016 2016 2013 2013

78 79 137 - 75 9510,7 12 18 24 12 1218 18 28 0 18 19

235 260 260 250 300 32075 75 75 NC 70 70/80- - - - - -

Bozankaya BC&C Bozankaya BC&C Bozankaya BC&C Bozankaya BC&C BYD BYDLi-Ion (LiFePO4) Li-Ion (LiFePO4) Li-Ion (LiFePO4) Li-Ion (LiFePO4) Li-Ion / LiFePO4 Li-Ion / LiFePO4

200 230 300 380 0 0- - - - - -

4-100 4-100 4-200 NC 2x40 kW 2x40 kWFrom 2 to 7 From 2 to 8 From 3 to 8 NC 4 to 4,5 4 to 4,5

Manual (plug-in) Manual (plug-in) Manual (plug-in) Manual (plug-in) Plug-in Plug-in

ZF/Siemens ZF/Siemens ZF/Siemens ZF/Siemens BYD BYDAC Asynchronous AC Asynchronous AC Asynchronous AC Asynchronous AC Synchronous (PMSM) AC Synchronous (PMSM)

2 2 4 4 2 2- - - - - -

120 120 120 120 90 150- - - - - -0 0 0 0 350 550- - - - - -- - - - - -

- - - - - -- - - - - -- - - - - -

BYD midi bus BYD 10,8m variants BYD Double Decker BYD 18m Articulated

BEV BEV BEV BEV2017 2017 2015 2016

54 90 95 1508,7 9,6 - 11,5 10,2 - 12 1813 19 20 28

200 340 330 20070 70/80 70 70- - - -

BYD BYD BYD BYDLi-Ion / LiFePO4 Li-Ion / LiFePO4 Li-Ion / LiFePO4 Li-Ion / LiFePO4

0 0 0 0- - - -

2x40 kW 2x40 kW 2x40 kW 2x40 kW2 4 to 4,5 4,5 Up to 3

Plug-in Plug-in Plug-in Plug-in

BYD BYD BYD BYDAC Synchronous (PMSM) AC Synchronous (PMSM) AC Synchronous (PMSM) AC Synchronous (PMSM)

2 2 2 2- - - -

90 150 150 150- - - -

350 550 350 350- - - -- - - -

- - - -- - - -- - - -

BYD 12m Coach e.City Gold eCobus Chariot ebus

BEV BEV BEV BEV2016 2016 2013 2016

59 88 112 9112 11,995 13,92 1219 19 20 19

200 200 170 2290 70 Airport - 50 70- - - -

BYD NC Actia Ultracapacitors by AowelLi-Ion / LiFePO4 Lithium titanate or NMC Lithium titanate Graphene ultracapacitors

0 250 85 21- - - -

2x40 kW 50 - 150 / 350 60 1503 Battery configuration depandant 1:15 00:05 up to 85%

Plug-in Manual / Overhead Manual Overhead fast-charging pantograph system

BYD Siemens Siemens SiemensAC Synchronous (PMSM) AC Synchronous (PMSM) AC Synchronous (PMSM) AC Synchronous (PMSM)

2 - - -- - - -

180 160 160 180- - - -

1500 1500 1500 2500- - - -- - - -

- - - -- - - -- - - -

Chariot ebus Chariot ebus Dancer

BEV BEV BEV2016 2017 2017

91 91 9312 NC 1219 19 6,50 33,7 58,4

70 70 70- - -

Ultracapacitors by Aowel Ultracapacitors by Aowel ICTP (Toshiba SCIB)Graphene ultracapacitors Graphene ultracapacitors Lithium titanate

32 32 29,2- - -

340 340 50000:03 up to 85% 00:03 up to 85% 00:06 - 00:10

Overhead fast-charging pantograph system Overhead fast-charging pantograph system 3-phase 400 VAC (option fast charging)

ZF Ave 130 Siemens ZFAC Synchronous (PMSM) AC Synchronous (PMSM) AC Asynchronous

2 - -- - -

76 180 125- - -0 2500 0- - -- - -

- - -- - -- - -

Ebusco 2.1 HV LF.311.HV-2/3 Ebusco 18M HV LF-414-HV-3/4 Electron E19 electric Modulo C68E

BEV BEV BEV BEV2014 2017 2017 2016

90 125 90 5512 18 12,1 7,98212 19,5 19 10,35

365,88 324,7 200 23080 80 70 65- - - -

Ebusco Ebusco Winston Battery ValenceLi-Ion / LiFePO4 Li-Ion / LiFePO4 Li-Ion / LiFePO4 Li-Ion / LiFePO4

311 414 225 144- - - -

75/120 75/120 40 604,5 / 3 6h/4h 6 5:00Plug-in Plug-in Plug-in Conductive

Ebusco ZF ZF SiemensAC Asynchronous AC Asynchronous AC Asynchronous AC Synchronous

- 2 2 -- - - -

220 125 125 160- - - -

3000 0 0 1019- - - -- - - -

- - - -- - - -- - - -

Modulo C88e TOSA BGT-N2D Swiss Trolley BGT-N2D LighTram Trolley BGGT-N2D

BEV BEV BEV BEV2016 2013 2016 2014

74 142 147 2219,457 18,74 18,74 24,7211,05 29 29,5 39,4140 0 0 065 80 65 65- - - -

Valence ABB VKD VKDLi-Ion / LiFePO4 Lithium titanate Li-Ion (LiFePO4) Li-Ion (LiFePO4)

84 70 20 32- - - -

60 600 Over 60 Over 605:00 Flash 15s / terminus 3min

Conductive Conductive pantograph Overhead in-motion charging Overhead in-motion charging

Siemens ABB TSA TSAAC Synchronous DC motor (PEM) AC asynchronous AC asynchronous

- - - -- - - -

160 240 240 240- - - -

1019 1520 0 0- - - -- - - -

- - - -- - - -- - - -

Heuliez Bus GX 337 ELEC Heuliez Bus GX 337 ELEC

BEV BEV2017 2017

94 15512 1820 30

200 080 80- -

Foresee ForeseeNMC NMC349 106

- -50 to 100 (slow overnight charge) / 150 (faster mid-day charge) 300 to 450

3 to 5 Few minutes, depending on charging powermanual plug Combo 2, CCS protocol Pantograph, CCD protocol

BAE Systems BAE SystemsAC Synchronous (PMSM) AC Synchronous (PMSM)

- -- -

190 200- -

3300 5100- -- -

- -- -- -

TEG6125BEV03 Hybricon Arctic Whisper HAW 18 LE 4WD

BEV BEV2017 2016

94 7912 1219 28

115 54,5470 80- -

Offnenbach / CATL Altair-NanoNMC ternary / LiFePO4 Lithium titanate

201 120- -

99-137 / 150 20 - 6502h (for 100kW) / 1h 4,5 min / 4 h depot

Both manual charging Overhead / depot manual

Hunan CRRC Times Electric Vehicle Co., Ltd Ziehl-AbeggAC Synchronous (PMSM) -

- 4- -

150 157- 2100

2500 6000- 2100- 2100

- -- -- -

Hybricon City Bus HCB 12 LF Hybricon model (no specific name) Irizar ie bus

BEV BEV BEVN/A N/A 201462 - 8012 12 11,9818 18 200 0 250,67

80 80 85- - -

BMZ BMZ FIAMMNMC NMC ZEBRA265 265 376

- - -20 - 200 20 - 200 80 - 100

TBD TBD 6 to 7 hOverhead / depot manual Overhead / depot manual Manual Combo 2

Ziehl-Abegg Ziehl-Abegg Siemens- - AC Synchronous 2 2 -- - 180

157 157 02100 2100 18006000 6000 02100 2100 18002100 2100 1800

- - -- - -- - -

Irizar ie tram Linkker 12+ LE

BEV BEV2017 2016150 80

18,73 12,828 160 0

85 80- -

Multiple suppliers Actia IM+ELi-Ion Lithium Ion Titanate180 79

- -Up to 500 / 80 to 100 6C, 300 - 480 kW

5 to 10 min / 2h 2 to 5 min in nrmal operationOpportunity charging pantograph / Depot charging Overhead roof mounted or inverted pantograph

Siemens VisedoAC Synchronous AC Synchronous (PMSM)

- -230 -

0 1802350 -

0 78002350 -2350 -

- -- -- -

Optare Solo EV Optare Metrocity EV Optare Versa EV

BEV BEV BEV2012 2014 2013

55 58 589,2 and 9,9 10,8 10,4 and 11,1

11,3 12,96 12,48270 205,97 205,9780 80 80- - -

Valence Valence ValenceLiFePO4, Lithium Iron Magnesium Phosphate LiFePO4, Lithium Iron Magnesium Phosphate LiFePO4, Lithium Iron Magnesium Phosphate

138 138 138- - -

42 kW 42 kW 42 kW2,5 h 2,5 h 2,5 h

Plug-in Plug-in Plug-in

Magtec Magtec Magtec- - -- - -- - -

150 150 150- - -

2000 2000 2000- - -- - -

- - -- - -- - -

Optare Metrodecker EV Otokar Electra Rampini E12 Skoda Perun HE

BEV BEV BEV BEV2017 - 2016 2013

99 55 70 8210,5 9 12 1218 13,5 19 18,6

200 170 130 164,28580 80 70 70- - - -

TBC Valence Winston Battery VariousLiFePO4, Lithium Iron Magnesium Phosphate Li-Ion (LiFePO4 or LFP) Li-Ion (LifePO4 or LFP) Li-Ion (LiFePO4)

200 170 180 230- - - -

40 32 15 to 30 kW Up to 1006 8 3 to 6 h 4 to 6h

Plug-in Manual Manual (plug) / Pantograph Plug-in

Magtec - Siemens Skoda- AC Asynchronous A/C AC Asynchronous - - - -- - - -

200 103 160 160- - - -

3570 380 2180 1800- - - -- - - -

- - - -- - - -- - - -

Skoda Perun HP Skoda 26 Tr Skoda 27 Tr Solaris Urbino 8.9 LE electric

BEV Trolleybus Trolleybus BEV2014 2013 2014 2011

82 85 125 6512 12 18 8,95

18,6 18 29 1657,14 33,3 33,3 200

70 70 70 Up to 80- - - -

Variuos Variuos Various SolarisLithium Titanate Lithium Titanate NMC Li-Ion (LiFePO4 or lithium titanate)

80 50 80 160- - - -

Up to 600 Up to 200 Up to 200 120 // 300Up to 10 min N/A N/A 1,33 kWh/min // 5 kWh/min

Overhead automatic Overhead trolley Overhead trolley Plug-in // Pantograph

Skoda Skoda Skoda TSAAC Asynchronous AC Asynchronous AC Asynchronous AC Asynchronous

- - - -- - - -

160 160 250 170- - - 903

1800 1800 2500 0- - - 903- - - 903

- - - -- - - -- - - -

Solaris Urbino 12 electric Solaris Urbino 18 electric Solaris Trollino 12

BEV BEV BEV2012 2013 2005

90 129 8312 18 1219 30 19

200 123,07 0Up to 80 Up to 80 Up to 70

- - -

Solaris Solaris Solaris, SkodaLi-Ion (LiFePO4 or lithium titanate) Li-Ion (LiFePO4 or lithium titanate) Li-Ion (LiFePO4 or lithium titanate)

160 160 69- - -

120 // 300 // 200 120 // 300 // 200 50 to 601,33 kWh/min // 5 kWh/min // 3,33 kWh/min 1,33 kWh/min // 5 kWh/min // 3,33 kWh/min Approx. 1kWh/min

Plug-in // Pantograph // Induction Plug-in // Pantograph // Induction In-motion charging

TSA // ZF TSA // ZF Skoda // TSA // EMITAC Asynchronouss // AC Asynchronous AC Asynchronous AC Asynchronous

1 // 2 1 -NA // 60 (x2) 240 160 // 160 // 175

125 270 280- 1304 18000 0 2266- 1304 1800- 1304 1800

- - -- - -- - -

Solaris Trollino 18/18.75 SOR EBN 11 SOR EBN 10.5 Temsa MD9 electriCITY Temsa Avenue EV

BEV BEV BEV BEV BEV2005 2015 2014 2017 2017139 90 82 65 90

18 / 18,75 11,1 10,37 9,3 1230 16,5 16,5 14 190 156,36 172 181,81 50

Up to 70 80 80 90 90- - - - -

Solaris, Skoda Winston Battery Winston Battery Mitsubishi MicrovastLi-Ion (LiFePO4 or lithium titanate) Li-Ion Li-Ion NMC Lithium titanate

69 172 172 200 75- - - - -

50 to 60 100 to 150 22 120 450Approx. 1kWh/min 1 to 2 (fully charged) 7 (fully charged) 2,5 7 minIn-motion charging Overhead, manual Manual Manual plug-in Overhead (also plug-in)

Skoda // TSA // EMIT Pragoimex Pragoimex TM4 TM4AC Asynchronous AC Asynchronous AC Asynchronous DC motor (PEM) DC motor (PEM)

- - - - -250 // 251 // 240 - - - -

296 120 120 200 2703750 - - - -4200 968 968 2200 27003750 - - - -3750 - - - -

- - - - -- - - - -- - - - -

Ursus Bus Ekovolt Ursus Bus City Smile Ursus Bus City Smile Ursus Bus City Smile

BEV BEV BEV BEV2015 2014 2013 2016

81 61 84 8211,96 8,5 9,95 12

18 16 18 18123,71 0 0 218,75

70 70 70 70- - - -

Impact BMZ EVC ImpactLi-Ion (LiFePO4) NMC Li-Ion (LiFePO4) Li-Ion (LiFePO4)

120 210 210 175- - - -

150 30 240 301 7 1 7

Manual Manual Manual Manual

TM4 TM4 TAM TM4- - - -- - - -- - - -

170 170 120 170- - - -

1100 1100 835 1100- - - -- - - -

- - - -- - - -- - - -

Ursus Bus City Smile Ursus Bus City Smile Van Hool Exqui.City 18m 100% Battery

BEV BEV BEV2013 2015 2016

62 104 11712 18 18,6118 28 280 0 120

100 100 70- - -

Hybricon Bus Systems Hybricon Bus Systems BFFTLithium titanate Lithium titanate Li-Ion

105 105 215- - -

625 625 80 // 25010 min 10 min 4h // 10 min

Overhead Overhead Conductive connector // Inverted pantograph

Ziehl-Abegg Ziehl-Abegg Siemens- - DC motor (PEM)- - 2- - -

226 226 160- - -

5400 5400 1500- - -- - -

- - -- - -- - -

Van Hool Exqui.City 18m Trolley Van Hool Exqui.City 24m Trolley VDL Citea LLE-99 Electric

BEV BEV BEV2014 2017 2016131 149 63

18,61 23,82 9,9529 36,5 14,870 0 0

60 65 80- - -

Kiepe Kiepe MultipleLithium titanate Li-Ion Various Li-Ion

35 20 180- - -

Nothing Pantograph, 75 Up to 270Nothing N/A 4,5h // 5 min

Overheah catenary Overhead Combo2 // inverted pantograph

Kiepe Kiepe/TSA SiemensSkoda, Asynchronous 3-phase - PMSM (central mounted)

- 2 -- - -

120 160 153- 1250 -0 0 2500- 1250 -- 1250 -

- - -- - -- - -

VDL Citea SLF-120 Electric VDL Citea SLFA-180 Electric Citea SLFA-181 Electric

BEV BEV BEV2014 2015 2015

92 145 14312 18 18,15

19,5 29 290 0 0

80 80 80- - -

Multiple Multiple MultipleVarious Li-Ion Various Li-Ion Various Li-Ion

180 248 248- - -

Up to 360 Up to 480 Up to 4804,5h // 5 min 4,5h // 5 min 4,5h // 5 min

Combo2 // inverted pantograph Combo2 // inverted pantograph Combo2 // inverted pantograph

Siemens Siemens SiemensPMSM (central mounted) PMSM (central mounted) PMSM (central mounted)

- - -- - -

153 210 210- - -

2500 3800 3800- - -- - -

- - -- - -- - -

Volvo 7900 Electric E12LF New E12LF E12LF for UK ICe 12

BEV BEV BEV BEV BEV2017 2015 2017 2016 2017105 77 77 77 6912 12 12 12 1212 19,1 19,1 18 19,4

96,2 280 300 305 24580 70 to 85 70 to 85 80 100- - - - -

SAFT CATL CATL CATL CATLLi-Ion (LiFePO4) Li-Ion (LifePO4) Li-Ion (LifePO4) Li-Ion (LifePO4) Li-Ion (LifePO4)

76 295 324 295 258- - - - -

300 60 60 60 603 to 6 min 5 5,5 5 4

Opportunity Charging, overhead pantograph Plug-in Plug-in Plug-in Plug-in

- YUTONG YUTONG YUTONG YUTONG- AC Synchronous AC Synchronous AC Synchronous AC Synchronous- - - - -- - - - -0 350 350 350 350- - - - -0 2600 2600 2600 2600- - - - -- - - - -

- - - - -- - - - -- - - - -

Thomas Saf-T-Liner C2

BEV2018

--0

160104,607

From 0 to 96,56 in 45 s

--

155--

Under 8 h (4 to 6 fot nominal charge)AC charging

----

234,895-0--

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N1 (under 3.5t)MODEL VW e-Transporter Mercedes-Benz eVito Renault Master ZE Nissan e-NV200GENERAL ASPECTSPropulsion system BEV BEV BEV BEVYear release 2019 2018 - -Gross weight (t) 3,2 3,2 3,1 2,2Curb weight (t) 2,014 2,185 2 1,5Range (km) 400 150 120 170,59Maximum speed (km/h) 120 120 100 122,31Acceleration (km/h in s) - - - 0-100 in 14sNet price (€) 71.281 34.105ENERGY STORAGEBattery manufacturer - - - -Cell type - - Li-Ion, ZE 33 Batterie Laminated Li-IonCapacity (kWh) 74,6 41 33 24Voltage range (V) - - - -AC Type of charger / Interface - - - -AC Charging power (kW) (max. Permissible) - - - 6,6AC Charging time (hh:mm) - - - 4:00DC Type of charger / Interface CCS - - -DC Charging power (kW) 40 - - 50DC Charging time (% charged in hh:mm) 1:38 - -Cooling systemMOTORElectric motor manufacturer - - Renault -Type of motor - - AC Syncronous AC SyncronousNumber of motors - - - -Nominal power (kW) - 85 - -Maximal power (kW) 82 0 57 80Nominal torque (Nm) - 295 - -Maximal torque (Nm) 200 0 225 254Speed (rpm) 0 11500 0 10500Operating voltage (V) - 365 - -Cooling system - - - -Regenerative braking - - - YesMECHANICAL COMPONENTSGear Shifting levels - Single-speed reduction Single-speed reduction Single-speed reductionGear transmission ratio - 1:13 9,3 9.301Front braking system - - - Discs (283)Rear breaking system - - - Disc (292)

Renault Kangoo EV Citroen Berlingo Electric Mercedes eSprinter IVECO Daily 35 S Peugeot Partner Electric

BEV BEV BEV BEV BEV2017 2017 - - -2,2 2,18 3,5 3,5 2,215

1,53 1,624 2,5 - 1,579165 110 150 120 170130 110 120 0 110

0 - 100 in 22,4s 0 - 100 in 19,5 s - - 0 - 100 in 19,5 s

- - - Akku -Li-Ion Li-Ion - NaNiCl2 Li-Ion

33 22,5 55 60 22,5- - - - -

Type 2 Type 1 - - Type 17,4 3,7 - - 3,7

5:00 6:45 - - 6:45- - - - CHAdeMO- 40 - - 40- 0:30 - - 0:30

Renault - - - -AC Syncronous AC Synchronous (PMSM) - - AC Synchronous (PMSM)

- - - - -- - - -

44 49 84 0 49- - - -

226 200 300 0 2000 0 0 0 9200- - - - -- - - - Watter cooling- - - - -

- - - - Single-speed reduction- - - - -- - - - Ventilated discs- - - - Discs

LDV EV80 VW eCaddy StreetScooter WORK 20 kWh StreetScooter WORK 40 kWh StreetScooter WORK L

BEV BEV BEV BEV BEV2017 2019 2018 2018 20183,5 2,33 2,18 2,18 2,6

2,55 1,694 1,46 1,595 1,695200 257 101 205 187

0 160 85 85 850 - 100 in 24 s 0-100 in 13 s - - -

- -Li-Ion (LiFePO4) - Li-Ion Li-Ion Li-Ion

56 38,8 20 40 40- - - - -- - Type 2, single-phase Type 2, single-phase Type 2, single-phase- 7,2 - - -- 10:00 - - -- - - - -- 40 - - -- 0:49 - - -

- - - - -- - AC Synchronous (PMSM) AC Synchronous (PMSM) AC Synchronous (PMSM)- 1 - - -- - - - -

92 82 48 48 48- - - - -

320 220 200 200 2000 0 - - -- - - - -- - - - -- - - - -

- - - - -- - - - -- - Discs Discs Discs- - Drums Drums Drums

N2 (3.5t to 12t)MODEL Fuso eCanter ORTEN E75GENERAL ASPECTSPropulsion system (energy carrier) Full electric Full electricYear release 2017Gross weight (t) 7,50 7,50Curb weight (t) 3 5.2Range (km) 100 150Maximum speed (km/h) 80 80Acceleration (km/h in s) -ENERGY STORAGEBattery manufacturer -Cell type (primary source) Li-Ion LiFePO4Secondary energy source -Capacity (kWh) 82,8 116AC Type of charger / Interface CAN bus / Type 2AC Charging power (kW) (max. Permissible) - 22AC Charging time (hh:mm) 9:00 4:00DC Type of charger / Interface CCS / Type 2 -DC Charging power (kW) - -DC Charging time ( hh:mm) 1:00 -Cooling system Water coolingMOTORElectric motor manufacturer - -Type of motor AC Synchronous (PMSM) AC Synchronous (PMSM)Number of motors - -Nominal power (kW) - -Maximal power (kW) 115 90Maximal torque (Nm) 390 1150Max. speed (rpm) 14000 -Cooling system Water cooling Water coolingMECHANICAL COMPONENTSFront braking system - -Rear breaking system - -

Isuzu N series LDV Truck BYD Class 6 truck BYD Class 5 truck BYD Class 6 Step van

Full electric, delivery20187,50 11,79 7,32 10,434.5 4,7 3,65 5,791100 199,559 249,45 201,1782 113 99,78 112,654

0-50 in 15 (fully charged)

Round-cells or pouch-cells

150 221 145 221- - - -- - - 33- 4:30 5:00 7:00- - - -- 150 40 120- 1:30 - 2:00

- - - -AC Synchronous (PMSM) - - -

- - - -- - -

185 250 149,886 249,811550 1800 550,462 1800,5

- - - -- - - -

- Air discs Discs Hydraulic discs- Air discs Discs Hydraulic discs

BYD Class 6 Refuse Truck Chanje V8100 EVI Medium Duty Zenith Cargo Van

BEV2018

11,79 7,50 11.8 4,555,1 4,778 1,723

201,17 0 145 217104,607 130 105 88,5

0-96.5 in 26s in full charge

Li-Ion (LiFePO4) Li-Ion (LiFePO4)

221 100 99 70- - - -

33 - - -7:00 - 6:00 -

- - - -120 - - -2:00 - - -

- - - -- AC Synchronous (PMSM) AC Synchronous (PMSM)- 2 - -

249,81 148 120 01800,5 764 900 0

- - - -- Liquid cooling* - -

Air discs - - -Air discs - - -

Zenith Step/Walk In Van eM2 Daimler Newton Truck VW eCrafter IVECO Daily 50 C

BEV2018 20179,98 12,00 12,00 4,25 5,20

2,721 Payload from 2.8 to 7.3 2,54 2,4152 370 160 120 13088,5 80 90 70 (check)

A123 Systems modules AkkuLiFePO4 NaNiCl2

0 325 120 35,8 80- - - - -- - - - -- - - 5:20 -- - - - -- - 120 - -- 1:00 - 0:45 -

- - - - -AC Synchronous (PMSM) - -

- - - - -

0 353 120 100 00 0 0 290 0- - - - -- - - - -

- - - - -- - - - -

StreetScooter WORK XL

4,052,77520090-

Li-Ion

76 Type 2, 3-phase

11----

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90276

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N3 (over 12t)MODEL EFORCE EF18 Mercedes-Benz eActrosGENERAL ASPECTSUsage Urban and inter-urban delivery Distribution for urban areasPropulsion system (energy carrier) BEV BEVModel year 2013 2018Gross weight (t) 18 25Curb weight (t) 8 9.42Range (km) 300 200Maximum speed (km/h) 87 -ENERGY STORAGEBattery manufacturer - AKASOLCell type (primary energy source) Li-Ion (LiFePO4-C) Li-Ion NMCSecondary energy source - NACapacity/energy (kWh) 120 240AC Type of charger / Interface - -AC Charging power (kW) (max. Permissible) 44 -AC Charging time (hh:mm) 6:00 -DC Type of charger / Interface CCS CCSDC Charging power (kW) 350 -DC Charging time (% charged in hh:mm) 1:00 -Cooling system Water cooling Liquid-cooling systemMOTORMotor manufacturer BRUSA -Type of motor Hybrid synchronous motor AC Asynchronous (3-phase)Number of motors 2 2Nominal power (kW) - -Maximal power (kW) 150 125Nominal torque (Nm) -Maximal torque (Nm) 305 485Speed (rpm) 2500 8250Operating voltage (V) - 400Required current (A)Cooling system - Liquid-cooling systemMECHANICAL COMPONENTSGear Shifting levels Single-speed reduction -Gear transmission ratio - -Front braking system - -Rear breaking system - -

Volvo FL electric BYD Class 8 Terminal Tractor BYD Class 8 Day Cab

Urban delivery routes, communl service and garbage removalBEV BEV BEV

2019 2018 201816 46.266 47- 8.98 11.5

300 0 268,76- 52,5 105

- - -Li-Ion - -

NA NA300 217 435

- - -22 - -

10:00 3:00 3:00CCS2 - -150 - -1:00 1:30 1:30

- - -

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130 - -185 179,7 360

425 1500 2400- - -- - -

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2 - -- - -- Air drums Air discs- Air drums Air drums

BYD Class 8 Refuse Truck Motiv ERV Class 8

Garbage truckBEV BEV

201726 309.8 210 128,7

105 80

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NA295 212

- -33 25

9:00 8:00- -

240 -1:30 -

- -

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320,65 250

1100,9 3000- -- -

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Air drums -Air drums -

ANÁLISIS COMPARATIVO DE ELEMENTOS DEL TREN DE...

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