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Unlike a conventional vehicle driven by an ICE，an electric vehicle（EV）is propelled by electricity which is stored in an energy storage system（ESS），such as batteries，ultracapacitors，or flywheels.Electric vehicles are also referred to as pure EV or battery EV（BEV）in case the main energy storage is a battery pack.The configuration of a BEV is shown in Figure 2.1.

The battery-powered electric vehicle is comprised of a battery for energy storage，an electric motor，and an inverter.The battery is charged through a charger which can be either carried onboard or fitted at the charging point.The inverter is responsible for the direction and amount of power flow to/from the electric motor such that the vehicle speed and moving direction can be controlled.It has to be noted that during the braking process，the battery is charged by regenerative energy.The DC/DC converter is used to match the battery pack voltage and that of the DC bus of the inverter and can be optional.The mechanical transmission shown here is a generic term for gears and speed reduction.In contrast to conventional vehicles，EVs and other advanced vehicles do not have the need for automatic transmission as the case in conventional vehicles.

The limited travel range of BEVs（without recharging）prompted the research and development of fuel cell electric vehicles（FCEV）.The fuel cell-powered electric vehicles have almost the same configuration as a BEV as shown in Figure 2.2，except for the energy source.Hydrogen fuel is required and stored on board.The FCEV represents a true zero-emission vehicle for a long term.The Honda FCX was the first FCEV to be certified for use in the US.

The traction motors used in electric vehicles are usually classified into DC motors，induction motors or permanent magnet motors.Disadvantages of DC motors have forced EV researchers to turn their attention to AC motors.The maintenance-free and low-cost induction motors have attracted many EV developers.However，the problems of size and weight for high-speed operation exist in the meantime.High power density offers a major advantage by permanent magnet motors，which is attractive for EV propulsion solution in spite of the high cost of the motors.

New words and expressions（单词和短语）

1.New words（单词）

2.Expressions（短语）

Notes to the text（难点解析）

★1.The inverter is responsible for the direction and amount of power flow to/from the electric motor such that the vehicle speed and moving direction can be controlled.逆变器负责控制流入或者流出电动机的功率流方向和大小以达到控制汽车的速度和运动方向。

★2.High power density offers a major advantage by permanent magnet motors，which is attractive for EV propulsion solution in spite of the high cost of the motors.高功率密度是永磁电动机的一个主要优势，尽管电动机的成本高，但是在解决电动汽车的推进问题时还是很有吸引力的。

Exercises（练习）

◆1.Translate the following passages（expressions）into Chinese（英译汉）

（1）The battery-powered electric vehicle is comprised of a battery for energy storage，an electric motor，and an inverter.

（2）The FCEV represents a true zero-emission vehicle for a long term.

（4）induction motors

（5）permanent magnet motors

◆2.Translate the following passages（expressions）into English（汉译英）

（1）机械变速器

（3）高功率密度是永磁电动机的一个主要优势。

◆3.Fill in the blanks with the suitable words according to the text

The battery-powered electric vehicle is comprised of______，______，and______.

◆4.Directions:Answer the following questions briefly according to the text

（1）What are the advantages of the AC motors？

（2）What are the disadvantages of the AC motors？

Reading material（阅读材料）

The EV has many advantages over the conventional internal combustion engine vehicle（ICEV），such as absence of emissions，high efficiency，independence from petroleum，and quiet and smooth operation.The operational and fundamental principles in EVs and ICEVs are similar.There are，however，some differences between ICEVs and EVs，such as the use of a gasoline tank versus batteries；ICE versus electric motor，and different transmission requirements.