2.3.2　Constituents of a PHEV

Text（课文）

A PHEV now has an extra connecting socket in the vehicle，from where a lead can be pulled out and plugged into the wall utility outlet.Obviously，when the vehicle is connected to a utility outlet，its propulsion motor is not needed and neither is the ICE as far as turning the wheels is concerned.However，the vehicle may still need to use auxiliary loads（normally low-voltage loads at 12V），the air-conditioner（can be low voltage as well），or the healer and some lights.Hence it is appropriate to deliver those loads at low voltage.If fast charging of the battery is necessary，it will also be appropriate to run the ICE and use the propulsion motor as a generator，or have a separate generator for this purpose.Depending on the scheme used，changes in the gear-train system are called for.Even though the whole process of interconnection between the utility and the PHEV system is simple in principle，there are quite a few considerations to be taken into account，as it will be obvious from the possible architecture for such a vehicle shown in Figure 2.11.

Figure 2.11　A possible architecture for the plug-in hybrid vehicle and home outlet interface

From Figure 2.11，it is apparent that in order to charge the battery，one path goes directly from the wall outlet to the battery，through a transformer isolation and a rectifier or DC/DC converter combination.This situation is directly involved with the plug-in part of the system.The bottom part of the figure shows that the charging process is done by either driving a standalone alternator，or using the propulsion motor itself run as a generator，ultimately charging the battery.Of course，it is understood that，when plugged in，the vehicle is stationary and the wheels are not moving.Even though the process indicated in the bottom part of Figure 2.11 is not involved directly with the plugin，an overall power management process has to coordinate both the plug-in and the ICE，since there may be a situation when fast charging becomes necessary，and both the plug-in and the ICE（in generation mode）need to run concurrently.Finally，note the inclusion of a bidirectional converter in the plug-in part of the figure.This covers the possibility that in future the utility regulations may allow power to be fed back into the utility grid from the vehicle，assuming it has enough power to do so.This issue is not an immediate consideration within the automotive industry at present.However，the possibility may in fact help use the vehicle as an emergency generator to light a home in case there is a utility power failure.

Fundamentally the only difference between the HEV and the PHEV is related to the upper part of Figure 2.11，where the wall outlet is used to charge the battery.The size of the battery may be substantially different.In addition，as indicated above，the plug-in system has to be properly coordinated with the rest of the charging process and the overall power management in the vehicular system.

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.Obviously，when the vehicle is connected to a utility outlet，its propulsion motor is not needed and neither is the ICE.显然，当汽车与电源插座相连时，它的驱动电动机和内燃机就不再需要了。

★2.If fast charging of the battery is necessary，it will also be appropriate to run the ICE and use the propulsion motor as a generator，or have a separate generator for this purpose.如果电池的快速充电是必需的，则应恰当运行内燃机，且驱动电动机被用作发电机，或利用一个独立的发电机来达到这一目的。

Exercises（练习）

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

（1）Fundamentally the only difference between the HEV and the PHEV is related to the upper part of Figure 2.11，where the wall outlet is used to charge the battery.

（2）However，the possibility may in fact help use the vehicle as an emergency generator to light a home in case there is a utility power failure.

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

（1）辅助负载

（2）空调

（3）电源插座

Reading material（阅读材料）

PHEVs are sometimes called range-extended electric vehicles or extended range electric vehicles.They always have on-board gasoline or diesel that can be used to drive the vehicle for an extended distance，when the on-board battery energy is depleted and furthermore，these vehicles can provide high fuel economy during the extended driving range.The large battery pack can accept more regenerative braking energy and provide more flexibility for engine optimization during the extended driving range.The Chevy Volt is equipped with a full-sized electric motor so that pure electric driving can be realized for all kinds of driving conditions.