5.3.2　Rectifiers

Text（课文）

1.Definition

Rectifiers are energy converters which transform an alternative-current electric source into a DC-current electric source.

2.Introduction

We can distinguish:

diode rectifiers:These converters establish a rigid relation between the output DC voltage and the input alternative voltage；

thyristor rectifiers which make it possible to vary continuously the relationship between the DC voltage recovered on their output terminals and the alternating voltage applied on their input terminals—while acting on the starting angle of the thyristors；

rectifiers associated with diodes and thyristors；

groupings of thyristor rectifiers intended to improve performance and decrease disturbances；

PWM（pulse with modulation）rectifiers which associate IGBT and diodes and which have the advantage of slightly disturbing their alternative input sources.

3.Use of rectifiers in electric vehicles

In an electric vehicle，rectifiers are used to convert alternative-current electric energy provided either by the public network，or by an on board alternator coupled with a thermal engine；in DCcurrent electric energy storable in an electric chemical battery and/or super caps.

If energy is provided by the public network，the rectifier system is called a“charger”with a single-phase structure.If energy is provided by an alternator，the rectifier is in general a threephase type.

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.Rectifiers are energy converters which transform an alternative-current electric source into a DC-current electric source.整流器是把交流电转化成直流电的能量装置。

★2.PWM（pulse with modulation）rectifiers which associate IGBT and diodes and which have the advantage of slightly disturbing their alternative input sources.由IGBT和二极管组合而成的PWM整流器，具有对输入控制源干扰较小的优点。

Exercises（练习）

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

（1）alternative-current electric source

（2）diode rectifiers

（3）PWM（pulse with modulation）rectifiers

（4）DC voltage

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

（1）连续改变

（2）车载发电机

（3）公共电网

（4）晶闸管整流器