电气工程及其自动化专业英语第三章翻译

电气工程及其自动化专业英语第三章翻译Semiconductor switches are very important and crucial components in power electronic systems.these switches are meant to be the substitutions

of the mechanical switches,but they are severely limited by the properties

of the semiconductor materials and process of manufacturing. 在电力

电

子系统，中半导体开关是非常重要和关键部件。半导体开关将要替换机械开关, 但半导体材料的性质和生产过程严重限制了他们。

Switching losses开关损耗

Power losses in the power eletronic converters are comprised of the Switching losses and parasitic losses. 电力电子转换器的功率损耗分为

开关损耗和寄生损耗

the parasitic losses account for the losses due to the winding

resistances of the inductors and transformers,the dielectric losses

of

capacitors,the eddy and the hysteresis losses. 寄生损失的绕组电感

器、变压器的阻力、介电损耗的电容器,涡流和磁滞损耗

the switching losses are significant and can be managed. 这个开关

损耗是非常重要的,可以被处理。they can be further divided into three components:(a)the on-state losses,(b)the off-state losses and the losses

in the transition states. 他们可以分为三个部分: 通态损耗，断态损耗和转换过程中产生的损耗。

On-State Losses：

The electrical switches conduct heavy current and have nonzero voltage

across the switch in the on-state.The on-state power losses are

given by

Pon=Uson if.这个电子开关能导通大电流，并且在通态时有非零的压降。这个通

态功率损耗的公式为Pon=Uson if.

The Uson and If are respectively the switch voltage in the on-state and the forward current through the switch.For example,the typical power

diodes and the power transistors have nearly 0.5 to l volt across them

in the on-state.The forward currents can be hundreds to thousands of amperes.The on-state power losses are very significant. 其中Uson是

通

态时开关上的压降，if是流过开关的电流。例如，典型的功率二极管和功率晶体管有近似0.5~1伏的通态压降。而电流会有数百到数千安培。这个通态损耗非

常重要。

Off-State Losses断态损耗

The electrical switches withstand high voltages and have nonzero

leakage current through the switch in the off-state.The off-state power

lesses are given by Poh=Uoff ir在关断状态时，电子开关到经受得起高电压，

并会有非零的漏电流。断态损耗的公式为Poh=Uoff ir.

The Usoff and Ir are respectively the reverse bias voltage in the off-state and the reverse current through the switch.For example,the typical power diodes and the power transistors have high reverse voltages

in hundreds to thousands of volts and microamps to milliamps through them

in the off state. 其中Uoff在断态时的反向偏置电压，ir是流过开关的反

向漏电流。例如，典型的功率二极管和功率晶体管有很高的反向压降几百到几千伏和几微安到几毫安的漏电流。

Transition-State Losses：

The practical switching devices have limited capabilities of rate of voltage transition and the rate of current steering.These nonabrupt transition rates give rise to power losses in the switching

devices.We

will examine these switching losses in two cases separately:the inductive

and capacitive loads. 在实际的开关装置限制了电压变换率和电流变化率。非