开关管电压浪涌的产生机理分析

在一些功率变换器中，由于寄生电感和寄生电容的存在，使得功率变换器中的开关管在工作过程中，产生较大的电压浪涌，不仅产生噪声，而且会增加开关管的功率损耗，本文以一种具有ＰＦＣ功能的单级，卫离式ＡＣ－ＤＣ功率变换器为例，利用开关管关断时的等效电路模型，分析了功率变换器中的开关管在关断时产生电压浪涌的机理，为提高功率变换器工作的可靠性，降低功率变换器的体积和重量、减小噪声污染，文中给出一种简单有效的抑制措

Origins Analysis of Surge on Switch-tube

In some power converters, because of the existence of parasitic inductance and parasitic capacity, surge generates when switch-tube acts witch brings noise and adds switch-tube energy loss. The origin of surge generated by the switching off of switch-tube in power converter is analyzed with the equivalent circuit model of switch-tube switching off, by using the example of a type of PFC single-stage, isolated AC-DC power converter. A simple, active inhibition plan is given in the paper which can improve the dependability of convert, reduce the volume and weight of power converter, lower the contamination caused by noise.