IGBT短路保护的控制策略分析

Control Strategy Analysis of IGBT Short-circuit Protection

简述了硅整流器和晶闸管的短路保护的基本方法,即利用交流电网侧加适度的电抗器、器件串联快速熔断器。但是这种方法仅适用于电流过零关断的工作条件,对于工作在硬开关条件下的IGBT不适用;分析了IGBT在短路模式下的工作状态、短路保护需要的时限以及其他相关元件对IGBT短路状态的承受能力;指出在短路保护过程中降低栅极电压减缓关断速度是IGBT短路保护的有效手段。

The basic method of short-circuit protection about silicon rectifier and thyristor was stated,that is adding moderate reactor at the side of AC network and making devices quick fuse in series.But this method is only applicable to the working condition of current zero-crossing turn-off,and when the working condition is hard switching it can′t work.The working condition of short circuit model,time limit of short-circuit protection and the endurance of other associative components about IGBT short-circuit protection were analyzed.The effective way of IGBT short-circuit protection is slowing turn-off speed of gate voltage in the course of short-circuit protection.