一种IGBT短路保护驱动电路的优化

摘要

Though analyzing the cause of losing efficacy when IGBT encounters short circuit fault,an effective way was presented to avoid IGBT to lose efficacy.Then,each part functions of EXB841 drive circuit with short circuit pro-tection function were explained.Later,for the defects of EXB841 drive circuit,an improved drive circuit was provid-ed.Not only the circuit improves the disadvantage that is caused by setting up the starting point of over-circuit protec-tion unreasonably,but also it increases delay block signal function,which is realized to shut off IGBT softly and avoid the damages caused by hard turn-off.It provided a great of reference values to further improve EXB drive circuit.%通过对IGBT短路失效原因的分析，提出了防止短路故障时IGBT失效的有效方法。进而对具有短路保护功能的EXB841驱动电路的各部分功能进行了详细地阐述，最后针对EXB系列电路存在的缺陷，给出了改进后的驱动电路。该电路不仅改善了因EXB模块过流保护起控点设置不合理带来的弊端，同时专门设置了延时封锁信号的功能，实现了对IGBT的软关断处理，避免了过流情况下硬关断所造成的危害。这对EXB系列驱动模块的进一步改进具有较大的参考价值。