基于瞬时功耗检测的SiC MOSFET短路保护策略

Short Circuit Protection Strategy of SiC MOSFET Based on Instantaneous Power Detection

针对SiC MOSFET对短路电流的耐受能力较弱的问题,设计了一种短路检测策略以提高其运行可靠性。基于SiC MOSFET在正常运行及短路故障状态下的瞬时功耗差异可形成短路判据,设计了瞬时功耗检测的SiC MOSFET短路检测方案和电路。仿真测试了其针对两种不同短路故障工况的监测性能,验证了提出的短路检测的有效性。结果表明提出的短路保护方法响应时间短,短路峰值电流小。

Because SiC MOSFET has weak tolerance to short circuit current,it is necessary to design a short circuit detection strategy to improve the reliability of SiC MOSFET.In this paper,the short circuit criterion can be formed based on the instantaneous power difference between normal operation and short circuit fault of SiC MOSFET.Thus,a SiC MOSFET short circuit detection scheme and circuit based on instantaneous power detection were designed.The monitoring performance for two different short-circuit fault conditions was tested by simulation and the validity of the proposed short-circuit detection was verified.The results show that the short-circuit protection method proposed in this paper has short response time and low short-circuit peak current.