碳化硅(SiC)MOSFETs短路承受能力弱,研究其短路保护方法成为保障电力电子设备安全运行的重要课题.现有方法大多围绕低压小功率SiC MOSFETs,然而随着电压和功率等级的提升,器件特性有所差异,直接套用以往设计难以实现高压大功率SiC MOSFETs的快速、可靠保护.该文首先详细研究了几种常用短路检测方法;其次基于高压大功率SiC MOSFETs器件特性,深入对比分析了不同短路检测方法的适用性,提出一种阻容式漏源极电压检测和栅极电荷检测相结合的短路保护方法;最后搭建了实验平台验证所提方法的可行性.结果表明,提出的方法在硬开关短路故障(hard switching fault,HSF)下,保护响应时间缩短了1.4μs,短路能量降低了62.5％;且能可靠识别负载短路故障(fault under load,FUL).
Short-circuit Protection Method for High-voltage and High-power SiC MOSFETs
SiC MOSFETs have weaker short-circuit tolerance. Therefore, research on short-circuit protection methods for SiC MOSFETs has increasing importance in ensuring safe operation of power electronic equipment. Most of the existing methods are mainly focused on low-voltage and low-power SiC MOSFETs. However, with the increase of voltage and power level, device characteristics are significantly different, which makes it difficult to achieve fast and reliable protec-tion for high-voltage and high-power SiC MOSFETs by simply applying previous designs. Firstly, this paper conducts a detailed study on several common short-circuit detection methods. Secondly, based on the device characteristics of high-voltage and high-power SiC MOSFETs, this paper comparatively analyzes the applicability of different short-circuit detection methods and then proposes a new method that combines resistance-capacitance drain-source voltage detection and gate charge detection. Finally, an experimental platform is built to verify the feasibility of the proposed method. The results show that the proposed method shortens the response time by 1.4 μs and reduces the short-circuit energy by 62.5 ％ under hard switching fault (HSF). Moreover, it is shown that the proposed method has the ability to identify fault under load (FUL) reliably.
SiC MOSFETshigh-voltage and high-powershort-circuit protectiondevice characteristicsdrain-source voltagegate charge
万方数据
维普
