基于优化无源缓冲的串联SiC MOSFET均压方法

A method of voltage balancing with series connected SiC MOSFETs based on optimized passive snubber

为解决驱动信号延迟造成SiC MOSFET在串联应用中电压失衡的问题,提出一种优化的无源缓冲方法。在MOS管栅极与漏极两端并联一个均压电容,通过改变器件的开关速度从而实现均压的目的。仿真结果表明,该方法在双管串联应用中能够较好的实现开关过程中的电压均衡,且只会引入很小的缓冲损耗和电流应力,证明了该方法的有效性。

In order to solve the voltage imbalance problem of the silicon carbide metal–oxide–semiconductor field-effect transistor(SiC MOSFET)in series application caused by drive signal delay,an optimized passive snubber method is proposed.A voltage balancing capacitor is connected in parallel between the gate and the drain of the MOS transistor,and the voltage balancing is achieved by changing the switching speed of the device.The simulation results show that this method can better realize the voltage balancing during the switching process in the application of two series connected SiC MOSFETs,and only introduces a small buffer loss and current stress,which proves the effectiveness of the method.