To solve the problem of voltage overshoot during switching-off transient in H-bridge, an active lossless H-bridge snubber composing of auxiliary switch and snubber capacitor is discussed, which aims to enable the H-bridge to realize a higher voltage and current. When the main switch is turned off, the capacitor absorbs the overshoot energy and the energy is returned to DC side through the auxiliary switch. Compared with the conventional RCD snubber, the voltage overshoot can be limited effectively by increasing the snubber capacitor value without considering ohmic loss. As a result, the working voltage of the switch is indirectly improved. In addition, the problem of resistance volume and heat dissipation has been avoided. All the work had been done provides a useful reference in optimizing the topology structure of Experimental Advanced Superconducting Tokamak (EAST) fast control power supply, which can reduce the volume of power supply and simplify the control strategy.

为了解决H桥关断瞬态过程中电压过冲的问题，讨论了一种由辅助开关和缓冲电容器组成的有源无损H桥缓冲器，旨在使H桥实现更高的电压和电流。当主开关断开时，电容器吸收过冲能量，并且能量通过辅助开关返回到直流侧。与常规RCD缓冲器相比，可以通过增加缓冲电容器的值而不考虑欧姆损耗来有效地限制电压过冲。结果，间接地改善了开关的工作电压。另外，避免了电阻体积和散热的问题。