5L-ANPC逆变器中器件过电压分析及抑制

针对光伏发电系统中的五电平中点有源钳位型逆变器进行研究，分析并抑制了三类引起低压器件过电压的问题。首先，通过引入吸收电容，抑制换流回路过长引起的高关断应力；其次，优化动作时序抑制前级高压器件切换引起的低压器件过电压；然后，设计特殊的关机模式抑制传统驱动全封锁关机造成的过电压问题。最后，在60kW的实验样机上验证了电压应力抑制方法的有效性。

Analysis and Suppression of Device Over-voltage in 5L-ANPC Inverter

In this paper, the five-level active neutral-point-clamped (5L-ANPC) inverter in a photovoltaic power generation system is studied, and three types of over-voltage in the low-voltage device are analyzed. First, by introducing snubber capacitors, the high turn-off stress caused by the long commutation loop is suppressed. Second, the action sequence is optimized to suppress the over-voltage in the low-voltage device caused by the switching of the previous high-voltage device. Third, a special shutdown scheme is designed to suppress the over-voltage caused by the traditional shutdown scheme that turns off all drivers. Finally, the proposed voltage stress suppression method was verified on a 60 kW exper-imental prototype.