Abstract This paper researches on overvoltage protection of neutral point clamped (NPC) three-level high voltage inverter which is based on IGCTs in series. A method of using ZnO varistor is first proposed to protect inverters from overvoltage. Through analyzing the different locations and connection structures of ZnO varistors, a reasonable design method is found. Taking all the IGCTs and clamping diodes with RC snubbers as the protected part of inverter solves the problem of hard to do overvoltage protection of each power electronic switch device. The withstand voltage of the protected part is analyzed based on practical parameters, and the design of ZnO varistors is given. The simulation results based on Matlab/Simulink are show that ZnO varistor is available to avoid overvoltage of NPC three-level high voltage inverter. The designed ZnO varistor is applied in practice.
Fang Jing,Mao Chengxiong,Lu Jiming等. Application of ZnO Varistor in Overvoltage Protection of Neutral Point Clamped Three-level High Voltage Inverter[J]. Transactions of China Electrotechnical Society, 2012, 27(4): 145-152.
2012, Vol. 27 
