Simulation Analysis Of 3300V/1500A Press Pack IGBT Failure

Flexible-HVDC is an effective technical mean to incorporate the wind power and other renewable energy for its highly controllability flexibility and efficiency.The HVDC in the near future can not only solve the problem of the renewable energy electricity in western China and off-shore wind power synchronizing with AC grid,but also become a essential part of grid mode-main transmitting network cooperating with area distributing network and Micro-grid.One of the key equipment of flexible multi-terminal HVDC system is HVDC breaker which plays a significant role in HVDC transmitting line and impose great influence on HVDC system's normally function.The main break branch inside of HVDC breaker is composed of serially connected press pack IGBT s,one of which contains paralleled connected IGBT chips.As a result,single press pack IGBT's current cut off capability will directly influence the HVDC breaker's performance.First,this paper aims at the waveform of 3300V/1500A press pack by GEIRI in experiment,utilizing the electrical characteristics of several main failure modes-thermalrunaway,dioxide gate failure,dynamic latch-up,and avalanche to judge the failure type of press pack and give analyses;Second,propose a hypothesis that current unbalanced distribution among IGBT chips should be responsible for IGBT chips' failure after device checked;Third,buliding equivalent circuit of chip failure to rebuild the failure waveform,verifying the judgment and analyses.Meanwhile,the simulation results of current distribution of press pack revealed that the outer of the IGBT chips array,the higher rising rate of the current,which is consistent to the results of checking;Finally,a solution came up that adjusting voltage between gate and emitter of IGBT chip to improve current distribution.