Turn-Off Over-Voltage character of 6500V/600A IGBT Module

this paper investigation the turn-off processes of 6500V IGBT module by analytical model and device physics, three types of commercial 6500V/600A IGBT module were tested with inductive load by double-pulse methods. The testing and analysis results show that turn-off over voltage semi controllable by the gate resistance, increases first and then decreases, mainly depend on the proportion of MOSFET electron current to the excess swept-out hole current when the voltage rise to the bus voltage. With increase IGBT junction temperature, the turn-off over voltage decreases, therefore turn-off over voltage failure is prone to occur when IGBT start working at low junction temperature.