Study On Influencing Factors Of IGBT Turn-Off Transient Voltage Overshoot Of Semiconductor Components In DC Circuit Breaker

Hybrid high-voltage DC circuit breaker is the core equipment for constructing the DC grid.The 500kV Zhangbei flexible DC grid adopts the MMC based on the half-bridge sub-module structure,it can not isolate the DC fault.The development of 500kV high voltage DC circuit breaker is essential to ensure the safe,reliable and economic operation of the system.The electrical stress of the 500kV high-voltage DC circuit breaker is close to the application limit of the semiconductor devices.The voltage overshoot of IGBT during the turn-off transient may cause the reverse bias voltage of the PN junction to exceed the safety limit.The effects of stray inductance,device and drive characteristics on IGBT high-current turn-off transient voltage stress are more prominent.Therefore,it is of great significance to study the influencing factors of IGBT turn-off voltage overshoot.This dissertation mainly studies the simulation and theoretical research on the influence of the loop and driving parameters of IGBT full-bridge semiconductor components on the IGBT turn-off transient voltage overshoot.Firstly,the parameters of the model are extracted for the trench gate-terminated IGBT used in the semiconductor component breaking current test.The mechanism model of the IGBT device is built and applied in the IGBT full-bridge semiconductor component simulation circuit model.Secondly,according to the semiconductor component simulation circuit model,the influence law of each mechanism model parameter on voltage overshoot is simulated and analyzed.The sensitivity of each model parameter is calculated,and the extraction process of IGBT mechanism model parameters is simplified.Then,the influence and influence degree of the IGBT full-bridge semiconductor component loop parameters and driving parameters on the IGBT turn-off voltage overshoot are simulated and analyzed.Finally,the theoretical analysis of the influence mechanism of the above parameters is carried out,and the peak expression of the IGBT turn-off transient voltage with the loop and driving parameters as variables is derived.