基于半导体物理和IGBT基本结构,深入论述了IGBT关断机理,推导出IGBT关断时间随电压和电流的变化规律:关断时间随电压的增大而增大,随电流的增大而减小.查明了变化规律的物理机理,仿真和实验结果验证了理论推导与所得变化规律的正确性.提出采用指数与双曲线复合规律描述IGBT关断时间的变化.对深化IGBT关断机理和解决电力电子装置死区时间设置等工程问题具有一定的理论意义和应用价值. Based on the basic structure of semiconductor and IGBT, the mechanism of IGBT turn-off is discussed in depth. The variation law of IGBT turn-off time with voltage and current is deduced. The turn-off time increases with the increase of voltage and decreases with the increase of current The physical mechanism of the variation rule was identified.The simulation and experimental results verified the correctness of the theoretical derivation and the resulting variation law.The exponential and hyperbolic composite law was used to describe the change of IGBT off time.To deepen the mechanism of IGBT turn- Power electronics dead time setting and other engineering problems have a certain theoretical significance and application value.