中文摘要：

电力电子变流装置中的开关续流元件功率二极管由续流到截止转换的反向恢复过程中会在负载上产生电压尖峰,且短时续流下电压尖峰会很大,极易造成器件过压失效.为了有效指导电力电子装置的可靠性设计,基于半导体物理和功率二极管基本结构,深入论述了PIN结构续流二极管开关瞬态工作机理,利用存储电荷的分析方法推导出二极管续流瞬态下的反向恢复电压尖峰机理及其随续流时间的变化规律：电压尖峰在短时续流下较大,随续流瞬态时间的增大而减小.以绝缘栅双极型晶体管和续流二极管组成的两电平半桥逆变单元为例进行实验,结果表明：二极管续流瞬态发生反向恢复的电压尖峰随续流瞬态时间的增大近似呈指数规律减小,待续流电流稳定后,电压尖峰趋于常数,并最终随着续流过程的结束而进一步减小直至恒定,验证了理论分析的正确性.对完善续流二极管反向恢复机理以及提高电能变换装置的可靠性具有一定的理论意义和应用价值.

英文摘要：

The freewheeling diode in power electronic converters may generate a voltage peak on the load during the reverse recovery process, and the peak voltage becomes larger when the forward conduction time is smaller, which very likely induces the over-voltage failure of the power devices. To effectively guide the reliability design of power electronic devices,the switching transition mechanism of the PIN freewheeling diode is discussed thoroughly based on semiconductor physics and the essential structure of power diodes. The law of reverse recovery voltage peak variation with switching transition time is deduced by methods of stored charge analysis, which shows that the peak voltage is larger for shorter conduction time and decreases abruptly as the transient conduction time increases. Experiments are carried out using the two-level half-bridge inverter unit with insulated-gate bipolar transistors and PIN diodes. Results show that the reverse recovery voltage peak decreases with the increase of the transition time, following an exponential rule, and tends to be constant after the freewheeling current becomes stable and finally approaches a steady state as the steady forward conduction current vanishes, thus proving the correctness of the presented analysis. This paper shows the theoretical and application values in the optimization of the reverse recovery mechanism of power diodes and the reliability improvement of power converters.