由于线路杂散电感存储能量的释放,绝缘门极双极性晶体管(insulatedgatebipolartransistor,IGBT)在开通和关断的瞬态过程中,其两端将产生电压尖峰。为了对该电压尖峰进行定量研究,需要对IGBT开关过程进行分析,抽取线路的杂散电感参数。传统抽取方法通常利用IGBT关断电压的最大幅值以及近似的电流斜率作为计算参数,其计算结果并不精确。为得到更精确的结果,提出一种新的参数抽取方法,通过将IGBT开通、关断的非线性过程分解为多个线性阶段,并充分考虑反并联二极管前向恢复和反向恢复的影响,在此基础上得到电压过冲△Uot。和相对应的di/dt,进而得到准确的杂散参数抽取过程。最后,将该分析方法在一台75kVA的单相逆变器进行实验验证,利用不同工况下的开通和关断过程进行线路杂散电感抽取,均得到一致的结果,从而证明了本方法的有效性与正确性。
When an insulated gate bipolar transistor (IGBT) is abruptly turned off or turned on, trapped energy in the circuit stray inductance is dissipated in the switching device, causing a voltage overshoot across the switching device. In order to quantitative analyze this voltage overshoot, the circuit stray inductance extraction is necessary. Against the traditional inaccurate extraction method, which chooses the maximum voltage point and an approximated current slope as the calculation parameters, this paper proposed a new extraction method, in which the turn-on and turn-off non-linear transient processes are divided into several piece-wise linear intervals, moreover, the forward and reverse recovery effects of the anti-parallel diode are also taken into account, so the accurate voltage overshoot ALice and the corresponding current slope di/dt are obtained accurately, and the accurate extraction period of turn-on and turn-off are obtained respectively. The proposed method is verified experimentally using a single-phase inverter prototype with 75 kVA capability. The stray inductance extracted from the turn-on and turn-off periods under different load conditions are consistency which proved the method's validity and accuracy.