基于LC谐振的叠层母排杂散电感测量的新方法

现有的叠层母排杂散电感测量方法主要是基于电压过冲和关断电流变化率的原理,在精度上存在不足。为此提出了一种基于LC谐振的精确测量方法。测量时需要在IGBT桥臂两端并联吸收电容,并且在桥臂的上管并联一个线性电感器。控制桥臂下管的开关动作,就可以使叠层母排杂散电感和吸收电容构成二阶LC谐振回路。由于谐振周期和吸收电容的电容量都可以精确测量获得,因此可以准确计算得到杂散电感值。用该方法测量H桥逆变器叠层母排的杂散电感,测量结果验证了所提出方法的准确性。

A Novel Measuring Method of Busbar Stray Inductance Based on LC Resonance

Traditional measuring method of busbar stray inductance is based on the voltage overshoot and the switching off current slew rate, and the accuracy is difficult to guarantee. Therefore, an accurate measuring method based on LC resonance was proposed. A snubber capacitor was placed in parallel with the IGBT bridge, and the upper transistor was shorted with a linear inductor. The busbar stray inductor and the snubber capacitor formed a second-order LC resonance loop by controlling the switching of the lower transistor. Since the resonant period and the snubber capacitance could be accurately measured, the stray inductance could then be calculated. Finally, the method was used to measure the stray inductance of a H bridge inverter, and the experimental result verifies the accuracy of the proposed method.