Analysis of the influence of the stray inductance of the mine-used inverter on the heat dissipation performance of the IGBT snubber capacitor

In order to suppress the IGBT peak voltage caused by the internal stray inductance of the mine-used inverter, a snubber circuit is usually connected in parallel at both ends of the IGBT in the actual circuit, but at the same time, it will inevitably bring about the problem of high-frequency oscillation of voltage and current, resulting in Fatigue and random failure of components inside snubber circuits. Therefore, it is necessary to deeply study the impact of the snubber circuits on the IGBT switching transient and its negative impact. In this paper, ANSYS Q3D is used to extract the stray inductance of the AC busbar, AC-DC busbar, and DC busbar, and ANSYS Simplorer is used to analyze the busbar. The influence of the stray inductance on the switching characteristics of the IGBT is analyzed; then, the IGBT peak voltage is suppressed by the parallel snubber capacitor, and the suppression effect of the IGBT peak voltage under different capacitance parameters and the negative impact after the introduction of the snubber capacitor are compared. ANSYS Icepak conducts numerical simulation on the internal temperature field characteristics of the snubber capacitor, analyzes the influence of the aforementioned negative effects on the heat dissipation performance of the absorption capacitor, and proposes an optimization scheme for heat dissipation design.