Abstract:

Junction temperature swing is a significant factor in causing IGBT failure due to internal temperature gradients. Smoothing junction temperature fluctuation can prolong the lifespan of IGBT modules. This paper explores the impact of junction temperature fluctuation smoothing on stator current and switching frequency and presents a hybrid control strategy to smooth junction temperature swing. The strategy adjusts the stator current and switching frequency based on heating up or cooling down stages of IGBTs. Simulation using Urban dynamometer driving schedule (UDDS) for the VEH_SMCAR model in ADVISOR shows that the proposed method reduces large junction temperature fluctuation cycles and increases the life-span by 90%. Experimental results validate the effectiveness of the hybrid control strategy in smoothing junction temperature fluctuation.