Impact of Thermal Stress and Power Cycling on PD in SiC Power Modules Under Sinusoidal Voltage Waveform

This study looks at the partial discharge (PD) behavior of silicon carbide (SiC) power modules under different electrical and thermal stressors. We evaluated commercial drive power modules for hybrid and electric vehicles traction applications at ambient temperature and 90° C, subjecting its six switches to Sinusoidal waveform. Prior to partial discharge testing, the switches were power cycled to ensure their longevity under longterm operational stress. The results revealed substantial variations in Partial Discharge Inception Voltage (PDIV) between switches. Elevated temperatures (90° C) generally lowered PDIV, demonstrating the importance of thermal stress on insulating efficacy. These findings underline the significance of power cycling in assessing SiC power module dependability and offer suggestions for enhancing the design and thermal management of these modules for high-performance applications.