Partial Discharge Characterization of Solid-Dielectric-Based Transformer Under High Frequency High dv/dt PWM Voltage for MV Applications

In this paper, the partial discharge (PD) of a solid-dielectric-based coreless transformer applied in an isolated gate driver power supply for 10-kV SiC MOSFETs is experimentally evaluated under a high frequency, high dv/dt PWM voltage. A PD test platform is built with a 10-kV SiC power module to generate high frequency, high dv/dt PWM voltage. Different PD detection equipment, including the photomultiplier tube (PMT), ultra-high frequency (UHF) antenna and high frequency current transformer (HFCT) are adopted to detect PD signals. Experimental results validated that the solid-dielectric-based coreless transformer achieves PD free at 100-kHz, up to 75-V/ns, 5-kV PWM voltage excitation. The PD results under high frequency, high dv/dt PWM voltage and 60-Hz ac voltage are also compared.