Study on Partial Discharge Characteristics of Epoxy Resin Under Bipolar High-Frequency Square Wave Voltage

One of the essential parts of the isolated DC-DC power converter is the high-frequency transformer (HFT). It typically functions with non-sinusoidal high-frequency excitation. Epoxy resin insulation is suffered from high dv/dt and high-frequency square voltage in HFT. Consequently, it is more vulnerable to cause degradation and failure. This study uses the Ultra-high frequency (UHF) antenna sensoring technique to examine the partial discharge (PD) characteristic parameters of 3 epoxy resin samples under high-frequency square wave voltage. PD characteristics and associated parameters are calculated and examined. Effects of frequency on discharge amplitude, discharge delay time etc. were discussed. They increase with the increase in frequency. It is noted that the coronal discharge is enhanced at high frequency. PD events at high frequency increases the discharge photon. This work is extremely important for the insulation design and optimization of HFT.