Partial Discharge Behavior on Twisted Pair under Ultra-short Rise Time Square-wave Excitations

The use of wide-bandgap (WBG) semiconductor device is increasing due to its capability to operate at much higher voltage, frequency and temperature compared with traditional semiconductor device. WBG semiconductor device is capable to generate voltages with ultra-high dv/dt (ultra-short rise time), which would alter the voltage stress in various electrical apparatus, e.g., inverter-controlled motors, and consequently change partial discharge (PD) behavior. Combine this with the fact that PD detection in inverter-controlled motor winding, even with slow-rising voltages, is intrinsically complicated, the study of PD behavior under ultra-fast squarewave voltages is much needed. In this paper, experimental observations and results for twisted pair samples stressed by an impulse generator with the ability of generating ultra-fast square-wave voltage are presented. Statements and hypotheses on PD behaviors and mechanism under ultra-fast dv/dt squarewave excitations are also put forward based on the test results.