Temperature Impact on Partial Discharge Induced Aging of Aviation Wires Under High DV/DT Voltage Excitations

The higher efficiency of wide-bandgap (WBG) power switching devices makes them a promising candidate for future more electric aircraft (MEA). However, partial discharge (PD) behavior and its impact on the failure of the insulation system under pulse width modulated (PWM) voltages are not yet fully understood. This paper investigates the impact of temperature on PD current pulse and time-to-failure of aircraft power wiring. The experimental setup includes a repetitive high dv/dt unipolar square pulse voltage excitation, with the test sample placed in a vacuum chamber containing dry air to minimize the influence of humidity. The aviation wires are tested at room temperature (22.5°C), 50 ° C, 75 ° C, and 100 ° C. The results show that the wire's temperature has a negligible impact on the partial discharge inception voltage (PDIV) or PD current pulse. However, when the voltage is higher than the PD IV, the failure time decreases significantly at higher temperatures. The findings show that the degradation rate due to PD accelerates exponentially at higher temperatures, even if the temperature is below the rated temperature of the wire. Furthermore, the results show the limitations of PD measurements as a stand-alone evaluation parameter for insulation status, and additional measurements such as temperature could enhance the evaluation accuracy.