Breakdown Performance of Motor Winding Insulation Under Low Pressure Conditions

Electrical insulation is the limiting factor that reduces the lifetime of power components. The aging of insulation, which is heavily caused by partial discharges (PDs) and harsh environmental conditions, eventually leads to complete insulation breakdown. The advancement in developing more- and all-electric aircraft is limited by the existing apparatuses that operate at lower voltages. High applied voltage and lower ambient pressure, commonly envisaged in more and all-electric aircraft, pose significant challenges, as their effects on PD activity and space charge accumulation differ, thereby affecting the apparatus's lifetime. To improve the reliability of aircraft electric motors' performance, it is essential to accurately predict the breakdown performance of the magnet wires used as windings in the motors at low-pressure levels. In this article, we investigate the effect of low pressures on the breakdown voltage of magnet wires with insulation Type I.