Can Corona Resistant wires ensure reliability in aerospace machine insulation?

In an electrical drive, the impulsive waveforms of the power inverter can increase the electrical stress on the insulation system of the rotating machines to a point where partial discharges are incepted, and failure occurs in very short times. Electrical drives in aerospace applications are subjected to even more challenging operating conditions, due to the reduced pressures, which highly enhances the probability to incept Partial Discharges. A solution often proposed by manufacturers involves the use of the so-called Corona Resistant (CR) materials, which are proved to be able to withstand a limited amount of PD activity in industrial drives. However, their performance in conditions typical of aerospace applications has not been verified yet. Thus, this paper investigates the endurance of twisted pairs featuring different types of corona-resistant insulations placing them in a reduced pressure environment under voltage impulse repetition frequency typical of modern electrical systems based on silicon carbide MOSFETs. Considerations on the feasibility of CR insulation systems for applications such as the more electrical aircrafts are discussed, with apparently negative indications.