Abstract
For electric rotating machines to become a viable large-scale option in aviation, increased power density is needed – without challenging the reliability. Fast and efficient SiC-based converters with increased switching frequency, slew rate, and higher voltage, is a part of the toolbox to achieve this. As voltage increases, a regime where partial discharges (PD) can occur in the insulation approaches, decreasing lifetime and reliability. When testing insulation systems where PD can occur, lifetime estimates are based on extrapolation of experiments conducted with sinusoidal voltages, only valid for a narrow range of parameters. In this work, electrical and mechanical characterization for a candidate insulation system is initiated, including accelerated degradation tests. Preliminary results show that PD under SiC-converter like voltages are much more severe than sinusoidal voltage at same level and frequency and reduces lifetime significantly. Keywords—Type II insulation, electrical machine, partial discharges, voltage endurance, higher power and voltage level