Probabilistic Analysis of Partial Discharges in the Stator Winding Insulation for Electrified Aviation

For the future integration of highly utilised electric machines into aircraft propulsion, these must be evaluated also with a focus on lifetime and reliability. One component that limits the lifetime of electric machines is the insulation of the stator winding. In general, ageing of the insulation system is determined by thermal, electrical, and mechanical stress, as well as environmental influences. Electrical ageing is characterised by the occurrence of partial discharges and is based on voltage, frequency and electric field strength. The analysis of partial discharge patterns allows for the evaluation of insulation partial discharge activity. This paper analyses the effects of different overvoltages due to transient voltage phenomena on partial discharge and partial discharge patterns using probabilistic methodologies and highlights uncertainties and sensitivities.