Partial Discharge Investigation of Electric Machine Winding due to Thermo-Mechanical Stresses for Electric Aircraft Propulsion

The power density requirements and mission profile of electric aircraft propulsion motors result in significant stress on the motor winding’s insulation. Traditional motor winding insulation design methods do not account for the thermomechanical stresses placed on motor windings in electric aircraft propulsion motor applications. This paper presents the results of initial experiments that aim to develop models and methodologies for designing high-reliability aircraft propulsion motors accounting for mechanical stress on the insulation. Twenty motorrette samples were manufactured and aged with thermal cycles. Partial discharge inception voltage (PDIV) was recorded as the samples were aged. Data is reported for PDIV as a function of thermal profile and the number of cycles experienced by the insulation.