Computational study of partial discharge events in electric drives with segmented power supply

The transportation industry (automobile, aerospace) is undergoing a significant shift towards higher voltage supply, to increase embedded power. Increasing the voltage can lead to an increase in the occurrence of partial discharges which have a deleterious impact on the insulators, and therefore of the system lifetime. The current study investigates two electric drives architecture, namely first a combination of a conventional motor with a single inverter and, second, a multi-Three-Phase machine based on highly coupled windings and combined with dedicated sub-inverter. The latter is based on CTAF concept (Chaîne de Traction à Alimentation Fractionnée for Electric Drive based on Segmented Power Supply). This innovative power supply concept is presented in the case study section. According to the goal of this study, a 54-turns coil is developed and modelled as the equivalent circuit, while the related lumped parameters are determined by a frequency-dependent electrostatic and magnetostatic COMSOL simulation. Subsequently, a MATLAB/SIMULINK simulation of the equivalent electric circuit enables assessing the voltage potential distribution. The latter is injected as input into the COMSOL electrostatic simulation to compute the electric field. Consequently, the maximum voltage supply without breakdown is determined, for both studied cases. The comparative study concludes that, between the two case studies analyzed, the minimum among the maximum voltage supplies without breakdown is observed in the system powered with the CTAF approach.