Insulation Design and Optimization of Laminated Busbar for More Electric Aircraft Motor Drive under High Altitude and Depressurized Environments

More electric aircrafts (MEA) recently attracts increasing attention due to improvements to efficiency, reduce weight, fuel cost, and carbon emissions. High-specific-power machines, and corresponding integrated motor drives have been identified as the crucial enabling technology for the realization of more electric aircraft propulsion. Such a concept requires converter working under depressurized environments, which poses challenges to the electric insulation due to partial discharge (PD). This threatens the reliability of the drive system. This paper proposes an insulation design and optimization methodology for a laminated busbar in a 450-kVA electric-aircraft motor drive. The design aims to avoid any partial discharge in the insulation and also achieves optimized busbar stray inductance. To achieve the targets, partial discharge inception voltage (PDIV) with respect to air pressure was obtained by the experiment, and the experimental results were used as PD -free design criteria in electric field simulation of the laminated busbar. Then, the insulation structure regarding insulation material selection and thickness selection was optimized by taking both the PD-free criteria and parasitic inductance into consideration. The proposed design procedure provides valuable references for future laminated busbar design, which is used for the MEA system.