Multi-Physics Based Analysis and Design of Stator Coil in High Power Density PMSM for Aircraft Propulsion Applications

The electrification of commercial aircraft propulsion requires the development of megawatt-class electrical machines possessing high power density, high efficiency, and effective cooling. These demands are explored in this presentation of a megawatt-class surface permanent magnet (SPM) synchronous machine for aircraft propulsion applications. Substantial losses are produced in the stator windings (> 16 kW), requiring aggressive cooling measures. Three direct in-slot liquid cooling methods are reviewed and analyzed including potted channels adjacent to rectangular litz turns, litz wire with central cooling channels, and solid copper turns with internal axial cooling ducts. Electromagnetic and thermal analyses are performed for each configuration, and machine winding loss and thermal performance tradeoffs are highlighted. It is shown the potted channel approach offers appealing stator cooling performance, contributing to a high machine full-load efficiency (> 97%) and active mass power density (> 20 kW/kg).