Detailed Design and Prototyping of a High Power Density Slotless PMSM

This article describes the detailed design and development of a 300 kW permanent magnet (PM) synchronous motor for electric aircraft propulsion, taking into consideration manufacturability, balancing ease, and cost of high-volume production with motor performance. The motor consists of a slotless stator structure with custom litz wire and an outer rotor with a Halbach PM array. The design of the proposed motor is based on multi-physics performance including electromagnetic field, thermal and mechanical analysis. For ease of manufacturing and economies of scale, the detailed design is refined by altering the PM segment number, PM shape and litz wire construction. The impacts of changing these parameters are evaluated in detail using analytical and finite element methods. The simulation results are compared with experimental results in terms of torque production, back electromotive force, and current level.