Multiphysics Design Methodology for High-Speed Synchronous Reluctance Machines

Abstract

This study introduces a multi-physics design methodology to enhance the performance of high-speed synchronous reluctance machines (SynRMs). The primary innovation is to optimize the design of the rotor flux guides (FGs), instead of the commonly optimized flux barriers. This may sound like a minor change and just a dual model, but the difference in results is significant and allows different mechanical solutions. In case of transversally laminated rotor targeting high speeds requires thick radial and tangential ribs to support the flux guides, but the ribs diminish torque and power factor and negatively impact efficiency. Reducing the rotor mass can decrease the thickness of these ribs, improving performance. This research combines the optimization of rotor FGs with effective mechanical support strategies based on the machine's maximum speed, comparing two constructional methods: conventional radial and tangential ribs, and non-magnetic backplates between flux guides. Optimizing the rotor geometry with FGs provides deeper insight into the design process and ensures the rotor is electromagnetically and mechanically optimized for maximum performance. To demonstrate the effectiveness of this methodology, a 6-pole-36-slot motor with 300 kW peak power featuring 2, 3, or 4 FGs, identical stator dimensions, and a maximum speed of 12,000 r/min is designed, optimized, and compared. A prototype of a 6-pole-36-slot motor with 3 FGs manufactured with backplates is presented, along with initial measurement results.