A New Mechanical-Strength-Oriented Rotor Parametric Model Design for the Optimization of a Very-High-Speed IPMSM

This paper presents a new rotor parametric model for the design optimization of a high-speed interior permanent magnet synchronous machine (IPMSM). The rotor topology is evolved from the conventional flat-type to a structure with long and smoothly curved iron-bridge edges on which the mechanical stress is distributed more evenly. The reduction of the maximum mechanical stress (MMS) could loosen the boundaries of optimization in the mechanical aspect, and hence, allowing the algorithm to explore a broader feasible region. A multi-objective optimization algorithm is combined with the proposed model in the design of a laminated 5kW, 50krpm high-speed IPMSM to achieve high-efficiency, low material cost, wide constant power speed range with practicable MMS. The optimization results show significant improvement in both electromagnetic and mechanical performances comparing to the case of using traditional flat-type model.