Optimal Design of a High-Efficiency Permanent Magnet-Assisted Synchronous Reluctance Motor Considering Anti-Demagnetization Performance

Abstract

To address the issues of low efficiency and susceptibility to demagnetization in ferrite permanent magnets for permanent magnet-assisted synchronous reluctance motors (PMaSynRMs), an optimal design method that comprehensively considers antidemagnetization performance is proposed. Based on anti-demagnetization analysis, design variables are determined under the constraint of a 5% maximum fault-current demagnetization rate. Moreover, a self-iterative expected improvement (EI) criterionbased kriging model is proposed, which automatically concludes the adding points process and improves the prediction accuracy of the surrogate model. Subsequently, multi-objective optimization, focused on improving efficiency and torque, is performed using a multi-objective particle swarm optimization (MOPSO) algorithm. The optimized motor achieves an efficiency of 94.9%, representing a 2.9% improvement over the initial design, while the maximum demagnetization rate of the ferrite under fault conditions is controlled within 4.91%. Experiments confirm an efficiency of 94.8% under rated operating conditions, a wide high-efficiency operating region, and satisfactory anti-demagnetization performance.