Multi-objective optimal design and analysis of variable leakage flux ipm motors for improve flux-weakening ability

—In this paper, two variable leakage flux permanent magnet (VLFPM) machines are proposed. The keys are to adopt the rotor with single-layer and double-layer PMs and intentionally create leakage flux paths to extend the operating speed range and increase the machine efficiency. The characteristics of the variable leakage flux of the proposed machines are investigated. In order to improve the performances of the VLFPM machines, the Multi-Objective Genetic Algorithm (MOGA) method is applied for achieving the multi-objective optimizations of variables. Then, the performances of the double-layer permanent magnet variable leakage flux motor (DLPM-VLFM) and the single-layer permanent magnet variable leakage flux motor (SLPM-VLFM) are analyzed and compared with conventional interior PM machine (CIPMM) in detail. The performances mainly include flux linkage and torque, flux-weakening capability and efficiency. Finally, it is shown by analysis and comparison that the DLPM-VLFM can have a wider range of speed and high efficiency. © 2021, Electromagnetics Academy. All rights reserved.