Investigation of an Intensifying-flux Variable Flux-leakage Interior Permanent Magnet Machine for Wide Speed Range

Abstract

In this paper, a novel intensifying-flux variable flux-leakage interior permanent magnet (IFVF-IPM) machine is proposed, in which flux barriers were designed deliberately between the adjacent poles to obtain intensifying-flux effect and variable flux-leakage property. The rotor topology and design principles of the proposed machine are also introduced. Then, a multi-objective optimization method is adopted based on the sensitivity analysis, and some design variables of IFVF-IPM machine with strong sensitivity are selected to optimization progress by using the non-dominated sorting genetic algorithm-Ⅱ (NSGA-Ⅱ). Moreover, the electromagnetic characteristics of conventional IPM machine, conventional IFVF-IPM machine (CIFVF-IPM) and the novel IFVF-IPM machine are compared based on the finite element analysis (FEA) method which includes flux linkage, inductances characteristic, torque-speed envelops and power characteristic, as well as evaluation of the risk of irreversible demagnetization. Finally, the experiment results show that the IFVF-IPM machine has a better performance in flux weakening capability for wide speed range and a lower risk of irreversible demagnetization, which indicates the validity and feasibility of the proposed machine.