Investigation of Hybrid-Magnet-Circuit Variable Flux Memory Machines With Different Hybrid Magnet Configurations

Abstract

This article investigates and compares the electromagnetic performance of two novel hybrid-magnetic-circuit variable flux memory machines (HMC-VFMMs) with different hybrid permanent magnet (PM) configurations. The investigated HMC-VFMMs are both geometrically characterized by a combination of series and parallel magnetic circuit topologies, but with different positions of series and parallel PM branches. The developed HMC design can combine the merits of wide flux adjustment range in parallel structure and excellent unintentional demagnetization withstand capability in series structure. The topologies, features, and working principles of the studied HMC-VFMMs with different hybrid magnet configurations are described, respectively. The magnetic circuit model is utilized to analytically reveal the performance metrics of the two machines. The electromagnetic characteristics of the radially magnetized (RM) and circumferentially magnetized LCF types of HMC-VFMMs are evaluated and compared by the finite-element method. Furthermore, the performance comparison of the proposed RM-type HMC-VFMM with a benchmark interior PM machine is conducted. The experiments on RM-type HMC-VFMM prototype with RM-structure are carried out to validate the FE analyses.