Analysis of Novel Hybrid-Magnet-Circuit Variable Flux Memory Machines with Different Magnet Arrangements

This paper presents two novel hybrid-magnetic-circuit variable flux memory machines (HMC-VFMMs) with different permanent magnet (PM) configurations. The proposed HMC-VFMMs are both characterized by a combination of series and parallel circuit topologies, but with different positions of series and parallel PM branches. The proposed HMC design can combine the merits of wide flux adjustment range in parallel structure and excellent unintentional demagnetization (UD) withstand capability in series structure. The topologies, features and working principles of the proposed HMC-VFMMs with different magnet arrangements are introduced, respectively. The magnetic circuit model is utilized to reveal the underlying working mechanism and performance metrics of the proposed HMC-VFMMs having different PM types. The electromagnetic characteristics of the HMC-VFMMs having radially-magnetized (RM) and circumferentially-magnetized (CM) LCF PM types are evaluated and compared by the finite-element (FE) method. The experiments on a 21-slot/4-pole prototype with RM-structure are carried out to validate the FE analyses.