Impacting Mechanism of Variable Leakage Flux on Magnetizing and Demagnetizing Effects in Dual-Variable Flux Memory Machines for EV Traction

This article explores the impacting mechanism of variable leakage flux on magnetizing (mag-) and demagnetizing (demag-) effects in dual-variable flux memory machines (D-VFMMs). By reasonably utilizing the variable leakage flux, this kind of machine can achieve higher air-gap flux density by enhancing the mag- effect under high magnetization states (MSs) and lower air-gap flux density by weakening the mag- effect under low MSs. Therefore, an expanded flux regulation (FR) range can be expected without sacrificing torque, which is desired for electric vehicle (EV) traction. The feasibility of regulating the mag- and demag- effects by adjusting the variable leakage flux is first analyzed. The influences of main parameters on the degree of mag- effects are then analyzed in detail. Three topologies are designed to quantitatively investigate the mag- effects by analyzing their electromagnetic properties. Finally, a D-VFMM prototype is manufactured and the impacting mechanism is verified by relevant experiments.