Magnetic Pole Equivalence and Performance Analyses of Multi-Layer Flux-Barrier Combined-Pole Permanent-Magnet Synchronous Machines Used for Electric Vehicles

Abstract

Multi-layer flux-barrier combined-pole permanent-magnet synchronous machines (MLFB-CP-PMSMs) are especially suitable for machines used in electrical vehicles (EVs), as they represent a tradeoff between electromagnetic performance and the consumption of high-priced rare-earth permanent magnets (PM). In this paper, magnetic pole equivalence and performance analyses of the MLFB-CP-PMSM are investigated. Firstly, three types of PM arrangements of combined poles are introduced, namely, parallel, series and series–parallel. Then, the magnetic circuit model and magnetic pole equivalence principle of MLFB-CP-PMSMs with different PM arrangements are analyzed. After that, the accuracy of the equivalence method is studied by comparing the machine electromagnetic performance before and after equivalence. Finally, the MLFB-CP-PMSM’s performance, including the loss, efficiency and electromagnetic torque, is analyzed. The results prove that the MLFB-CP-PMSM has the advantage of high efficiency, and the equivalence method can retain precision when the MLFB-CP-PMSM armature reaction degree varies.

Keywords

• magnetic pole equivalence
• magnetic circuit model
• multi-layer flux barrier
• combined poles
• permanent-magnet synchronous machine
• electric vehicles