Performance Evaluation of a Four-Port PM Vernier Motor for Hybrid Electric Vehicles

Abstract

This paper proposes a Four-Port PM Vernier Motor (FP-PMVM) for Hybrid Electric Vehicles (HEVs). The motor is equipped with two mechanical and two excitation ports. The mechanical ports are referred to as outer and inner rotors, and the excitation ports are referred to as outer and inner stators, combining two PM vernier motors in one, namely outer permanent magnet (OPM) and inner permanent magnet (IPM) vernier motors. The OPM vernier motor has an inner stator and an outer rotor, while the IPM vernier motor has an outer stator and inner rotor. The FP-PMVM rotors are designed with 20-poles, while the stator windings are designed with 4-poles concentrated modular tooth coils housed in 12 slots. In this paper, the two-dimensional Finite Element Analysis (FEA) is used to analyse the electromagnetic parameters of the FP-PMVM. The FEA results evidenced that both OPM and IPM vernier motors exhibit satisfactory electromagnetic performance. The OPM vernier motor provides traction to the rear wheels, while the IMP vernier motor is connected to the internal combustion engine (ICE) through a belt-driven system. The IEC is providing traction to the front wheels. A single, robust and efficient electric motor is used in place of two separate electric motors, thus reducing the size and mitigating the complicated mechanical connection of the traction systems that requires a gearbox to couple two separate electric motors with the ICE. This advantage positions the FP-PMVM as a strong candidate in HEVs traction applications.