Investigation of field-modulation effect of consequent-pole vernier motor for electric vehicles

Abstract

An analytical model is applied to investigate and reveal the field modulation effect (FME) of consequent-pole permanent magnet vernier machine (CP-PMVM). A regular surface-mounted permanent magnet vernier machine (SPMVM) model is also built as a comparison and the detailed parameters of both models were established utilizing vernier machine design methodology. From the perspective of magnetomotive force (MMF) - permeance theory, the analytical method characterizes and elaborates the air-gap flux density and torque generation mechanisms of the vernier machine. The simulation results from MATLAB with analytical method and finite element analysis (FEA) software are compared to validate the analytical method's accurateness and performance of the two machine models. According to the results of the analytical modelling and simulation validation, it has been demonstrated that the CP-PMVM is capable of considerably reducing the permanent magnet (PM) consumption and torque ripple, while simultaneously maintaining comparable output torque performance in comparison to the conventional SPMVM. This benefit is primarily owing to the reduced leakage flux and the consequently magnetized salient iron poles validated by simulation.