Research on the Performances and Parameters of Interior PMSM Used for Electric Vehicles

TLDR

Interior permanent‑magnet synchronous machines are widely used as traction devices in modern electric vehicles. This study designs and compares IPMSMs with spoke‑, tangential‑, U‑shape, and V‑shape rotor topologies. The V‑shape PM IPMSM is examined in detail using finite‑element analysis, evaluating geometrical parameters, magnetic saturation, cross‑magnetization, and PM flux linkage effects on d‑ and q‑axis inductances, and assessing back‑EMF, flux leakage, torque characteristics, cogging, power density, power factor, and flux‑weakening ability. Results show the V‑shape PM IPMSM delivers superior performance overall, and experimental data confirm the accuracy of the proposed design and analysis approach.

Abstract

As a kind of traction device, interior permanent-magnet synchronous machines (IPMSMs) are widely used in modern electric vehicles. This paper performs a design and comparative study of IPMSMs with different rotor topologies (spoke-type PMs, tangential-type PMs, U-shape PMs, and V-shape PMs). The research results indicate that the IPMSM with V-shape PMs is more satisfying with comprehensive consideration. Furthermore, the IPMSM with V-shape PMs is investigated in detail. The influences of geometrical parameters (magnetic bridge and angle between the two V-shape PMs under each pole, etc.) on the performances of V-shape motor are evaluated based on finite-element method (FEM). For accurate research, the effects of saturation, cross-magnetization, and the change in PM flux linkage on d- and q-axis inductances are considered. The back-electromotive force (EMF), flux leakage coefficient, average torque, torque ripple, cogging torque, power per unit volume, power factor, and flux-weakening ability are investigated, respectively. The experimental results verify the validity and accuracy of the process presented in this paper.