A Parameterized Nonlinear Magnetic Equivalent Circuit Model for Fast Design and Comparison of Surface Permanent Magnet Synchronous Machines

Permanent magnet synchronous machines (PMSMs) are widely used in high-performance applications such as electric vehicles. This paper demonstrates the use of high-resolution, parameterized magnetic equivalent circuits (MECs) to analyze a broad range of PMSM designs. Simulation results show that MECs are, on average, 21 times faster than finite element analysis (FEA), with an average torque prediction error of just 0.55% and a maximum error below 8%. Based on a parametric sweep, a design is selected. The design is then modified and validated using FEA software, where fillets are added to the magnets and tooth tips, and a step skew is applied to the rotor to reduce torque ripple. A prototype was fabricated, and the measured back EMF is shown to closely match the FEA predictions.