Analysis and Design of Interior Permanent Magnet Synchronous Motor Using a Sequential-Stage Magnetic Equivalent Circuit

In the interior permanent magnet synchronous motor (IPMSM) design for the traction motor of fuel cell electric vehicles (FCEVs), it is necessary to analyze the nonlinear characteristics including saturation due to the requirement of a high torque density. The finite element method (FEM) is the most widely used technique for electric machine designs because complicated computations can be taken into account. However, a large amount of analysis over the entire design is a computationally large burden. To address this problem, this paper proposes a fast and accurate analysis method, sequential-stage magnetic equivalent circuit (SSMEC). The proposed method consists of no-load, q-axis circuit analysis, d-axis circuit analysis, and motor characteristic calculation. Because the proposed method can quickly and accurately analyze the complex shapes of an IPMSM, it can be used effectively throughout the entire motor design process. The effectiveness of the proposed SSMEC was verified in comparing with experimental results.