An Improved 2-D Subdomain Method Toward Electromagnetic-Performance Analysis of Line-Start Permanent Magnet Synchronous Motor

The 2-D subdomain method (SDM) has proven to be a time-efficient approach suited for determining the magnetic field of permanent magnet synchronous motor (PMSM); however, further application of this method into the field analysis for the line-start PMSM (LSPMSM) is limited by its natural defects, including 1) inability to consider the saturation effect of iron material and 2) failure to deal with the rotor eddy currents allowing self-start. In this work, the step-by-step or iterative numerical calculation using the finite difference method (FDM) is embedded into the execution of conventional 2-D SDM, through which an enhanced version addressing all issues as stated above is obtained. The improved SDM avoids the limitations of the pure analytical method and possesses higher calculation efficiency than that of the pure numerical method. The reliability of the presented method is validated by the finite element analysis (FEA) and tests.