Systematic Design Method of a PMSM for EVs Using Analytical Characteristic Equations

This paper proposes a systematic design method for surface permanent magnet synchronous motors for variable speed operation system, such as in EVs, using various electromagnetic equations that determine the characteristics of the motor. In the proposed design method, accurate electric loading and magnet’s flux to meet the power requirements are determined using four geometric design variables. With the obtained two loadings, the detailed motor geometries are designed, and the winding specifications are determined. As a case study, various 4 kW PMSMs for EV are designed using the proposed method within the given range of four variables. Among various motor candidates designed, the model with the smallest volume is selected as the optimal model. Finally, the validity of the proposed method is verified by comparing the suggested analytical and FE analysis results of the selected 4kW SPM synchronous motor.