Analytical prediction of cogging torque for interior permanent magnet synchronous motors

The cogging torque calculation of interior permanent magnet synchronous motors (IPMSMs) has only been conducted by the finite element method (FEM) due to their complexities. However, FEM analysis requires considerable computational time during the design process. To deal with this problem, a new analytical method is proposed to calculate the cogging torque in IPMSMs. The radial and circumferential air-gap flux density for calculating the cogging torque utilizes the magnetic equivalent circuit model, conformal mapping method, and approximate equations of the magnet end. The validity of the proposed method was confirmed by comparing the results of the proposed method with those of FEM.