Radial electromagnetic force waves are a primary cause of noise in Permanent Magnet Synchronous Motor (PMSM). Introducing auxiliary slots into the stator teeth can weaken certain harmonic of electromagnetic force (EMF). However, calculating the EMF for PMSM with auxiliary slots is complex. For this problem, the finite element (FE) method requires a large amount of computing resources and time. This paper establishes an analytical model of the EMF for PMSM with auxiliary slots. First, the auxiliary slot subdomain is added. By combining the vector field general solutions of each subdomain and listing the boundary conditions, the calculation formulas for EMF are obtained. Then, the calculation results of the proposed model are compared with the FE simulation results to systematically verify the accuracy and applicability of the model under different working conditions. Finally, the effects of auxiliary slot parameters are studied in combination with the proposed model. The research in this paper provides theoretical basis and technical reference for effectively suppressing the electromagnetic vibration and noise of PMSM.

permanent magnet synchronous motor (PMSM),accurate subdomain model,electromagnetic force,auxiliary slot