Analytical Method to Calculate Inductances of Spoke-Type Permanent-Magnet Synchronous Motors With Damping Bars

This article proposes an analytical method to calculate inductances and resistances related to damping circuits of spoke-type permanent-magnet synchronous motor (PMSM) with damping bars. Harmonics of inductances are taken into account analytically in order to obtained the performance of line-start PMSM. Damping bars of spoke-type PMSM are divided into direct-axis and quadrature-axis damping circuits. The magnetic field, self-inductances, and resistances of damping circuits and mutual inductances between damping circuits and stator winding are predicted analytically. The calculating results show that the inductances and resistances of spoke-type PMSM with damping bars by the proposed analytical method are well agreement with that predicted by the finite-element method. The line-start process of spoke-type PMSM with the multidamping circuit model in which the inductances and resistances are calculated analytically is also similar with the experimental results. The finite-element and experimental results confirm that the developed analytical method has high accuracy for predicting inductances, resistances, and performance of spoke-type PMSM.