Analytical Calculation and Optimization of Magnetic Field in Spoke-Type Permanent-Magnet Machines Accounting for Eccentric Pole-Arc Shape

Abstract

This paper presents an analytical method for calculating and optimizing magnetic field in spoke-type permanent-magnet machines accounting for eccentric pole-arc shape. Normalized flux density is derived from conformal transformation taking into account eccentric pole-arc shape, and final field solution is predicted according to the flux continuity theorem. The optimal results show the harmonic content of flux density can be reduced a lot by optimizing eccentric distance of eccentric pole arc while fundamental content will reduce a little. The proposed analytical solution on prototype machines is implemented. The finite element (FE) and experimental results confirm that the developed analytical method has high accuracy for predicting and optimizing magnetic field.