Inductance analytical calculations of brushless surface-mounted permanent-magnet machines based on energy method

Abstract

PurposeThis paper aims to show the proposed energy method for inductance calculation is valid for any number of poles, phases and any winding layout.Design/methodology/approachA two-dimensional (2-D) analytical energy-based approach is presented to calculate self-inductances and mutual inductances of brushless surface-mounted permanent-magnet machines.FindingsThe proposed calculation procedure is valid for brushless permanent-magnet machines with slotted or slotless stator structure. Comparisons between energy method and flux linkage method are presented based on simulation and experimental results. It shows that the energy method has an excellent agreement with the result obtained from finite element method (FEM) and experimental study.Originality/valueThis paper compares energy-based method with flux linkage method and FEM for inductance calculations in slotless and slotted permanent-magnet motors. The relations for inductance calculation are presented which are obtained based on 2-D analytical representation of magnetic field.