Estimation of Eddy Current Losses in SPMSM Based on Harmonic Decomposition

Algorithm for evaluating eddy current losses in surface-mounted permanent magnets situated in synchronous machine is discussed in this paper. Whereas variable air gap permeance causing a ripple of magnetic flux density produced by permanent magnets is considered the main source of these losses. The key objective of this project is to create a fast and relatively accurate tool for setting up the average value of losses in permanent magnets at the prime stage of the electromagnetic design process of such a machine. The method is based on the harmonic decomposition of variable quantities, described by the Fourier series’s analytical formulae. First, evaluation is performed for a specified number of discretely organized layers in the permanent magnet. Afterwards, the final result is obtained from the numerical integration of these particular solutions. The algorithm’s efficiency is compared with finite element analysis (FEA) in the last part of this paper.