Calculation of Additional Losses in Windings of Permanent Magnet Motors Using the Femm Package

Abstract

The calculation of additional losses in the windings of permanent magnet synchronous motors is proposed to be performed using the FEMM package. The article describes a system of equations that allows to determine the distribution of instantaneous values of currents in the elementary wires of the winding. As an example, a low-voltage permanent magnet motor with concentrated windings on a stator is considered. To determine the matrix of inductances of elementary phase wires, the FEMM program was used. To speed up the calculations, a control script for FEMM (in the lua scripting language) was used, which made it possible to automatically determine the matrix of own and mutual inductances for a given distribution of elementary wires in a slot. The results of calculating the instantaneous values of the currents in the elementary wires of the winding are used to determine the additional losses. Variants of the distribution of elementary conductors in a slot are considered, the corresponding coefficients of increasing losses in the winding are determined.