Torque evaluation of permanent magnet DC commutator motor using FEM data

Abstract

In this paper a torque calculation of a permanent magnet DC commutator motor (PMDCCM) by using FEM data is performed. For the FEM calculation of the torque a 2D FEM magnetic field calculation, as very suitable for this type of geometry, is performed. Therefore a proper modelling of the motor is required. The method used for the torque calculation using FEM data is the Weighted Stress Tensor (WST) method. The necessary data for the calculation of the electromagnetic torque and the cogging torque is provided by calculating the magnetic vector potential for rated current load, as well as for no load for different rotor displacements. The values of the electromagnetic torque for rated load calculated by the weighted stress tensor method show good agreement compared to the measured ones.