On calculation of electromagnetic torque in PMDC motor

The electromagnetic torque was calculated directly from the change of magnetic vector potentials at moving conductors of a dc motor with permanent magnets. The higher accuracy of field calculations was achieved using the procedure with Gauss points. Numerical operations which usually diminish accuracy in electromagnetic torque calculations were avoided. The momentarily values of EM torque at motor rotation were calculated. The results were compared to those obtained by the Maxwell method. They were in better accordance with the commutation effect and test results of a PMDC motor.