Investigation of influences of various losses on electromagnetic torque for surface-mounted permanent magnet synchronous motors

Traditionally, vector controlled permanent magnet synchronous motor (PMSM) drives have been performed under the assumption that there is no iron loss, mechanical loss, and stray loss in motors. However, influences of these losses on the vector controlled PMSM drive are hardly evaluated so far. Thus, there is a need to investigate the influences in order to evaluate whether these losses can be neglected. This paper investigates the influences of the iron loss, mechanical loss, and stray loss on surface-mounted PMSM drives. In the first phase, a formulation of the electromagnetic torque taking the various losses into account are developed. In the second phase, the influences of the various losses on the electromagnetic torque under vector control strategy are investigated based on the developed mathematical model. These influences are confirmed by experimental results for torque control of a tested 160 W surface-mounted PMSM.