Experimental comparison of reference current waveform techniques for pulsating torque minimization in PMAC motors

Many methods have been published for minimizing pulsating torque using reference current waveforms, however there are still several problems that prevent these methods for being serious contenders for high performance drives. A major problem has been the lack of experimental implementation to prove the concept. In this paper, theoretical comparison of the existing reference current methods suggests that the "time-domain" method is the most suitable for the majority of motors. This method can potentially achieve zero pulsating torque regardless of back emf or cogging torque shape. Experimental implementation of this method has achieved a pulsating torque of 6% without considering the effects of cogging torque and 9% when it is considered. These results confirm the potential for reference current weveform methods to be used in high performace drives.