An alternative strategy for emulating mechanical loads on the shaft of induction machines subject to power quality disturbances

For a laboratory evaluation of the effects of PQ phenomena on three-phase induction motors (TIM), one of the challenges is to set up equipment that allows adjusting the machine´s nominal current and selecting the type of load to be driven. Direct Current Generators (DCG) can be used to emulate different kinds of mechanical loads on the motor shaft. To do this, it is necessary to adopt a control strategy which allows variation of the load torque according to the profile desired. In this paper, the proposed strategy is compared with one conventionally adopted and it is applied to a study of a TIM´s performance. This type of research makes it possible to investigate the effects of PQ disturbances on a TIM.