Efficiency optimization considerations for standard induction motor fed by PWM inverter

The paper investigates efficiency in standard induction motors fed by PWM inverters, taking into consideration criteria in the control algorithm enabling to minimize motor losses. For this purpose an overview of the relevant techniques was carried out, adequate simulation software tools were adopted and an experimental setup involving a 2 HP induction motor supplied by an inverter driven by DSP was developed. It was shown that the main efficiency improvement can be obtained by conveniently tuning the magnetizing flux to the desired operating conditions while the switching frequency choice does not considerably affect the overall motor losses, in the case considered.