The evaluation of the effects of the voltage amplitude modulations on induction motors

The voltage fluctuations of the electrical power supply can generate many undesirable effects on both industrial and domestic apparatuses. The aim of this paper is the evaluation of the effects of the low-frequency voltage amplitude modulation on induction motors. An experimental analysis has been applied to a three phase, 7.5 kW induction motor with the adoption of an ad hoc system for the EMC low-frequency immunity testing. The experimental results show that a few percent amplitude modulations can involve a critical behavior in terms of torque. As for the light flicker effect measurement, a statistical approach can be adopted for the evaluation of the torque fluctuation.