Intermittent duty of induction machine: investigations of energy efficiency for environmental impact minimisation

The speaker presents an approach for estimating the efficiency of an induction motor operating in periodic intermittent service. The theoretical approach is based on a space vector model. This model yields the electrical behaviour of the motor during transients and, by extension, losses and instantaneous powers. The energy efficiency is calculated for the considered intermittent service. The accuracy of the theoretical model and its associated hypothesis are discussed considering experimental data recorded on a testing bench for periodic starting from zero speed. The differences between the efficiency for an intermittent service and the classical permanent operating point may be significant. This model gives extra information for the design of motorized systems working in intermittent services, in order to minimize their global environmental impact determined for their whole life.