Computational analysis of temperature rise phenomena in electric induction motors

In developing electric machines in general, and induction motors in particular, temperature limits is a key factor affecting the efficiency of the overall design. Since conventional loading of induction motors is often expensive, the estimation of temperature rise by tools of mathematical modelling and computational experiments becomes increasingly important. In the present paper we develop and validate experimentally a model accounting for losses and describing thermal phenomena in induction motors. The developed model has been implemented in FEMLAB, and has been applied to predict temperature rise in totally enclosed fan-cooled induction motors. Comparisons with experimental results obtained with a 1.5 kW standard squirrel-cage induction motor show the effectiveness of the developed model in predicting temperature rise for a range of operating conditions, in particular for different frequencies and voltages. Finally, a SIMULINK-based control loop has been developed by using the thermal model as an input.