Dynamic model of induction machine with faulty cage in rotor reference frame

This paper presents a simplified model of an induction machine with broken rotor bars. The model is founded on the fact that broken bars cause asymmetries in the normally homogeneous cage's resistance and inductance. Thus, the rotor becomes pseudo-salient. This effect could be best comprised through the rotor time constants that differ in the orthogonal axes of a rotor reference frame. A method for their evaluation is also presented. Consequently, a choice of rotor co-ordinates for the model of a faulty machine to be developed in, is obvious. Experiments show good agreement with simulation results obtained from the developed model.