On reduced models of induction motors with faulty cage

This paper discusses a problem of modeling induction machines when some faults appear in a cage by using a model reduced to four equations. Starting from an advance mathematical model with full representation of a cage and considering arbitrary cage faults the steady-state equations are developed. Those equations are reduced to four equations using symmetrical components of stator and rotor quantities. Base on it, dynamic reduced models of induction motors with cage asymmetry are suggested. Numerical tests show when such simplified modes can be used for correct prediction of basic phenomena in stator currents to cage faults.