Effects of rotor bar and end-ring faults over the signals of a position estimation strategy for induction motors

The effect of rotor faults, such as broken bars and end rings, over the signals of a position estimation strategy for induction motor drives is analyzed using a multiple coupled circuit model. The objective is to establish the possibility of using the estimation strategy signals for fault diagnosis in variable speed electric drives. This strategy is based on the effect produced by inductance variation on the zero sequence voltage, exciting the motor with a predefined inverter-switching pattern. Experimental results illustrate the feasibility of the proposal.