Investigation of induction motors with unbalanced secondary winding connections

Unbalanced circuits in an induction motor due to unsymmetrical rotor-winding connections are con sidered, and their equivalent circuits have been derived with the aid of positive- and negative-sequence networks. The equivalent circuits are verified by experimental investigations. The effects of unbalance in the rotor on motor performance are studied. The factors of importance in choosing certain unbalanced circuits suitable for halfspeed operation are presented.