Simplified Models for Induction Machine Transients under Balanced and Unbalanced Conditions

Several simplified models of induction machines are presented. Included is a novel second-order model, which reduces the computational requirements previously considered necessary to predict electrical rotor transients, as well as mechanical transients. It is shown that the reduced-order models can be readily adapted to unbalanced voltage inputs without raising model order, thus providing increased flexibility. The model responses are compared for symmetrical voltage dips, start-up, and a sudden single-phasing condition.