Induction Motor Theory - Some Elementary Concepts Extending to Suprasynchronous Speeds [includes discussion]

There are two facts about single-phase induction motors which have not been generally recognized. 1. The magnitude of the flux in the quadrature axis at the instant the main flux is zero diminishes as the speed is increased above synchronism. 2. The rotor current resulting from the rotor voltage due to the backward-rotating flux component provides the magneto-motive force for the positive flux in the quadrature axis. The purpose of this paper is to promote clear concepts somewhat beyond those normally encompassed by the cross-field theory,1 the rotating-field theory,2 or the equivalent circuit theory of the single-phase induction motor, extending to speeds above synchronism.