Novel method for reversal of single-phase squirrel-cage induction machines

Several systems have been devised for the reversal of single-phase induction motors, the majority of which utilise quadrature, or approximately quadrature, stator windings. However, if the windings are constructed so that their axes are at an angle considerably less than 90° electrical, an alternative method of reversal can be obtained. Auxiliary-winding design criteria are developed for this novel method of reversal, and computed theoretical results are compared with test results for an experimental design of a split-phase start motor. It is demonstrated that this novel method has performance features which make it preferable to the other reversal systems of single-phase motors for ertain application.