Electronic pole-changing for induction motors

Abstract

An induction motor includes a plurality of flux linkage configurations that control current to drive relative movement between a rotor and a stator. Each flux configuration powers a different number of poles. A controller is configured to droop switch flux linkage configurations by ramping up torque in a new configuration hat the same rate as torque decay by decaying flux from a previous configuration h. Multiple flux configurations can also be powered during steady state. A method for smoothing torque transitions receives a command to change from one of a plurality of flux configurations to another of the plurality of the flux configurations. Torque is ramped up in the another flux configuration at the same rate as decaying torque in the one of the plurality of flux configurations.