Field-oriented control of an induction machine in the field-weakening region with DC-link and load disturbance rejection

A method of actively maintaining voltage margin in field-oriented induction machine controllers is proposed. A voltage-margin controller is developed that rejects DC-link and load disturbances, such that current regulation and field orientation is maintained. In addition, the voltage-margin controller coupled with rotor-flux-oriented control is shown to provide maximum torque capability equivalent to stator-flux-oriented control.