Control system for an induction motor

Abstract

A control system for an induction motor of the present invention independently commands the torque current component and the exciting current component of a stator current group supplied to the stator of an induction motor so as to feed-back control the amplitude and phase of the stator current group. The torque current component is commanded to control the output torque of the induction motor in correspondence with the output of a steering force sensor for detecting the steering force. According to an electric power steering apparatus using an induction motor controlled by the control system, a permanent magnet is not used for the motor so additional equipment such as a clutch is not required. Consequently, the structure can be simplified and the size of the unit can be reduced. Further, manual steering operation can be performed in the case of failure.

Dependencies are inferred from the claim text.