HARDWARE REALIZATION OF A PC-BASED CONTROL SCHEME FOR BALANCING A THREE-PHASE INDUCTION MOTOR SUPPLIED FROM A SINGLE-PHASE SOURCE

摘要

A control scheme using the PC-based LabWindows/CVI is proposed in this paper to supply a three-phase induction motor from a single-phase source. The proposed scheme adopts two static var compensators (SVC) that allow a single-phase source to be converted to a balanced three-phase source. The firing angles of the SVCs are so controlled by the controller that the motor runs under a balanced condition regardless of changes in the motor speed. Analysis of the induction motor's sequence equivalent circuits is carried out to find the reactance values that balance the motor. This is followed by finding the relations between the motor slip and the firing angles. Finally, prototype hardware is implemented to verify the proposed control scheme.