A New Open-Loop Volts/Hertz Control Method for Induction Motors

Three-phase induction motors are generally controlled by volts/hertz (V/Hz) control method for general-purpose applications. Lower cost and higher robustness are obtained in case of open-loop system but with lower accuracy. There were many attempts to enhance the performance of open-loop scheme, but these attempts lack the simplicity required by the system. In this paper, a simple and accurate open-loop control scheme is proposed. The scheme is appropriate for loads of speed-dependent torque.