High performance control strategy of current controlled PWM inverter fed induction motor servo drive system

The authors describe a newly developed high-performance control system for a vector-controlled induction motor. In order to realize this system, the authors adopted the current controlled PWM (pulse-width modulated) inverter with a hysteresis controller. Changes in temperature, current, and slip frequency vary motor parameters. If these parameters are not compensated in the vector controller, poor performance results. Therefore, a priori knowledge of the motor parameters is needed to implement indirect vector control on a high-performance induction motor servo system where the position of rotor flux is estimated. A parameter adaptation scheme has been proposed to compensate for the machine parameter variations. The authors present some of the relevant mathematics necessary to study parameter sensitivity in the time-optimal position control of an induction motor. Simulation and experimental results verify the predicted performance