Observer based vector control system for induction motors

This paper proposes a speed control system for induction motors based on observers. The observers estimate the equivalent disturbance torque and disturbance voltage, which are useful for speed control and current control in the vector control system for induction motors. The robustness for disturbance torque and parameter variations in the speed controller and the current controller is indicated with computer simulations. Also, the design of feedback gains in the controllers are discussed in this paper. The control errors for commanded speed and currents are confined to specified ranges, which can be formulated with the allowable maximum errors and the estimation errors for the equivalent disturbance torque observer and the disturbance voltage observer