Stable point-wise optimal LPV control of induction motors

According to new results concerning linear parameter varying (LPV) systems, a regulator is designed for the stator current control of an asynchronous motor which is the most commonly used electric motor in industrial applications. It is shown that the proposed LPV control strategy renders the closed loop stable independently of how the rotor speed, taken as the scheduling parameter, varies in time within the admissible range, while being point-wise optimal with respect to a quadratic performance index. This result is obtained by properly realizing the parametric transfer function of the regulator that ensures stability and optimal performance for all fixed values of the rotor speed. Simulations carried out on a recent benchmark model show that the proposed control scheme performs well.