Adaptive robust control for speed sensorless field-oriented controlled induction motor drives

An adaptive robust control strategy is proposed to increase robustness of parameters variation and load disturbance for sensorless field-oriented controlled induction motor drives. Improved method of the adaptive full-order observer is presented. Observer error system is transformed to synchronous reference frame for avoiding nonlinear and complicated dynamics of the observer. Stability conditions can be achieved through the single-input and single-output error system. To improve robustness of parameter variation for the observer, stator resistance is estimated through an improved adaptive mechanism synchronously. Based on the analysis of dynamic model of field-oriented controlled induction motor considering the load disturbance, an adaptive disturbance torque feedforward controller is adopted to achieve satisfactory dynamic response. The feasibility of the proposed control strategy is verified by experimental results of speed sensorless field-oriented vector controlled 11 kW induction motor drive.