A novel rotor flux estimator for vector-controlled induction motor drives

This work presents a new method for rotor flux estimation in vector controlled induction motors. Only the acquisition of stator currents and rotor speed are required and there is no need for coordinate transformation. It has a simple conception and is therefore attractive for real time implementations in microprocessor-based systems. Algorithms to compensate for the rotor time constant variation as well as magnetic circuit saturation are incorporated giving the overall control system a good degree of independence on these parameters. The estimator was analysed in different conditions of operation and the results were found to be very good.