A hybrid sensorless induction motor control strategy for high performance drive applications

This paper presents a sensorless induction motor drive scheme comprising a model-based speed estimator for dynamic performance and a rotor slot harmonic estimator for speed accuracy. The slot harmonic speed estimate is used to tune the machine model, providing speed-holding accuracy comparable to a sensored drive fitted with a 10000 line encoder sampled every 0.01 sec. System performance is evaluated over the full speed and load range, with a view to its use in multi-motor, speed-synchronized drives, an application typically requiring the performance of an encodered system