Recent progress in sensorless vector-controlled induction motor drives

This paper reports the basic concept and recent progress in sensorless vector-controlled inverter fed induction tor (IM) drives. In field oriented control, a rotational transducer such as a tachometer, an encoder or a resolver, was often mounted on the IM shaft. However, a speed sensor cannot be mounted on a shaft in some cases such as motor drives in a hostile environment or high-speed motor drives. Further, these sensors suffer from low reliability, high cost and noise. Therefore, a sensorless speed drive is increasingly employed in modern industrial applications. This paper gives a short review of sensorless vector control of an induction motor drive.