Sensorless Vector Control of Spindle Induction Motors Using Rotor Flux Observer with a Variable Bandwidth

This paper presents a new speed sensorless vector control scheme of spindle induction motors (SIM) which can be successfully applied to at any speed including even zero speed. The proposed sensorless vector control of SIM uses rotor flux estimator with a variable bandwidth. This approach is based on the closed-loop rotor flux observer (CLRFO) which includes a variable bandwidth of the PI controller. For low speed operation, the bandwidth of CLRFO has a variable bandwidth structure according to the estimated rotor velocity. The experimental results show the satisfactory operation of the proposed sensorless algorithm