Speed Sensorless Vector Control Based on Full-order Adaptive Observer for Induction Motor Drives at Low Speed

This paper presented a speed sensorless vector control method based on adaptive full-order state observer for induction motor. The rotor speed estimated by an adaptive full-order observer is fed back to the vector control system as a feedback signal to form a closed-loop control of speed. In addition, the stator resistance is also recognized and updated in real time, so the effect of change of stator resistance on accuracy of speed estimation can be eliminated. The parameter identification system is achieved according to the Popov’s hyperstability theory, therefore the system is stable enough even at very low speed. The simulation and experimental results illustrated the correctness and effectiveness of the presented control algorithm.