A precise torque and high efficiency control for Q-axis flux-based induction motor sensorless vector control system

This paper presents a sensorless vector control system for induction motors by taking into account iron loss, in which a flux-observer-based method is applied. Since the flux observer is constructed in a synchronously rotating reference frame with respect to the rotor flux of a current model and the iron loss resistance of parallel exiting circuit is used, the proposed system is very simple and the compensation of iron loss related to the operating frequency is directly realized while calculating rotor fluxes and slip frequency. The accuracies of estimated torque and speed are improved. Furthermore, a high efficiency control method that minimizes the loss is proposed. The effectiveness of the proposed system has been verified by digital simulation and experimentation