A new vector control strategy of induction motor based on iron loss model

Abstract

To solve the problems of rotor flux field orientation loss and operation performance degradation caused by neglecting iron loss in the conventional vector control system, a new vector control strategy based on iron loss model of induction motor (IM) is proposed in this paper. In this strategy, a slip-type indirect field oriented vector control (IFOC) is designed by setting the magnetizing currents as controlled variables directly, which allows for decoupling control between the rotor flux and electromagnetic torque. Starting from the iron loss model of IM, the detrimental effects of the iron loss on the conventional IFOC is analyzed, and a sliding-mode observer is invented to obtain the magnetizing currents. One of the outstanding points pertinent to the proposed control strategy is that the iron loss representation is not need either in the observer or in the vector control itself, resulting in high implementability in engineering. As proved through simulation and experiments, the negative effects of neglecting the iron loss on the orientation and torque accuracy are overcome in this proposed strategy, and the operation performance is improved.