Vector control of induction motor is widely used in industrial applications. Many methods have already been proposed in this field. There are many restrictions involved in using mechanical sensor; moreover, the extra expense and allocation problems make using such sensor difficult in some cases. Stability analysis of a speed sensorless vector control system based on the feedback of the estimated torque-producing current is performed.
In this paper, a novel differential equation for an adaptive rotor flux observer, taking core loss into account, is introduced. Next, small signal stability analysis is carried out on the speed sensorless vector control system of an induction motor and stability analysis method is proposed.