Application of Servo Controller Design for Speed Control of AC Induction Motors Using Polynomial Differential Operator

Abstract

This paper proposes a servo controller design method for speed control of AC induction motors using polynomial differential operator. To do this task, the followings are done. First, nonlinear modeling for an induction motor is introduced and is linearized at equilibrium points using Taylor’s series. Second, an observer is designed to estimate flux, and an extended system incorporating the internal model principle to construct the extended system is shown using polynomial differential operator in case that the types of reference inputs are differential polynomials. Third, a state feedback control law for the extended system to track the given reference input is designed by a regulator design method. A control system is constructed for speed control of the 1.5 KW AC induction motor. The simulation and experimental results are shown to verify the applicability of the proposed controller compared to conventional PI controller for the AC induction motor with a step type of disturbance to track its speed of 3 types of the references such as step, ramp and parabola.