Modified Robust Model Reference Adaptive System Scheme for a Speed Sensorless Vector Control of Induction Motor

Abstract

This paper presents a robust rotor speed sensorless control strategy for induction motor. The main purpose is to overcome the instability issue for zero/low speed operating mode while considering that the rotor resistance is subject to uncertainties or variations. A Modified Model Reference Adaptive System speed estimation scheme is presented, and its sensitivity to stator resistance mismatches is investigated. The proposed approach introduces a discrete reference and adjustable models of the motor. Moreover, an adaptive discrete speed estimation scheme is synthesized on the basis of the extended Kalman filter technique. The proposed sensorless control scheme is tested using the professional Hardware simulator AMEsim (LMS). The obtained results confirm the superiority and ability of the proposed method compared to the classic Model Reference Adaptive System speed estimation scheme to guarantee a good dynamic performances and a stability of the control loop for low/zero speed operating mode and under stator resistance mismatches.