Abstract
This article presents a modified stator current-based model reference adaptive system (SC-MRAS) observer for sensorless speed control of induction motor (IM) drives. The proposed MRAS algorithm utilizes the actual value and the estimation error of the stator current in an adjustable model of IM. Sensitivity analysis for the IM resistance variations is also studied. To enhance the robustness of the proposed method, an adaptation mechanism employs a fuzzy logic controller (FLC) instead of a conventional PI controller. A detailed simulation study using MATLAB/Simulink is presented. Experimental validation using a DSP-DS1104-based laboratory prototype is provided. Analytical, simulation, and experimental studies proved that superior performance and accurate speed estimation of the proposed observer at very low speed under different operating conditions are achieved.