New Robust and Mechanical Sensorless Scheme for SVM Inverter Fed Induction Motor Drive Using Variabe Structure Controllers and MRAS

This paper presents a new control strategy in variable speed drives for induction motor that is aimed at improving the indirect rotor field-oriented control, which is well known to be sensitive to internal and external uncertainties. The control principle is based on sliding-mode control (SMC) combined with space vector modulation technique. The SMC contributes to the robustness and good dynamics of induction motor drives, and the space vector modulation improves the torque and current steady-state performance by reducing the ripples. To obtain accurate velocity estimation and remove all mechanical sensors, the method of adaptive system with reference model (MRAS) and a Luenberger observer have been used to get the signals of speed and load torque, respectively. The performances of the proposed control method are tested in Matlab/Simulink.