Robust WTE Sensorless Design based on Soft-VSI structure for Three-Phase IM Drive using Sliding Mode Observer Controller

In this paper, a Sliding Mode Observer (SMO) for flux and then speed-sensorless of three-phase Induction Motor (IM) as robust Wind Turbine Emulator (WTE) design is investigated. A Soft-Voltage Source Inverter (VSI) structure, which is controlled by a specific Space Vector Modulation (SVM), is applied to drive the IM. Hence, appropriate three vectors which synthesize the desired output voltage are selected to allow the proposed system to react as a real turbine considering the wind velocity, static and dynamic behaviors, and parametric variations. Mathematical models of each system part are described to highlight electrical, mechanical, and electromagnetic relations. Simulation results confirm that the presented control method provides good flux and speed estimations despite rotor resistance and load torque variations in terms of trajectory tracking.