Nonlinear Integral Terminal Sliding Mode Control for DFIG-Based Wind Energy Conversion System

Abstract

This article focuses on the nonlinear control of a wind energy conversion system (WECS) based on a doubly-fed induction generator (DFIG). A fixed-time observer is developed to estimate the mechanical torque of the generator. Based on this, an Integral Terminal Sliding Mode Controller (ITSMC) is designed to control the Rotor Side Converter (RSC) and Grid Side Converter (GSC), with the aim of ensuring Maximum Power Point Tracking (MPPT) as well as precise tracking of the control variables to their reference values. The stability of the proposed approach has been demonstrated using Lyapunov theory. The overall system is simulated in MATLAB/Simulink. The obtained results demonstrate a satisfactory dynamic response and accurate mechanical torque estimation, as well as the performance of the developed control strategy, particularly in terms of accuracy and robustness.