An Improved Sliding Mode Control Approach for the Enhancement of Wind Energy Conversion Systems Based on PMSG

Abstract

Recently, researchers have increasingly focused on enhancing the quality of grid-supplied power while efficiently controlling wind energy conversion systems (WECS) under variable wind conditions. This study presents an improved control method to mitigate the chattering phenomenon often encountered in traditional approaches. By integrating maximum power point tracking (MPPT) with pitch angle control, the efficiency and performance of WECS utilizing permanent magnet synchronous generators (PMSG) are significantly improved. The primary objective is to regulate the generator and grid-side converter to precisely track the wind speed reference determined by the MPPT algorithm. The proposed sliding mode control (SMC) employs a unique, smooth, and continuous switching mechanism to address the chattering issue. Its stability is rigorously analyzed using Lyapunov's stability function. The control framework is straightforward to implement, and simulation results demonstrate its superior performance, achieving a total harmonic distortion (THD) below 2%, accurate current injection, and a near unity power factor. The MATLAB/Simulink based system is also validated through real-time hardware-in-the-loop (HIL) testing using an OPAL-RT simulator, confirming the model's effectiveness. Finally, the proposed method is benchmarked against existing schemes, highlighting its competitive advantages.