Design and analysis of nonlinear observer to reduce torsional vibrations in shaft of wind energy conversion systems

This paper addresses the challenge of torsional vibrations in wind energy conversion systems (WECSs) with multiple interconnected rotating masses. A Nonlinear Extended State Observer (NESO) is designed and implemented in a multi-modular axial-flux permanent magnet synchronous generator (AFPMSG)-based WECS to estimate and suppress torsional vibrations. The proposed NESO accurately estimates system states and external disturbances without requiring a detailed system model, maintaining structural simplicity and robustness. MATLAB/SIMULINK results demonstrate effective vibration suppression under varying wind conditions, with low estimation errors in angular positions and speeds. The study provides a practical observer-based solution for enhancing the reliability and performance of wind turbine drivetrains.