Performance analysis of robust and nonlinear MPPT controllers for autonomous wind power system

This paper presents the performance analysis of nonlinear and robust control strategies for the maximum power extraction from permanent magnet synchronous generator (PMSG) based autonomous wind energy conversion system (WECS) under varying wind speed. The Nonlinear control strategy aims to achieve improvement in speed tracking performance by using feedback linearization method used to select the optimal control input by compensating nonlinearities in the WECS directly driven by PMSG. In order to design the Robust Quantitative Feedback Theory (QFT) based controller and multi model QFT controller for the WECS based on PMSG, the nonlinear system is represented by a series of linear time invariant transfer functions around different operating points. Robust controllers are designed for proper selection of optimal control input to extract maximum power for every wind speed. Performance analysis is done from the MATLAB simulation results among the controllers for the PMSG based WECS. Multi model QFT controller is recommended for their enhanced performance.