MULTI-OBJECIVE LPV CONTROL OF WIND ENERGY CONVERSION SYSTEM UNDER WIDE-SCALE OPERATING CONDITIONS

摘要

Wind energy conversion system (WECS) is essentially a time-varying system with high nonlinear characteristics, which leads to the difficulty of guaranteeing the control performance in a wide-scale operating conditions for the conventional linear control strategies. In this paper, a linear-parameter-varying (LPV) gain-scheduled controller is proposed for variable-speed-variable-pitch wind turbines above rated wind speed, which improves both steady- and dynamic-response performances under wide-scale operating conditions. Firstly, the H_2/H_∞ technique is adopted to reduce the rated power tracking errors, while enhancing the robustness against high-frequency turbulence. Secondly, the regional pole placement technique is applied on WECS, which builds the connections to the dynamic response performance. To verify the effectiveness of the proposed method, the simulation is implemented on the NREL 5 MW wind turbine, which is compared with the conventional local linear control strategy with a full analysis on the related performances.