Variable speed control of two-mass wind turbine with unknown stiffness

This paper presents a variable speed control of two-mass wind turbine with unknown stiffness. The aim of the algorithm is to control rotor speed in order to maintain optimum tip-speed ratio and obtain maximum power output of the turbine with the appearance of unknown stiffness. The algorithm is formulated using full-state feedback which stabilizes in the sense of Lyapunov. Adaptation law is embedded into the variable speed algorithm to assure adaptability towards unknown stiffness. To validate the effectiveness of proposed speed control, a simulation in MATLAB/SIMULINK® is carried out. The results show that optimum tip speed ratio is obtained via the proposed controlled rotor speed regardless