Design of dynamic surface controller for robust performance of variable speed wind turbine

Abstract

The operation of variable speed wind turbine (VSWT) greatly affects the efficiency and quality of wind power generation. The conventional controllers are not able to improve VSWT performance in the presence of higher degree of nonlinearity, uncertain changes in wind speed, and coupling effects in the dynamical modelling. This study presents a controller design based on dynamic surface control (DSC) for a three-bladed, horizontal axis VSWT. The DSC design provides the robust performance while considering the problem of irregularity of wind speed, extraction of maximum available power from the wind, and vibration effect due to tower dynamics. The boundedness and the convergence of the proposed control have been ensured through a formal proof, leading to minimum tracking error. A comparative evaluation of a VSWT performance from the proposed DSC scheme has been analysed with the performances using quantitative feedback theory control, standard wind turbine controller, and conventional proportional integral control. The simulation results confirm that the application of DSC control has effectively produced maximum power and least tracking error than the other three existing controllers, performing robustly in presence of parametric variations upto ±15% and external disturbances.