Pitch Control Study Of Offshore Floating Wind Turbine

Continuous improvement and development of today’s society, traditional energyconsumption serious, and growing shortage. While the wind energy as a clean, renewableenergy is widespread concern around the world. Due to advances in engineering andtechnology, offshore wind power technology also will develop. While offshore windturbines can be toward larger, higher capacity development, but there are many technicalproblems. Which, because of the special marine environment, offshore floating windturbine output power fluctuations and turbine vibration is more common technicalproblems. In this paper,3MW doubly-fed wind turbine as a research object, for pitchcontrol and vibration control in-depth study. The purpose is to make offshore floating windturbine output power more stable and reduce the turbine vibration.This paper describe the current development of offshore wind power technology athome and abroad, and the existing main control strategies. Describes the basicaerodynamic principles and dynamics of offshore wind turbines. Analyzes the principleand work process of pitch control.In this paper, a mathematical model of each part of turbine is builded based on thebasis dynamics theory of offshore floating wind turbines. Analyzed vertical movement ofthe offshore floating wind turbines, and its impact on the turbine’s output power. Proposeand design a pitch control method based on H∞disturbance rejection. Simulation comperedwith the tuaditional PI pitch controller to verify the correctness of the pitch controller. Thesimulation results show that the pitch controller based on H∞disturbance rejection methodcan effectively reduce the output power fluctuations, improved anti-jamming capability ofthe system.To achieve the object of stable power output while reducing vibration, proposed amixed sensitivity H∞pitch control strategy, and introduced acceleration feedback controlof tower. Adjust the pitch angle according to the acceleration feedback, changingadditional damping to reduce the longitudinal vibration tower. The simulation results showthat the proposed H∞mixed sensitivity pitch controller not only reduces the output power fluctuations, but also reduces the tower vertical vibration, reducing the load of gearbox andother components.In this paper, based on3MW doubly-fed wind turbine, using MATLAB/Simulinksoftware to calculate and analysis the controller. Preparation and introduction the externalcontroller of wind power simulation software GH_Bladed. And traditional PI controlstrategy were compared to verify the proposed control strategy is feasible and effective.