| Human is now facing a shortage of resources, environment pollution and ecological deterioration problems. Wind power industry, especially for offshore, has many advantages such as: widely distributed, renewable, no depletion, no pollution, safe, reliable and so on. Therefore, the development of offshore wind power has become a global trend. However, offshore wind need to overcome more complicated and more severe natural environment conditions. Some manufacturers generally by reducing weight way to control the cost of the whole machine parts. The decrease of the parts weight often lead to changes the structure of the wind power generator components properties, make its flexible increase. At this time, the Wind turbine can be regarded as the flexible systems with rigid modal. the offshore wind turbine has long been under a random superposition of wind and ocean wave will produce strong dynamic load, We must focus on the fatigue load of the wind turbine. Study on the suitable control strategies to reduce the purpose of the dynamic load of offshore wind power.The wind turbine load composed mainly of aerodynamic forces. By changing the pitch angle of the blades, Wind Turbines can reduce the aerodynamic loads. For improving the economic benefits of wind turbines, we can improve the system reliability, prolonging the service life. Pitch control is divided into uniform pitch control and independent variable pitch control. Unified pitch control is only valid for balancing the load on its wind turbine. But the independent variable pitch control can suppressed unbalanced load. In this paper we only study uniform variable pitch control strategy. Dynamic model of wind turbine parameters have large uncertainties. It brings some difficulties to controller design. This paper presents a multi-objective control strategy which can reduce the load of wind turbine.However, the flexible components of Wind turbines violent vibration will cause the fatigue damage and increase the cost of the maintenance, reduce the service life. Pitch variable is an effective means of control to prevent the sea wind of the interference.In recent years, robust control has a bigger development. In the paper a multi-objective pitch control strategy based on robust theory is proposed for large wind turbines. The experimental results show that the robust H_∞ control has a good effect on the Wind Turbines Variable Pitch Control.This work focuses on solving the control problem in wind turbine and hydrogen fuel cell.Based on the state feedback theory and linearized model of the system, use LMI approach to design a H_∞ controller. In the end of the paper, the simulation results shows that the control strategy can effectively reduce the tower and blade vibration and it has good robustness to parameter variations.In recent years, the rapid development of hydrogen fuel cell technology make it more and more mature. It is one of the efficient methods to resolve the key problem in wind power integrated to the power grid. It can also enhance the grid to accept more new energy. the proton exchange membrane fuel cell(PEMFC) is one of mainstream energy storage device. In order to control the air supply system of proton exchange membrane fuel cell,the air supply system of pressure is important for its efficiency. In the last chapter, using the H_∞ mixing sensitivity theory to design a pressure controller. The method achieves very good control effect. |
