| The development and utilization of renewable energy has opened new ways to solve the problems of world energy crisis and environmental pollution.Thus,they are strategically important to help upgrade Chinese energy structure and ensure sustainable economic development.Wind energy is the most potential non-hydro renewable energy for large-scale commercial development in China.With the continuous improvement of installed capacity and permeability of wind power in power grid,the fluctuation and intermittence of wind power output have a negative impact on frequency modulation and dispatch of grid system.Therefore,in order to ensure the safe and stable operation of the power grid,how to improve the grid capacity to absorb wind power has become an important problem to be solved.To improve the power grid's capacity to absorb wind power and to restrain the adverse effects of large-scale wind power integration on FM and dispatching of power grids,it is necessary to enough study the control strategy of wind turbine under high wind speed and build a reasonable wind-storage system,which will restrain the impact of wind power generation system on the reliability and stability of power grid system and reduce the wind abandonment rate.First of all,the pitch control strategy of the wind power system is investigated to achieve a constant power output of the unit at high wintd speeds.The main characteristic parameters of the wind turbine are described,and the nonlinear model of wind power system is established.Then,the necessity of designing constant power controller is explained by simulation research.Secondly,the wind power system is linearized at three different points on the wind conditions.Based on optimal control theory and H ? theory,the three local controllers are respectively designed.Then,the global controller can be designed based on T-S fuzzy theory.Thirdly,wind power system model containing variable pitch controller is established.For the step wind and random wind cases,simulation research is carried out.Then the pitch angle curve,the power coefficient curve and the output power curve are analyzed,which shows that the designed controller can ensure that power system has the good performance.Fourthly,a new type of hydrogen storage system for wind power generation is proposed.The structure and function of wind energy hydrogen energy storage system are firstly designed,and the functions of the components in the system are also introduced.Then,combining the combination of electrochemical analytical model and empirical model,the models of water electrolytic cell and fuel cell system are established.Fifthly,the grid-connected control strategy of wind power-energy storage system is designed.The DC buck converter at the end of the electrolytic cell is controlled via vector control to guarantee that the working power of the electrolytic cell can be controlled,firstly.Then,combining constant DC voltage output and frequency/voltage sag control technologies,a control strategy is adopted for the fuel cell grid-connected converter system.Sixth,in order to reduce the abandoned wind rate and improve the power grid's capacity to absorb wind power,according to the characteristics of each unit and the requirements of access to the grid,the grid-connected strategy of each unit and the optimal allocation algorithm of system energy are designed.Take the wind power project in Jiangsu Huadian Binhai as an example,simulation research is made.Simulation results show the rationality of system modeling and the effectiveness of energy optimization algorithm.Finally,taking Jiangsu Huadian Binhai wind power project as an example,the economic analysis of the wind hydrogen energy storage project is carried out.The feasibility of the project is verified by calculating its internal rate of return on investment. |
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