| 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 energy structure and ensure sustainable economic development of China. Among non-hydro renewable energy sources, wind energy currently has the greatest potential for large-scale commercial developing. The networking operation of wind power can be an effective way for large-scale development and utilization of wind energy. The characteristics of fluctuation and intermittence of wind power have exerted adverse impacts on the grid and restricted the capacity of wind power integrated into the grid. Therefore, how to accept more wind power while ensuring the safe and stable operation of the existing power grid is a critical problem yet to be solved.The energy storage system can absorb and release power timely. The energy storage system may effectively stabilize the fluctuations of wind power and improve the capacity of wind power integrated into the grid. At present, the cost of energy storage system is quite expensive, and the charge and discharge control mode significantly affects its life. Thus, research on the operation control strategy of energy storage system, capacity allocation and economic evaluation can be substantial both in theories and applications.In this dissertation, the mathematical models of the main circuit and the control system of a direct driving wind permanent magnet generator was analyzed at first. An energy storage system which includes battery units, two-way chopped circuits and grid inverter was constructed. Parameters of the main circuit were determined according to the system's requirements. To improve the efficiency of the system and the performance of the power control, a power decoupling controller of grid-connected inverter was designed by using the feedback linearization approach.The waveform characteristics of steady power output from a single typhoon electric unit to wind farm were analyzed. To reveal the fluctuating characteristic of wind power, the statistical analysis of its historical data in the time domain and frequency domain was carried out. These analyses have laid foundations for deciding the installation locations of energy storage system and the demands of maximum power, capacity, and climbing rate in a wind farm.To reduce the adverse effects caused by the random fluctuating of wind power, the operating control strategy based on low pass filtering which can smooth wind farm output active power is applied. Through analyzing the advantages and disadvantages of using batteries and super capacitor individually for energy storage, a scheme of hybrid energy storage composed of batteries and super capacitors was presented, and the ratio relations between these batteries and super capacitors and their effects on attenuation were studied. The economic characteristics of these three schemes were compared and analyzed.An algorithm of wind power integration during low load time was presented. An method of using energy storage system to increase the wind power integration during low load time was proposed as well. The economic benefits of energy storage system was investigated. Considering the investment cost and economic benefits of energy storage system, an optimal energy storage capacity allocation method to maximize economic benefits of energy storage systemwas proposed to relax peak load regulation ability and increase wind power integration.A numerical simulation platform for combined operating of wind power-energy storage system was developed based on the electromagnetic transient simulation software PSCAD/EMTDC. The effectiveness of the grid-connected converter control strategy was verified on this platform. A physical simulation platform for combined operating of wind power-energy storage system was also established. The rationality of the combined operating control strategy of wind power-energy storage system was verified on this platform.
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