Research On Capacity Planning And Control Method Of Large-scale Wind Farm Energy Storage Unit

With the rapid development of the global economy,the fossil energy consumption is becoming more and more tense,the energy crisis and environmental problems are at risk,and the new energy is widely concerned,among which wind power becomes the mainstream.China’s wind power industry is mainly concentrated in the inland areas,but in order to save the trans-regional transmission costs and to reduce the difficulty of power grid construction,the development of offshore wind farm near the coastal load center becomes a new trend,especially the far offshore wind farm,can make full use of more abundant and stable wind power sources.With the development of high voltage and large capacity in the offshore wind farm,the increase of its operating power leads to the increasing of the capacity of wind power components,the high system cost and the overall benefit not being improved significantly.Moreover,the largescale wind power grid has a certain impact on the power system,the operation reliability and stability of wind farm are not fully guaranteed.In order to improve the economy and reliability of wind farm,this paper aims at optimizing energy storage device and converter capacity configuration,and optimizing charge and discharge control of energy storage system.Firstly,this paper introduces the development of wind power generation at home and abroad,points out the cost and stability of mainstream offshore wind farm development in China,and at the same time clears the research direction of optimizing energy storage capacity and control strategy of wind power system aiming at reducing the cost of wind farm and improving the ability to respond to instantaneous power mutation.Finally,the current research status of energy storage capacity optimization and control is introduced.Then,by comparing and analyzing different types of generator sets,energy storage equipment and energy storage access modes in wind farm,it is clear that the distributed storage battery type direct-drive permanent magnet wind power generating set is more suitable for the offshore wind farm,and it is used as the research object to analyze the energy model of wind power system.Thirdly,according to the influence of wind farm grid on the main power impact of power system,this paper analyzes the calculation process of battery charging and discharging power under the condition of grid-connected power fluctuation,establishes the mathematical model of capacity optimization of battery and converter unit with the maximum annual profit of wind power system,and analyzes the constraint conditions.An improved nonlinear programming genetic algorithm is used to analyze the target solving process,and it is proved that the economy of the wind power system is significantly improved by the analysis and simulation of the optimal capacity.Finally,in order to improve the capacity of the wind power system to cope with the abrupt increase of wind energy or power grid active demand,this paper puts forward a charge and discharge control strategy of battery based on wind speed prediction,and analyzes the specific calculation process of the battery charge and discharge energy based on ARIMA forecast model on the premise that the wind power system satisfies the grid-connected power fluctuation.The stability and reliability of the grid-connected wind power system based on the new battery control strategy are verified by simulation.