Research On Control Strategy Of Supplementary Frequency Regulation Of Power System With Wind Power Using Energy Storage

Under the sustainable growth in dual pressure of energy and environment,more and more attention has been paid to the effective utilization of new energy,as a new type of environment-friendly and renewable energy wind power has been widely used.However,the output of wind power has the characteristics of randomness,volatility and intermittence,which brings great challenges to the safe and stable operation of the power grid.How to improve the permeability of wind power effec tively and reduce the impact of wind power on the operation of power grid is a urgent problem for the power sector at present.Meanwhile,energy storage technologies has been developed rapidly in recent years,which has been paid much attention by research ers because of its fast response speed,precision tracking of power instruction and no climbing rate limit.a certain capacity storage equipment,which is adapted to the application scene,is set on the grid side,and energy storage works in with traditional units properly to participate in AGC,which is one of the effective methods to solve the problem of frequency fluctuation caused by large-scale wind power connected to the power grid.This paper research the control strategy of supplementary frequency regulation of Power System with wind power using energy storage.First,the impact of wind power on the frequency stability of power grid is analyzed.According to the measured wind power data in a certain area,the output characteristics of wind power are analyzed with mathematical statistics,including the volatility,uncertainty and cluster effect of wind power output.The load fluctuation variation of short time scale in typical days and nearly three years caused by output of wind power is analyzed,that is the demand change of system ramp rate.Seting up the simulation model of Load-Frequency Control of regional power grid,and the maximum entropy spectrum analysis method is used to analyze the system frequency fluctuation quantificationally,which is the influence of wind power on the system frequency.Secondly,technical and economic characteristics indicators of various types of energy storage are summarized,which is influce their effect on AGC,and compares the characteristics of the severel common types of energy storage.Combined with the measured data in typical days in a province,the short time scale fluctuation tracking of the traditional generation to net load is calculated,and the demand of power grid AGC to storage power is analyzed quantitatively.The optimization method of interval number and multi index scheme is used to choose proper type of energy storage for AGC.The first three of the energy storage is sodium-sulfur,lithium battery and superconducting magnetic storage energy.Finally,a fuzzy coordinated control method of energy storage and thermal power unit participating in AGC frequency regulation is proposed.According to the situation of ACE and state of energy storage,the power supply of energy storage is adjusted by using the fuzzy controller to make sure the SOC in a reasonable range.Different target is determined according to the division of ACE,and within different division the distribution ratio to energy storage and thermal power unit is adjusted dynamically.The model of MATLAB/Simulink is used to simulate the energy storage power in the AGC.The result of simulation shows that the energy storage power can reduce the system frequency regulation and other evaluation indexes,improve the frequency response speed of the system.Compared with the fixed proportion allocation method,the dynamic proportion allocation method can ensure the tracking of ACE better,and the SOC is in a more desired range.