| With the rapid development of science and technology,the demand for load in the power system has also undergone tremendous changes.At the same time as the load demand has increased,the operating conditions of the power system have become more and more complicated,and higher demands have been placed on frequency regulation of the power grid.At present,the frequency modulation task of the power system is still mainly borne by the traditional frequency modulation unit.However,the increasingly complex load changes make traditional frequency modulation units have increasingly prominent problems such as slow response speed and delay.The battery energy storage system has many advantages in the frequency modulation of power grids due to its advantages such as reversible charge and discharge,fast output,and simple control.This paper studies the mechanism of power system frequency modulation,and analyzes the deficiencies of the existing primary and secondary frequency modulation methods.By establishing the regional power grid frequency simulation model and the simulation model of the energy storage battery,the frequency response of the power system under the condition of energy storage participation is simulated and analyzed to verify the high efficiency of the energy storage participation in grid frequency modulation.The paper also studies the influence of energy storage system access to distribution network,and analyzes the impact of different access capacity and access location of energy storage during grid frequency modulation on the economic operation of distribution network.Through the establishment of objective function,the impact of different access capacity and access position is evaluated to provide a basis for optimal configuration of battery storage.In the research of energy storage participating in the first and second frequency modulation of power grids,different control strategies are designed based on the different frequency requirements of the primary and secondary grids.First of all,in the process of one frequency modulation,the classical PID controller is designed and the frequency of the system is adjusted by using the characteristics of energy storage tracking and rapid output.Based on the characteristics of frequent frequency modulation operations,the effect of energy storage under continuous load changes is simulated to verify the high efficiency of energy storage in the primary frequency modulation.Then,for the grid secondary frequency modulation in which the battery energy storage participates,a frequency simulation model of the interconnected regional system is established.Taking grid ACE as a control variable,a fuzzy control strategy was designed to simulate the secondary frequency modulation effect.The use of existing frequency modulation evaluation indicators to assess the effect of battery energy participation in frequency modulation to verify the efficiency of energy storage participation in power grid frequency modulation.In addition,consider the impact of energy storage access to the distribution network,establish an objective function based on network loss and voltage deviation,and establish the constraints of the objective function.Then,based on the interior point optimization algorithm,the optimal values of the objective function under different access conditions are solved.IEEE33 node distribution network model is used for algorithm simulation to analyze the impact of battery energy storage access on the economic operation of the system,so as to provide reference for optimal configuration of access capacity and access position of battery energy storage participation in grid frequency modulation. |
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