| Distribution,interconnection and diversity have become the characteristics of modern power grid.Traditional power generation,transmission and distribution,power consumption have changed imperceptibly.A large number of new energy sources,such as wind and light,increase the available capacity of the power grid,but also increase the complexity of the power grid;high-voltage and long-distance transmission at the transmission and distribution side require more and more stability of the power grid;with the addition of a large number of new loads at the power consumption side,the negative load in the power grid has evolved from a single energy consumption into an important role of multi-functional grid regulation.Firstly,the access of a large number of renewable energy brings the deviation of power grid frequency and voltage.Secondly,the change of power consumption rules and regulations in the power market also affects the power demand side.Moreover,with the accelerated development of social economy and the continuous pursuit of high-quality living standards,the power system is facing more and more challenges.However,the methods of power grid frequency modulation and voltage regulation are relatively backward,which is a little inadequate to meet the needs of modern power grid frequency modulation,voltage regulation and peak regulation.The method of energy storage grid connected to participate in power grid regulation came into being.Energy storage has brought effective and promising solutions to the above problems.Because of its own characteristics,energy storage has extremely fast response time and regulation accuracy,which can be applied to various scenarios such as power generation,transmission and distribution,power consumption side,etc.,and is of great significance to the frequency modulation,voltage regulation,peak regulation and black start of modern power grid.This dissertation first summarizes the application of energy storage system in power grid,and the research status of several grid connected strategies of energy storage system,briefly describes the working principle and technical characteristics of energy storage technology,establishes the energy storage model of power grid side,explains the different scenarios of energy storage applied to power grid,and then specifically expounds the application of energy storage in power grid side frequency modulation,peak regulation,voltage regulation,black start.Principle and control strategy.In the application of energy storage in grid side frequency modulation,firstly,the analysis method of amplitude frequency characteristic is introduced,which is used to analyze and verify that energy storage can effectively participate in grid side frequency modulation.In this dissertation,BP neural network and traditional PID are combined to introduce the relevant principles and specific design process in detail,which has the advantages of taking into account the dynamic characteristics and static errors of grid.Finally,based on IEEE33 power grid system,the simulation model of energy storage frequency modulation is established,and the difference between the system frequency modulation and the ground frequency modulation is compared when there is energy storage system or not,which verifies the theory proposed in this dissertation.The load characteristics and voltage characteristics of the power grid are analyzed,and then the PID controller based on BP neural network is applied to the simulation model of peak load regulation and frequency modulation energy storage.In the study of the application of black start in the auxiliary power grid,firstly,the traditional black start scheme design is studied for different black start power units,and the influence of the capacity of the energy storage system on the black start is analyzed.Secondly,the design method of black start scheme based on energy storage system is studied,considering the recovery time and capacity demand of energy storage system under different access points,the same access points but different recovery paths,different levels of load and other situations.On this basis,a variety of black start schemes are proposed.Finally,aiming at IEEE30 power grid system,the feasibility of using energy storage system as black start power source to realize black start of power grid is verified by simulation.This dissertation aims at the research of energy storage applied to the frequency modulation,voltage regulation,peak regulation and black start of power grid side,which makes the energy storage power station get the function reuse,can improve the utilization rate of energy storage,improve the power grid revenue,fully tap the power grid support capacity of the power grid side energy storage power station,and provide reference for the establishment of a new stable operation and maintenance system of power grid. |
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