Research On Access And Typical Operation Scheme Of Distributed Energy Storage In Power Grid

Energy storage system has dual characteristics of load and power supply,and has special operation mode.In the future,many distributed energy storage systems will be applied in the power grid.The access mode,operation strategy and economic analysis method of distributed energy storage are the research focus of this paper.The main research contents of this paper are as follows:Firstly,the application of distributed energy storage in distribution network is analyzed.Distributed energy storage access schemes in multi-scenarios of distribution network are proposed.Three kinds of energy storage batteries with distributed application potential are analyzed.The time-of-use electricity price in peak and valley of general industry and commerce is investigated,and the policy influence is considered.The "aggregation" operation of distributed energy storage and the operation strategy for peak-shaving and valley-filling and loss reduction are introduced.Secondly,the cooperative operation of distributed energy storage and photovoltaic is studied.The advantages,disadvantages and applicability of common AC bus access and common DC bus access in distributed energy storage and photovoltaic systems are analyzed.Four kinds of cooperative operation strategies with different functions are introduced.The calculation method of the electricity cost of the energy storage system is studied and an operation strategy considering the electricity cost of the energy storage system is presented in this paper.Thirdly,the economic evaluation method of distributed energy storage system is studied.A three-parameter empirical aging model of energy storage battery is established.Rainflow counting method is used to process SOC sequence data of energy storage battery and an aging estimation method of energy storage battery is proposed.An economic estimation method based on net present value calculation is proposed.The project duration is determined by aging estimation of energy storage battery.Particle swarm optimization is applied to solve the optimal scale of energy storage system.Finally,the examples show the effectiveness of operation strategy considering the power cost of energy storage system,the estimation method of energy storage battery aging,the economic estimation method of energy storage system and the application of particle swarm algorithm to solve the optimal scale of economy.The results show that the economic level of energy storage system is installed in the existing photovoltaic system,and the effect of subsidizing the energy storage capacity is further analyzed.