Optimal Operation Strategy For Micro Energy Grid With Sharing Energy Storage

In the context of energy crisis,accelerating the construction of energy Internet can provide a strong guarantee and important support for energy transformation.Micro-energy grid(MEG)is a kind of energy system near the user side,which is the end of the energy Internet and an effective way to realize primary energy saving effectively.The strong uncertainty of distributed energy generation power and demand for cooling and heating power in MEG,as the strong coupling of multiple heterogeneous energy sources in MEG,bring great challenges to the safe and stable control and economic operation of micro-energy grids.This paper investigates the operation strategies of MEG based on the issues of supply-demand synergy,energy sharing,"source-load" uncertainty,and demand-side flexibility as follows.(1)To address the problem of multi-time-scale cooperative optimization operation of micro-energy grids,a multi-time-scale cooperative optimization operation model of microenergy grids considering demand-side flexibility is constructed by studying the uncertainty of both supply and demand sides of micro-energy grids and the flexibility of demand-side resources.In the day-ahead stage,a day-ahead economic dispatch strategy based on robust linear optimization is proposed to obtain the day-ahead plan of each distributed unit within a micro-energy grid,and in the intra-day rolling optimization stage,the flexible cooling and heating loads are regulated by dynamically adjusting the room temperature to realize the source-load fluctuations in the intra-day stage.In the intra-day rolling optimization stage,the flexible cooling and heating loads are regulated by dynamically adjusting the room temperature to achieve the suppression of intra-day "source-load" fluctuations.In the realtime adjustment stage,the efficient charging and discharging characteristics of the battery and the flexibility of interruptible load are used to solve the problem of real-time power fluctuation on both sides of the supply and demand.The reasonableness and effectiveness of the proposed multi-time cooperative scheduling method for micro-energy grids considering demand-side flexibility are verified by the calculation example.(2)Based on the background that wind farms,photovoltaic power plants and combined cooling and heating power systems in a micro-energy grid belong to different interest subjects,a cooperative operation model of micro-energy grid with market-oriented transactions is proposed in conjunction with Nash bargaining theory.The article proves that the model is equivalent to the problem of common convergence of interests of each subject and illustrates the stability of the cooperative game.And the original optimization problem is equivalently transformed into two sequential convex subproblems: the social welfare maximization problem and the payment benefit maximization problem.The alternating direction multiplier method is used to solve the above two subproblems in a distributed manner,and the impact of feed-in tariff of renewable energy generation on the cooperative operation of multiple subjects in the micro-energy grid is analyzed.The reasonableness and effectiveness of the proposed cooperative operation strategy of micro-energy grid with market-oriented transactions are verified by arithmetic examples.(3)To address the problems of low clean energy consumption rate and unreasonable configuration of energy storage equipment when a high proportion of renewable energy is integrated into a micro-energy grid,the operation mode of shared energy storage power plants is analyzed,the energy interaction mechanism between shared energy storage power plants and multiple micro-energy grids is studied,and the cooperative operation optimization model of multiple micro-energy grids for shared energy storage power plants is constructed.The distributed trading framework between the shared energy storage plant and multiple micro-energy grids is constructed,in which each micro-energy grid only needs to exchange the desired trading power and trading tariff with the shared energy storage plant to realize the purchase of energy storage services.The analysis shows that the cooperative operation strategy of multiple micro-energy grids for shared energy storage plants can realize the mutual benefits of micro-energy grids and shared energy storage plants.(4)A two-level coordinated optimal scheduling model based on a hybrid game is proposed for multiple micro-energy grids and different ownership of energy suppliers and shared energy storage operators.Among them,the energy supplier is the leader of the game,and the micro-energy grids operator and the shared energy storage operator are the followers of the game.The article proves the existence and uniqueness of the equilibrium solution of the game.The energy interchange between micro-energy grids is used to improve the new energy local consumption.The mechanism of allocating the cooperative surplus of microenergy grids based on the asymmetric Nash bargaining method is studied.The mechanism of dynamic leasing of shared energy storage capacity in micro-energy grids is investigated.The simulation results verify that the proposed method can effectively improve the revenue of energy suppliers,shared energy storage operators,and micro-energy grids operators while taking into account the energy storage demand of micro-energy grids and the profitability of shared energy storage operators.