Distribution Network Optimized Planning Method Study Considering Demand-side Flexibility Resources Allocation

Under the vision of building a new power system in China,the distribution network is evolving from an uncontrollable traditional operation mode to a new distribution network with the ability of "source,grid,load and storage"coordination and interaction,the system structure is undergoing far-reaching changes,opportunities and challenges coexist:on the one hand,under the trend of high proportion of new energy grid-connected,how to give full play to the flexible and adjustable endowment of demand-side resources,and ensure the adequacy of the flexible adjustment capacity of the system to adapt to uncertainty by carrying out joint planning with the distribution network;on the other hand,under the background of electricity marketization reform,how to reasonably delineate the interest relationship between distribution network operators and differentiated investment entities with the participation of private capital in power grid planning and construction,and design a matching planning model to effectively coordinate the benefits of all parties has become urgent problems to be solved.Aiming at the optimization planning of distribution network considering the allocation of demand-side flexibility resources and uncertainty of new energy output,a research framework combining the selection of flexibility lackness scenarios and the improvement of uncertainty analysis methods is proposed.Firstly,at the level of resource modeling,a flexible supply and demand model is established based on the analysis of their physical operation characteristics by taking flexible resources such as energy storage,micro-gas turbines and flexible loads as research objects.Then,endowing the extreme scenarios of new energy output with new meaning of flexibility lackness,and a scenario selection strategy based on shadow price theory is proposed to establish a closed-loop connection between planning resources,operational constraints and scenario selection.Then,the scenario screening strategy is embedded in the distribution network-multiresource joint planning model,in order to reflect the common impact of the two types of scenarios on planning decisions,the model transformation and solution are completed under improved distributionally robust optimization based on scenario probability driven.The proposed method can effectively reduce the comprehensive cost,significantly improve the problem of lackness of flexibility through the rational allocation of demand-side flexibility resources,and obtain further balanced economic and conservative planning conclusions compared with traditional uncertainty analysis methods.Aiming at the problem of differentiated multi-agent coordinated planning in incremental distribution network environment,a bi-level Stackelberg-Nash("SN")game planning framework considering distribution network operator and demand-side multi-agent is proposed.Firstly,the interest competition relationship between investors and distribution network operators after photovoltaic,energy storage and flexible load are connected to the distribution network is analyzed,and the "leader&follower-competition" game relationship between all agents with distribution system operator as leader and demand-side multiple-agents as followers is established,which lays a theoretical foundation for the subsequent establishment of game planning models.Then,according to the characteristics of differentiated agents,the planning revenue model is established with the goal of maximizing the income of each entity.After that,a bi-level S-N game planning framework is introduced,specifically describes the game relationship between each subject,explains the game process,and proves the existence and uniqueness of the equilibrium solution.The simulation verifies the advantages of the proposed method in balancing the benefits of all parties,and can provide a reference for multi-agent to participate in the planning and construction of distribution network.