Research On Energy Storage Configuration Strategy Of Active Distribution Network Considering Demand-side Response

Under the goal of "carbon peaking and carbon neutrality",after the large-scale integration of renewable energy generation represented by distributed photovoltaic into the distribution network,energy storage must be configured due to its low utilization rate and inherent uncertainty.In terms of macro unified power grid operation,energy storage allocation should be solved from the whole power system,and the improvement of load rate,power utilization rate and equipment utilization rate should be pursued to obtain macro-economic and social benefits.Therefore,proper energy storage configuration strategy will be an extremely complex and difficult problem to solve.In terms of micro distribution network operation,active distribution network with flexible regulatory resources,such as controlling energy storage and flexible load,can effectively deal with many problems caused by large-scale grid connection of distributed power through independent control and external power exchange,improve the distribution of power flow within the network and so on.It is a key technology to realize local consumption of renewable energy power generation and reduce the centralized regulation pressure of large power grids.Focusing on the latter,this paper aims at the operation regulation of active(self-active,and external-active),and aims to realize the controllable exchange power and adjustable internal voltage between active distribution network and superior network.The basic unit containing photovoltaic,energy storage,flexible load and conventional load,the station area containing several basic units and the distribution network containing multiple station areas are respectively taken as the research objects.The optimal configuration relationship between demand-side response and energy storage under different scenarios is analyzed,so as to achieve active autonomous operation at the distribution network level.The main work and research achievements are as follows:(1)Taking the basic unit consisting of photovoltaic,controllable load,uncontrollable load and energy storage equipment as the object,an energy storage configuration model was established based on the basic unit and the controllable load response,which was used to analyze the energy storage configuration strategy to minimize the deviation between the external exchange power of the basic unit and the expected planned exchange power.To deal with the uncertainty of photovoltaic output and load power by robust optimization,the column-and-constraint generation algorithm was used to solve the robust optimization model,and combined with the calculation and evaluation process of energy storage configuration,the rated energy storage power and capacity configuration,the demand-side response at each time and the operation results of energy storage charging and discharging could be obtained.Example analysis shows that this model can accurately control the external exchange power of the basic unit,limit the net load fluctuation caused by the grid connection of distributed photovoltaic to the basic unit,and the energy storage configuration strategy including demand side response can significantly improve the system operating characteristics,and reduce the rated energy storage power and capacity.(2)Taking the station area which composed of several photovoltaic,energy storage and utility units as the research object,and a station area energy storage configuration model considering demand-side response is proposed,which is used to analyze the energy storage configuration strategy to minimize the deviation between the exchange power and the expected planned power between the station area and the distribution network trunk.In the optimization model,energy complementation among each unit is considered to avoid redundancy or resource waste caused by independent energy storage configuration of each unit.The case study shows that the configuration scheme obtained by this model can make the exchange power between the station area and the main distribution network accurately controllable,which is conducive to the local consumption of distributed photovoltaic.The energy complementary behavior between each unit can reduce the allocation scale of energy storage capacity,improve the utilization efficiency of flexible resources.(3)Taking the active distribution network which composed of several stations as the research object,an energy storage configuration model of distribution network with demand-side response is proposed,which is used to analyze the energy storage configuration strategy that minimizes the deviation of the power exchange between distribution network and superior network and the expected plan.A two-stage robust optimization model was established considering the energy complementarity and network power flow constraint in the internal station area of distribution network.A data-driven linearized power flow was used to replace the AC power flow equation to reduce the complexity of mathematical processing of the model.The case studies shows that the optimization model combined with the configuration scheme obtained from the calculation process of energy storage configuration can meet the adjustment requirements of external power exchange and internal node voltage of the distribution network,and play a significant role in improving the timing mismatch between distributed photovoltaic and electricity load and eliminating the adverse effects of source and load uncertainty on the system operation.