Research On Planning And Scheduling Of Island Microgrid Considering Uncertainty

The AC-DC active distribution network integrates a variety of adjustable power equipment,which is an important way to realize the flexible consumption of renewable energy and improve the stability and reliability of grid operation.However,under the trend of large-scale grid integration of renewable energy represented by wind and light,AC and DC active distribution networks are facing complex uncertainties.In order to cope with the natural volatility and uncertainty of renewable energy and suppress the impact of the randomness of forecast errors,scientifically and quickly formulate effective and economical power dispatch plans to respond to the above impacts and improve the stable operation of the power grid.In the process of evaluating power dispatching decisions,it is often necessary to implement grid power flow calculations more accurately and quickly.In order to improve the speed of power flow calculation and scheduling decision-making on the basis of meeting the accuracy requirements,distributed power flow calculation and distributed scheduling decision-making have attracted people’s attention.This paper takes AC and DC active distribution network as the research object.It conducts power flow calculation and day-ahead optimization dispatching research from both centralized and distributed aspects.From the perspective of connecting power dispatching and generation control as much as possible,it studies how it can serve the power grid.Multi-time scale optimization scheduling strategy for operation control.First of all,it introduces the domestic and foreign development and application status of AC-DC active distribution network,sorts out and summarizes the development process and research status of power flow calculation and optimal dispatch in distribution network,and discusses the correlation between power flow calculation and optimal dispatch algorithm.The basic principles are explained.Secondly,in terms of power flow calculation,a centralized power flow calculation for the AC distribution network is carried out based on the forward-backward method.Based on the alternating direction multiplier method,the distributed power flow calculation of the AC distribution network is carried out,and the rapidity of the distributed power flow calculation is verified through a calculation example.Then the research object was transformed into AC/DC hybrid distribution network,and two different distributed power flow calculation researches were carried out.Third,in terms of day-ahead optimal dispatching,a mathematical model is established for each adjustable power component in the AC-DC active distribution network,and a day-a-day centralized optimal dispatch strategy is formulated according to its active control characteristics,and different work plans of adjustable power equipment are compared.analysis.On this basis,the recent distributed optimization scheduling strategy was studied,and the superiority of the distributed optimization scheduling strategy was verified by comparing the results of the two optimization scheduling strategies.Finally,the research work of multi-time scale dispatching of AC-DC active distribution network is introduced.First of all,under the assumption that renewable energy output and load demand are accurately predicted,a hierarchical multi-time scale dispatch strategy for AC-DC active distribution network based on model predictive control is proposed,and the closed-loop control method is used to ensure the economic efficiency of grid operation And reliability;then,further considering the influence of random factors,the scene analysis method is integrated into the model predictive control,and the hierarchical multi-time scale scheduling strategy based on the random model predictive control is proposed.The optimal dispatch method based on stochastic model predictive control can effectively deal with the uncertainty of power grid operation.