Research On Robust Restoration Of Distribution Network Considering Wind Power And Load Correlation

With the rapid development of new energy generation technology represented by wind power generation,distributed generation(DG)has been widely connected to distribution network.When the distribution network loses power support due to the main network failure,the initial load recovery after the power grid is out of power with DG priority can minimize the power outage loss,which is of great significance to ensure the reliability of the important load.Among them,the uncertainty of DG output and load demand has a great impact on the formulation of recovery plan.For this reason,the following work has been done for the initial load recovery of distribution network considering DG:Firstly,PSCAD/EMTDC simulation software is used to build the simulation model of small black-start system with DG in the initial stage of distribution network.The simulation results prove the feasibility of black-start.The model includes diesel generators,wind turbines and some important loads.According to the output characteristics of different types of DG,the starting control strategy of black start of small system in initial stage is determined,and the corresponding steps of black start are summarized.The feasibility is verified by the system frequency waveform,the output of diesel generator and wind generator.Then,in order to take into account the influence of uncertainties of wind power output and load fluctuation on distribution network fault recovery,the risk value method is used to quantitatively describe the uncertainties of the two factors,and a binary normal distribution model of wind speed and load is established by correlation analysis.Based on this model,the recovery path is taken as the decision variable,the minimum equivalent load loss is taken as the optimization objective,and the wind speed and load are taken as the disturbance variables.Distribution network robust restoration model considering power flow security constraints and wind load correlation is proposed.The model can minimize the equivalent load loss and ensure the priority recovery of important loads under the scenarios of specified confidence level and wind speed load correlation coefficient.Finally,aiming at the robust restoration model of distribution network considering wind power load correlation,the model is solved by using YAMIP toolbox,GUROBI mathematical programming optimization system and MATLAB.Taking the standard distribution system of IEEE-69 bus with multiple DGs as an example,the simulation results show that the uncertain intervals of the two factors will change after taking into account the correlation between wind speed and load,which can quantify the bad degree of scenarios in the robust model more carefully,thus forming initial load recovery schemes with different robust control levels,and providing more detailed information for dispatchers.Decision support for load recovery.