Coordinated And Optimal Operation Of Active Distribution Networks Considering Multiple Types Of Uncertainty Sources

In the background of global energy crisis and increasingly serious environmental pollution,it is an important trend for power grid development in the future to convert renewable distributed power sources into usable electric energy and connect to the power distribution network.With the access of a large number of renewable distributed power sources and active power control equipment,the traditional distribution network is changing into an active distribution network composed of multiple power sources and various adjustable resources.The renewable distributed power sources such as wind power and photovoltaic power supply that have random output bring uncertainty to the safe operation of distribution network.Therefore,reasonable coordination of various control resources of active distribution network is very important to realize energy saving and loss reduction and ensure the reliability and economy of power network operation.Based on the analysis of the uncertainty of source-charge,combined with the form of all kinds of power accessing to the grid and the control ability of electrically controlled equipment,the coordinated and optimized operation considering multiple sources intensively and multiple sources scatteredly accessed into distribution network is studied in depth.The main content is as follows:In view of the uncertainties of power supply,Photovoltaic renewable distributed power output and active power load in active distribution network,the source-charge uncertainty model based on scenario method is established in this paper.By modeling the prediction error of each uncertain source with probability density function.Under the condition of multiple sources intensively accessed into distribution network,considering the uncertainty of the renewable distributed power source output,we introduced the micro grid concept to effectively integrate the areas with distributed power sources accessed.By taking the distribution network and micro network as different interest subjects,the High Polygon modeling of optimization of distribution network with multi-source accessed is carried out.The interactive power between the distribution network level and the micro grid level is decoupled by the objective cascade analysis method,and the autonomous model of the micro grid level and the scheduling model of the distribution network level are solved by the parallel idea,so as to optimize the operation cost of the distribution network and the micro grid,The validity and feasibility of the proposed model are verified by taking the improved IEEE33 node as an example.Under the condition of multiple sources scatteredly accessed into distribution network,considering the uncertainty of source load output,the coordination optimization problem with multiple types of power active controllable equipment participated is explored.The model involves the power flow control equipment such as intelligent soft switch,transferable load and reactive power compensation device.The coordination optimization model of active distribution network is considered to be established by converting the power loss into economic index,and taking the total operating cost of the grid as the target.The second-order cone relaxation technique is used to deal with the non-convex nonlinear conditions.By taking IEEE 33-node system as an example,the treated model is solved and analyzed by using YALMIP and GUROBI on the Matlab platform.The results show that the access of various active control equipment will improve the power flow distribution and play a role in supporting the system voltage.It can obviously improve the system power loss and effectively reduce the total comprehensive operation cost of the active distribution network.