Research On Multi-scene Online Network Identification Method Of New Energy Base

Under the background of the large-scale development of extreme high voltage(EHV)long-distance transmission in new energy bases,the chain disconnection accident of new energy will cause inestimable consequences to the power system.Nowadays,online data lacks transient parameters and cannot be used for transient analysis.It can only be carried out by off-line network and data,but it cannot meet the real-time and accuracy requirements of interconnected power grids.The development of online risk assessment and early warning system is based on detailed models and equipment parameters which reflect the real-time operation status of power grid,and the speed of data model formation should be shortened as much as possible.In this paper,the detailed model of new energy power plant,D5000 online data and typical off-line planning operation mode are fully utilized to generate the grid topology model for multi-scene display demand and the display data of the network.The main research contents and results include:1)Considering the frequent switching changes of new energy base and the numerous operation scenarios of power system,a new multi-path search algorithm is developed to improve the efficiency of topology analysis.It is applied to local topology analysis.Topological modification is carried out by using the two ends of the breaker gate as the starting points of different search paths,which provides a topological basis for the identification of the model.2)An on-line network model identification scheme for stability analysis is proposed,which divides the new energy bases network model into three parts:the internal model of new energy power plant,the transmission and transformation model from grid-connected point to EHV hub substation and other simplified models in small areas affected by accidents.The internal model adopts the homology equivalence idea based on fuzzy C-means clustering,and the complex model is equivalent to the multi-machine model.Using the new energy base network model extracted from the online and offline data according to the topological relationship,the power transmission and transformation model is a detailed model that refreshes the offline data to the online data through the dynamic mapping table.The simplified model takes the form of a machine-to-load access boundary node.The scheme forms a new energy base network model and corresponding display data for a specific scenario,which can be used for both stability analysis and speed requirements for online computing.3)Finally,a provincial M wind power base is taken as the test object.Firstly,the fastness of multipath local topology correction is verified.Then the dynamic equivalent of the new energy base is carried out.The simulation results prove that the multi-machine model can characterize the active output characteristics of the detailed model.At last,taking provincial D5000 as on-line data and typical operation mode in summer of 2018 as off-line data,data integration is carried out to verify the integrity and availability of the integrated data.