Research On Differential Construction And Evaluation Method Of The Core Backbone Network Of Power Grid

In recent years,extremely natural disasters such as ice disaster,tsunami,earthquake have happened frequently aroud the world,which seriously affected the safe operation of the power system.Thus,the research of power system to resist disasters was very necessary.China put forward the concept of network differential planning after experiencing the south big ice disaster in 2008.It made difference between the part of the important element and the other unimportant element by improve design standards in power network,to ensure continuous supply for important load,reduce the major economic loss caused by the loss of important load and security the normal operation of society under extreme disasters.The key point of differential planning and design was to build the core backbone network.Previous studies have focused on the importance evaluation of nodes and lines in the grid.The core backbone network,which was constructed in this way,is large in scale,and did not conform to the concept of the core backbone network as the core of the network.Therefore,the mathematical model of load need,generation need and line need were created based on the core backbone network,and combining with practical experience in the initialization process.A small part of the man-made lines and nodes were put into the core backbone.An improved quantum behaved particle swarm optimization(PSO)algorithm with the dynamic rotation angle,the early detection mechanism and the chaos mutation strategy was proposed to solve the problem.At the same time,in order to ensure the effectiveness of the particle,connectivity repair strategy based on the graph theory was introduced.From the four aspects of resistance,accessibility,security and recoverability,a hierarchical integrated index system of survivability was established,and the information entropy method and principal component analysis were used to evaluate the index,excluding the impact of human factors in the process of integrating index.The quantitative analysis of the core backbone network was carried out by using the quantitative index.In this paper,we propose a method to construct the core backbone network based on the defferent needs and the core backbone network evaluation method based on survivability.The effectiveness of the proposed method was verified by a IEEE-118 system The method was applied to the design of 500kV power grid and above in 2015 and 2020 in HB province,Guiding practical engineering works.