Identification Method Of Key Link In Power Grid Based On Elastic Theory And Complex Network Theory

The identification of key lines is of great significance to prevent power grid accidents and improve the safety and stability of power grid.This paper presented a kind of breadth index based on the grid elastic network model and complex network model,and a kind of depth index based on branch outage distribution factor.Combining these two indexes,the paper puts forward a kind of comprehensive index to evaluate the key line.The advantage of this method is that the breadth index is based on the betweenness of the lines,representing the hub property of the line,and there is no shortest path problem.The breadth index not only does not have the shortest path problem,and a pair of nodes only need to search a main transmission path,the calculation process is greatly simplified,and taking into account the direction of power flow.The depth index represents the severity of the impact of a line fault on other lines nearby.Comprehensive indicators can identify key lines that can cause cascading failures and large power outages after the failure.The simulation results of IEEE39 node system verify that the critical line fault can lead to cascading failure.It is very important for the safe and stable operation of the system to study,determine and monitor the key transmission sections.This paper presents a new method of determining key section,the principle of this method is that,directly in the elastic network topology,search for those who meet the characteristics of cross section of transmission line set near key line,determine the initial transmission section.Take the safety margin of small section as the key transmission section.This method saves the step of power grid partition,which is simple and intuitive.The application of grid elastic network model can realize the visualization of power grid stability analysis,and the characteristics of this visualization can be reflected in the determination method of key sections in this paper.The IEEE-39 node system is taken as an example to verify the rationality of the key section.