Reliability Analysis Of Dual-network In Complex Large Power Grid Based On Cascading Failure

In recent years, power system technology develop rapidly and power grid becomes bigger and smarter. A lot of equipment need to be monitored or controlled, this leads to the data increase in communication network dramatically. At the same time, communication facility need power support. So power grid and communication network become closer, the intimate relationship may bring huge potential safety hazard.The paper analyzes the relation between power grid and communication network and builds the coupling model. The influence of load is considered. The load of failure node will be redistributed in the network. According to the different redistribution distance, three load redistribution methods, including nearest redistribution, global redistribution and middle situation, are proposed. Then cascading failure process of coupling network is described in detail. When nodes are attacked at random, coupling network reveals different robustness in different redistribution methods. The simulation shows that global redistribution yields better performance and enough capacity cannot prevent cascading failure completely.Considering the deficiency of node importance algorithm in single network and the coupling relation between power grid and communication network, a new algorithm applying to coupling network with load is presented, which is based on cascading failure. The new algorithm considers network coupling characteristic, topology structure and load redistribution. The algorithm defines Maximum Load Branch and brings in load balancing degree of adjacent nodes and network load rate to weigh the influence of failure node, then to calculate node importance. The coupling model based on IEEE 30-bus system is built to simulate and contrast with contraction method and algorithm. Simulation results show the algorithm is feasible and can identify the difference of node importance in coupling network.