Research On Survivability Mechanism In Communication Network Of Complex Large Power Grid

The multi-domain Optical network structure is being built in large complex power grid. In such a network, the computation of the constrained path becomes extremely complicated. The demand of the path calculation seriously affects the reliability of services in communication network. Therefore, IETF proposed PCE to be responsible for a variety of complex path calculations. PCE enhances the scalability of the routing mechanism. It is conducive to development of the large-scale network.In this dissertation, the features of the business and structure of the complex power grid communications network environment and the application modes of PCE techniques in a multi-domain optical network are analyzed. Then, a method of disjoint path construction based on hierarchical PCE with Parallel Node Configuration (HPCE-PNC) is provided. First, the parent-PCE use the virtual topology construct which consists of source node, the destination node and boundary nodes of each domain to calculate a set of disjoint virtual paths from source node to the destination node. Then, the sub-domain PCE calculates the disjoint physical path segments mapping the virtual path segments and the resource information of the links, and sends the result to the parent-PCE. Finally, the parent-PCE calculates the set of complete disjoint physical paths and selects a pair of disjoint paths with minimum cost to be working path and backup path, and allocates wavelength to this pair of disjoint paths. Simulation results show that the algorithm have a high rate of path establishing and a small setup delay.In addition, the impact on the consolidated communication cost cased by the position distribution of PCE is discussed. According to HPCE-PNC path construction process, we establish a mathematical model of the comprehensive communication cost and provide a PCE location planning approach based on quantum genetic algorithm. This algorithm can reduce the cost of communication to reach or approach the global optimal solution. Simulation results show that the proposed algorithm can effectively reduce the delays of the path establishment and the network blocking rate.