Robustness Analysis of Complex Power Grids in Evolution Process

Based on the complex network theory and real power system, the initial loads of buses are defined with the electric betweenness, the cascading failure model is built, and the robustness of the small-world power grid in evolution process is evaluated based on such indexes as the normalized avalanche size, the average connection level and the weighted network efficiency. The results show that the robustness of the small-world power grid will be enhanced with the enlarging of network capacity, and the influence of increasing network capacity on the robustness of the small-world power grid is small when network capacity reaches a certain limit value. In addition, the links between buses and robustness are enhanced with the development and evolution of the small-world power grid. So during the planning and designing phase, the network capacity should be determined scientifically and rationally by combing with real operation status, and the power grid with strong robustness and low cost can be designed by referencing the developing and evolving mode of the small-world power grid.