Risk Assessment Of Power Grid Based On Complex Networks And Fuzzy Theory

Power systems which play a crucial role in any country’s economic and security inevitably tend to become more complex and larger. A single line fault could result in large-scale cascading failure. So it’s a severe challenge for the stability and operation safety of the grid.Risk assessment of power system is great significant for its secure operation. This paper summarized the defects of the traditional assessment methods for grid and proposed an innovative way based on the complex network theory and fuzzy mathematics. In the paper, a new index is introduced to evaluate the performance of power grids, which is more consistent with the physical characteristics of the actual power system. Power system topology structure is associated with the operation mode of power system when analyzing the power grid. And the influence caused by variation of grid operation is also considered. Meanwhile, fuzzy mathematics is proposed to the risk assessment in order to describe the uncertainty of the grid. Using fuzzy probability theory, this paper considered both the membership degree of the line and the probability of failure to assess the risk of grid.The method not only determines the influence of the line, but also can be used to analyze the sphere of the fault line of the power grid. In the end, this method is illustrated in the IEEE-39-bus, which demonstrated its effectiveness.