Research On Power Grid Integrative Vulnerability Assessment Based On Multiple Theories And Scenarios

With the continuous development of city, people’s increasingly demand for power makes the electric power system more and more complicated. Regional power grid contact more and more closely has caused the possibility of cascading failure increasing. Then large area blackout accident could happen caused by the potential threat. A lot of research shows the source of large area blackout accident is often a few weak links in system. So we need to seek effective and scientific analysis method for identifying these weaknesses part. Vulnerability analysis comes into being.The vulnerability levels of components in power system depend not only on the position in network configuration, but also the effect on power flow in the process of system operation. On this basis, complex network theory is used to model the power grid and define the branches and nodes as vulnerable sources. Electrical betweenness is improved to calculate the structural vulnerability index because of the supporting role of the components. Then consider the influence of the component’s own fault and the sensitivity to other components’ fault, risk indexes are applied to indicated running state vulnerability. Aiming at the shortcomings of considering the maximum operation mode only, this paper points out that the element shows different vulnerability characteristics under the different load condition. Then multiple load levels is proposed to evaluate component integrated vulnerability in many situations. Through the analysis and calculation of examples, the method in this article has proved to have strong ability of recognition and high precision, at the same time be able to provid powerful reference for planning and operation maintenance of power system.