Extended Power System Based On Complex Network Security Assessment

With the development of power grids, the blackouts occur more frequently than ever before, which cause tremendous losses. Prevention of large blackout is in the category of system engineering. From the microscopic perspective, the stability under disturbance should be enhanced, while in the general aspect, the growing demands should be met. As a new interdisciplinary field, complexity theory is widely used in computer network, ecology, sociology and economics. However, in power system, we only know that cascading failure of power system has the characteristic of self-organized criticality. Using complexity theory to study the impact of topology and prevent the large blackout is of importance.This paper studies the complexity of power system, analyzes its self-organized criticality, introduces some models of cascading failure and complex networks like small world, scale free and neighbourhood evolving networks, based on which, upgrade strategy of network expansion is proposed. Starting from the New England 39-bus system, we expand the network by adding nodes and transmission lines between the nodes, so that the network is growing to different topology such as neighbourhood evolving, scale free and random networks respectively. Evaluation of blackout size in these different networks shows that topology of power grids is relative to the distribution of blackout size.