Prevention control of blackouts in power system based on fault chain and risk theory

A new method based on fault chain and risk theory is presented in this paper to prevent the blackouts caused by cascading failures in power system. First, the view of fault chain based on security science is introduced to build up the model of cascading failures, and then three risk indices of fault chains are proposed from the aspects of voltage instability, voltage beyond limit and overload to assess the system security level. Furthermore, the objective function of prevention control model is represented to be minimized by quantifying the influence of control measures on these risk indices and the additional risk associated to the cost of control measures. The control nodes are selected according to the importance index of the link in fault chains, and the prevention control measures are determined by the multi-population genetic algorithm. The proposed method is effective to provide the best possible prevention control measures to improve the security of the system and to reduce the unnecessary control expenditures. Finally, comparative simulations on IEEE 39-bus test system verify that the proposed method is more utilizable and efficient than the method meeting the requirement that the security risk is the minimum for preventing the blackouts of power system.