Risk theory based on-line power system security assessment

Power system is approaching its limits due to the deregulation of power industry and unavailability of new transmission corridor. However power system security assessment is carried out and the operating limits are set according to the given contingency list which might happen in very rare frequency. In other words, the frequency of fault occurrence and the risk of blackout is varied when the operating condition (load level, status of power equipment, and weather) changes. How can we do the security assessment based on the operating condition to get the best equilibrium between the security and the profit is the focus of this paper. The idea of risk based on-line power system security assessment is suggested. A precise calculation method of average failure rates of components is presented. Besides, operating condition based failure rates of components are also analyzed systematically in the paper. The Monte-Carlo simulation demonstrates the viewpoint of the paper.