Estimation of power outage size based on the dominating differential equation

This paper describes a method to estimate how much power will drop after severe generation outage. When a large generation outage occurs, system frequency plummets to an unacceptable frequency level. Frequency drop affects both customers and generation systems. Thus adequate and quick load-shedding must be done to prevent problems. To institute any load-shedding policy effectively, the size of the generation outage must be precisely estimated in a very short time. So far, several methods have been proposed to estimate the power outage amount by measuring the decaying frequency variations that are obtained at each local bus. These methods are easily applied, but cannot be expected to provide good results in real power system operations because of the noises that are a part of decaying frequency variations. To cope with this problem, a new estimation method based on one that uses the dominating differential equation is proposed in this paper. The most precise estimation at this point is obtained by using additional factors, such as the sine wave included in the decaying frequency fluctuations and considered as a part of the equation. Simulation studies on a model power system consisting of five generating stations and four load points show that the newer method is encouraging.