An external network modeling for on-line security analysis

A state-estimation-based external power network modeling approach is proposed. The proposed approach is designed to improve the numerical stability and provide an external network model for online security analysis. An initial load flow study that provides a preliminary solution for the external network is followed by a state estimation using pseudo-measurements and proper weighting factors. Methods for handling multiple observable islands in the external network modeling process are described, and simulation tests are carried out on a practical system with realistic complexity. The proposed method provides a way of dispersing external data errors to the remote portions of the external network. Information for error detection and identification is available from the proposed method. It is believed that continual update of the external network model using real-time data available from neighboring utilities in conjunction with the identification and removal of erroneous data assumptions could lead to a more accurate and realistic external network for use during online contingency analysis.<>