On-line power systems security assessment

When a power system state is normal, one must then determine whether it is secure or insecure with respect to the consequences associated with a set of network contingencies. An on-line state estimation and security assessment (SESA) facility has been developed at the National Grid Research and Development Centre, Leatherhead as part of a project for the computer-based operation of a power system. The authors describe enhancements made to ensure the robustness of the security assessment facility and to provide an effective man-machine interface. On-line computation provides an opportunity to use the latest system data and to adopt more refined procedures. The authors will conclude with a prediction of future algorithmic developments