Power System State Estimation Considering Real-time Equivalents of the External Networks

One common problem associated with interconnected power systems is that the complete topology information and measurement data of the areas are not generally available or difficult to handle in real-time. This paper proposes a methodology to determine in real-time the reduced networks for the systems external to a given area. A sensitivity-based methodology is proposed to identify the nodes to be retained from the external areas. A network reduction methodology is then used to obtain the reduced equivalent for the entire system. A real-time network parameter adjustment algorithm is subsequently used to update the parameters of the reduced network under changes in operating condition. The proposed methods are validated with the help of the modified IEEE 14-bus and IEEE 118-bus systems.