An Intelligent Approach to Observability of Distribution Networks

This paper presents a novel intelligent observability approach for active distribution systems. Observability assessment of the measured power system network, which is a preliminary task in state estimation, is handled via an algebraic method that uses the triangular factors of singular, symmetric gain matrix accompanied by a minimum meter placement technique. In available literature, large numbers of pseudo measurements are used to cover the scarcity of sufficient real measurements in distribution systems; the values of these virtual meters are calculated value based on the available real measurements, network topology, and network parameters. However, since there are large margin of errors exist in the calculation phase, estimated states may be significantly differed from the actual values though network is classified as observable. Hence, an approach based on numerical observability analysis is introduced in this work to overcome such a critical issue. The proposed method takes the number of meters, location and choice of pseudo measurements into account and assesses the network observability. The developed method is successfully applied to a real-life Danish network, followed by discussion on results.