A Practical Approach to Observability Analysis and State Estimation in Distribution Networks

This paper presents a novel approach to distribution network observability. The observability analysis is a part of the state estimation process and traditionally determines whether the state estimation can be performed. This works well in transmission networks, where generally numerous measurements are available. However, in distribution networks only a limited number of measurements are usually available. If real measurements are not available pseudo-measurements with large margins of error are often used instead. This implies that the estimated state of a distribution network can be significantly different from the real network state even if the network is classified as observable. Therefore, this paper proposes a novel approach to distribution network observability, which focuses on the state estimation accuracy. The proposed approach has been tested via simulations on a modified IEEE 34 bus test feeder.