A Convex Method of Generalized State Estimation using Circuit-theoretic Node-breaker Model

An accurate and up-to-date grid topology is critical for situational awareness. However, it is non-trivial to obtain due to inaccurate switch status data caused by physical damage, communication error, or cyber-attack. This paper formulates a circuit-theoretic node-breaker (NB) model to create a generalized state estimation (GSE) method that is scalable and easily solvable for a practical grid with RTU and PMU measurements. We demonstrate that all switching devices (with discrete status) and meters (with continuous measurements) can be replaced with linear circuit models without relaxation so that the entire grid is mapped to an expanded linear circuit. Using this grid model, the state estimation is formulated as a Linear Programming (LP) problem whose solution includes a sparse vector of noise terms, which localizes suspicious wrong status and bad data separately. The proposed method provides the benefits of convexity and a reliable state estimation with intrinsic robustness against wrong switch status and bad measurement data.