Field results for a distribution circuit state estimator implementation

Distribution automation encompasses function that rely on knowledge of the state of the distribution circuit in realtime. This paper presents field results for a distribution circuit state estimator that was implemented on an electric utility distribution circuit. The state estimation algorithm is based on a probabilistic radial power flow approach that incorporates real-time measurements as solution constraints. A load modeling technique based on using customer billing information and daily load profiles is used to provide needed load estimates. This paper provides an assessment of how accurately the developed state estimation algorithm is able to predict circuit states. The improvement in circuit estimates as a function of available feeder measurements is illustrated as well. Finally, difficulties encountered with implementing an actual distribution state estimator are discussed.