Impact of PMUs on state estimation accuracy in active distribution grids with large PV penetration

The growing penetration of photovoltaic (PV) systems as well as the increasing presence of time-varying loads exacerbate the variability of electrical quantities in distribution networks, thus posing new challenges for grid monitoring and management. Among the various problems that may originate from the intermittent, periodic and generally random nature of PV generation and dynamic load conditions, the uncertainty affecting Distribution System State Estimation (DSSE) techniques might be particularly critical as it could lead to false or missed alarms (e.g. in fault detection) or to improper control actions. In this paper, the accuracy of the well-known Weighted Least Squared (WLS) state estimator is analyzed under the effect of different levels of PV penetration and loading. The reported simulation results can be useful to provide some general guidelines on how to improve state estimation accuracy in active distribution networks.