Low voltage state estimation based operation analysis of smart distribution assets

Abstract

The growing number of distributed energy resources transforms the electricity distribution into an active system. This leads to integration challenges in the operation, while the extensive topologies with low level of instrumentation could have observability issues. Control centers of the future will have numerous advanced energy management options, but the basis of those applications must be a reliable system representation. Distribution system state estimation is an important research area and recent advancements in smart grids offer new data sources and simplifications in the process. Assets with distributed control capabilities and flexible resources are highly reliable pseudo measurement inputs for the algorithm which can help to reduce the estimation error and solve observability issues even on low voltage grids. This paper overviews the role of smart assets in the state estimation process and analyzes the characteristics of serial voltage regulators, smart distribution transformers, energy storage systems, distributed generator inverter control and direct load control. The goal is to integrate these devices in the weighted least square optimization algorithm to estimate the voltages and currents in the low voltage areas. The analysis concludes in the methodical description as further research will deal with the algorithmic implementation. Smart assets can be developed into cornerstones of industrial distribution system state estimators in critical areas to help operators keep the power quality and security of supply.