State Estimation of Medium Voltage Distribution Line with Distributed Generations: Selected Utilization of Smart Meter Measurements

Abstract

AbstractWith regard to a medium‐voltage distribution system with low voltage electrical loads (hereafter written as ELs) and distributed generations (hereafter written as DGs), this study proposes a new calculation method for estimating electrical states such as line‐to‐line voltage vectors and line current vectors at connection points. The proposed method uses the following selected electrical data as input data: (i) active powers and reactive powers measured with the smart meters (hereafter written as SMs) on low voltage ELs and DGs and (ii) a line‐to‐line voltage and a current measured with a load break switch on the medium voltage distribution line, but does not use voltages and currents measured with the SMs on low voltage ELs and DGs. The selection of the used data attains reduction in the enormous number of data collected from SMs and also contributes to needless information on vast number of low voltage distribution lines such as their line impedances. Simulation results obtained, using the proposed method, show that the accurate electrical state of a medium voltage distribution line is derived through a small correction number for various generation powers of a DG. The knowledge acquired through this study is actually applied to the centralized voltage control system installed in an electric power company. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.