Electric Grid Topology and Admittance Estimation using Phasor Measurements

TL;DR

This paper presents methods to estimate electric grid topology and admittance parameters using phasor measurements, establishing conditions for measurement requirements and demonstrating robustness with noisy data through simulations.

Contribution

It introduces necessary and sufficient conditions for measurement requirements and a structured total least squares approach for noisy data in grid parameter estimation.

Findings

Conditions for the number of measurements needed for topology and admittance estimation.

A structured total least squares method effectively estimates admittance with noisy measurements.

Numerical simulations validate the approach on various IEEE test networks.

Abstract

Recent advances in precise phasor measurement units are enabling new approaches to estimate distribution and transmission grid parameters in real-time. In this paper, we investigate voltage and current phasor measurement requirements to estimate the electric grid topology and admittance parameters. We show necessary and sufficient conditions for the number of independent operating points (measurements) required to determine the topology and admittance of a completely unknown electric grid. With prior topology information, we also show that there is a minimum number of measurements required to uniquely determine the admittance matrix and corresponding grid topology. In the presence of noisy phasor measurements, we show that the admittance matrix can be estimated using a structured total least squares approach. By means of numerical simulations on the IEEE 13-node distribution feeder, the IEEE 14-node transmission network, and the IEEE 123-node distribution feeder, we demonstrate our approach is suitable for applications in radial and mesh grid topologies in the presence of measurement noise.