Electric Grid Topology and Admittance Estimation using Phasor Measurements
For power system operators, this work provides theoretical guarantees and practical methods for real-time grid parameter estimation, though it is incremental as it builds on existing total least squares techniques.
The paper establishes necessary and sufficient conditions for the number of phasor measurements required to estimate electric grid topology and admittance parameters, and demonstrates a structured total least squares approach for noisy measurements, validated on IEEE test feeders.
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.