Distributed estimation of inter-area oscillation modes in large power systems using alternating direction multiplier method

In this paper we present a distributed algorithmic approach to estimate the electro-mechanical oscillation modes of a large power system network using real-time Synchrophasor measurements of phase angles and frequencies. Considering the underlying network to exhibit strong coherency, we are particularly interested in estimating the inter-area oscillation frequencies and their damping factors in a distributed fashion. For this we first integrate the centralized Prony method with a commonly used distributed optimization algorithm, namely, alternating direction method of multipliers (ADMM), and show how the resulting approach can utilize PMU data to identify the modes of interest asymptotically. We illustrate our results using IEEE 39-bus, and 68-bus power systems, and also show the robustness of our method in face of communication failures.