1Distributed Optimization Algorithms for Wide-Area Oscillation Monitoring in Power Systems Using Inter-Regional PMU–PDC Architectures

Abstract—In this paper, we present a set of distributed algo-rithms for estimating the electro-mechanical oscillation modes of large power system networks using Synchrophasors. With the number of Phasor Measurement Units (PMUs) in the North American grid scaling up to thousands, system operators are gradually inclining towards distributed cyber-physical architec-tures for executing wide-area monitoring and control operations. Traditional centralized approaches, in fact, are anticipated to become untenable soon due to various factors such as data volume, security, communication overhead, and failure to adhere to real-time deadlines. To address this challenge, we propose three different communication and computational architectures by which estimators located at the control centers of various util-ity companies can run local optimization algorithms using local PMU data, and thereafter communicate with other estimators to reach a global solution. Both synchronous and asynchronous communications are considered. Each architecture integrates a centralized Prony-based algorithm with several variants of Al-ternating Direction Method of Multipliers (ADMM). We discuss the relative advantages and bottlenecks of each architecture using simulations of IEEE 68-bus and IEEE 145-bus power system as well as an Exo-GENI-based software defined network. Index Terms—Distributed optimization, Prony, phasor mea