Mode shape estimation algorithms under ambient conditions: A comparative review

TitleMode shape estimation algorithms under ambient conditions: A comparative review
Publication TypeJournal Article
Year of Publication2013
AuthorsLuke Dosiek, Ning Zhou, John W Pierre, Zhenyu Huang, Dan Trudnowski
JournalIEEE Transactions on Power Systems
Pagination779 - 787
Date Published05/2013
KeywordsAA07-001, AARD, Automatic Switchable Network (ASN), phasor measurement units (PMUs), power systems

This paper provides a comparative review of five existing ambient electromechanical mode shape estimation algorithms, i.e., the Transfer Function (TF), Spectral, Frequency Domain Decomposition (FDD), Channel Matching, and Subspace Methods. It is also shown that the TF Method is a general approach to estimating mode shape and that the Spectral, FDD, and Channel Matching Methods are actually special cases of it. Additionally, some of the variations of the Subspace Method are reviewed and the Numerical algorithm for Subspace State Space System IDentification (N4SID) is implemented. The five algorithms are then compared using data simulated from a 17-machine model of the Western Electricity Coordinating Council (WECC) under ambient conditions with both low and high damping, as well as during the case where ambient data is disrupted by an oscillatory ringdown. The performance of the algorithms is compared using the statistics from Monte Carlo simulations and results from measured WECC data, and a discussion of the practical issues surrounding their implementation, including cases where power system probing is an option, is provided. The paper concludes with some recommendations as to the appropriate use of the various techniques.

Short TitleIEEE Trans. Power Syst.