01705nas a2200217 4500008003900000022001400039245008300053210006900136260001200205300001100217520101800228653001301246653000901259653001001268653001701278653003601295100001701331700002601348700003801374856007501412 2014 d a0885-895000aTwo-Level Ambient Oscillation Modal Estimation From Synchrophasor Measurements0 aTwoLevel Ambient Oscillation Modal Estimation From Synchrophasor c12/2014 a1 - 103 aThis paper proposes a decentralized two-level structure for real-time modal estimation of large power systems using ambient synchrophasor data. It introduces two distributed algorithms that fit the structure well, namely, 1) decentralized frequency domain decomposition and 2) decentralized recursive stochastic subspace identification. As opposed to present-day oscillation monitoring methodologies, the bulk of the algorithmic computations is done locally at the substation level in the two-level framework. Substation modal estimates are sent to the control center where they are grouped, analyzed, and combined to extract system modal properties of local and inter-area modes. The framework and the proposed algorithms provide a scalable methodology for handling oscillation monitoring from a large number of substations efficiently. The two-level structure and the two decentralized algorithms are tested using simulated data from standard test systems and from archived real power system synchrophasor data.10aAA13-00410aAARD10aCERTS10aoscillations10aphasor measurement units (PMUs)1 aNing, Jiawei1 aSarmadi, Arash, Nezam1 aVenkatasubramanian, Vaithianathan uhttps://certs.lbl.gov/publications/two-level-ambient-oscillation-modal