Synchrophasors-Based Identification for Subsynchronous Oscillations in Power Systems

An Interharmonic Phasor and Frequency Estimator for Subsynchronous Oscillation Identification and Monitoring

“…However, these instruments cannot obtain interharmonic parameter estimates. In China, PMU is also expected to play an important role in SSO identification and monitoring, i.e., measuring interharmonics within [10,40] and [60,90] Hz [8]. This is because most interharmonics caused by SSOs have frequencies within these two bands [9].…”

“…This is because most interharmonics caused by SSOs have frequencies within these two bands [9]. Concerning SSO identification and monitoring, the key is to obtain sub-and supersynchronous interharmonic phasors and frequencies for mitigation equipment operation [10]. The goal of this paper is to propose an interharmonic phasor and frequency estimator with high accuracy, low computational complexity (thus high reporting rate) and short latency.…”

“…There are two kinds of sub-/supersynchronous interharmonic parameter estimation methods in literature: 1) fundamental phasor estimates-based methods and 2) signal field data-based methods. As for 1), two typical methods were proposed in [9] and [10] to identify SSOs. Nevertheless, they have an extremely long latency due to the long observation window, which reaches 1 s. [6] proposed a method to estimate SSO frequencies based on the fundamental phasor estimates.…”

“…The fast-TFM needs to precompute interharmonic and harmonic model frequencies based on the zero-padding DFT. When there are several components within [10,90] Hz, the sub-or supersynchronous interharmonic model frequencies cannot be selected accurately due to the mutual interferences. This incorrect signal model will lead to large errors.…”

A Robust Online Identification of Sustained Low Frequency Oscillation in Steady‐State Power Systems

“…Contrarily, when o =0.5Hz from t=20s to t=40s, the red dashed lines show much slower convergence speed even unstability. These facts reveal that the algorithm equipped with the frequency estimator of [15] possesses the contradiction between fast transient speed for higher frequency and steady-state convergence property for low frequency.…”