Strategies and limitations for the detection of sub-synchronous oscillations in power systems

Sub-synchronous oscillations pose a significant challenge in modern power systems, particularly in networks with high penetration of power electronic converters. While phasor measurement units (PMUs) are generally used for grid monitoring, their ability to detect sub-synchronous oscillations is being challenged. This paper discusses PMU limitations in measuring sub-synchronous oscillations, introducing a novel algorithm to detect their occurrence by leveraging PMU phasor data and rate of-change-of-frequency analysis to trigger high-resolution voltage waveform recordings. This approach enables direct comparison between PMU-reported events and raw waveform data, which paves the way to analysing discrepancies and limitations in PMU based detection. Key words. Measurement techniques, power grids, phasor measurement units, oscillations, power quality.