A Tutorial on Identification of Subsynchronous Mode Frequencies in Power Transmission Systems using Parametric and Non-parametric Methods

The burgeoning utilization of converter-interfaced generation is expanding the range of power system dynamics at both the distribution and transmission levels. The prevalence of inverter controllers leads to the emergence of transient phenomena different from those found in traditional synchronous machine-based grids. The interaction between the complex and faster converter and the traditional plant compensators is increasing the risk of forced power system oscillations. Accurately identifying the frequency of such transient phenomena is essential for executing effective corrective measures and sustaining service. Despite not providing a statistical guarantee on the estimate, power system professionals have widely adopted deterministic methods for mode frequency identification. This paper seeks to bridge the gap between deterministic and stochastic estimation methods by providing a tutorial for applying parametric and non-parametric statistical identification techniques.