Fig. 1
From: Revealing interactions between HVDC cross-area flows and frequency stability with explainable AI
a Indicators of frequency stability in hourly resolution. The RoCoF is the slope of the frequency at the beginning of the hour while the Nadir is the largest frequency deviation within 1 hour. We also considered the Mean Square Deviation (MSD) and the integral for each hourly frequency trajectory. b Map of northern Europe including the HVDC links we considered in this study. The differently colored regions reflect the five synchronous areas adjoining these HVDC connections