Impact of Inverter-Based Resources on Different Implementation Methods for Distance Relays—Part I: Phase Comparators

Unconventional fault currents of inverter-based resources (IBRs) can adversely impact distance relays. Despite extensive investigation in the literature, the available studies on this topic mostly suffer from three main shortcomings: (i) they consider only the apparent-impedance-based implementation method of distance protection and do not cover the methods used by relay manufacturers to realize the distance element, (ii) they focus on only the relays that protect the direct tie-lines of IBRs, severely limiting the benefits of these studies for future IBR-centric grids, and (iii) they do not consider the requirements of recent grid codes and standards for the low-voltage ride-through current of IBRs. This article addresses these three shortcomings. Part I of this article is on distance relays that use phase comparators.