This paper discusses the impact of inverter-based resources (IBRs) in traditional digital protection relays applied in the interconnection transmission line between the IBR and bulk power system. Real events involving a photovoltaic (PV) power plant are used to show the behavior of the fault currents, which is different from power systems with synchronous generators, especially for negative- sequence components. The paper discusses how to properly handle this kind of source by presenting modern protective relays features, time-domain functions, and special settings for traditional protection intelligent electronic devices (IEDs).
