Impacts of inverter-based resources on directional elements during asymmetrical faults

The large-scale integration of Inverter-Based Resources (IBRs) significantly alters the fault characteristics of synchronous generator-dominated power systems, posing a challenge to the conventional sequence component-based directional elements in the grid protection system. To reveal the impacts of IBRs on sequence component-based directional elements during asymmetrical faults, this paper first investigates the impacts of various priority modes of current reference generation. Subsequently, the impacts of control dynamics in the cases where the control scheme has not yet reached a steady state are investigated. It is found that the current reference generation and Phase-Locked Loop (PLL) dynamic can adversely affect the performance of directional elements. Electromagnetic transient (EMT) simulations are given to verify the theoretical analysis.