Abstract
The increasing penetration of inverter-based resources (IBRs) is reshaping fault current dynamics in modern power systems, posing new challenges for conventional transmission line protection schemes. One critical factor influencing these dynamics is the use of fault current limiters within IBR control strategies. Among them, dynamic saturation-based and magnitude-based current limiters are the most prevalent, each modifying the fault current behavior in terms of magnitude, sequence components, and phase angle relationships. These alterations can significantly affect the sensitivity, directionality, and reach accuracy of traditional protection elements. This paper presents a comprehensive investigation of two distinct implementations, dynamic saturation-based and magnitude-based current limiters, and evaluates their impacts on directional and distance protection performance. By quantifying changes in symmetrical components and phase angle deviations under fault conditions, the study offers practical insights into the protection coordination and reliability implications in IBR-dominated transmission networks. The findings aim to support the development of more robust and adaptive protection strategies for evolving grid architectures.