Performance Assessment of Single Ended Fault Locator for Lines Connected with Inverter Based Renewable Resources: Problems and Practical Solutions

Fault location on transmission lines is a critical function in protection relays for accelerating system restoration, minimizing outage durations, and reducing operational and maintenance costs. Conventional single-ended fault location algorithms rely on the assumption that the fault current at the fault point is in phase with the terminal current. However, this assumption becomes invalid in modern grids with high penetration of inverter-based resources (IBRs), such as renewable energy systems, HVDC links, and FACTS devices. IBRs introduce significant phase angle deviations between local and fault-path currents due to converter control strategies and grid code compliance, resulting in severe impedance estimation errors and inaccurate fault location. This paper addresses these challenges by…