IEC TR 61850-90-21:2025

IEC TR 61850-90-21:2025, which is a Technical Report, aims to provide background information, use cases, data models and guidance on the application of such a technique. This document will 1) describe the principles of fault location based on travelling waves aided by communications; 2) specify use cases for this method under the following application scenarios: a) Single-ended fault location, b) Double-ended fault location through communications between two devices, c) Double-ended fault location with communications to a master station, d) Wide area fault location applications, e) Pulse radar echo method, f) Substation integration with other fault location and disturbance recording functions, g) Testing and calibration; 3) describe the information model for each use case; 4) give guidance on scheme configuration.