Optimization of the double-ended traveling wave fault location model for transmission lines based on the integrated device of dynamic capacity expansion and traveling wave location

Abstract Although conventional traveling-wave fault location devices can detect fault points, their positioning accuracy degrades under complex operating conditions due to sag effects, dynamic line parameter variations, and environmental interference, failing to meet the requirements of high-reliability power grids. Concurrently, existing dynamic capacity expansion devices primarily focus on real-time monitoring of conductor temperature, current-carrying capacity, and environmental param but lack precise fault location functionality. To address these challenges, this paper proposes an integrated dynamic capacity expansion and traveling-wave positioning device capable of monitoring conductor temperature, ambient temperature, power-frequency current, and traveling-wave current. For the first time, a temperature-sag-line length coupling correction model is introduced. By real-time monitoring ambient and conductor temperature variations, the dynamic influence of environmental temperature on conductor sag effects is quantified to correct the actual transmission line length, thereby optimizing the double-ended traveling-wave fault location model. Case study results demonstrate that the positioning accuracy for the same fault point is improved to within 200 m, providing theoretical foundations and technological breakthroughs for intelligent operation-maintenance and rapid fault resolution in transmission lines.