Travelling Wave Based Velocity-Free Single-Ended Fault Location Method for Transmission Lines

Travelling wave based fault location methods are promising to accurately determine fault location in transmission lines. The velocity of travelling wave could be inaccurate, due to various operating conditions, weather conditions and transmission line types. The errors of travelling wave velocity will propagate to the fault location results. To overcome this challenge, this paper proposes a velocity-free single-ended fault location method based on travelling waves, by fully investigating the redundant information within the subsequent arrival times of travelling waves. First, with different system and fault conditions, the possible paths of travelling waves are classified into 9 different scenarios. Next, with the polarities and arrival times of subsequent wavefronts, the fault scenario is identified and the fault location is determined. Simulation results show that, with local end instantaneous measurements, the proposed method demonstrates robustness against wave velocity errors compared to existing single-ended and double-ended travelling waved based approaches. The proposed method works for both overhead transmission lines and underground cables.