An Efficient Travelling Wave based Fault Localization for MTDC Transmission System

This article proposes a low sampling frequency travelling wave-based fault location technique for the MTDC grid. It is based on the matrix pencil method applied on the DC terminal voltage samples in the sliding window moving along the time axis. The sliding matrix pencil method decomposes the voltage signal samples in the sliding window into time-indexed damping factors. In the absence of a travelling wave, the damping factor is zero. But in the presence of a travelling wave, depending on the position of the travelling wave in the sliding window, the damping factor is either positive, negative, or zero. After that linear regression is used to find the zero-crossing point of the time-indexed damping factor, which will help further to calculate the travelling wave arrival time. Finally, first travelling arrival time information from both DC terminal end will help to calculate the estimated DC fault location at the low sampling frequency.