Practical issues of fault location at extra-high voltage overhead transmission lines using RTDS-based synchrophasor measurements

Application of Phasor Measurement Unit (PMU) is a modern technology in electric power systems with quite a few possible applications. Remote identification of fault location (FL) at extra-high voltage transmission lines is one of the possible applications of PMU. The number of research works dedicated to this issue is rather limited. Also, there is no in-depth analysis of the PMU digital filter performance in case of short circuit; some factors that affect the FL accuracy are not covered; and the number of methods to identify FL remotely is insufficient. The current research goal is to study all the above-mentioned issues. The research has been conducted using the methods of mathematical modeling of fault-initiated transients represented with a real-time digital simulator RTDS (including the RSCAD software). A total of 16 FL expressions both in Russian and foreign scientific papers have been analyzed. Monte-Carlo method has been used to assess the impact of various factors on the FL accuracy. The PMU functionality presented in the RTDS simulator has been used to obtain required synchrophasors. A typical timespan of faults at extra-high voltage transmission lines has been deduced (it turns out to be at least three cycles of the fundamental frequency component). Dynamic characteristics of both M and P class PMUs have been thoroughly examined. The authors have made a conclusion that PMU-based FL is as accurate as that provided by conventional FL units. The influence of some major factors on the FL results has been investigated as well. PMU-based FL is considered to be a promising application. At the same time, P filter class PMUs are primarily used. One is to avoid getting synchrophasor data of different class PMUs at the line terminals. The obtained results are meant to be introduced to improve the PMU-based FL accuracy, especially in the context of processing real PMU data.