Characteristics analysis of traveling wave for boundary protection in distribution system

摘要

Since there is no significant difference in the transient component spectral energy between the internal and external faults in a distribution line, it is difficult to apply the boundary protection theory in the single-ended protection of a distribution line. Based on the analysis of the traveling wave of internal and external faults in the distribution line by the grid method, we propose a new method by connecting band-pass filters at line boundaries in parallel to strengthen the difference of transient voltage spectrum energy between internal and external faults. The results of PSCAD/EMTDC simulation and physical test prove that when external faults happen, great attenuation occurs after the traveling wave in passband goes through the band-pass filter. But for internal faults, the traveling wave just suffers little attenuation since it does not go through the band-pass filter, thus the difference of transient voltage spectrum energy in the frequency band between internal and external faults is obvious. This method can distinguish internal and external faults, and provides an effective theoretical basis and solutions for distribution line single-ended boundary protection. (c) 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.