Development of Fault Locator for Branch Line

Abstract

Formerly, only pulse radar and the Murray loop bridge could be utilized in a cable fault location method that is applicable to branch lines. Those methods need a terminal connection at the far end. Therefore, it is difficult in fault location involving branch lines. Pulse radar is applicable only for high‐resistance ground faults and the Murray loop bridge is applicable only for low‐resistance ground faults. We have developed current‐detection pulse radar and tested it. In high‐resistance ground fault location, the measured result includes discharge delay error. Therefore, we have proposed an error correction method and confirmed it. In addition, we have designed a new cable fault location method of pulse radar and tested it. © 2000 Scripta Technica, Electr Eng Jpn, 134(2): 19–28, 2001

Analysis of electromagnetic field transient on branch feeders by numerical electromagnetic field computation

“…In addition, advanced instruments are capable of detecting abrupt lightning currents with a rise time on the order of 0.1 µs when lightning strikes a high structure [2], which produces severe working conditions for line protection devices. When failure locators are employed to identify fault points in a power system, the detection of waves reflected from such fault points becomes increasingly difficult in direct proportion to the number of branches [3]. In this technique, pulses are injected into a power system, the waves reflected from a fault point are detected, and the distance to the fault point is calculated from the propagation time; however, the reflected waveforms become complicated because of attenuation and distortion.…”