TRANSMISSION LINE FAULT LOCATING DEVICE AND METHOD

PURPOSE:To enable locating accuracy in a surge system to be improved and an application range to be expanded by obtaining an order of surge detection and optical signal detection which differ in propagation speed greatly or the time difference. CONSTITUTION:Surge signal reception/transmission devices 11 are provided on three or more points in a distance which is shorter than both edges of a transmission line. This device 11 allows a trigger pulse e which is output from a signal of an antenna (sensor) for detecting surge voltage 12 by a wave shaping circuit 13 to be subjected to E/O conversion 14 and to be transmitted as optical signal to the left and right adjacent devices which are of the same type as the device 11 by optical fibers 20 and 21. Also, optical signals from these adjacent devices are transmitted to the device 11 by optical fibers 22 and 23, are subjected to O/E conversion 15 and 16, and trigger pulses f and g are output. The time difference of these pulses e and f and the pulses e and g is measured 17 and direction and position of fault are determined by judgment of a comparison locating circuit 18 according to the result. The propagation speed difference between the transmission line and the optical fiber minimizes locating error.