| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily and efficiently specify fault points present in a complicate multi-branch cable line, such as a branch cable line which branches further from a branch line. SOLUTION: A d.c. high voltage is impressed by a charging device 11 to the main line 1 and the first-the fifth branch lines 16-20 and discharged at a fault pointβ. A surge current generated as a consequence of this is detected by sensors (1)-(7), and arrival times are obtained. Calculation for obtaining the fault pointβis conducted on the basis of measured values of the sensor (4) of the earliest arrival time and the sensor (5) of the second earliest arrival time. The calculated value represents a branch part 21. The fault pointβis calculated, on the basis of measured values of the sensor (3) set to an end part of a part, branched from the branch part 21 and the sensor (4).</p> |
