| 摘要 |
<p>PURPOSE:To exactly detect the occurrence position of a grounding accident and the like by forming an excess length part unrelated to the position of a longitudinal direction of a power cable line in a part of a longitudinal direction of an optical fiber. CONSTITUTION:An optical fiber 5 is provided along the whole power cable line 1. In this case, because an excess length parts 51, 52 are formed in a part of the longitudinal direction of the optical fiber, the information of the length of the excess length parts 51, 52 is previously stored in a computer 9 and the other information obtained from the signals through the optical fiber is operated to process in the host computer 9, so a temperature increase peak position, namely, the occurrence position of a grounding accident and the like can be obtained.</p> |
