| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a bus line protecting relay system which does not accompany a cost increase resulting from addition of a waveform determining function to a current differential calculating unit, and does not cause a delay in outputting a judgment on an accident. <P>SOLUTION: The bus line protecting relay system 1 protects a bus line B1 that is connected to a plurality of lines L1 to L6 to relay power to be supplied to these lines L1 to L6. The bus line protecting relay system 1 includes photosensors 11a to 11f which detect currents flowing through the lines L1 to L6, respectively, and a relay device 12 which is connected to the photosensors 11a to 11f via optical lines 13a to 13f and judges the presence/absence of an accident related to the bus line B1, using respective detected optical signals indicative of detection results by the photosensors 11a to 11f, to carry out a step for protection of the bus line B1, based on the result of the judgment. <P>COPYRIGHT: (C)2009,JPO&INPIT |
