| 摘要 |
PROBLEM TO BE SOLVED: To automatically prohibit turning-on of a switch for a loop point for communication between distribution lines by a change in the loop point if excessive transition current may flow. SOLUTION: A controller 6 of a switch 5 for an existing loop point is provided with a means of computing a potential difference between distribution lines 2, 4 based on the measured result of voltage of the distribution lines 2, 4 by inputting an turning-on command, a means of setting the impedance of all of the distribution lines 2, 4 as loop impedance and storing the set impedance, a means of computing and estimating transition current which flows through between the distribution lines 2, 4 when the switch 5 for the existing loop point is turned on based on the potential difference and the loop impedance before being turned-on, and a means of prohibiting the switch 5 for the existing loop point from being turned on if the transition current exceeds set allowable current. |
