PROTECTIVE DEVICE FOR GROUNDING CURRENT SUPPRESSING DEVICE AND GROUNDING SUPPRESSING METHOD

摘要

PROBLEM TO BE SOLVED: To make a voltage applied to a grounding current suppressing device smaller, and to manufacture high reliability devices by fitting a connecting means for connecting a single-phase transformer, between specified phase of a power distribution line and the output section of a grounding power suppressing device which outputs a grounding suppressing current. ;SOLUTION: The output side of a power source 2 is connected to bus-bars 3a-3c and connected to distribution lines 4a-4c, 5a-5c. To the distribution lines 4a-4c, a zero- phase sequence current transformer 7a for detecting the zero-phase sequence current I01 of the distribution lines is connected. To the distribution lines 5a-5c, a zero-phase sequence current transformer 7b for detecting a zero-phase sequence current I02 is connected. To the bus-bars 3a-3c, a zero-phase sequence transformer 8 composed of a grounded potential transformer for detecting a zero-phase sequence voltage V0 is connected. A switch corresponding to a grounding phase is closed on the basis of a closing command signal It from a grounding fault detector 10, and an injecting transformer 30 is connected to the grounded phase out of the bus-bars 3a-3c. Consequently, an applied voltage to a grounding current suppressing device can be made small, and to manufacture high reliability devices.;COPYRIGHT: (C)2000,JPO