Detecting the ground return which flows to the earthing conductor, due to the earth entry

摘要

PROBLEM TO BE SOLVED: To provide a method for confirming ground-closing of a grounding device and a ground-closing confirmation device which allow reliable and easy confirmation of the grounding state of a system circuit both during operation and shutdown.;SOLUTION: A ground current flowing through a ground wire in response to a contact closing in a grounding device is detected to confirm the ground- closing state. When a contact in the grounding device is closed for its own circuit which is in a shutdown state among a multiple circuits in a power transmission and distribution system, an induction current flowing into the ground wire of its own circuit from an adjacent operating circuit or a charging current flowing through the ground wire of its own circuit is detected to confirm the ground-closing state. Additionally, a low-frequency or high-frequency monitor signal is injected into the ground wire, and the signal is detected to confirm the ground-closing state.;COPYRIGHT: (C)2003,JPO