| 摘要 |
PROBLEM TO BE SOLVED: To provide a neutral grounding resistor (NGR) automatic insertion system that can automatically insert an NGR into a system with which the NGR is not connected.SOLUTION: An NGR automatic insertion system is configured to comprise: an A transformer 2 and a B transformer 7 installed on an A-system power transmission line 1 and a B-system power transmission line 6, respectively; an NGR 3 and an NGR 9 comprised in the A transformer 2 and the B transformer 7, respectively; a route transformer 20 for circumventing between the A-system power transmission line 1 and the B-system power transmission line 6; a zero phase current circuit breaker 8 for breaking/connecting zero-phase current flowing in the NGR 9; and an NGR control device 16 which controls braking/connecting of the zero-phase current circuit breaker 8 on the basis of an OVG relay 15 operated by overvoltage generated when the B transformer 7 looses balance and a DG relay 13 comprised in an electromagnetic induction object power transmission line 12 to which a communication line is disposed closely if blackout has occurred to an alternative route connecting between the A-system power transmission line 1 and the B-system power transmission line 6, and a ground fault accident has occurred to another power transmission line 14 connected with the B-system power transmission line 6 during the blackout. |
