| 摘要 |
PURPOSE:To prevent the consumer's power source being installed for each consumer that a substation supplies power from becoming single operation by installing a single operation preventive device in a distribution system. CONSTITUTION:In case that a substation 40 falls into a power failure, this judges whether the first breaker 11 is off or on, and if it is off, this measures the voltage of a distribution system 12, and judges the existence of voltage. When the first breaker 11 is off, if an input breaker 14 too is off, voltage is not applied to the distribution system 12 and it is zero, eve if the first power source 16 is in operation, while if the first power source 16 is in operation and besides an input breaker 14 is on, the distribution system 12 is charged, so it detects the existence of voltage. Accordingly, if it judges that there is voltage, it operates the one-line earth of a single operation preventive device 41, so artificial one-line earth condition continues for a certain time. By this one-line earth condition, the earth detection relay provided for the first power source 16 operates, and turns off the breaker 14. |
