Grounding circuit, electrical device, grounding control method, and grounding control program

Patent metadata

Field	Value
Publication number	US-10666044-B2
Application number	US-201716303218-A
Country	US
Kind code	B2
Filing date	May 19, 2017
Priority date	May 25, 2016
Publication date	May 26, 2020
Grant date	May 26, 2020

Abstract

[Solution] A grounding circuit equipped with: a first relay contact connected to a device to be grounded; a resistor that is connected between the first relay contact and an earth, and that suppresses current flowing to the first relay contact when the contact of the first relay is closed; and a second relay contact that is connected in parallel with the resistor, and that is closed before the first relay contact is opened when the grounding state of the device to be grounded is released.

First claim

What is claimed is:

1. A grounding circuit comprising:
a contact of a first relay connected to a grounded device;
a resistance being connected between the contact of the first relay and an earth, and suppressing current that flows through the contact of the first relay when the contact of the first relay is closed; and
a contact of a second relay being connected in parallel with the resistance, and closed before the contact of the first relay is opened when the grounded device is un-grounded.

2. The grounding circuit according to claim 1 , wherein,
when the grounded device is un-grounded, in a case where the contact of the second relay is opened, the contact of the second relay is closed before the contact of the first relay is opened.

3. The grounding circuit according to claim 2 , wherein,
when the grounded device is grounded, the contact of the second relay is closed after the contact of the first relay is closed and a current flow to the contact of the first relay calms down.

4. The grounding circuit according to claim 2 , wherein
the grounded device is connected to a terminal with a cable, and, based on a control signal received from the terminal via the cable, opening and closing of the contact of the first relay and the contact of the second relay is controlled.

5. The grounding circuit according to claim 4 , wherein
electric power is supplied to the circuit from the terminal via the cable.

6. The grounding circuit according to claim 5 , wherein
the grounded device relays communication performed via the cables between or among the two or more terminals.

7. An electrical device comprising:
the grounding circuit according to claim 2 ; and
a controller that is configured to open and close the contact of the first relay and the contact of the second relay, based on a received control signal.

8. The grounding circuit according to claim 1 , wherein,
when the grounded device is grounded, the contact of the second relay is closed after the contact of the first relay is closed and a current flow to the contact of the first relay calms down.

9. The grounding circuit according to claim 8 , wherein
the grounded device is connected to a terminal with a cable, and, based on a control signal received from the terminal via the cable, opening and closing of the contact of the first relay and the contact of the second relay is controlled.

10. The grounding circuit according to claim 9 , wherein
electric power is supplied to the circuit from the terminal via the cable.

11. The grounding circuit according to claim 1 , wherein
the grounded device is connected to a terminal with a cable, and, based on a control signal received from the terminal via the cable, opening and closing of the contact of the first relay and the contact of the second relay is controlled.

12. The grounding circuit according to claim 11 , wherein
electric power is supplied to the circuit from the terminal via the cable.

13. The grounding circuit according to claim 4 , wherein
the grounded device relays communication performed via the cables between or among the two or more terminals.

14. The grounding circuit according to claim 11 , wherein
the grounded device includes a sensor, and transmits data measured by the sensor to the terminal via the cable.

15. The grounding circuit according to claim 12 , wherein
the grounded device relays communication performed via the cables between or among the two or more terminals.

16. The grounding circuit according to claim 1 , wherein
the earth is grounded to seawater.

17. The grounding circuit according to claim 1 , wherein
the first relay and the second relay are each a vacuum relay or a gas filled relay.

18. An electrical device comprising:
the grounding circuit according to claim 1 ; and
a controller that is configured to open and close the contact of the first relay and the contact of the second relay, based on a received control signal.

19. A grounding control method comprising:
by using a resistance connected between a contact of a first relay connected to a grounded device and an earth, suppressing current that flows through the contact of the first relay when the contact of the first relay is closed; and
closing a contact of a second relay connected in parallel with the resistance, before the contact of the first relay is opened when the grounded device is un-grounded.

20. A non-transitory storage medium that stores a grounding control program causing a computer to perform:
processing of closing a contact of a first relay connected to a grounded device, while suppressing current that flows through the contact of the first relay by using a resistance connected between the contact of the first relay and an earth; and
processing of closing a contact of a second relay connected in parallel with the resistance, before the contact of the first relay is opened when the grounded device is un-grounded.

Assignees

• Nec Corp

Inventors

• Yamaguchi Shohei

Classifications

• H02G9/02

  laid directly in or on the ground, river-bed or sea-bottom; Coverings therefor, e.g. tile · CPC title

• H04B3/44 Primary

  Arrangements for feeding power to a repeater along the transmission line · CPC title

• H02H9/02 Primary

  responsive to excess current {(current limitation for voltage regulators G05F1/573; disconnection after limiting H02H3/025)} · CPC title