Inverse current injection-type direct current blocking device and method using vacuum gap switch

Patent metadata

Field	Value
Publication number	US-11049677-B2
Application number	US-201716472718-A
Country	US
Kind code	B2
Filing date	Dec 19, 2017
Priority date	Dec 21, 2016
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

The DC interrupting device includes a main current conduction unit including a main interrupting switch, which is a mechanical switch, a reverse current power supply unit connected to an input terminal of the main current conduction unit and configured to generate a predetermined reverse current, and a reverse current conduction unit configured to supply the reverse current to an output terminal of the main current conduction unit. The reverse current power supply unit includes a first reverse current dedicated capacitor charged by a voltage applied to an input terminal of the main current conduction unit, a polarity reversing inductor configured to reverse a polarity of the first reverse current dedicated capacitor, and a reverse current power supply unit switch configured to perform circuit connection such that the polarity reversing inductor reverses the polarity of the first reverse current dedicated capacitor.

First claim

The invention claimed is:

1. A DC interrupting device comprising:
a main current conduction unit including a main interrupting switch, which is a mechanical switch;
a reverse current power supply unit connected to an input terminal of the main current conduction unit and configured to generate a predetermined reverse current; and
a reverse current conduction unit configured to supply the reverse current to an output terminal of the main current conduction unit,
wherein the reverse current power supply unit comprises:
a first reverse current dedicated capacitor charged by a voltage applied to an input terminal of the main current conduction unit;
a polarity reversing inductor configured to reverse a polarity of the first reverse current dedicated capacitor; and
a reverse current power supply unit switch configured to perform circuit connection such that the polarity reversing inductor reverses the polarity of the first reverse current dedicated capacitor,
wherein the reverse current conduction unit comprises a first conduction unit switch for performing a circuit connection such that the reverse current is supplied to an output terminal of the main current conduction unit after the reverse current power supply unit switch is separated,
wherein the reverse current power supply unit further comprises a second reverse current dedicated capacitor symmetrically connected to the first reverse current dedicated capacitor with respect to the polarity reversing inductor and the reverse current power supply unit switch, and
wherein the reverse current conduction unit further comprises a second conduction unit switch symmetrically connected to the first conduction unit switch with respect to the polarity reversing inductor and the main interrupting switch.

2. The DC interrupting device of claim 1 , wherein the reverse current is a current discharged from the first reverse current dedicated capacitor in a polarity reverse state.

3. The DC interrupting device of claim 2 , wherein the reverse current power supply unit switch and the first conduction unit switch are vacuum gap switches.

4. The DC interrupting device of claim 3 , wherein the reverse current power supply unit switch and the first conduction unit switch are movable gap switches for controlling a current flow by a change in electrical distance between electrodes.

5. The DC interrupting device of claim 4 , wherein the reverse current power supply unit switch and the first conduction unit switch set a connection time interval between the reverse current power supply unit switch and the first conduction unit switch according to a predetermined electrode moving speed and a distance between electrodes.

6. The DC interrupting device of claim 5 , wherein the reverse current power supply unit switch and the first conduction unit switch comprise a fixing part where an electrode is located and a moving part for performing connection and separation between the electrodes,
wherein the reverse current power supply unit switch and the first conduction unit switch are selectively connected according to moving of the moving part.

7. The DC interrupting device of claim 6 , wherein the fixing part and the moving part are connected at least at one contact point.

8. The DC interrupting device of claim 7 , further comprising a surge arrester for limiting a voltage of the first reverse current dedicated capacitor or the second reverse current dedicated capacitor.

9. The DC interrupting device of claim 8 , further comprising a current limiting inductor connected in series with the main interrupting switch between the main current conduction unit and the load input terminal.

10. The DC interrupting device of claim 9 , further comprising a capacitor charging switch in which one of two terminals is connected to each of the reverse current power supply unit and the reverse current conduction unit.

11. The DC interrupting device of claim 10 , further comprising a diode connected between the load input terminal and the terminal of the capacitor charging switch respectively connected to the reverse current power supply unit and the reverse current conduction unit.

12. A DC interrupting method comprising:
by the DC interrupting device of claim 1 ,
when a current flowing in the main current conduction unit corresponds to a predetermined first interruption range, separating the main interrupting switch and reversing the polarity of the first reverse current dedicated capacitor by connecting the reverse current power supply unit switch; and
connecting the first conduction unit switch at a predetermined time point to generate zero in a current flowing in the main interrupting switch and interrupting the current flowing through the main interrupting switch.

13. The method of claim 12 , wherein the predetermined time point is a time point at which after the separation of the main interrupting switch, a gap of the main interrupting switch is set so that the main interrupting switch maintains the insulation from the voltage charged in the first reverse current dedicated capacitor.

14. The method of claim 13 , wherein the reverse current power supply unit further comprises a second reverse current dedicated capacitor symmetrically connected to the first reverse current dedicated capacitor with respect to the polarity reversing inductor and the reverse current power supply unit switch, and the reverse current conduction unit further comprises a second conduction unit switch symmetrically connected to the first conduction unit switch with respect to the polarity reversing inductor and the main current conduction unit switch,
further comprising:
determining a direction of a current flowing in the main current conduction unit before the main interrupting switch is separated;
determining a predetermined first interruption range or second interruption range according to the direction of the current; and
connecting the second conduction unit switch if corresponding to the second interruption range.

15. The method of claim 14 , wherein the DC interrupting device further comprises a capacitor charging switch in which one of two terminals is connected to each of the reverse current power supply unit and the reverse current conduction unit,
further comprising connecting the capacitor charging switch for load current interruption.

Assignees

• Korea Electro Tech Research Institute
• Lsis Co Ltd

Inventors

• Lee Woo Young
• Park Hae Yong
• Lee Gyeong Ho
• Park Sang Hun
• Bae Chae Yoon
• Sim Jung Wook
• Jang Hyun Jae

Classifications

• H01H33/66 Primary

  Vacuum switches · CPC title

• H01H33/596 Primary

  for interrupting DC · CPC title

• H01H33/59

  Circuit arrangements not adapted to a particular application of the switch and not otherwise provided for, e.g. for ensuring operation of the switch at a predetermined point in the AC cycle · CPC title

• H01H2009/546

  the static switching means being triggered by the voltage over the mechanical switch contacts · CPC title

• H02H3/087

  for DC applications · CPC title