Passive resonance DC circuit breaker

Patent metadata

Field	Value
Publication number	US-9640974-B2
Application number	US-201414513939-A
Country	US
Kind code	B2
Filing date	Oct 14, 2014
Priority date	Apr 13, 2012
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

A DC circuit breaker including a pair of arcing contact members for holding an arc, an interaction element, adapted for interacting with the arc in dependence of whether the arc is in a first or second state such that the arc voltage drop in the first state is lower than the drop in the second state, a resonance branch coupled in parallel to the contact members thereby forming a resonance circuit adapted for letting a resonance branch current I r oscillate thereby inducing oscillations of an arc current I a , wherein the resonance branch includes a coupling element for coupling the resonance branch with the arc, such that the arc is brought to the first state when the current I r in the resonance branch has a first direction, and that the arc is brought to the second state when the current I r in the resonance branch has a second direction.

First claim

What is claimed is:

1. A DC circuit breaker comprising:
a pair of arcing contact members for holding an arc;
an interaction element configured to interact with the arc in dependence of whether the arc is in a first state or in a second state such that due to the interaction element the arc voltage drop in the first state is lower than the arc voltage drop in the second state;
a resonance branch coupled in parallel to the contact members, the resonance branch and contact members forming a resonance circuit adapted to enable a resonance branch current to oscillate thereby inducing oscillations of an arc current, the resonance branch including
a coupling element configured to couple the resonance branch with the arc, such that the arc is brought to the first state when the current in the resonance branch has a first direction, and that the arc is brought to the second state when the current in the resonance branch has a second direction, wherein the coupling comprises a force acting on the arc and adjusting the arc between the first state that is further away from the interaction element and the second state that is closer to the interaction element.

2. The DC circuit breaker according to claim 1 , wherein the coupling element is a coil adapted for inducing a magnetic field in a region of the arc for coupling with the arc.

3. The DC circuit breaker according to claim 2 , wherein a coil axis is substantially perpendicular to an axis defined by the contact members.

4. The DC circuit breaker according to claim 1 , wherein the resonance branch further comprises a capacitor.

5. The DC circuit breaker according to claim 1 , wherein the interaction element comprises at least one arc splitting element.

6. The DC circuit breaker according to claim 1 , wherein the interaction element is an ablating element.

7. The DC circuit breaker according to claim 1 , wherein in the first state the arc is located in a first position and in the second state the arc is located in a second position, which is closer to the interaction element than in the first position.

8. The DC circuit breaker according to claim 1 , wherein the arc voltage drop in the first state is less than half of the arc voltage drop in the second state.

9. The DC circuit breaker according to claim 1 , wherein the interaction between the interaction element and the arc includes cooling of the arc.

10. The DC circuit breaker according to claim 1 , wherein due to the interaction element the arc has a first shape in the first state and a second shape, different from the first shape, in the second state, wherein the first shape has a first cross section and/or a first length and the second shape has a second cross section and/or a second length.

11. The DC circuit breaker according to claim 1 , wherein at least one root of the arc moves by at least 1 mm when the arc moves between the first state and the second state.

12. A method for interrupting a DC current, the method including:
forming an arc between a pair of arcing contact members;
inducing current oscillations in a resonance circuit comprising a resonance branch and the arcing contact members;
inducing a magnetic field by a coupling element of the resonance branch, the magnetic field depending on the resonance branch current;
bringing the arc to a first state by the magnetic field when a current in the resonance branch has a first direction;
bringing the arc to a second state by the magnetic field when the current in the resonance branch has a second direction;
interacting by an interaction element with the arc in dependence of whether the arc is in the first state or in a second state such that due to the interaction element the arc voltage drop in the first state is lower than the arc voltage drop in the second state;
wherein the magnetic field is configured to act on the arc and adjust the arc between the first state that is further away from the interaction element and the second state that is closer to the interaction element.

13. The method for interrupting a DC current according to claim 12 , further including: superimposing the resonance branch current on an arc current such that the arc current oscillates due to the oscillations of the resonance branch current.

14. The method for interrupting a DC current according to claim 13 , further including: increasing an amplitude of oscillations so that the arc current becomes zero.

15. The DC circuit breaker according to claim 6 , wherein the ablating element is an ablating wall.

16. The DC circuit breaker according to claim 2 , wherein the coil comprises one of a Helmholtz coil or a pair of Helmholtz coils on both sides of the contact members.

17. The DC circuit breaker according to claim 2 , wherein the coil is wound on top of the contact members.

18. The DC circuit breaker according to claim 5 , wherein the at least one arc splitting element comprises splitter plates arranged parallel to each other and oriented perpendicular to the arc or to an axis defined by the contact members.

19. The method for interrupting a DC current according to claim 12 , wherein the coupling element is a coil adapted to induce the magnetic field in a region of the arc for coupling with the arc.

Assignees

• Abb Schweiz Ag

Inventors

• Abplanalp Markus
• Gati Rudolf

Classifications

• H02H3/087 Primary

  for DC applications · CPC title

• H01H33/6641

  making use of a separate coil · CPC title

• H01H33/08 Primary

  Stationary parts for restricting or subdividing the arc, e.g. barrier plate · CPC title

• H02H1/063

  primary power being supplied by fault current · CPC title

• H01H33/596

  for interrupting DC · CPC title