Assembly and method for damping contact bounce in high-voltage circuit breakers

Abstract

An assembly and a method for damping contact bounce in high-voltage circuit breakers include a vacuum interrupter and a holder for the vacuum interrupter. The vacuum interrupter includes a housing, at least one movable contact piece and at least one fixed contact piece. At least one mass body is mechanically connected to the at least one fixed contact piece in order to effect damping of the contact bounce between the at least one fixed contact piece and the at least one movable contact piece during a switch-on operation of the high-voltage circuit breaker.

Claims

1. An assembly for a high-voltage circuit breaker, the assembly comprising: a vacuum interrupter including a housing, at least one movable contact piece and at least one fixed contact piece; a holder for said vacuum interrupter, said holder having a tubular shape and an intermediate floor; a connecting element guiding said fixed contact piece through said intermediate floor; and at least one mass body mechanically connected to said at least one fixed contact piece to effect damping of contact bounce between said at least one fixed contact piece and said at least one movable contact piece during a switch-on operation of the high-voltage circuit breaker.

2. The assembly according to claim 1, wherein said at least one mass body is mechanically connected to or disposed in said holder.

3. The assembly according to claim 1, wherein said vacuum interrupter is suspended from said holder.

4. An assembly for a high-voltage circuit breaker, the assembly comprising: a vacuum interrupter including a housing, at least one movable contact piece and at least one fixed contact piece; a holder for said vacuum interrupter, said holder having a tubular shape and an intermediate floor; and at least one mass body mechanically connected to said at least one fixed contact piece to effect damping of contact bounce between said at least one fixed contact piece and said at least one movable contact piece during a switch-on operation of the high-voltage circuit breaker, said at least one mass body being mounted on said intermediate floor.

5. The assembly according to claim 1, wherein said at least one fixed contact piece and said at least one mass body have identical masses.

6. The assembly according to claim 1, which further comprises at least one damping element disposed between said holder and said at least one mass body.

7. The assembly according to claim 6, wherein said at least one damping element is at least one of a spring or a hydraulic damper.

8. An assembly for a high-voltage circuit breaker, the assembly comprising: a vacuum interrupter including a housing, at least one movable contact piece and at least one fixed contact piece; a holder for said vacuum interrupter; at least one mass body mechanically connected to said at least one fixed contact piece to effect damping of contact bounce between said at least one fixed contact piece and said at least one movable contact piece during a switch-on operation of the high-voltage circuit breaker; and at least one guide for at least one of guiding a movement of said at least one mass body or spatially fixing said at least one mass body along a longitudinal axis.

9. The assembly according to claim 8, wherein said at least one guide is fastened to said holder.

10. The assembly according to claim 1, wherein said at least one mass body is at least one of solid or formed in one piece or cylindrical.

11. The assembly according to claim 1, wherein said at least one mass body has a weight in a range of several kilograms.

12. The assembly according to claim 1, wherein said at least one mass body is composed of a metal or includes a metal.

13. The assembly according to claim 1, wherein said at least one mass body is composed of steel, lead or copper or includes alloys of steel, lead or copper.

14. A method for damping contact bounce in high-voltage circuit breakers, the method comprising the following steps: providing an assembly including a vacuum interrupter having a housing, at least one movable contact piece and at least one fixed contact piece, and at least one mass body mechanically connected to the at least one fixed contact piece; providing a holder for the vacuum interrupter, the holder having a tubular shape and an intermediate floor; using a connecting element to guide the fixed contact piece through the intermediate floor; moving the at least one movable contact piece when switching on the vacuum interrupter, causing the at least one movable contact piece to strike the at least one fixed contact piece with a pulse; and transmitting the pulse to the at least one mass body, causing a contact bounce to be partially or completely damped.

15. The method according to claim 14, which further comprises damping the contact bounce with an aperiodic limiting case.

16. The method according to claim 14, which further comprises using a damping element to damp a movement of the at least one mass body in a direction of the at least one fixed contact piece.

17. The method according to claim 16, which further comprises fastening the damping element to a holder of the vacuum interrupter.

18. The method according to claim 14, which further comprises using a movement of the at least one mass body to effect complete absorption of the pulse which is transmitted when the vacuum interrupter is switched on and the at least one movable contact piece strikes the at least one fixed contact piece.

19. The method according to claim 18, which further comprises selecting a mass of the at least one mass body to be in a region of a mass of the at least one fixed contact piece.

20. A method for damping contact bounce in high-voltage circuit breakers, the method comprising the following steps: providing an assembly including a vacuum interrupter having a housing, at least one movable contact piece and at least one fixed contact piece, and at least one mass body mechanically connected to the at least one fixed contact piece; providing a holder for the vacuum interrupter, the holder having a tubular shape and an intermediate floor; mounting the at least one mass body on the intermediate floor; moving the at least one movable contact piece when switching on the vacuum interrupter, causing the at least one movable contact piece to strike the at least one fixed contact piece with a pulse; and transmitting the pulse to the at least one mass body, causing a contact bounce to be partially or completely damped.

21. A method for damping contact bounce in high-voltage circuit breakers, the method comprising the following steps: providing an assembly including a vacuum interrupter having a housing, at least one movable contact piece and at least one fixed contact piece, at least one mass body mechanically connected to the at least one fixed contact piece, and a holder for the vacuum interrupter; using at least one guide for at least one of guiding a movement of the at least one mass body or spatially fixing the at least one mass body along a longitudinal axis; moving the at least one movable contact piece when switching on the vacuum interrupter, causing the at least one movable contact piece to strike the at least one fixed contact piece with a pulse; and transmitting the pulse to the at least one mass body, causing a contact bounce to be partially or completely damped.

Description

BRIEF DESCRIPTION OF THE SINGLE VIEW OF THE DRAWING

(1) The FIGURE schematically shows a sectional view through an assembly 1 according to the invention for a high-voltage circuit breaker, having a vacuum interrupter 18 and having a mass body 12 which effects damping of contact bounce between a fixed contact piece 4 and a movable contact piece 3 of the vacuum interrupter 18 during a switch-on operation.

DETAILED DESCRIPTION OF THE INVENTION

(2) FIG. 1 schematically illustrates a sectional view through an assembly 1 according to the invention for a high-voltage circuit breaker. The assembly 1 according to the invention comprises a vacuum interrupter 18 and a holder 10 for the vacuum interrupter 18 and also a mass body 12. The vacuum interrupter 18 has a housing 2, at least one movable contact piece 3 and at least one fixed contact piece 4. The vacuum interrupter 18 is fastened to the holder 10, in particular suspended so as to point away from the holder 10 in the downward direction, on the side of the fixed contact piece 4. The mass body 12 is arranged in the holder 10 and is in mechanical contact, in particular in direct mechanical contact, with the fixed contact piece 4.

(3) The housing 2 of the vacuum interrupter 18 comprises two hollow-cylindrical, that is to say tubular, ceramic parts 8 which are connected to one another by means of a hollow-cylindrical, that is to say tubular, metal part 9. The housing parts can be connected, for example, by soldering, welding and/or adhesive bonding. The ceramic parts 8 and the metal part 9 have substantially the same diameter, wherein the metal part 9 comprises, at its ends, bent annular shields 7, in each case extended into the inner diameter of the ceramic parts 8. At the upper and the lower end of the vacuum interrupter 18, the ceramic parts 8 are each sealed in a vacuum-tight manner by means of closure caps 15, for example composed of circular or hat-like sheet metal. The closure caps 15 each have annular shields 7 which are bent at the outer circumference of said closure caps and which point into the inner diameter of the ceramic parts 8 and are arranged opposite the shields 7 of the metal part 9. The shields 7 and the metal part 9 shield electromagnetic fields of the contact pieces 3, 4 to the outside and protect the ceramic parts 8 against particles which are created, for example, by arcs between the contact pieces 3, 4 during switching or due to erosion of the contact pieces 3, 4.

(4) The movable contact piece 3 is guided in a vacuum-tight manner by means of a folding bellows 5 in a movable manner through the lower closure cap 15 of the housing 2 of the vacuum interrupter 18. The movable contact piece 3 can be moved during switching, that is to say can be moved in a manner accelerated in the direction of the fixed contact piece 4 during switch-on and can be moved in a manner accelerated away from the fixed contact piece 4 during switch-off, in particular by means of a switching rod 6 and further elements, not shown in the FIGURE for reasons of simplicity, of the kinematic chain. The kinetic energy for the movement is provided, for example, by a drive, in particular a stored-energy spring drive. Movements with large forces, large accelerations and a large pulse for switching times in the millisecond range can therefore be generated and transmitted to the movable contact piece 3.

(5) In the upper region of the vacuum interrupter 18, the fixed contact piece 4 is connected to the upper closure cap 15 by way of a connecting element 11 with mechanical stability and guided through the upper closure cap 15 of the housing 2 of the vacuum interrupter 18 in a vacuum-tight manner. The closure caps 15 are, for example, composed of a metal sheet, in particular a steel sheet, which has, for example, a thickness in the region of a few millimeters or less. In the event of movements of the fixed contact piece 4, wherein fixed is used in the sense of fixed in a mechanically stable manner or fastened to the closure cap 15 in the following, the metal sheet of the closure cap 15 can be bent, as a result of which the fixed contact piece 4 moves to a slight extent. Analogously to a spring, a restoring force acts in such a way that the metal sheet deforms back to its initial shape, as a result of which the fixed contact piece 4 moves back. Movements of the contact pieces 3 and 4 take place substantially along a center axis 16 of the assembly 1 or of the vacuum interrupter 18. As an alternative, the metal sheet of the closure cap 15 can be of mechanically stable, rigid design, wherein the fixed contact piece 4 is connected to the closure cap 15 in a non-movable manner, in particular by means of the connecting element 11. Pulse transmission from the fixed contact piece 4 to the mass body 12 is then performed without a movement of the fixed contact piece 4, in particular by means of the connecting element 11 on the movably mounted mass body 12, in particular without a spring action of the closure cap 15 or without bending of the closure cap 15.

(6) The holder 10, on/to which the vacuum interrupter 18 is arranged and/or fastened, that is to say is suspended as in the exemplary embodiment of the FIGURE for example, is of cylindrical design, in particular in the form of a hollow tube with an intermediate floor 17 in the interior of the holder 10. The holder 10 can be designed, for example, analogously to a hat with a brim, wherein the vacuum interrupter 18 is fastened in a mechanically stable manner to the brim in particular. The fixed contact piece 4 comprises a connecting element 11 which is of, for example, cylindrical or bolt-like design. The connecting element 11 is fastened, for example welded or soldered, in a vacuum-tight manner to the upper closure cap 15 of the vacuum interrupter 18 in a mechanically stable manner, and runs through the, in particular metal sheet-like, upper closure cap 15. A plate-like electrical contact piece 4 or an electrode is formed at one end of the connecting element 11 in the interior of the vacuum interrupter 18. A plate-like electrical contact piece 3 or a second electrode is formed at one end, for example, of an electrically conductive switching rod 6, which is comprised by the movable contact piece 3, parallel and opposite to said plate-like electrical contact piece 4 or electrode in the interior of the vacuum interrupter 18.

(7) Outside the vacuum interrupter 18, the mass body 12 is arranged so as to be, in particular, in direct mechanical contact with the connecting element 11 at the other end of the connecting element 11. The connecting element 11 is guided in a movable manner through an opening in the intermediate floor 17, in particular a round opening, and can be held, for example, by lateral union nuts above the opening. The mass body 12 is arranged above the connecting element 11, at its end on the intermediate floor 17 of the holder 10, in the interior of the, in particular tubular, holder 10. The mass body 12 is, in particular, of cylindrical or hat-like design, for example is designed in an interlocking manner with the inner diameter of the holder 10, and rests in a mechanically stable manner, in particular owing to its weight force, on the end of the connecting element 11 and the intermediate floor 17.

(8) At least one guide 14 is, in particular laterally, arranged on the mass body 12, for example in the form of a bolt which is anchored, in particular screwed or welded, in the intermediate floor 17 and which is guided through the mass body 12 through a bore. A plurality of, in particular three, guides 14 can be arranged at regular distances from one another, for example, in the region of the outer periphery of the mass body 12 in order to prevent jamming during movements of the mass body 12. In particular, at least one damping element is laterally arranged on the mass body 12, for example in the form of a hydraulic damper which is anchored, in particular screwed or welded, in the intermediate base 17 and which acts from below, in particular, on a brim of the mass body 12 and/or is mechanically connected, for example screwed or welded, to the mass body 12. A plurality of, in particular three, dampers 13 can be arranged at regular distances from one another, in particular offset in relation to the guides 14, for example, in the region of the outer periphery of the mass body 12 in order to render possible uniform damping of the movement of the mass body 12 in the direction of the intermediate floor 17.

(9) When the high-voltage circuit breaker, that is to say the vacuum interrupter 18, is switched on, the movable contact piece 3 is moved in the direction of the fixed contact piece 4 until the gap between the two contact pieces 3 and 4 is closed and the movable contact piece 3 is in mechanical and electrical contact with the fixed contact piece 4. The movable contact piece 3 moves along the center axis 16, in particular in a sharply accelerated manner at the start and at high speeds in order to render possible switching in the millisecond range. During switch-on at a high-speed, the movable contact piece 3 hits the fixed contact piece 4 and transmits a large pulse onto the fixed contact piece 4. As a result, the fixed contact piece 4 which is fixedly fastened to the upper closure cap 15 of the vacuum interrupter 18 is moved. The movement takes place away from the moved contact piece 3 along the center axis 16, wherein the metal sheet of the upper closure cap 15 curves outward. The pulse of the fixed contact piece 4 is transmitted to the mass body 12, that is to say the mass body 12 is moved away from the movable contact piece 3 along the center axis 16 together with the fixed contact piece 4. In the process, the guide 14 secures the movement of the mass body 12 along the center axis 16.

(10) A restoring force by the upper closure cap 15, which acts analogously to a leaf spring, leads to a movement of the fixed contact piece 4 back in the direction of the movable contact piece 3. As an alternative or in addition, the weight force of the mass body 12 can lead to a movement of the fixed contact piece 4 back in the direction of the movable contact piece 3. In this case, the pulse from the movable contact piece 3, in a manner transmitted to the fixed contact piece 4 and further to the mass body 12, is absorbed by the mass body 12 and a return movement of the mass body 12 and of the fixed contact piece 4 in the direction of the movable contact piece 3 takes place in manner braked by the damping element or elements 13. The movement of the fixed contact piece 4 in comparison to the initial movement of the movable contact piece 3 is small and takes place over a small distance, for example in the region of millimeters, until the fixed contact piece 4 is in mechanical and electrical contact with the movable contact piece 3. Owing to the small travel or distance, the slow, braked movement of the fixed contact piece 4 in the direction of the movable contact piece 3 does not cause a great switching delay or long arc burning. The movement takes place only briefly owing to the small travel. Large pulse transmission and movement of the movable contact piece 3 by the moved-back fixed contact piece 4 substantially does not take place owing to the pulse absorption by the mass body 12 and, in particular, owing to the braked return movement of the fixed contact piece 4 by the damping elements 13.

(11) The movable contact piece 3 is held in its contact position with the fixed contact piece 4 and pressed against the fixed contact piece 4, for example, by a spring which is not illustrated in the FIGURE for reasons of simplicity. The fixed contact piece 4 is held in its contact position with the movable contact piece 3 and pressed against the movable contact piece 3 by the restoring force of the upper closure cap 15 and/or the weight force of the mass body 12. As a result, good mechanical and electrical contact of the movable contact piece 3 with the fixed contact piece 4 is provided in the switched-on state of the high-voltage circuit breaker, that is to say the vacuum interrupter 18. Contact bounce with the contact pieces 3, 4 mutually bouncing against one another several times and with pulse transmissions to one another does not take place since, after the said contact pieces first bounce against one another and pulse transmission takes place from the movable contact piece 3 to the rebounding fixed contact piece 4, the pulse of the movement is absorbed by the mass body 12 and is transmitted, in particular, to the damping elements 13.

(12) As a result, a long burning period of an arc between the contact pieces 3 and 4 is avoided during switch-on, and there is little erosion of the contact pieces 3 and 4, this being associated with little wear of the contact pieces 3 and 4, and welding of the contact pieces 3 and 4 can be avoided. The service life of the contact pieces 3 and 4 and therefore of the high-voltage circuit breaker, that is to say of the vacuum interrupter 18, is increased and functioning with long-term stability is ensured. Complicated, costly optimization of the drive and/or of the kinematic chain for preventing or minimizing contact bounce is not necessary since simple and cost-effective optimization can be performed by the mass body 12. In particular, a mass body 12 with substantially the same mass as the mass of the fixed contact piece 4 and/or movable contact piece 3 can provide optimum absorption of the pulse of the switch-on movement with minimal contact bounce and/or a minimal arc burning period.

(13) The above-described exemplary embodiments can be combined with one another and/or can be combined with the prior art. Therefore, for example, springs can be used instead of hydraulic damping elements 13, which springs produce, for example, a contact pressure by the fixed contact piece 3 on the movable contact piece 4 in the switched-on state. The mass body 12, elements of the holder 10 and/or shields 7 and/or the metal part 9 and also the folding bellows 5, the closure cap 15, the connecting element 11, the switching rod 6 and the movable and/or fixed contact piece 3, 4, can be composed of steel and/or copper for example. The opposite surfaces of the contact pieces 3, 4, that is to say the contact areas, can be coated against erosion and/or can be slotted in order to push an arc through electrical fields outward in a targeted manner and to extinguish said arc. The fixed contact piece 4 can be movably mounted in the upper closure cap 15 by means of a folding bellows, wherein a restoring force in the direction of the movable contact piece 3 is not generated by a spring action of the closure cap 15, but rather, for example, by the weight of the mass body 12 and/or, for example, springs as damping elements 13.

LIST OF REFERENCE SYMBOLS

(14) 1 Assembly having a vacuum interrupter

(15) 2 Housing

(16) 3 Movable contact piece

(17) 4 Fixed contact piece

(18) 5 Folding bellows

(19) 6 Switching rod

(20) 7 Shield

(21) 8 Ceramic part

(22) 9 Metal part

(23) 10 Holder

(24) 11 Connecting element, in particular bolt

(25) 12 Mass body

(26) 13 Damping element

(27) 14 Guide

(28) 15 Closure cap

(29) 16 Center axis

(30) 17 Intermediate floor

(31) 18 Vacuum interrupter