CN114503235A - Circuit breaker with vacuum arc-extinguishing chamber - Google Patents

Abstract

The invention relates to a circuit breaker (1). The circuit breaker (1) comprises: a vacuum interrupter (3); metallic holding means (5, 7) arranged on opposite sides of the vacuum interrupter (3); a housing with a housing wall (25) body (9), the walls of which are arranged around the outer surface (27 to 29) of the vacuum interrupter (3) and the holding device (5, 7) at a distance from the outer surface (27 to 29); arranged at the plastic jacket (11) on the outer surface (27) of the vacuum interrupter (3) and the partial areas (28.1, 29.1) of the outer surfaces (28, 29) of the two holding devices (5, 7); and the plastic A volume (31) filled with insulating gas (33) between the casing (11) and the housing wall (25).

Description

Circuit breaker with vacuum interrupter

technical field

The invention relates to a circuit breaker with a vacuum interrupter. A vacuum interrupter is understood here to mean an evacuable vacuum tube in which the switching process is carried out.

Background technique

In such a circuit breaker, the switch contact elements movable relative to each other are arranged in a vacuum interrupter to avoid or reduce switching arcs when the switch contact elements are separated. The arc extinguishing chamber is usually arranged in the housing in an insulating gas, which is compressed by high pressure in order to increase its dielectric strength, so that the metal parts can be arranged in the housing at a smaller distance from one another and thus save installation space. .

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide an improved circuit breaker with a vacuum interrupter.

According to the invention, the above-mentioned technical problem is solved by a circuit breaker having the features of claim 1 .

Advantageous refinements of the invention are the subject of the dependent claims.

The circuit breaker according to the present invention includes

- vacuum interrupters,

- a metallic holding device arranged on the opposite side of the vacuum interrupter,

- a housing having a housing wall arranged around the outer surface of the vacuum interrupter and the holding device at a distance from the outer surface,

- a plastic hood, which is arranged on the outer surface of the vacuum interrupter and on parts of the outer surfaces of the two holding devices, and

- A volume filled with insulating gas between the plastic jacket and the housing wall. The housing wall is made, for example, of an electrically insulating material, for example of a ceramic material or of glass fiber-reinforced plastic.

On the one hand, the insulating gas can be saved by means of the plastic jacket, in that the plastic jacket supports the function of the insulating gas. On the other hand, the pressure of the insulating gas can be reduced by means of a plastic jacket with a high dielectric strength, so that a sufficient dielectric strength of the system comprising the plastic jacket and the insulating gas can also be achieved with reduced pressure. Thereby, the use of pressure vessel components in the interrupter unit of the circuit breaker can be dispensed with. In addition, the otherwise necessary gas monitoring can be omitted or significantly simpler, since in the event of a leak and the resulting pressure drop, no immediate functional interruption is required. Additionally, cost advantages are obtained by simplifying or omitting components and assemblies and by omitting expensive component testing. Also, get lower maintenance overhead. Furthermore, an important technical advantage is that the instantaneous switching capability of the circuit breaker is ensured even in the event of a sudden drop in the pressure of the insulating gas.

Correspondingly, in one configuration of the invention, the plastic jacket is made of a plastic with a higher dielectric strength than the insulating gas. The plastic cover is made of silicone, for example.

In another configuration of the invention, the insulating gas is dehumidified air or carbon dioxide. These insulating gases are environmentally harmless, but their insulating effect is lower than, for example, sulfur hexafluoride. Therefore, especially where these insulating gases are used to increase the dielectric strength, a plastic jacket is advantageous.

In a further configuration of the invention, the plastic jacket is a plastic layer which is injection-molded or cast on the outer surface of the vacuum interrupter and a partial region of the outer surface of the holding device. Advantageously, this enables the precise production of plastic boots.

In an alternative design of the aforementioned design of the present invention, the plastic jacket is a plastic sleeve that covers the outer surface of the vacuum interrupter and a partial area of the outer surface of the holding device. This enables the manufacture of the plastic boot without the need for tools for injection moulding or casting the plastic boot.

In another configuration of the invention, the plastic jacket has a varying thickness. As a result, the thickness of the plastic jacket can be adapted to the local requirements for the dielectric strength. For example, the plastic jacket is designed to be thicker in the edge region of the vacuum interrupter or holding device than in other regions.

In a further configuration of the invention, the circuit breaker has at least one field control element, which is arranged between the plastic jacket and a partial region of the outer surface of the vacuum interrupter and/or the outer surface of the holding device. A field control element refers to an element that locally changes the field strength of an electric field. Particularly high local electric field strengths can be advantageously avoided by the field control element.

For example, the at least one field control element is made of a conductive plastic, for example of a silicon elastomer filled with carbon black. Such a field control element can advantageously be produced by injection molding or casting, in particular together with a plastic jacket designed as a plastic layer. Where the plastic housing is designed as a plastic sleeve, the field control element can be integrated into the plastic sleeve.

Furthermore, at least one field control element is preferably arranged on the holding device end of the holding device. As a result, high local electric field strengths in the region of the end of the holding device can advantageously be avoided.

In a further configuration of the invention, the arc-extinguishing chamber end of the vacuum arc-extinguishing chamber protrudes into each holding device. This simplifies, in particular, the manufacture of the plastic jacket in the transition region between the vacuum interrupter and the holding device.

Description of drawings

The features, characteristics and advantages of the invention described above, as well as the manner of their realization, will be more clearly and clearly understood in conjunction with the following description of the embodiments set forth in more detail in conjunction with the accompanying drawings. Here in the attached image:

Figure 1 shows a first embodiment of a circuit breaker,

Figure 2 shows a second embodiment of the circuit breaker.

Parts that correspond to each other are provided with the same reference numerals in the figures.

Detailed ways

FIG. 1 shows a cross-sectional view of a first embodiment of a circuit breaker 1 . The circuit breaker 1 comprises, among other things, a vacuum interrupter 3 , tubular metal holding means 5 , 7 , a housing 9 and a plastic jacket 11 .

The holding devices 5 , 7 are arranged on opposite sides of the vacuum interrupter 3 and in particular serve as a base for the vacuum interrupter 3 . The metallic interrupter ends 13 , 15 of the vacuum interrupter 3 protrude into each holding device 5 , 7 . Arranged on the first holding device 5 is a first switching contact element 17 which projects into the vacuum interrupter 3 through a first interrupter opening in the first interrupter end 13 . A second switching contact element 19 projects into the vacuum interrupter 3 through a second interrupter opening in the second interrupter end 15 , which second switching contact element can be relative to the first interrupter by means not shown. The switch contact element 17 moves. The regions of the vacuum interrupter 3 surrounding the switching contact elements 17 , 19 each have insulating sections 21 , 23 made of an electrically insulating material, for example a ceramic material. The insulating sections 21 , 23 are arranged on opposite sides of the metallic central region of the vacuum interrupter 3 .

The housing 9 comprises a housing wall 25 which is arranged around the outer surfaces 27 to 29 at a distance from the outer surface 27 of the vacuum interrupter 3 and the outer surfaces 28 , 29 of the holding devices 5 , 7 . The housing wall 25 is designed as an insulating tube made of an electrically insulating material, for example of a ceramic material or of fiberglass-reinforced plastic, and arranged between the metal flanges. Therefore, the circuit breaker 1 is designed in a so-called live tank construction (Live Tank-Bauweise), which is different from the so-called dead tank-Bauweise with a grounded metal case.

The plastic jacket 11 is arranged on the outer surface 27 of the vacuum interrupter 3 and on partial regions 28 . 1 , 29 . 1 of the outer surfaces 28 , 29 of the two holding devices 5 , 7 . The volume 31 between the plastic jacket 11 and the housing wall 25 is filled with an insulating gas 33, for example dehumidified air or carbon dioxide.

The plastic jacket 11 is made of plastic having a higher dielectric strength than the insulating gas 33 . The plastic cover 11 is made of silicone, for example.

The plastic shroud 11 has varying thicknesses. For example, the plastic jacket 11 in the transition region from the outer surface 27 of the vacuum interrupter 3 to the partial regions 28 . Thickly designed.

The plastic jacket 11 is, for example, a plastic layer which is injection-molded or cast on the outer surface 27 of the vacuum interrupter 3 and the partial regions 28 . 1 , 29 . 1 of the outer surfaces 28 , 29 of the holding devices 5 , 7 . Alternatively, the plastic jacket 11 is a plastic sleeve that is fitted over the outer surface 27 of the vacuum interrupter 3 and the partial regions 28 . 1 , 29 . 1 of the outer surfaces 28 , 29 of the holding devices 5 , 7 .

FIG. 2 shows a cross-sectional view of a second embodiment of the circuit breaker 1 . This embodiment differs from the embodiment shown in FIG. 1 only by the annular field control elements 35 to 38 : in the case of the field control elements 36 , 37 , the field control elements are arranged between the plastic jacket 11 and the vacuum interrupter. 3 between the outer surfaces 27; in the case of the field control elements 35, 38, the field control elements are arranged between the plastic jacket 11 and the outer surface 27 of the vacuum interrupter 3 and the outer surfaces 28, 29 of the holding devices 5, 7 Part of the area between 28.1 and 29.1.

Here, the first field control element 35 is arranged on the holding device end 5 . 1 of the first holding device 5 facing the vacuum interrupter 3 and the second field control element 36 is arranged on the first insulating section 21 facing away from the first holding device On the end of the device 5 , the third field control element 37 is arranged on the end of the second insulating section 23 facing away from the second holding device 7 , and the fourth field control element 38 is arranged on the second holding device 7 facing the vacuum. On the holding device end 7.1 of the arc-extinguishing chamber 3 . However, the field control elements 35 to 38 can also be arranged on other regions of the outer surfaces 27 to 29 .

The field control elements 35 to 38 are each made of, for example, an electrically conductive plastic, for example, of a silicon elastomer filled with carbon black. In the case where the plastic casing 11 is a plastic casing, the plastic casing is placed over the outer surface 27 of the vacuum interrupter 3 and the partial regions 28.1, 29.1 of the outer surfaces 28, 29 of the holding devices 5, 7, the field control The elements 35 to 38 can be integrated into a plastic sleeve, for example.

Although the invention has been illustrated and described in greater detail by means of preferred embodiments, the invention is not limited to the disclosed examples and other variants can be derived therefrom by those skilled in the art without departing from the scope of the invention .

Claims (11)

1. A circuit breaker (1) comprises

-a vacuum interrupter (3),

-metallic holding means (5, 7) arranged on opposite sides of the vacuum interrupter (3),

-a housing (9) having a housing wall (25) which is arranged around an outer surface (27 to 29) of the vacuum interrupter (3) and the holding device (5, 7) at a distance from the outer surface (27 to 29),

-a plastic casing (11) arranged on an outer surface (27) of the vacuum interrupter (3) and on partial regions (28.1, 29.1) of outer surfaces (28, 29) of the two holding devices (5, 7), and

-a volume (31) filled with an insulating gas (33) between the plastic encasement (11) and the housing wall (25).

2. The circuit breaker (1) of claim 1 wherein said plastic encasement (11) is made of plastic having a higher dielectric strength than said insulating gas (33).

3. The circuit breaker (1) of claim 1 or 2 wherein said plastic encasement (11) is made of silicone.

4. Circuit breaker (1) according to any of the preceding claims, wherein the insulating gas (33) is dehumidified air or carbon dioxide.

5. Circuit breaker (1) according to any of the preceding claims, wherein the plastic encasement (11) is a plastic layer injection molded or cast on the outer surface (27) of the vacuum interrupter (3) and on partial areas (28.1, 29.1) of the outer surfaces (28, 29) of the holding means (5, 7).

6. The circuit breaker (1) according to any of claims 1 to 4, wherein the plastic encasement (11) is a plastic sleeve that is sleeved over an outer surface (27) of the vacuum interrupter (3) and a partial area (28.1, 29.1) of an outer surface (28, 29) of the holding arrangement (5, 7).

7. The circuit breaker (1) of any of the preceding claims wherein the plastic encasement (11) has a varying thickness.

8. Circuit breaker (1) according to one of the preceding claims, having at least one field control element (35 to 38) which is arranged between the plastic encasement (11) and a partial region (28.1, 29.1) of the outer surface (27) of the vacuum interrupter (3) and/or of the outer surface (28, 29) of the holding device (5, 7).

9. The circuit breaker (1) of claim 8 wherein at least one field control element (35 to 38) is made of an electrically conductive plastic.

10. The circuit breaker (1) according to claim 8 or 9, wherein at least one field control element (35 to 38) is arranged on a holding device end (5.1, 7.1) of the holding device (5, 7).

11. Circuit breaker (1) according to any of the preceding claims, wherein the interrupter ends (13, 15) of the vacuum interrupter (3) protrude into each holding device (5, 7).

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