JP2013093276A - Vacuum circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum circuit breaker which dramatically improves external dielectric strength of a vacuum valve.SOLUTION: A vacuum circuit breaker includes: a vacuum valve 3 having a pair of contacts 2 which contact with or separate from each other; an insulation layer 4 provided by molding an insulation material, such as an epoxy resin, around the vacuum valve 3; a first polymer outer sheath 9 provided around the insulation layer 4 and formed by rubber; an insulative operation rod 10 connecting with a movable shaft 6 of the vacuum valve 3 in the axial direction of the movable shaft 6; a first FRP 11 which houses the insulative operation rod 10 and couples and fixes to the insulation layer 4; and a second polymer outer sheath 15 provided around the first FRP 11 and formed by rubber.

Description

  Embodiments described herein relate generally to a vacuum circuit breaker that can improve external dielectric strength that is outside a vacuum valve.

  Conventionally, in a vacuum circuit breaker applied to a substation or the like, a vacuum valve having a pair of contactable and separable contacts is housed in a porcelain insulator tube, and an insulating gas such as SF6 gas or dry air is enclosed therein. It is known to improve the dielectric strength of the outer side of (see, for example, Patent Document 1). Also, in gas bushing, it is known that an insulating gas is sealed in a porcelain or polymer insulator tube to improve the dielectric strength (for example, see Patent Document 2).

  Thus, since the dielectric strength is proportional to the gas pressure in the case of encapsulating the insulating gas, it has been necessary to make the insulation tube a pressure vessel that can withstand high pressure in order to improve the dielectric strength. However, raising the pressure of the container has a limit, making it difficult to improve the dielectric strength. In addition, when SF6 gas with good dielectric strength is used for the insulating gas, handling becomes difficult. On the other hand, when trying to use dry air that is easy to handle, the dielectric strength is inferior, and a further increase in pressure is required.

JP 2002-281620 A Japanese Patent Laid-Open No. 11-273475

  The problem to be solved by the present invention is to improve the external dielectric strength of the vacuum valve without using a pressure vessel, using solid insulation having better dielectric strength than insulating gas such as SF6 gas and high-pressure dry air. It is to provide a vacuum circuit breaker to obtain. In addition, the creepage distance is increased so that it can be applied outdoors.

  In order to solve the above-described problem, a vacuum circuit breaker according to an embodiment includes a vacuum valve having a pair of contactable contacts, an insulating layer provided by a mold around the vacuum valve, and around the insulating layer. A first polymer sheath provided; an insulating operating rod connected in the axial direction of the movable shaft of the vacuum valve; and a first FRP that houses and fixes the insulating operating rod and is connected and fixed to the insulating layer And a second polymer jacket provided around the first FRP.

Sectional drawing which shows the structure of the vacuum circuit breaker which concerns on Example 1 of this invention. Sectional drawing which shows the structure of the vacuum circuit breaker which concerns on Example 2 of this invention. Sectional drawing which shows the structure of the vacuum circuit breaker which concerns on Example 3 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, a vacuum circuit breaker according to Embodiment 1 of the present invention will be described with reference to FIG. 1 is a cross-sectional view illustrating a configuration of a vacuum circuit breaker according to a first embodiment of the present invention.

  As shown in FIG. 1, the vacuum circuit breaker includes an upper cut-off portion 1 a and an operation mechanism portion 1 b at the lower portion of the drawing.

  The blocking portion 1a is provided with a vacuum valve 3 having a pair of contactable and separable contacts 2, and an insulating layer 4 formed by molding an insulating material such as epoxy resin or polyester resin around it. . The upper conductor 5 is fixed to the fixed side of the vacuum valve 3, and the movable shaft 6 is led out in the axial direction on the movable side. The movable shaft 6 penetrates the lower conductor 8 fixed to the insulating layer 4 through the contact 7 so as to be movable. Around the insulating layer 4 between the upper conductor 5 and the lower conductor 8, there is provided a cylindrical first polymer jacket 9 having a plurality of pleats formed of rubber such as silicone rubber or EP rubber. Yes.

  The operation mechanism portion 1b is provided with a movable insulating operation rod 10 connected in the axial direction of the movable shaft 6. The insulating operation rod 10 is accommodated in a cylindrical first FRP 11 (glass fiber reinforced plastic) laminated with, for example, an epoxy resin. An upper flange 12 is fixed to the upper portion of the first FRP 11 and is fixed to the lower conductor 8. A lower flange 13 is fixed to the lower portion, and is fixed to a housing of an operation mechanism 14 that opens and closes the contact 2. Around the first FRP 11 between the upper flange 12 and the lower flange 13, a cylindrical second polymer jacket 15 made of the same material as the first polymer jacket 9 is provided. The inside of the first FRP 11 is in the air, but it is preferable to enclose dry air at a positive pressure.

  Here, the lower conductor 8 is fixed to the insulating layer 4, the upper flange 12 is fixed to the first FRP 11, and the lower conductor 8 and the upper flange 12 are fixed with bolts or the like. Thus, the first FRP is connected and fixed.

  Thereby, since the insulating layer 4 has a dielectric strength of several tens of kV / mm, the external dielectric strength that is outside the vacuum valve 3 can be greatly improved. SF6 gas has an equal electric field of 1 atm and a dielectric strength of about 9 kV / mm, and the dielectric strength of the insulating layer 4 is much higher than this. Moreover, since the creeping distance is increased by the first polymer jacket 9, it can also be applied outdoors.

  Similarly, the creeping distance can be increased by the second polymer jacket 15 in the operation mechanism portion 1b. Although not shown, the insulating operation rod 10 has a simple electrode arrangement with a hemispherical pad facing the tip, and the electric field strength does not increase as compared with the blocking portion 1a. Therefore, the first FRP 11 needs to be a pressure vessel. There is no.

  Here, when silicone rubber is used for the first polymer sheath 9, the relative dielectric constant is about 2.7, and when a filler such as silica or titanium oxide is added to the insulating layer 4, the relative dielectric constant is 4-8. It can be. Thereby, the relative permittivity of the inner peripheral side can be made larger than that of the outer peripheral side, and the electric field of the vacuum valve 3 can be reduced.

  According to the vacuum circuit breaker of the first embodiment, the insulating layer 4 is provided by molding the vacuum valve 3 with an insulating material, and the first polymer jacket 9 is provided therearound. High dielectric strength and a high dielectric strength in the creeping direction by the first polymer jacket 9 can be obtained, and the external dielectric strength can be greatly improved.

  Next, a vacuum circuit breaker according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 2 is a cross-sectional view illustrating the configuration of the vacuum circuit breaker according to the second embodiment of the present invention. The second embodiment is different from the first embodiment in that a second FRP is provided on the outer periphery of the insulating layer. In FIG. 2, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 2, a cylindrical second FRP 16 laminated with, for example, an epoxy resin is provided on the outer periphery of the insulating layer 4, and a first polymer jacket 9 is provided around the second FRP 16. Yes.

  In manufacturing, the insulating layer 4 can be provided by setting the vacuum valve 3 in the second FRP 16 and filling it with an insulating material. In Example 1, since the casting mold is used and the insulating layer 4 is provided by filling the insulating material, the casting mold becomes unnecessary. The second FRP 16 has heat resistance equal to or higher than that of the insulating material to be filled, and can withstand the mold if it has an insulating thickness of several mm.

  According to the vacuum circuit breaker of the second embodiment, in addition to the effects of the first embodiment, the molding operation of the insulating layer 4 can be facilitated.

  Next, a vacuum circuit breaker according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view illustrating a configuration of a vacuum circuit breaker according to Embodiment 3 of the present invention. Note that Example 3 is different from Example 2 in that the crease of the first polymer jacket is increased. In FIG. 3, the same components as those in the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 3, the height of the folds of the first polymer jacket 9 provided around the second FRP 16 is increased. That is, the creepage distance is increased as compared with the second polymer jacket 15. Note that the number of pleats may be increased.

  The first polymer jacket 9 is an insulation between electrodes, and the second polymer jacket 15 is an insulation between grounds. For this reason, by increasing the creepage distance of the first polymer jacket 9 rather than the second polymer jacket 15, insulation coordination can be achieved to increase the dielectric strength between the poles rather than between the ground, and accident expansion Can be prevented.

  According to the vacuum circuit breaker of the third embodiment, in addition to the effects of the second embodiment, insulation coordination can be achieved.

  According to the embodiment described above, the vacuum valve is molded with an insulating material and the polymer jacket is provided around it, so that the dielectric strength in the penetration direction and the creeping direction can be greatly improved.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1a Blocking part 1b Operation mechanism part 2 Contact 3 Vacuum valve 4 Insulating layer 5 Upper conductor 6 Movable shaft 7 Contact 8 Lower conductor 9 First polymer jacket 10 Insulating operating rod 11 First FRP
12 Upper flange 13 Lower flange 14 Operating mechanism 15 Second polymer jacket 16 Second FRP

Claims (5)

A vacuum valve having a pair of detachable contacts;
An insulating layer provided by a mold around the vacuum valve;
A first polymer jacket provided around the insulating layer;
An insulating operation rod connected in the axial direction of the movable shaft of the vacuum valve;
A first FRP which houses the insulating operation rod and is connected and fixed to the insulating layer;
A second polymer jacket disposed around the first FRP;
A vacuum circuit breaker characterized by comprising:   The vacuum circuit breaker according to claim 1, wherein the first polymer jacket and the second polymer jacket are formed of silicone rubber.   The vacuum circuit breaker according to claim 1 or 2, wherein a second FRP is provided between the insulating layer and the first polymer jacket.   The vacuum circuit breaker according to any one of claims 1 to 3, wherein a creeping distance of the first polymer jacket is larger than that of the second polymer jacket.   The vacuum circuit breaker according to any one of claims 1 to 4, wherein a relative dielectric constant of the insulating layer is made larger than that of the first polymer jacket.

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