WO2004051816A1

WO2004051816A1 - Switchgear bus connection structure

Info

Publication number: WO2004051816A1
Application number: PCT/JP2002/012718
Authority: WO
Inventors: Masahiro Arioka
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 2002-12-04
Filing date: 2002-12-04
Publication date: 2004-06-17
Also published as: TW591833B; JPWO2004051816A1; TW200412002A; CN1623260A

Abstract

A switchgear bus connection structure having a reduced number of components and produced with improved connection workability at low cost. T bushings are gas-tightly attached to respective insulating gas enclosed containers in such a way that an end of a branch conductor is electrically connected to a feed circuit and ends of busses adjoin to each other coaxially. A connection conductor is slidably fitted on the pair of ends of the opposed busses while maintaining the electrical contact. An insulating tube of an elastic material covers the connection conductor and the ends of the busses and is fitted on a pair of opposed insulators while being radially enlarged in such a way that the conductive coatings of the paired opposed insulators are electrically short-circuited through a grounding conductive layer. Thus the number of components is reduced, the connection workability is improved, and the cost is lowered.

Description

Switch gear busbar connection structure

Technical field

The present invention relates to a bus connection structure of a switch gear, and more particularly to a bus connection structure applied when interconnecting a power supply circuit housed in an adjacently disposed insulating gas sealed container outside the container. Light

Background art

The conventional bus connection structure consists of bushings extending from adjacent insulating gas enclosures.

The bushing conductor and the end of the connection conductor are placed close to each other, and a pair of connection conductors having an arc-shaped cross section are applied to the end of the bushing conductor and the connection conductor from above and below, and the pair of connection conductors are tightened with tightening screws. And the two pushing conductors were electrically connected via the connection conductor and the connection conductor. A rubber stress cone was attached to the connection between the bushing conductor and the connection conductor, and the cover was fitted over each stress connector to ensure insulation at the connection. (For example, Japanese Patent Application Laid-Open No. 2002-238338)

However, in the conventional bus connection structure, a pair of pushers, one connection conductor, two pairs of connection conductors, two stress cones, and two covers are used to connect the two insulating gas sealed containers to the bus. Required, the number of parts increased, the connection workability deteriorated, and the cost could not be reduced. Disclosure of the invention

An object of the present invention is to obtain a switch gear bus connection structure that reduces the number of components, improves connection workability, and realizes cost reduction.

According to the present invention, each of the insulating gas sealed containers is configured such that the T-shaped pushing electrically connects the ends of the branch conductors to the power supply circuit and arranges the ends of the bus bars adjacent to each other and coaxially. And the connecting conductors are Slidably fitted to the pair of conductors while maintaining an electrical contact state, and furthermore, an insulating tube made of an elastic material covers the connection conductor and the end of the opposing busbar, and has a conductive property of the opposing insulator pair. The conductive coatings are externally fitted to the pair of opposing insulators in a radially expanded state so that the conductive coatings are electrically short-circuited by the grounding conductive layer. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a sectional view of an essential part for explaining a bus connection structure of a switch gear according to the present invention.

FIG. 2 is a sectional view showing an insulating tube applied to the bus connection structure of a switch gear according to the present invention.

FIG. 3 is a cross-sectional view showing a connection conductor applied to the bus connection configuration of the switch gear according to the present invention.

FIG. 4 is an enlarged sectional view of an essential part for explaining a bus connection structure of the switch gear according to the present invention.

FIG. 5 is a sectional view of an essential part for explaining the connection operation of the bus connection structure of the switch gear according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Embodiment

FIG. 1 is a cross-sectional view of a main part for explaining a bus connection structure of a switch gear according to the present invention. FIG. 2 is a cross-sectional view showing an insulating tube applied to the bus connection structure of the switch gear according to the present invention. FIG. 4 is a cross-sectional view showing a connection conductor applied to the busbar connection structure. FIG. 4 is an enlarged cross-sectional view of a main part of the switchgear busbar connection structure according to the present invention. FIG. 5 is a connection operation of the switchgear busbar connection structure according to the present invention. It is principal part sectional drawing explaining.

In each of the figures, the switch gear is composed of a plurality of hermetically sealed insulating gas containers 1 filled with insulating gas 3 such as SF ₆ gas, arranged in a row, and a power supply circuit 2 housed in each of the insulating gas sealed containers 1 having a T-shape. Configured interconnected via pushing 4 . In some cases, the insulating gas sealed container 1 interconnected via the T-shaped pushing 4 is housed in a housing (not shown).

The Τ-shaped pushing 4 is composed of a bus bar 5 formed in a linear shape with a circular cross section, and branch conductors 6 extending from the center in the length direction of the bus bar 5 so as to be orthogonal to the length direction. Further, the bus bar 5 and the branch conductor 6 are buried with an insulator 7 such as an epoxy resin so as to expose the end of the branch conductor 6.

Further, both ends of the portion of the insulator 7 where the bus 5 is buried are formed in a stepped columnar shape having a large diameter portion 7a and a small diameter portion 7b, and a large diameter portion 7a and a small diameter portion 7b are formed. A step 7c is formed between them. A boundary portion 7d between the large-diameter portion 7a and the stepped portion 7c and a boundary portion 7e between the stepped portion 7c and the small-diameter portion 7b are formed on a curved surface having a radius of 2 mm. There is no particular problem if the radius of this curved surface is about lmm to 3mm. Thus, the large diameter portion 7a and the stepped portion 7c are connected by a smooth continuous surface, and the stepped portion 7c and the small diameter portion 7b are connected by a smooth continuous surface.

Further, the flange portion 7f is integrally formed on the busbar 5 side of the portion of the insulator 7 where the branch conductor 6 is embedded. An annular groove 7 g is recessed on the surface of the flange portion 7 f on the side opposite to the busbar so as to surround the branch conductor 6. Furthermore, for example, a screw is applied to an end of the branch conductor 6 extending from the insulator 7 so that the end can be electrically connected to the power supply circuit 2.

Further, a conductive film 8 serving as a ground layer is formed on the outer surface of the insulator 7 so as to be electrically separated from the bus 5 and the branch conductor 6. The conductive film 8 is formed by, for example, applying a conductive paint to the surface of the insulator 7 by applying a metallicone spray (a process of spraying a metal such as zinc or aluminum onto a base material). As shown in FIG. 4, the conductive film 8 is formed near the step 7c of the small diameter portion 7b, but the conductive film 8 is formed on the other portion of the small diameter portion 7b. Not. As shown in FIG. 3, the connection conductor 10 is formed in a cylindrical shape, and has an annular concave groove 1.

0b is formed at each end of the center hole 10a, and an annular four groove 10c is formed on the central outer peripheral surface in the length direction. The annular contact 11 is fitted in each groove 1 Ob so as to protrude a part thereof. The inner diameter of the center hole 10a is formed slightly larger than the diameter of the bus 5, and the inner diameter of the contact 11 is smaller than the diameter of the bus 5. It has a slightly smaller diameter. Further, the outer diameter of the connection conductor 10 substantially matches the outer diameter of the small diameter portion 7 b of the insulating layer 7.

As shown in FIG. 2, the insulating tube 12 has a cylindrical insulator 13 made of an elastic material having electrical insulation and an electric conductivity integrally formed on the inner peripheral surface of the insulator 13. An electric field relaxing conductive layer 14 made of a conductive material and an electrically conductive elastic material integrally formed on the insulator 13 so as to cover both outer and inner peripheral surfaces of the insulator 13. It has a three-layer structure composed of a grounding conductive layer 15. The convex portion 14a is formed in an annular shape with the central portion of the electric field relaxing conductive layer 14 protruding radially inward. The projection 14a is shaped to fit into the annular groove 10c of the connection conductor 10. Further, the inner diameter of the insulating tube 12 is formed slightly smaller due to the outer diameter of the small diameter portion 7 b of the insulating layer 7. In addition, the length of the insulating tube 12 is formed slightly shorter than the distance between the steps 7c of the T-shaped pushing 4 attached to the adjacent insulating gas-tight container 1 so as to reduce the electric field. The length of the electric layer 14 is formed longer than the distance between the tips of the small diameter portions 7b. Here, as the elastic material having electrical insulation, for example, a silicone resin, a polyethylene resin, or the like is used. As the elastic material having electrical conductivity, for example, a material obtained by adding carbon or the like to a silicone resin, a polyethylene resin, or the like is used.

Next, a bus connection method for the power supply circuit 2 will be described.

First, the insulating gas sealed containers 1 accommodating the power supply circuits 2 are arranged in a row. Then, the branch conductor side of the T-shaped pusher 4 is inserted through an opening 1 b formed in the mounting portion 1 a of the insulating gas sealed container 1, and the end of the branch conductor 6 is electrically connected to the power supply circuit 2. Next, the flange portion 7 f is fastened to the mounting portion 1 a by the port 17, and the T-shaped pushing 4 is mounted on the insulating gas sealed container 1. At this time, the O-ring 16 as a packing is fitted into the annular groove 7 g of the flange 7 ί, and the airtightness of the insulated gas tight container 1 is ensured. Then, an insulating gas 3 such as SF ₆ gas is sealed in the insulating gas sealed container 1.

Therefore, the connection conductor 10 is fitted over the end of the bus bar 5. At this time, connecting conductor 10

The insulator 7 is pushed into the vicinity of the small diameter portion 7b of the insulator 7, and the mother It is in electrical contact with line 5. Next, the insulating tube 12 coated with the insulating grease 18 on the inner peripheral surface is fitted to the insulator 7 from the end of the busbar 5. At this time, the insulating tube 12 is pushed in so as to ride on the large diameter portion 7 a of the insulator 7. Therefore, the insulating tube 12 is mounted on the large-diameter portion 7a by expanding radially outward.

Next, the T-shaped pushing 4 is attached to the adjacent insulating gas sealed container 1. As a result, as shown in FIG. 5, the ends of the bus 5 of the T-shaped pushing 4 are arranged close to each other and coaxially.

Then, while expanding the open side of the insulating tube 12 to the outside in the radial direction, insulate the insulating tube 12 in the direction indicated by the arrow in FIG. 5 until the convex portion 14a and the concave groove 10c are fitted. Move. Therefore, when the expansion of the insulating tube 12 is released, the insulating tube 12 contracts radially inward, and the convex portion 14a fits into the concave groove 10c. Thereafter, the tube moves in the direction indicated by the arrow in FIG. 5 until the insulating tube 12 is positioned on the small-diameter portion 7 b of the insulator 7. With the movement of the insulating tube 12, the connection conductor 10 slides on the bus 5, and finally one side of the connection conductor 10 is fitted to the opposing bus 5, and the connection conductor 10 between the bus 5 and It is electrically connected via the contact 11. That is, the power supply circuits 2 in the two insulating gas sealed containers 1 are electrically connected. At this time, as shown in FIG. 1, the insulating tube 12 covers the connection conductor 10 and the end of the corresponding busbar 5 and is radially expanded to the small-diameter portion 7 b of the facing insulator 7. It is fitted externally in a state where it is placed. The opposing conductive films 8 of the insulators 7 are electrically connected via the grounding conductive layer 15. Further, as shown in FIG. 4, the insulating grease 18 is filled in the gap between the insulating tube 12 and the small-diameter portion 7b of the insulator.

By repeating this operation, the power supply circuits 2 housed in the insulating gas sealed containers 1 arranged in a line are electrically connected to each other.

Then, when the power supply circuit 2 is to be electrically disconnected, hold the center of the insulating tube 12 and move it to the busbar 5 side. As a result, the connecting conductor 10 slides on the bus 5 and moves to one bus 5 side, and the power supply circuit 2 is electrically disconnected. Then, when the insulating tube 12 is further moved to one busbar 5 side, The connecting conductor 10 comes into contact with the end of the small diameter portion 7b, and further movement is prevented. As a result, the fitting between the convex portion 14a and the concave groove 10c is released, and only the insulating tube 12 moves and rides on the large-diameter portion 7a while expanding in the radial direction. The state shown is shown.

Furthermore, when only the insulating tube 12 is moved to the one busbar 5 side to expose the connecting conductor 10, the main circuit resistance can be measured.

According to this bus connection structure, two power supply circuits 2 are configured to be connected by a pair of T-shaped pushing 4, one connection conductor 10 and one insulating tube 12 so that The number of parts is reduced, the connection workability is improved, and the cost is reduced. Further, since the connection between the buses 5 can be disconnected by moving the bus 5 of the insulating tube 12 in the axial direction, workability is improved. In addition, the interfacial insulation between the insulators 7 is reduced, and the reliability of the bus connection is improved. Furthermore, since the insulating tube 12 is made of an elastic material and has an inner diameter smaller than the outer diameter of the small-diameter portion 7b, when the insulating tube 12 is externally fitted to the small-diameter portion 7b, the radial inner side is formed. As a result, the outer tube is securely fitted to the small-diameter portion 7b.

Both ends of the portion of the insulator 7 where the bus 5 is buried are formed by the large diameter portion 7a and the small diameter portion 7b formed from the large diameter portion 7a through the step 7c. The small-diameter portion 7b restricts the movement of the insulating tube 12 due to vibrations, etc., so that accidental exposure of the connection conductor 10 can be avoided. .

In addition, since the boundary 7 d between the large diameter portion 7 a and the stepped portion 7 c is formed in a curved shape, it is possible to suppress damage to the insulating tube 12 when the insulating tube 12 is moved. .

Also, since the boundary 7 e between the step 7 c and the small diameter portion 7 b is formed in a curved surface, the transition operation from the small diameter portion 7 b of the insulating tube 12 to the large diameter portion 7 a and the large diameter The transition operation from the portion 7a to the small diameter portion 7b is performed smoothly.

Also, since insulation grease 18 is filled between the insulation tube 12 and the small diameter portion 7b, deterioration of withstand voltage performance and partial discharge performance due to air gap is prevented. In addition, the movement of the insulating tube 12 becomes smooth.

Also, the convex portion 14a is formed in an annular shape by protruding the central portion of the electric field relaxing conductor layer 14, and an annular concave groove 10c is formed on the central outer peripheral surface in the longitudinal direction of the connection conductor 10. As a result, with the insulating tube 12 attached, the convex portion 14a and the concave groove 10c are fitted, and the externally fitted state of the connection conductor 10 to the opposing busbar 5 is maintained. . Therefore, an accident in which the connection conductor 10 moves and the power supply circuit 2 is electrically disconnected is prevented beforehand, and the reliability of the bus connection can be improved.

Also, an O-ring 16 is interposed between the flange portion 7 g formed at the portion of the insulator 7 where the branch conductor 6 is provided and the mounting portion 1 a of the insulating gas sealed container 1. Since the flange portion 7 g is fastened to the mounting portion 1 a, the airtightness of the insulating gas sealed container 1 is ensured.

In the above embodiment, the contact 11 is described as being attached to the connection conductor 10, but the contact 11 may be attached to the bus 5.

Industrial applicability

As described above, the busbar connection structure according to the present invention is useful for interconnecting a power supply circuit housed in an insulating gas hermetic container constituting a switch gear outside the container.

Claims

The scope of the claims

1. A switch gear bus connection structure in which a plurality of insulating gas sealed containers accommodating a power supply circuit are arranged adjacent to each other,

A bus bar formed in a linear shape with a circular cross section, a branch conductor extending from the center in the length direction of the bus bar so as to be orthogonal to the length direction, both ends of the bus bar, and ends of the branch conductor. An insulator for burying the bus bar and the branch conductor so as to be exposed, and a conductive film formed on an outer surface of the insulator so as to be electrically isolated from the bus bar and the branch conductor. Bushing and

A cylindrical connection conductor;

A cylindrical insulator made of an elastic material having electrical insulation; a conductive layer for electric field relaxation made of an elastic material having electrical conductivity integrally formed on an inner peripheral surface of the insulator; and an outer surface of the insulator And an insulating tube having a grounding conductive layer made of an electrically conductive elastic material formed integrally with the insulator so as to cover both edges of the inner peripheral surface,

The τ-shaped pushing electrically connects the ends of the branch conductors to the power supply circuit and places the ends of the bus bars adjacent to each other coaxially so as to be coaxial with each other. Airtightly attached,

The connection conductor is slidably fitted to the pair of opposing ends of the bus bar while maintaining an electrical contact state,

The insulating tube covers the connection conductor and the end of the bus bar facing each other, and electrically shorts the conductive coatings of the pair of insulators facing each other by the grounding conductive layer. A busbar connection structure for a switch gear, wherein the switchgear is externally fitted to the pair of insulators opposed to the pair in a radially expanded state.

2. Both ends of the portion of the insulator in which the bus is buried are composed of a large-diameter portion and a small-diameter portion formed from the large-diameter portion through a step portion and into which the insulating tube is fitted. A stepped cylindrical shape, wherein a boundary between the large diameter portion and the step portion and a boundary portion between the step portion and the small diameter portion are formed in a curved surface shape. The switch gear bus connection structure according to claim 1,

3. The bus connection structure for a switch gear according to claim 2, wherein an insulating grease is filled between the insulating tube and the small diameter portion.

4. A convex portion is formed in an annular shape by protruding a portion of the electric field relaxing conductor layer at the center of the inner periphery of the insulating tube, and an annular concave groove fitted to the convex portion is formed in a longitudinal direction of the connection conductor. 2. The bus connection structure for a switch gear according to claim 1, wherein the bus connection structure is formed on a central outer peripheral surface of the switch gear.

5. A flange portion is formed at a portion of the insulator where the branch conductor is buried, and the T-shaped bushing is provided with a packing interposed between the flange portion and the insulating gas sealed container to form the flange portion. 2. The bus connecting structure for a switch gear according to claim 1, wherein the switch is mounted on the insulating gas sealed container by tightening.