JP5152148B2 - Gas insulated switchgear and method for manufacturing the same - Google Patents

Description

  The present invention relates to a gas insulated switchgear used in power transmission / distribution and power distribution facilities.

  A conventional gas insulated switchgear electrically insulates between a pressure tank filled with dry air and a conductor to which a high voltage is applied, so that a high gas pressure of about 0.4 to 0.5 MPa-g is used. Insulation was secured by enclosing dry air and covering the conductor with an insulator such as epoxy resin. (For example, refer to Patent Document 1). At this time, the terminal conductor that engages with the external device and the lead conductor that connects the terminal conductor and the vacuum valve are often integrated by welding or screw fastening. At the time of assembly, it is attached to the main body of the gas insulated switchgear in a state where the soot tube, the terminal conductor and the lead conductor are combined.

Japanese Unexamined Patent Publication No. 2003-319515 (FIG. 1)

  In the gas insulated switchgear as described above, since a high gas pressure of about 0.4 to 0.5 MPa-g is loaded on the pressure tank, it is necessary to provide a strong pressure tank such as increasing the thickness of the pressure tank. In addition, there is a problem that it is difficult to reduce the weight and cost of the apparatus. Moreover, since the dielectric strength of dry air is about 1/3 that of SF6 gas, there is a problem that if the gas pressure in the pressure tank is lowered, the insulation performance in the pressure tank cannot be secured. In particular, the insulation part of the installation part of the soot pipe which draws electric power from the outside, and the location where the current transformer is installed has a short insulation distance, and it is difficult to insulate only with dry air.

  The present invention has been made to solve the above-mentioned problems, and ensures insulation performance in a pressure tank using an insulating gas such as dry air, nitrogen, carbon dioxide, etc., which is inferior in dielectric strength to SF6 gas. However, it aims at providing the gas insulated switchgear which can reduce the gas pressure in a pressure tank.

A gas-insulated switchgear according to the present invention comprises a pressure tank that is electrically grounded, has a plurality of openings and is filled with an insulating gas, one end connected to the pressure tank, and the other end connected to a terminal conductor. An airtightly sealed soot tube, a vacuum valve that is provided in the pressure tank and accommodates a fixed conductor and a movable conductor provided so as to be able to contact with and separate from the fixed conductor, the fixed conductor or the movable conductor, and the terminal conductor A gas insulated opening / closing device comprising a lead conductor connected to the terminal conductor and an opening / closing means for driving the movable conductor via an insulating rod connected to the movable conductor A device comprising: a bushing conductor cast so that a hollow conductor arranged coaxially is covered with an insulator thickly except for at both ends thereof; and a conductive or semiconductive member formed on the surface of the insulator. Conductive ground layer An intermediate bushing having a fixed flange portion fixed to the flange portion of the pressure tank is provided between the pressure tank and the lead conductor, and one end of the bushing conductor is electrically connected to the fixed conductor or the movable conductor. And the other end extends with a gap from the inner wall of the inner cavity of the soot tube and is connected to the lead conductor, the terminal conductor and the lead conductor are separable, and the lead conductor and the lead conductor The bushing conductor can be separated.

  A gas insulated switchgear that can reduce the gas pressure in the pressure tank while ensuring the insulation performance in the pressure tank can be provided.

It is sectional drawing of the whole gas insulation switchgear in Embodiment 1 of this invention. It is sectional drawing which expands and shows the soot pipe part of the gas insulated switchgear in Embodiment 1 of this invention. It is sectional drawing to which the extraction conductor in Embodiment 1 of this invention was expanded. It is sectional drawing which shows the assembly procedure of the soot pipe part in Embodiment 1 of this invention. It is sectional drawing which expands and shows the soot pipe part of the gas insulated switchgear in Embodiment 2 of this invention. It is sectional drawing which expands and shows the soot pipe part of the gas insulated switchgear in Embodiment 3 of this invention.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view of the entire gas insulated switchgear according to Embodiment 1 for carrying out the present invention. FIG. 2 is an enlarged cross-sectional view of the soot tube portion 66b in the gas insulated switchgear 1 shown in FIG. Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings.

  In FIG. 1, the electrically grounded pressure tank 2 is installed with the body portion 2 a being horizontal, and a pair of openings 2 b and 2 c are provided above the pressure tank 2. A vacuum valve 4 is installed in the pressure tank via the body 2a and a gap. Opening / closing means 3 for operating the vacuum valve 4 is provided outside the pressure tank 2, and the opening / closing means 3 is connected to the vacuum valve 4 via an operation rod 5 and an insulating rod 6. The vacuum valve accommodates a fixed conductor 4a and a movable conductor 4b each provided with an electrode at the tip. At both ends of the vacuum valve 4, a fixed side shield 51 connected to the fixed conductor 4 a and a movable side shield 54 connected to the movable conductor 4 b are provided, and above the fixed side shield 51 and the movable side shield 54. Are provided with insertion portions 51a and 54a into which one ends of the bushing conductors 22 and 32 of the intermediate bushings 21 and 31 are inserted. That is, one end of each of the bushing conductors 22 and 32 is electrically connected to the fixed conductor 4a and the movable conductor 4b. Above the intermediate bushings 21, 31, soot pipe portions 66 a, 66 b are attached to the flange portions 2 d, 2 e of the pressure tank 2. The tub tube portions 66a and 66b have the same structure.

  The intermediate bushings 21 and 31 are bushing conductors 22 cast so as to cover a hollow conductor arranged coaxially with insulators 21a and 31a (for example, epoxy resin, etc.) with the exception of at least both ends thereof. , 23 and conductive or semiconductive ground layers 21b, 31b (for example, conductive rubber, conductive paint, etc.) formed on the surfaces of the insulators 21a, 31a, and bolts on the flange portions 2d, 2e, respectively. Etc. (not shown) to be grounded.

  In FIG. 2, the intermediate bushing 31 is provided between the pressure tank 2 and the lead conductor 11, and is fixed to the pressure tank 2 by a fixing flange portion 62 provided on the intermediate bushing 31. More specifically, the fixed flange portion 62 is formed integrally with a part of the insulator 31a that covers the hollow conductor thickly in a disk shape, and the fixed flange portion 62 is a flange portion of the pressure tank 2. 2e and the soot tube 20. The fixing flange portion 62 is sandwiched between the flange portion 2e and the fixing flange 67, and is fastened by a bolt or the like (not shown). The bushing conductor 32 of the intermediate bushing 31 extends with a gap between the coaxial hollow pipe 20 and the inner end thereof, and the tip thereof is not covered with the insulator 31a and is connected to the lead conductor 11 via the contactor 64. ing. Here, the reason why the contactor 64 is applied is to absorb expansion and contraction due to a temperature rise of the bushing conductor 32 when the gas insulated switchgear 1 is operated. At this time, as the contactor 64, a tulip contact that presses the contact terminal from the outside with a garter spring, a copper alloy wire formed into a coil spring shape, a spring contact formed in a ring shape, and a part of the copper alloy plate as a louver For example, a contact that is formed into a protruding shape is applied. Further, the position of the contactor 64 is arranged at a position close to the terminal conductor 12. The lead conductor 11 includes a contact portion 78 that is in contact with the contactor 64, a through hole A74 for penetrating the internal ventilation hole 65 of the bushing conductor 32, a through hole B75 for penetrating the inner space of the vertical pipe, and the terminal conductor 12. It has a screw part 76 for connection and a packing groove 77 for maintaining airtightness with the outside air.

  The soot tube 20 is fastened and fixed by a bolt or the like (not shown) between the soot tube mounting portion 61 and the fixing flange 67. A terminal conductor 12 is provided on an end surface of the soot tube 20 that is not the soot tube mounting portion 61, and is connected to the soot tube 20 and the lead conductor 11 with bolts (not shown). The terminal conductor 12 has a mounting hole for connecting the soot tube 20 and the lead conductor 11, a packing groove for maintaining airtightness with the outside air, and a connection hole for connecting with an external device.

  FIG. 3 shows an enlarged view of the lead conductor 11. Here, the through hole A74 and the through hole B75 have substantially the same cross-sectional area as the internal vent hole 65. The through-hole B75 is provided in only one direction in the figure, but a plurality of holes may be provided radially, and the total cross-sectional area may be the same as the cross-sectional area of the internal vent hole 65.

In the manufacturing method of the gas insulated switchgear according to this embodiment, first, one end of the pre-assembled intermediate bushing 31 is connected to the opening 2b of the pressure tank 2 in which the vacuum valve 4 is installed via the body 2a and the gap. 2c, one end of the bushing conductors 22 and 32 is inserted into the insertion portion 51a of the fixed shield 51 or the insertion portion 54a of the movable shield 54, and the fixed flange portion 62 is connected to the flange portions 2d and 2e of the pressure tank 2. Secure with bolts. Subsequently, the tub tube portions 66a and 66b are assembled.

  Since the soot tube portions 66a and 66b have the same shape, FIG. 4 shows an assembling procedure only for the soot tube portion 66b. First, in FIG. 4A, the intermediate bushing 31 is disposed above the flange portion 2 e of the pressure tank 2 and fastened together with the fixing flange 67. The lead conductor 11 is slidably inserted into the tip of the bushing conductor 32 of the intermediate bushing 31 via the contactor 64. Next, in FIG. 4B, the soot tube 20 is arranged so as to cover the bushing conductor 32 from the bottom surface side, and the soot tube 20 is fixed above the fixing flange 67 with a mounting bolt or the like. Finally, in FIG. 4C, the terminal conductor 12 is arranged on the end surface (the end surface opposite to the bottom surface) of the soot tube 20 which is not the soot tube mounting portion 61, and the rubber packing is put in the terminal conductor 12 and the packing groove. The conductor 11 is connected with a bolt or the like. At the same time, the terminal conductor 12 and the end face of the soot tube 20 which is not the soot tube mounting portion 61 are fixed, and the opening of the end surface of the soot tube 20 is sealed in an airtight state.

  If such a manufacturing process is applied, it is not necessary to assemble the hoist pipe, the terminal conductor, and the lead conductor in advance and attach them as a unit to the intermediate bushing, so that the parts constituting the hoist pipe portion 66a are stacked from the pressure tank 2 side. In the final stage of assembly, it is possible to cover the opening 20 and cover the opening with the terminal conductor 12. Further, since the terminal conductor 12 and the lead conductor 11 can be separated, and the lead conductor 11 and the bushing conductor 32 can be separated, the conductor connection between the bushing conductor 32 and the lead conductor 11 is performed after the state of FIG. Since the lead conductor 11 and the bushing conductor 32 can be directly seen, at the final stage of the manufacturing process of the gas-insulated switchgear, the engagement dimensions of the conductor connection portion are confirmed, and the occurrence of foreign matters such as metal scraps and excessive grease leakage is confirmed and cleaned. be able to. Thereby, the insulation reliability of the gas insulated switchgear can be enhanced.

  Further, the insulating performance between the bushing conductor 32 and the pressure tank 2 can be improved by covering the bushing conductor 32 with the insulator 31a and providing the ground layer 31b on the surface thereof. In particular, since the pressure tank 2 and the grounding layer 31b can be set to the same potential, the insulating gas such as dry air, nitrogen, carbon dioxide, etc., which is inferior to SF6 in terms of dielectric strength but excellent in environmental performance, can be increased in gas pressure. Can be used.

  As described above, the intermediate bushing 31 including the bushing conductor 32 provided between the pressure tank 2 and the vertical pipe 20 and arranged coaxially, and the grounding layer 31b provided on the surface of the insulator 31a. By providing a gas insulated switchgear that can reduce the gas pressure in the pressure tank 2 while ensuring the insulation performance in the pressure tank 2 can be provided.

  By the way, when energizing a large current, the contact portion 78 between the bushing conductor 32 and the lead conductor 11 has a contact resistance of approximately 10 μΩ or less, so heat is generated and temperature rises easily. If the contact portion 78 is provided on the fixed flange portion 62 side, that is, at a position adjacent to the portion where the bushing conductor 32 is surrounded by the insulator 31a, the main heat of the portion of the bushing conductor 32 surrounded by the insulator 31a. The temperature of the adjacent position, which is the outlet of the bushing conductor 32, rises, and the heat of the portion surrounded by the insulator 31a of the bushing conductor 32 is not dispersed to the terminal conductor 12 side of the soot tube portion 66b. Therefore, heat conduction from the bushing conductor 32 surrounded by the insulator 31a toward the terminal conductor 12 is hindered, and a local temperature rise occurs.

  On the other hand, if the structure is such that the position of the contactor 64 is close to the terminal conductor 12 as in this embodiment, the contactor 64 is away from the tip of the intermediate bushing 31, and therefore the insulator 31a. The heat conduction in the direction of the terminal conductor 12 from the bushing conductor 32 surrounded by is not obstructed. Therefore, the temperature rise locations of the bushing conductor 32 and the contactor 64 can be dispersed without concentrating the temperature rise.

Embodiment 2. FIG.
FIG. 5 is an enlarged cross-sectional view of a soot tube portion 66b that is a component of the gas insulated switchgear according to the second embodiment. In FIG. 5, the bushing conductor 32 protruding from the insulator 31 a is configured using a conductor connecting component 68 and an intermediate conductor 69. In this embodiment, a threaded portion is formed at the tip of the bushing conductor 32 and can be connected to the conductor connection component 68. The conductor connection component 68 has screw portions formed at both ends so that the bushing conductor 32 and the intermediate conductor 69 can be fastened, and further has a vent hole penetrating the inside of the intermediate conductor 69 and the inside of the bushing conductor 32. The intermediate conductor 69 has a threaded portion that can be fastened to the conductor connecting component 68 at one end, and a groove that attaches a contactor 64 that can be connected to the lead conductor 11 at the other end.

  According to this configuration, since the bushing conductor 32 can be shortened by a length corresponding to the intermediate conductor 69 and the conductor connection component 68, a large-scale facility can be used in the casting process of the insulator 31a (for example, epoxy resin) of the intermediate bushing 31. This makes it easy to handle the product.

Embodiment 3 FIG.
FIG. 6 is an enlarged cross-sectional view of a soot tube portion 66b that is a component of the gas insulated switchgear according to the third embodiment. Even in the structure in which the contactor 64 is disposed in the vicinity of the intermediate bushing 31, the heat conduction from the tip of the bushing conductor 32 is applied with a sufficient energization current with respect to the temperature rise limit of the bushing conductor 32 surrounded by the insulator 31a. In this case, the contact conductor 70, the nut 71, the lead-out connection 72, and the adapter 73 may be configured as shown in FIG. In this example, a contact 64 that can be connected to the contact conductor 70 is provided at the tip of the bushing conductor 32, and is connected to the contact conductor 70. The contact conductor 70 has a contact portion that is in contact with the contactor 64 and a screw portion that is connected to the lead-out connection 72. The contact conductor 70 is fastened to the lead-out connection 72 together with the nut 71. The nut 71 has a function of stopping and positioning the contact conductor 70. The lead-out connection 72 has a screw portion that connects the contact conductor 70 and the nut 71 at one end and a screw portion that fastens the adapter 73 at the other end. The adapter 73 has a screw portion for connecting the lead-out connection 72, a screw hole for connecting to the terminal conductor 12, and a packing groove for maintaining airtightness with the outside air.

  According to this configuration, the contact conductor 70, the nut 71, the lead-out connection 72 and the adapter 73 are coupled between the terminal conductor 12 and the bushing conductor 32, so that the length corresponding to the contact conductor 70, the lead-out connection 72 and the adapter 73 is obtained. As a result, the length of the bushing conductor 32 can be shortened. In addition, by using the contact conductor 70, the nut 71, the lead connection 72, and the adapter 73 instead of the lead conductor 11, complicated processing of the elongated lead conductor 11 can be omitted. The cost can be reduced.

  DESCRIPTION OF SYMBOLS 1 Gas insulated switchgear, 2 Pressure tank, 2a Body part, 2b, 2c opening part, 2d, 2e Flange part, 3 Opening / closing means, 4 Vacuum valve, 4a Fixed conductor, 4b Movable conductor, 5 Operating rod, 6 Insulating rod, 11 Lead conductor, 12 Terminal conductor, 20 Steel pipe, 21, 31 Intermediate bushing, 21a, 31a Insulator, 21b, 31b Ground layer, 22, 32 Bushing conductor, 51 Fixed side shield, 51a, 54a Insertion part, 54 Movable side shield , 61 碍 pipe mounting part, 62 fixing flange part, 64 contactor, 65 internal vent hole, 66a, 66b 碍 pipe part, 67 fixing flange, 68 conductor connecting part, 69 intermediate conductor, 70 contact conductor, 71 nut, 72 lead connection , 73 Adapter, 74 Through hole A, 75 Through hole B, 76 Screw part, 77 Packing groove, 78 Contact Part.

Claims (4)

A pressure tank that is electrically grounded and has a plurality of openings and is filled with an insulating gas; a soot pipe having one end connected to the pressure tank and the other end hermetically sealed by a terminal conductor; and the pressure A part of the electric circuit between the fixed conductor or the movable conductor and the terminal conductor, and a vacuum valve that is provided in the tank and accommodates the fixed conductor and the movable conductor provided so as to be able to contact and separate from the fixed conductor. And a gas insulated switchgear comprising a lead conductor connected to the terminal conductor and an opening / closing means for driving the movable conductor via an insulating rod connected to the movable conductor.
A bushing conductor cast so that a hollow conductor arranged coaxially is covered with an insulator thickly except for at both ends thereof, and a conductive or semiconductive ground layer formed on the surface of the insulator; An intermediate bushing having a fixed flange portion fixed to the flange portion of the pressure tank is provided between the pressure tank and the lead conductor, and one end of the bushing conductor is electrically connected to the fixed conductor or the movable conductor. And the other end extends with a gap from the inner wall of the inner cavity of the soot tube and is connected to the lead conductor, the terminal conductor and the lead conductor are separable, the lead conductor and the bushing A gas insulated switchgear characterized by being separable from a conductor. The gas insulated switchgear according to claim 1,
A gas insulated switchgear characterized in that a contact for electrically connecting the bushing conductor and the lead conductor is disposed on the terminal conductor side between the terminal conductor and the fixed flange portion. The gas insulated switchgear according to claim 1,
A gas insulated switchgear characterized in that a contact portion between a bushing conductor and a lead conductor is disposed in the vicinity where the bushing conductor is exposed from an insulator, and the lead conductor is constituted by a contact conductor, a nut, a lead connection, and an adapter. A bushing conductor cast so that a hollow conductor arranged coaxially is covered with an insulator thickly except for at both ends thereof, and a conductive or semiconductive ground layer formed on the surface of the insulator; Pre-assembling an intermediate bushing having a fixing flange portion for fixing to the flange portion of the pressure tank at the center portion of the bushing conductor;
Installing a vacuum valve in the pressure tank through the body and the gap;
Inserting one end of the bushing conductor into the insertion part of the fixed side shield or the movable side shield at both ends of the vacuum valve, and fixing the fixed flange part to the flange part of the pressure tank with a bolt;
Engaging the lead conductor slidably through the contact with the other end of the bushing conductor;
A soot tube mounting portion provided on the bottom portion by disposing a hollow soot tube having an opening on the opposite end surface of the bottom portion and the bottom portion so that the bottom surface covers the intermediate bushing from one end portion side of the bushing conductor Fixing the bolt to the fixing flange part,
A terminal conductor for connecting an external electric circuit is disposed on the end surface opposite to the bottom of the steel pipe, the terminal conductor and the lead conductor, and the terminal conductor and the end surface are connected by bolts, respectively, and an opening in the end surface And a step of sealing the gas-insulated switchgear while maintaining hermeticity.

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