JP2018201292A - Cable head of gas-insulation switchgear - Google Patents

Abstract

To provide a cable head of a gas-insulation switchgear capable of preventing fall of foreign matters onto an external surface of a cable cone and a bottom surface in a head case.SOLUTION: A cable head of a gas-insulation switchgear includes a head case, an insulation cable cone, a coupler, a shield member, and a cover member. Into the head case, a conductor of a device body tank side and a conductor of an external power cable are pulled. The cable cone covers a periphery of the conductor of the power cable that is pulled into the head case. The coupler electrically connects the conductor of the power cable with the conductor of the device body tank side on an upper side of the cable cone. The shield member covers an area from an upper side of the coupler and a side section outer periphery area of the coupler to a side section outer periphery area of the cable cone to alleviate electric field concentration between the coupler and the cable cone. The cover member covers a side section peripheral area and downward of the coupler at an upper side than the cable cone.SELECTED DRAWING: Figure 2

Description

  Embodiments described herein relate generally to a cable head of a gas insulated switchgear.

  In power facilities that handle high-voltage power such as substations and power plants, gas-insulated switchgear that is excellent in reduction of installation area, safety, maintainability, etc. is often used as a power switchgear. The gas insulated switchgear is equipped with a cable head at an external power cable connection.

In the cable head, the conductor on the apparatus body tank side and the conductor of the external power cable are drawn into the head case connected to the apparatus body tank. In the head case, the insulation cable cone (stress cone) that covers the periphery of the power cable conductor, the power cable conductor protruding upward from the cable cone, and the conductor on the device body tank side are located above the cable cone. A connector for electrical connection is accommodated. Further, in the head case, a shielding member that covers a region extending from the upper side of the connector and the outer peripheral region of the side of the connector to the outer peripheral region of the side of the cable cone is disposed. The lower edge of the shielding member is not in contact with the outer peripheral surface of the cable cone.
The cable cone suppresses the distribution of the electric field from being disturbed by the conductors and connectors in the head case, thereby improving the withstand voltage characteristics. Further, the shielding member relaxes electric field concentration between the connection tool and the cable cone.

  Since this type of cable head has a reduced withstand voltage characteristic when foreign matter such as metal powder remains inside, the foreign matter is removed and cleaned after the assembly of the internal components is completed. However, even after the removal and cleaning of the foreign matter is completed in the cable head, new foreign matter such as metal powder may be generated inside due to rattling or the like accompanying the movement of the device.

  Further, a conductor such as a power cable is usually subjected to tin plating or zinc plating for the purpose of ensuring energization performance and preventing the formation of an oxide film. In this case, a whisker that is a needle-like metal crystal is naturally generated on the metal surface of the conductor due to use over time, and the whisker may float in the head case.

  Foreign matter such as metal powder or whisker generated in the cable head falls to the outer surface of the cable cone or the bottom surface of the head case due to vibration caused by electromagnetic force acting on the current path, vibration due to earthquake, etc. There is concern about the deterioration of the characteristics.

Utility Model Registration No. 3203676

  The problem to be solved by the present invention is to provide a cable head of a gas insulated switchgear that can prevent a foreign substance from falling onto the outer surface of the cable cone or the bottom surface of the head case.

  The cable head of the gas insulated switchgear according to the embodiment includes a head case, an insulating cable cone, a connector, a shielding member, and a cover member. In the head case, the conductor on the apparatus main body tank side and the conductor of the external power cable are drawn. The cable cone covers around the conductor of the power cable drawn into the head case. The connector electrically connects the conductor of the power cable and the conductor on the apparatus main body tank side above the cable cone. The shielding member covers an area from the upper part of the connection tool and the outer peripheral area of the side part of the connection tool to the outer peripheral area of the side part of the cable cone, thereby relaxing the electric field concentration between the connection tool and the cable cone. The cover member covers the side area and the lower side of the connection tool on the upper side of the cable cone.

Sectional drawing which shows the gas insulated switchgear of 1st Embodiment. Sectional drawing which follows the II-II line | wire of FIG. 3 of the cable head of 1st Embodiment. Sectional drawing which follows the III-III line | wire of FIG. 2 of the cable head of 1st Embodiment. Sectional drawing which follows the IV-IV line | wire of FIG. 5 of the cable head of the 1st modification of embodiment. Sectional drawing which follows the VV line | wire of FIG. 4 of the cable head of the modification of 1st Embodiment. Sectional drawing which follows the VI-VI line of FIG. 7 of the cable head of the other modification of 1st Embodiment. Sectional drawing which follows the VII-VII line | wire of FIG. 6 of the cable head of the other modification of 1st Embodiment. Sectional drawing similar to FIG. 2 of the cable head of 2nd Embodiment. Sectional drawing similar to FIG. 2 of the cable head of 3rd Embodiment.

  Hereinafter, a cable head of a gas insulated switchgear according to an embodiment will be described with reference to the drawings. In the following description, the same reference numerals are given to configurations having the same or similar functions. And the description which overlaps those structures may be abbreviate | omitted.

(First embodiment)
First, the cable head of the gas insulated switchgear according to the first embodiment will be described with reference to FIGS.
FIG. 1 is a schematic cross-sectional view of a part of a gas-insulated switchgear 1 that employs the cable head 10 of the present embodiment. 2 is a cross-sectional view of the cable head 10 taken along the line II-II of FIG. 3, and FIG. 3 is a cross-sectional view of the cable head 10 taken along the line III-III of FIG.
Although detailed illustration is omitted, the gas insulated switchgear 1 includes a gas insulated circuit breaker having an arc extinguishing chamber therein, and a disconnector unit connected to the upstream side and the downstream side in the power transmission direction of the power of the gas insulated circuit breaker It has. The disconnector unit includes a disconnector for separating the electric circuit, a current transformer for measurement, a work grounding switch, a busbar, and the like. In the gas insulated circuit breaker and disconnector unit, an insulating gas such as SF ₆ (sulfur hexafluoride) gas is sealed inside the apparatus main body tank.

For example, as shown in FIG. 1, the cable head 10 is connected to the apparatus main body tank 2 of the disconnector unit. A conductor 3 is disposed in the apparatus main body tank 2. The conductor 3 is held at the end of the apparatus main body tank 2 via an insulating spacer 6. The cable head 10 has a head case 11 into which the conductor 3 on the apparatus main body tank 2 side and the conductor 5 of the external power cable 4 are drawn. The head case 11 is connected to the apparatus main body tank 2 at the upper side, and the conductor 5 of the power cable 4 is drawn from below the bottom wall 11a. In addition, an insulating gas such as SF ₆ (sulfur hexafluoride) gas is sealed inside the head case 11.

  An insulating cable cone 12 that covers the periphery of the conductor 5 of the power cable 4 is installed on the bottom wall 11 a of the head case 11. The cable cone 12 is formed in a substantially conical shape whose outer diameter gradually narrows toward the upper side, and its upper end portion is formed flat. The conductor 5 of the power cable 4 protrudes upward through the axial center portion of the cable cone 12. Above the cable cone 12, a connector 13 that electrically connects the conductor 5 protruding upward from the cable cone 12 and the conductor 3 on the apparatus main body tank 2 side is disposed.

  As shown in FIG. 2, on the flat upper surface of the cable cone 12, a connection tool 13 and a shielding block 15 that covers the periphery of the connection tool 13 are installed via an arbitrary number of spacer rings 14. The conductor 5 of the power cable 4 is inserted through the through hole 14a at the center of each spacer ring 14 from below.

The shielding block 15 includes a thick cylindrical first shielding member 16 that holds the upper part of the connection tool 13, peripheral area covers 17 </ b> A and 17 </ b> B and a bottom plate 18 that cover the outer peripheral area and the lower side of the connection tool 13, And a thin cylindrical second shielding member 19 that is attached to the shielding member 16 and surrounds the outer periphery of the peripheral area covers 17A and 17B and the bottom plate 18. The lower edge of the second shielding member 19 extends to the vicinity of the tapered outer peripheral surface of the cable cone 12. A gap d is secured between the second shielding member 19 and the outer peripheral surface of the cable cone 12. The first shielding member 16 and the second shielding member 19 are formed of a metal material having a large electric resistance such as an aluminum alloy. The peripheral covers 17A and 17B and the bottom plate 18 are also made of a metal material having a large electric resistance such as an aluminum alloy, like the first shielding member 16 and the second shielding member 19.
The first shielding member 16 and the second shielding member 19 constitute a shielding member that alleviates electric field concentration between the connector 13 and the cable cone 12 when a voltage is applied. Further, the peripheral area covers 17 </ b> A and 17 </ b> B and the bottom plate 18 constitute a cover member that covers the side outer peripheral area and the lower side of the connection tool 13 above the cable cone 12.

  The connection tool 13 includes a connection tool main body 13A attached to the first shielding member 16, and a clamping piece 13B attached to the connection tool main body 13A and holding the conductor 5 on the power cable 4 side together with the connection tool main body 13A. ing. The connector main body 13A and the sandwiching piece 13B are made of a highly conductive metal material and are electrically connected to the conductor 5 on the power cable 4 side.

  The connector main body 13A includes a perforated disk-shaped mounting base 21 fastened and fixed to the lower surface of the first shielding member 16 by a bolt 20, a boss portion 22 protruding from the upper surface side of the mounting base 21, and a mounting base. Arm piece 23 extending downward from the lower surface side of 21, and clamping piece 24 connected to the lower end of arm piece 23. As shown in FIG. 3, the clamping piece 24 of the connector main body 13A is formed in a substantially symmetrical shape with the clamping piece 13B. Both sandwiching pieces 24 and 13B include a substantially arc-shaped sandwiching portion 25 that sandwiches the outer peripheral surface of the conductor 5 on the power cable 4 side, and a pair of fastening flanges 26 that extend in opposite directions from both ends of the arc of the sandwiching portion 25. And have. In the state where the conductor 5 is interposed between the sandwiching portions 25 of the sandwiching pieces 24 and 13B, the opposing fastening flanges 26 are fastened and fixed by bolts 27. Thereby, the connection tool 13 is electrically connected to the conductor 5 on the power cable 4 side.

  The first shielding member 16 has a conductor insertion hole 28 formed in the center on the upper surface side. In addition, a substantially circular recess 29 that communicates with the conductor insertion hole 28 is formed at the center of the lower surface side of the first shielding member. In the lower region of the recess 29, the boss portion 22 of the connector main body 13A is fitted from below. In the space surrounded by the recess 29 and the boss 22, a plurality of connection claws 30 made of conductive metal and a biasing spring 31 that biases the connection claws 30 radially inward of the recess 29 are accommodated. Has been. The plurality of connection claws 30 are contact-connected to the boss portion 22 of the connection tool main body 13A at the base end portion (lower end portion). The end portion of the conductor 3 on the apparatus main body tank 2 side is inserted into the conductor insertion hole 28 of the first shielding member 16 from above. At this time, when the end portion of the conductor 3 is inserted into the connection claw 30 against the urging force of the urging spring 31, the connection tool 13 is connected to the apparatus main body tank 2 side via the plurality of connection claw 30. The conductor 3 is electrically connected.

  Further, a connection flange 32 is extended on the outer periphery of the lower end of the first shielding member 16. An inward flange 33 extending to the upper end portion of the second shielding member 19 is fastened and fixed to the connection flange 32 by a bolt 34.

  The bottom plate 18 is formed in a perforated disk shape, and the conductor 5 of the power cable 4 is inserted into the central through hole 18a from below. A pair of brackets 35 having a substantially L-shaped side view are attached to the upper surface of the bottom plate 18. Each bracket 35 has one side fixed to the bottom plate 18 by a bolt 36a and a nut 36b, and the clamping piece 24 of the connector main body 13A is fastened and fixed to the other side by a bolt 27. Thereby, the connection tool 13 is fixed to the upper surface side of the bottom plate 18.

  In each of the peripheral area covers 17A and 17B, a joining flange 37b is extended at the end in the arc direction of a semi-cylindrical main wall 37a that surrounds the outer peripheral area of the side portion of the connector 13. The pair of peripheral area covers 17A and 17B have the joining flanges 37b butted together, and the joining flanges 37b are fastened and fixed by bolts 38a and nuts 38b. Further, a flange portion 37c that is bent outward in the radial direction is extended to the lower end of the main wall 37a of each of the circumferential cover 17A, 17B. Each of the peripheral area covers 17A and 17B has a flange portion 37c that is abutted against the upper surface of the bottom plate 18, and is fastened and fixed to the bottom plate 18 by bolts 39a and nuts 39b.

  Thus, the shielding block 15 in which the bottom plate 18 and the surrounding area covers 17A and 17B are assembled is placed in a state where the lower surface of the inner peripheral edge of the bottom plate 18 is in contact with the upper surface of the uppermost spacer ring 14. As a result, the outer peripheral area and the lower side of the side portion of the connector 13 are closed by the peripheral area covers 17 </ b> A and 17 </ b> B and the bottom plate 18. Therefore, even if metal powder is generated at the connector 13 and its vicinity after the parts are assembled in the cable head 10 or whiskers are naturally generated on the metal surface of the conductor 5, these foreign matters are The cable cone 12 does not fall on the outer peripheral surface of the cable cone 12 or the bottom wall 11 a in the head case 11 through the gap d below the second shielding member 19.

  As described above, the cable head 10 of the present embodiment includes the peripheral cover 17A, 17B and the bottom plate 18 that cover the outer peripheral area and the lower side of the connection tool 13 on the upper side of the cable cone 12. For this reason, even if metal powder is generated in the connection tool 13 and the vicinity thereof, or whiskers are naturally generated on the metal surface of the conductor 5, these foreign substances pass through the gap d below the second shielding member 19. It is possible to prevent the cable cone 12 from dropping onto the outer peripheral surface of the cable cone 12 or the bottom wall 11 a in the head case 11. Therefore, it is possible to prevent the withstand voltage characteristics of the cable head 10 from deteriorating due to foreign matters adhering to the outer peripheral surface of the cable cone 12 or the bottom wall 11 a in the head case 11.

4 is a cross-sectional view taken along line IV-IV in FIG. 5 of a modification of the cable head 10 of the first embodiment, and FIG. 5 is a cross-section taken along line V-V in FIG. 4 of the modification. FIG.
The cable head 10 according to the present modification includes cap nuts 38bA, 39bA, 27bA, which are nuts to be penetrated, between the fastening portions of the peripheral covers 17A, 17B and the bottom plate 18 and the fastening portions of these internal members. 36bA is employed. Specifically, the fastening portions between the circumferential covers 17A and 17B, the fastening portions of the circumferential covers 17A and 17B and the bottom plate 18, the fastening portions of the clamping piece 24 and the clamping piece 13B of the connector 13, and the bracket 35 And cap nuts 38bA, 39bA, 27bA, 36bA are employed in the fastening portion of the bottom plate 18. Each cap nut 38bA, 39bA, 27bA, 36bA is fixed by welding to a member having a bolt insertion hole.

  In the cable head 10 of this modification, the cap nuts 38bA, 39bA, 27bA, and 36bA are employed in the fastening portions between the members of the circumferential covers 17A and 17B and the bottom plate 18 and the fastening portions between these members. Therefore, it is possible to prevent the metal powder generated by tightening each bolt from dropping from the tightened portion of the bolt and nut to the outside. Therefore, by adopting this configuration, it is possible to more reliably suppress the metal powder from adhering to the outer peripheral surface of the cable cone 12 and the bottom wall 11a in the head case 11 and deteriorating the withstand voltage characteristics. .

6 is a sectional view taken along line VI-VI in FIG. 7 of another modification of the cable head 10 of the first embodiment, and FIG. 7 is taken along the line VII-VII in FIG. 6 of the modification. It is sectional drawing.
In the cable head 10 of this modification, a sealing member 40 such as a rubber plate or a resin is interposed between the butted portions of the peripheral covers 17A and 17B and the bottom plate 18 and the butted portions of these internal members. Yes. Specifically, for example, between the joining flanges 37b of the peripheral area covers 17A and 17B, between the flange portions 37c of the peripheral area covers 17A and 17B and the upper surface of the bottom plate 18, and between the clamping piece 24 and the clamping piece 13B of the connector 13 In the meantime, the sealing member 40 is interposed between the upper end portions of the circumferential cover 17A, 17B and the lower surface of the first shielding member 16 or the like.

  In the cable head 10 of this modification, since the sealing member 40 is interposed at the abutting portions of a plurality of members arranged above the cable cone 12, foreign matter such as metal powder is present between or inside these members. Even if it remains, it is possible to more reliably prevent foreign matter from falling on the outer peripheral surface of the cable cone 12 and the bottom wall 11a in the head case 11.

(Second Embodiment)
Next, the cable head 110 of the second embodiment will be described with reference to FIG.
The basic configuration of the cable head 110 of the present embodiment is substantially the same as that of the first embodiment, but the peripheral cover 117 that constitutes a part of the cover member is configured integrally with the first shielding member 116. ing. The peripheral cover 117 is formed in a cylindrical shape, and an upper end portion thereof is continuously provided on the lower surface of the outer peripheral portion of the first shielding member 116. In the case of the present embodiment, since the peripheral area cover 117 is formed integrally with the first shielding member 116, the bottom plate 18 is fastened and fixed to the lower surface of the peripheral area cover 117 by a plurality of screws 41.

  In the cable head 110 of the present embodiment, the peripheral cover 117 that constitutes a part of the cover member is configured as an integral part of the first shielding member 116, so that the same effect as that of the first embodiment is obtained. Therefore, it is possible to reduce the number of parts and suppress an increase in product cost.

(Third embodiment)
Next, the cable head 210 according to the third embodiment will be described with reference to FIG.
The cable head 210 according to the present embodiment is provided with a cover member (the peripheral covers 17A and 17B and the bottom plate 18 according to the first embodiment) that covers the outer peripheral area and the lower side of the connection tool 13 above the cable cone 12. Instead of providing, the following structure is adopted.
That is, in the cable head 210 of the present embodiment, an annular covering member 50 that covers the side peripheral region of the connector 13 and extends to the upper end surface of the cable cone 12 is provided. The annular covering member 50 can be constituted by, for example, a heat shrinkable tube or a soft resin tape. In the case of this embodiment, the upper edge portion of the annular covering member 50 is attached around the annular portion 49 on the lower surface of the attachment base 21 of the connector 13, and the lower edge portion of the annular covering member 50 is attached to the spacer ring 14. It is attached to the outer peripheral surface. For this reason, the periphery of the connector 13 and the spacer ring 14 is continuously sealed by the annular covering member 50.

  The cable head 210 according to the present embodiment is provided with an annular covering member 50 that covers the side peripheral region of the connection tool 13 and extends to the upper end surface of the cable cone 12. For this reason, even if metal powder is generated in the connection tool 13 and its vicinity, or whiskers are naturally generated on the metal surface of the conductor 5, these foreign substances are generated in the outer peripheral surface of the cable cone 12 and the head case 11. Can be prevented from falling on the bottom wall 11a. Therefore, also in the case of this embodiment, it can suppress that the withstand voltage characteristic in the cable head 210 deteriorates with a foreign material.

  According to at least one embodiment described above, the outer surface of the cable cone is provided by having a head case, an insulating cable cone, a connector, a shielding member, a cover member, or an annular covering member. And foreign matter can be prevented from falling to the bottom surface in the head case.

  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 embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Gas insulation switchgear, 2 ... Apparatus main body tank, 3 ... Conductor, 4 ... Power cable, 5 ... Conductor, 10, 110, 210 ... Cable head, 11 ... Head case, 12 ... Cable cone, 13 ... Connection tool, 16, 116 ... first shielding member (shielding member), 17A, 17B, 117 ... peripheral cover (cover), 18 ... bottom plate (cover member), 19 ... second shielding member (shielding member), 27bA, 36bA, 38bA , 39bA ... cap nut (non-penetrating nut), 40 ... sealing member, 50 ... annular covering member.

Claims (5)

A head case in which the conductor of the device main body tank side and the conductor of the external power cable are drawn,
An insulating cable cone covering the periphery of the conductor of the power cable drawn into the head case;
A connector for electrically connecting the conductor of the power cable protruding upward from the cable cone and the conductor of the apparatus main body tank on the upper side of the cable cone;
A shielding member that covers an area extending from the outer peripheral area of the connector and the side outer peripheral area of the connector to the side outer peripheral area of the cable cone, and that relaxes electric field concentration between the connector and the cable cone;
On the upper side of the cable cone, a cover member that covers the outer peripheral area and the lower side of the side of the connector,
The cable head of the gas insulated switchgear equipped with.   The cable head of the gas insulated switchgear according to claim 1, wherein at least a part of the fastening portion of the member disposed on the upper side of the outer surface of the cable cone has a non-penetrating nut.   3. The gas insulated switchgear according to claim 1, wherein a sealing member that seals between the butted portions is interposed in abutting portions of the plurality of members disposed on the upper side of the outer surface of the cable cone. Cable head.   The cable head of the gas insulated switchgear according to any one of claims 1 to 3, wherein at least a part of the cover member is configured as an integral part with at least a part of the shielding member. A head case in which the conductor of the device main body tank side and the conductor of the external power cable are drawn,
An insulating cable cone covering the periphery of the conductor of the power cable drawn into the head case;
A connector for electrically connecting the conductor of the power cable protruding upward from the cable cone and the conductor of the apparatus main body tank on the upper side of the cable cone;
A shielding member that covers an area extending from the outer peripheral area of the connector and the side outer peripheral area of the connector to the side outer peripheral area of the cable cone, and that relaxes electric field concentration between the connector and the cable cone;
An annular covering member that covers the side periphery of the connector and extends to the upper surface of the cable cone;
The cable head of the gas insulated switchgear equipped with.

Images