JP2005006424A - Termination connection for power cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a termination connection for power cable which has a simple structure for easy construction as well as easy modification, braking up, and re-connection. <P>SOLUTION: The termination connection for power cable has an equipment case filled with an insulating gas, and an enclosure detachably provided outside it. A conductor connection rod is extended from the inside of the equipment case to the inside of the enclosure. The enclosure has within it a conductor connection part where a conductor at the tip of a power cable can be inserted/taken out from the conductor connection rod, and an insulation process for reinforcing and insulating the interior of the conductor connection. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power cable termination connection portion, and more particularly to a device direct connection type high voltage power cable termination connection portion.
[0002]
[Prior art]
As an example of the structure of a conventional device direct connection type terminal connection portion, for example, there is one shown in Patent Document 1.
[0003]
[Patent Document 1]
Japanese Utility Model Laid-Open No. 2-17925 [0004]
This terminal connection part is detachably attached to the opening of the casing of the switchgear so that the insulator having a cable insertion hole is positioned in the casing, and the end of the cable is inserted into the end of the cable insertion hole. A removable cable connection is provided.
[0005]
Further, FIG. 11 shows a structural example of a typical GIS (gas insulated switchgear) direct connection terminal connection part as a conventional apparatus direct connection terminal connection part.
[0006]
In this GIS direct connection termination connection portion, an epoxy hollow insulator 7 is disposed in the cable termination portion GIS case 2 supported at a predetermined location via a mounting flange 12 and an insulator flange 13. In the upper part of the hollow insulator 7, the cable conductor 23 is compression-connected to the conductor connecting rod 5, and the conductor connection 5 is transferred from the uppermost through hole of the insulator 7 to the space of the insulating gas 3 in the GIS case 2. It is pulled out and connected to the GIS bus bar 1 through the adapter 4. The lead-out portion from the insulator 7 of the conductor lead bar 5 is hermetically sealed by an O-ring or the like.
[0007]
The electric field control of this GIS direct connection terminal connection is performed by the insulating rubber stress cone 9 and the semiconductive rubber stress cone installed around the cable insulator 8 from which the cable outer shielding layer 17 is removed. 10 and controlled within the allowable electric field strength. A high voltage embedded shield 6 is embedded in the upper part of the hollow insulator 7 for electric field control of the connection portion between the cable conductor 23 and the conductor connecting rod 5. On the other hand, an earth-embedded shield 11 is embedded under the hollow insulator 7 in order to control the electric field at the end of the cable outer shield layer 17.
[0008]
In the insulation design by the insulating rubber stress cone 9 and the semiconductive rubber stress cone 10, the insulation performance depends on the contact interface between the surface of the cable insulator 8 and the tapered surface of the hollow insulator 7. It is necessary to maintain the surface pressure properly. For this reason, a relatively uniform pressure is applied from the lower part of the insulating rubber stress cone 9 and the semiconductive rubber stress cone 10 by the spring 15 via the metal fitting 14. Further, the lower part covers and protects the insulation portion of the cable 19 by a protective metal fitting 16 and an end seal 18 so as to be blocked from the outside.
[0009]
[Problems to be solved by the invention]
However, in such a structure of the GIS direct connection terminal connection portion, the connection portion between the cable conductor 23 and the conductor connection rod 5, and the insulating treatment portion by the insulating rubber stress cone 9 and the semiconductive rubber stress cone 10 are provided in the GIS case 2. Since it is located in the hollow insulator 7 provided inside, it is necessary to first disassemble the GIS case 2 when assembling, and then the hollow insulator 7 is attached to the GIS case 2 and the cable conductor 23 It is necessary to perform connection and insulation processing, and seal processing of the lead-out part of the conductor connection dedicated 5 to the GIS case 2 side, and processing (encapsulation) of the insulating gas 3 is required, and it takes time and labor for assembly work. However, there is an inconvenience that the above is restrained.
[0010]
For this reason, when the cable processing worker and the worker on the GIS equipment side are different, there is a complaint that the role sharing of the work and the adjustment of the work schedule are required. Furthermore, since these processing units are all located within the GIS case 2, when any trouble or accident occurs in the cable connection, the cable processing operator and the GIS equipment side There was also a problem that it was difficult to clearly define the responsibilities of workers.
[0011]
Furthermore, the connection of the cable conductor 23 and the insulation treatment work in the hollow insulator 7 may be blind work after the insulator is once covered, and the reliability may be lowered.
[0012]
Moreover, in the structure of the apparatus direct connection type terminal connection part shown in Patent Document 1, the insulator having the cable insertion hole is attached in the casing of the switchgear, and the cable connection part is provided therein. It had the same problem as the GIS direct connection termination connection.
[0013]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a power cable termination connection portion that has a simple structure and is easy to construct, and that can be easily repaired, disassembled and reconnected.
[0014]
Another object of the present invention is to provide a power cable terminal connection portion that can be constructed with high reliability without a blind operation.
[0015]
Further, another object of the present invention is that when the equipment side operator such as GIS is different from the cable side connection operator, work such as new assembly and inspection / repair during use can be completely separated. Therefore, it is possible to provide an end connection for a power cable that can be carried out independently, and the spillover range in the event of an accident is clarified.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, the terminal connection part for a power cable of the present invention has a device case filled with an insulating gas and a housing detachably provided on the outside, and a conductor connecting rod is the device. A conductor connecting portion that extends from the inside of the case to the inside of the housing and in which the conductor portion at the tip of the power cable can be inserted into and removed from the conductor connecting rod, and performs internal reinforcement insulation of the conductor connecting portion. An insulation processing unit is provided.
[0017]
It is preferable to use a rubber insulator as the main insulator in the insulation processing section.
[0018]
It is desirable to use an energizing contact for the conductor connecting portion.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a power cable termination connecting portion of the present invention will be described with reference to the drawings.
[0020]
FIG. 1 shows an embodiment of a power cable termination connecting portion of the present invention.
This power cable termination connection part is an example of a GIS direct connection type 300 kV high voltage power cable termination connection part, and the dimensional joint part with the basic GIS equipment manufacturer side is IEC standard TC60859 “CABLE CONNECTIONS FOR GAS-INSULLATED METAL- ENCLOSED SWITCHGEAR FOR RATED VOLTAGOF OF 72.5kV AND ABOVE ". According to this IEC standard, 300kV Dry type cable connection of _S 1 -S ₂ between dimensions (Figure 1) is a 620 mm.
[0021]
The power cable terminal connection portion shown in FIG. 1 has a simple structure in which the periphery of the conductor connecting rod 5 is molded by an epoxy resin insulator 7a in the GIS case 2. For this reason, the connection part of a cable conductor and the part which performs an insulation process are not arrange | positioned in the GIS case 2. FIG.
[0022]
Outside the GIS case 2 (lower side in FIG. 1), a conductor sleeve 22 that compressively connects the cable conductor 23 is inserted into the conductor connecting rod 5 that is integrated with the insulator 7, and is electrically contacted electrically. It is connected via a child 21 to be a conductor connecting portion. The conductor sleeve 22 and the conductor connecting rod 5 are mechanically fixed by a cable fixing bracket 24 to prevent the current-carrying contactor 21 from being pulled out due to the expansion / contraction force of the cable or dropping of its own weight.
[0023]
The electric field shielding of the cable conductor connecting portion and the electric field control of the end portion of the cable outer shielding layer 17 are performed by the rubber insulator 20 installed around the electric field. The rubber insulator 20 is electrically connected to the conductive treatment portion 27 formed in contact with the insulator 7a and electrically connected to the stress cone 1 (20a) formed of semiconductive rubber and the cable external shielding layer 17. The stress cone 2 (20d) formed of semiconductive rubber, the internal electrode 20c that electrically shields the conductor connection portion, and the insulating layer 20b that is the main insulation are used as an insulation processing portion. As the material of the rubber insulator 20, EPR or silicon rubber is used, which is molded at a factory, subjected to a sufficient electrical test, and shipped. In addition, the conductive treatment part 27 forms a ground electrode without electric field concentration on the outer surface of the epoxy insulator 7a, and electrically connects the rubber insulator (stress cone 1) 20a and the ground electrode. It is formed by applying and baking-hardening an epoxy-based paint in which silver particles or the like are blended in the required range of the outer surface of the epoxy insulator 7a.
[0024]
A protective body tube 25 is installed on the outer periphery of the rubber insulator 20, and a protective metal fitting 16 is installed on the lower part thereof. Further, an end seal 18 is applied to the cable 19 so as to be shielded from the outside.
[0025]
Next, a method for manufacturing such a power cable termination connection will be described.
First, FIG. 2 shows only the configuration on the GIS equipment side, which is a part of the configuration of the power cable termination connection portion of the present embodiment. This corresponds to a state after all the work on the GIS equipment side is performed without cable connection. As described above, in the GIS case 2, the conductor connecting rod 5 has a simple structure in which the periphery of the conductor connecting rod 5 is molded by the epoxy resin insulator 7a. When the operator is different, the work on the GIS side can be performed independently of the work on the cable side from the installation of the insulator 7a to the GIS case 2 to the enclosure of the insulating gas 3. Thereafter, cable side connection processing can be performed in accordance with the cable connection construction process. Further, when there is a time lag between the GIS side work and the cable side work, a protective case 26 as shown in FIG. 3 can be attached to protect the cable connection side.
[0026]
Next, the cable side connection construction process example of this power cable termination connection part is shown in FIGS. 4 shows a state immediately after the cable side processing is completed and the insulator 7a is just inserted and connected, and FIG. 5 shows a state where the cable conductor 23 is connected to the insulator 7a and the rubber insulator 20 is moved to the final position. 6 shows a state when all connections including the protective metal fitting 16 are completed.
[0027]
In this cable side connection construction process, it is necessary to expand the diameter of the rubber insulator 20 in advance. The shape design of the rubber insulator 20 will be described with reference to FIGS. 7 shows the shape of the rubber insulator 20 in the power cable terminal connection portion of FIG. 1, and FIG. 8 shows the state when the diameter of the rubber insulator 20 is expanded by the diameter expansion jig 28. FIG. It is. FIG. 9 shows the shape of the insulator 7a at the portion where the rubber insulator 20 is inserted.
[0028]
The shape design of the rubber insulator 20 is set as follows in order to ensure the minimum surface pressure by the difference in the diameter of the insertion portion, since the surface pressure of the insertion inner surface by the contraction force of the rubber is an absolute condition. That is, the inner diameter _{d 1} of the internal electrode 20c shown in FIG. 7 is smaller than the outer diameter _{D 1} of the portion where the internal electrode 20c is abutted (see Fig. 9), the inner diameter _{d 2} This stress stress cone 1 (20a) smaller than the outer diameter _{D 2} (see FIG. 9) of the cone 1 (20a) is brought into contact, the inner diameter _{d 3} of the stress cone 2 (20d) is smaller than the outer diameter of the cable insulation 8, the outer diameter of the expanded diameter jig 28 D ₃ is slightly smaller or the same diameter as the inner diameter d ₁ of the internal electrode 20c. Although the minimum surface pressure depends on the type of rubber material, it is initially set to a high value in view of the effects of long-term use. The long-term minimum surface pressure is preferably about 0.2 to 1 kg / mm ² .
[0029]
Next, the cable insulation process will be described. First, the rubber insulator 20 before diameter expansion shown in FIG. 7 is expanded by inserting a diameter expansion jig 28 from the small diameter side as shown in FIG. A tool generally used in cable joints, such as a hydraulic tool, can be used for insertion and extraction of the diameter expansion jig 28.
[0030]
In this state, as shown in FIG. 4, it is inserted into the cable 19 in advance, and the protective body tube 25 and the protective metal fitting 16 are also inserted. Next, the cable conductor sleeve 22 is compression-connected, the cable insulator 8 is stripped, the cable is lifted and inserted into the conductor connecting rod 5 of the insulator 7a, and fixed with the cable fixing bracket 24. Thereafter, as shown in FIG. 5, the rubber insulator 20 is pushed up and inserted to a normal position. Finally, the diameter expansion jig (split structure) 28 is extracted downward to complete the insulation process. Thereafter, the connection work is completed by processing the protective body tube and the protective metal fitting (FIG. 6).
[0031]
In the power cable terminal connection portion of the present embodiment, the following effects can be obtained.
(B) Since the cable conductor connection part and insulation processing part are not arranged in the equipment side case (such as GIS case), it is arranged outside the equipment side case. Work such as disassembling the device side case, reassembly, and sealing with insulating gas is no longer necessary.
(B) Once the insulator 7a is assembled on the GIS case 2 side, the cable connection work can be performed regardless of the work range of the GIS equipment manufacturer, so that the work coordination with the equipment manufacturer becomes unnecessary. As a result, both the device side and the cable side can proceed with work at their own pace.
(C) Since all the cable connection work is visible, blind work is eliminated and highly reliable construction is possible.
(D) By adopting the rubber insulator 20 as the main insulation, a spring or the like is not required, the structure is simplified, and the work efficiency can be greatly improved and the construction can be performed in a short time.
(E) By adopting the electrical connection by the energizing contact 21, repair, disassembly and reconnection can be easily performed.
(F) The insulator 7a can be attached before shipment from the GIS equipment manufacturer's factory.
(G) Since the cable connection part is outside the GIS case 2, the scope of responsibility in the event of an accident is clarified, and the cause can be investigated quickly.
(H) Since the insulator 7a has no through-hole or a secret seal portion by field work and is a completely sealed type, there is no concern about gas leakage.
[0032]
In addition, in FIG. 10, it shows about other embodiment of the termination | terminus connection part for electric power cables of this invention. This power cable termination connection portion is obtained by reducing the dimension M between S _{1 and} S ₂ of the GIS case 2 in FIG. 1 to m. The size M between S _{1 and} S ₂ according to the IEC standard is 620 mm for 300 kV due to the limitation of the cable connection processing size located in the GIS case 2 having the conventional structure shown in FIG. Then, since the structure inside the GIS case 2 becomes extremely simple by positioning the cable processing portion outside the GIS case 2, the above-described dimensional restrictions are eliminated. For this reason, it is possible to greatly reduce the size of the m dimension which is about one third of M.
[0033]
【The invention's effect】
The cable termination connecting portion of the present invention is provided with the conductor connecting portion and the insulation processing portion provided inside the device case in the casing outside the device case, so that the structure inside the device case is simplified, The necessary operations such as disassembly, reassembly, and insulation gas filling of the equipment case at the time of cable connection work are no longer necessary, and repair and disassembly / reconnection can be easily performed.
[0034]
In addition, since the conductor connection portion is provided outside the device case, the cable connection work is performed where it can be seen. Therefore, the blind work is eliminated and the construction with high reliability can be performed.
[0035]
In addition, when the equipment operator and the cable connection operator are different, work such as new assembly, inspection, repair during use, etc. can be completely separated and performed independently. The range can also be clarified.
[0036]
Further, by using a rubber insulator as the main insulator in the insulation processing portion, a spring or the like is not required, the structure is simplified, and the work efficiency can be greatly increased and the construction can be performed in a short time.
[0037]
Furthermore, by using an energizing contact for the conductor connection portion, repair, disassembly and reconnection can be easily performed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of an embodiment of a power cable termination connection portion of the present invention.
FIG. 2 is a cross-sectional view showing a part of the configuration of the present embodiment.
3 is a cross-sectional view showing a structure in which a protective case is attached to the structure shown in FIG.
FIG. 4 is a cross-sectional view showing a cable-side connection construction process of a power cable terminal connection portion according to the present embodiment, showing a state immediately after the cable-side processing is completed and inserted and connected to an insulator.
FIG. 5 is a cross-sectional view showing the cable side connection construction process of the power cable terminal connection portion of the present embodiment, showing a state where the cable conductor is connected to the insulator and the rubber insulator is moved to the final position. It is.
FIG. 6 is a cross-sectional view showing a cable-side connection construction process of a power cable terminal connection portion according to the present embodiment, and shows a state when all connections including a protective metal fitting are completed.
FIG. 7 is a cross-sectional view showing the shape of a rubber insulator in the present embodiment.
FIG. 8 is a cross-sectional view showing a state when a rubber insulator is expanded in diameter by a diameter expansion jig.
FIG. 9 is a cross-sectional view showing the shape of an insulator at a portion where a rubber insulator is inserted.
FIG. 10 is a cross-sectional view showing another embodiment of the power cable terminal connection portion of the present invention.
FIG. 11 is a cross-sectional view showing an example of the structure of a conventional GIS (gas insulated switchgear) direct connection termination connection part.
[Explanation of symbols]
2 GIS case (equipment case)
3 Insulating gas 5 Conductor connection 7a Insulator 8 Cable insulator 19 Cables 20a to 20d Rubber insulator (insulation processing section)
21 Current carrying contact (conductor connection part)
22 Conductor sleeve (conductor connection part)
23 Cable conductor (conductor connection part)
25 Protective trunk (housing)
26 Protective case (housing)

Claims (3)

A device case filled with an insulating gas; and a housing provided detachably on the outside thereof, a conductor connecting rod extending from the inside of the device case to the inside of the housing, and in the housing A power cable termination comprising: a conductor connecting portion in which a conductor portion at the tip of the power cable can be inserted into and removed from the conductor connecting rod; and an insulation processing portion for performing internal reinforcing insulation of the conductor connecting portion. Connection part. The end connection portion for a power cable according to claim 1, wherein a rubber insulator is used as the main insulator in the insulation processing portion. The terminal connection part for electric power cables according to claim 1, wherein an energizing contact is used for said conductor connection part.

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