JPS627321A - Assembling of rubber plastic cable connection - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of assembling a rubber or plastic cable connection.

(Prior Art) For example, a rubber or plastic cable connection part 1, such as a C■ cable terminal connection part of an ultra-high voltage class of 220 kV to 500 kV, was assembled as follows. At the factory, as shown in FIG. 2, a reinforcing insulator 2 mainly consisting of a capacitor cone or a stress cone is coated with a protective tape 3 such as insulating paper around the outer periphery, and then heated and vacuum-dried to form a transport case 4. After the inside of the transport case 4 is vacuum degassed, it is filled with insulating oil 5 and sealed by applying a predetermined pressure. This transport case 4 is transported to the site, where the insulating oil 5 is removed from the transport case 4, the internal reinforcing insulator 2 is taken out, and the reinforcing insulator 2 is attached to a rubber or plastic cable 6 as shown in FIG. An epoxy bell mouth 8 is mounted on the cable insulator 7 , an epoxy bell mouth 8 is mounted on the reinforcing insulator 2 , and a shielding layer 9 is provided on the base side of the epoxy bell mouth 8 and the reinforcing insulator 2 . After that, a magnetic or epoxy insulator tube 10 was placed over the outer periphery of the part to which the reinforcing insulator 2 was attached, and after the inside of the insulator tube 10 was vacuum degassed, it was filled with insulating oil 11.

In this case, the reinforcing insulator 2 is formed at the factory by wrapping and wrapping the insulating paper 13 for adjusting the inner diameter around the outer periphery of the shaft 12, which is divided into two parts, and placing the inside of the cone on top of it. A heat-shrinkable tube 14 serving as a core is covered and shrunk, and an embossed plastic film made of, for example, polyethylene or polyester is rolled up around its outer periphery with a narrow or wide width, and metal foil is inserted at a predetermined position as necessary in between. This was done by forming a stress cone or condenser cone 15. Note that the insulating paper 13 for adjusting the inner diameter is
This is to adjust the inner diameter of the reinforcing insulator 2 to the outer diameter of the cable insulator 7 by extracting it from the inner layer when installing the reinforcing insulator 2 on the cable insulator 7 at the site.

As the insulating oil 5, 11, for example, silicone oil, which is compatible with the embossed plastic film, cable insulator 7, or conductive layer constituting the stress cone or capacitor cone 15, is used.

(Problem to be solved by the invention) However, stress cone or capacitor cone 1
If 5 is made of an embossed plastic film or the like, the embossed plastic film or the like has poor heat resistance, so heating cannot be performed until the moisture in the insulating paper 13 is completely removed when the reinforcing insulator 2 is dried. First, moisture remained in the insulating paper 13, and there was a risk that this residual moisture would spread into the insulating oil impregnated within the reinforcing insulator 2 at the time of shipment.

On the other hand, at the construction site, the insulating oil 5 is discharged from the transport case 4, the reinforcing insulator 2 impregnated with the insulating oil 5 is taken out from the transport case 4, the inner insulating paper 13 is removed, and the inner diameter is adjusted. After attaching to the cable insulator 7, the insulator tube 10
Since the reinforcing insulator 2 is exposed to the atmosphere for 2 to 3 days to perform shielding treatment, reinforcing insulation treatment, etc. before it is covered and vacuumed, the insulating oil 5 absorbs moisture during this time, causing the above-mentioned Coupled with the problem of diffusion of residual moisture, there was a problem that electrical insulation performance deteriorated. In addition, when vacuuming the reinforcing insulator 2 impregnated with insulating oil 5, there is a problem that the insulating oil 5 between the embossed plastic films becomes an oil trap, making it difficult to vacuum, and it takes time to vacuum. There was a point. Furthermore, since the insulating oil 5 placed in the transport case is likely to have absorbed moisture, it has to be discarded, resulting in an uneconomical problem.

An object of the present invention is to provide a rubber that does not require the use of insulating oil during transportation and can solve the problems associated with using insulating oil.

An object of the present invention is to provide a method for assembling a plastic cable connection.

(Means for Solving the Problems) The means of the present invention for achieving the above object will be explained with reference to FIGS. 1 and 3 corresponding to embodiments. The reinforcing insulator 2 mainly consisting of the cone 15 is vacuum dried and stored in the transport case 4, and after the inside of the transport case 4 is vacuum degassed, the air is replaced with dry inert gas 16 and sealed under positive pressure. The transport case 4 is transported to the site, and after opening, the reinforcing insulator 2 is taken out from inside the transport case 4 and installed on the cable insulator 7 of the rubber or plastic cable 6, and the insulator tube 10 is attached to the outer periphery of the reinforcing insulator 2.
This is characterized in that the insulating oil 11 is filled into the insulating oil 11 after the insulating tube 10 is covered and vacuum degassed.

(Function) After the inside of the transport case 4 containing the reinforcing insulator 2 is vacuum degassed, it is replaced with dry inert gas 16, sealed under positive pressure, and transported to the site. Since the reinforcing insulator 2 is not impregnated with insulating oil when attached to the cable insulator 7, there is no problem of moisture absorption of the insulating oil, and vacuum degassing on site is not hindered by the insulating oil. It can be done in a short time.

(Example) Examples of the present invention will be described below in accordance with the process order with reference to FIGS. 1 and 3.

(a) The reinforcing insulator 2 is vacuum-dried at a predetermined temperature to remove moisture in the capacitor cone or stress cone 15 and insulating paper 13.

(b) This dried reinforcing insulator 2 is stored in a transport case 4, and after the inside of the case 4 is vacuum degassed, the air is replaced with dry inert gas (for example, dry N2 gas) to the extent of O to 1 Kg/adG. Apply positive pressure and seal.

(c) Transport the transport case 4 that has completed the t1 stop to the site,
After opening the package, remove the inner layer of the insulating paper 13 and adjust the inner diameter.
It is mounted on the cable insulator 7.

2) After performing reinforcing insulation treatment such as attaching an epoxy bell mouth 8 to the reinforcing insulator 2 on the cable insulator 7, and shielding treatment such as forming a shielding layer 9, the insulator tube 10 is covered, and vacuum evacuation is performed. After cooling, the insulating oil 11 is filled into the insulator tube 10.

Note that the stress cone or capacitor cone 15 is not limited to the embossed plus deck film, and may be formed using a plastic nonwoven fabric or the like.

The inert gas 16 is not limited to N2 gas, but may also be SFs gas or the like.

275 kVX using the conventional assembly method and the assembly method of the present invention
A prototype condenser cone for a 600m+r air termination connection was made, an actual air termination was assembled, and various numerical values were compared, and the following results were obtained.

However, n is the number of samples.

Normally, when the water content of silicone oil exceeds 150 ppm, the electrical characteristics gradually deteriorate, and when the water content exceeds 100 ppHl, the electrical characteristics deteriorate rapidly. Therefore, in the conventional method, there is a possibility that the threshold value may be exceeded due to variations in the working environment (time, humidity) during on-site execution. According to the present invention, since the plastic film itself hardly absorbs moisture, the moisture content can be stably suppressed to a low level regardless of the working environment at the site, and the properties can therefore be stabilized.

In the above embodiment, a terminal connection part for an ultra-high voltage C■ cable was explained, but the present invention is applicable to other types of connection parts formed by a combination of a plastic insulator that does not easily absorb moisture and an insulating oil that easily absorbs moisture. It can be applied to

(Effects of the Invention) As explained above, in the method for assembling a rubber/plastic cable connection part according to the present invention, the inside of the transport case containing the reinforcing insulator is vacuum degassed, and then replaced with dry inert gas. Since it is sealed under pressure and transported to the site, when it is opened on site and installed on the cable insulator, the reinforcing insulator is not impregnated with insulating oil, so there is no problem of moisture absorption of the insulating oil. It also has the advantage of being able to perform vacuum degassing on site in a short time without being hindered by insulating oil. Furthermore, since the present invention uses a dry method during transportation, no insulating oil is required, and costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing the reinforcing insulator in a state during transportation using the method of the present invention, Fig. 2 is a longitudinal sectional view showing the reinforcing insulator in a state during transport using the conventional method, and Fig. 3 FIG. 4 is a vertical cross-sectional view of one half of a rubber/plastic cable connection portion, and FIG. 4 is a vertical cross-sectional view of one half showing the manufacturing process of the reinforcing insulator. 1...Rubber, plastic cable connection part, 2...
Reinforcement insulator, 4... Transport case, 5... Insulating oil, 6
...Rubber, plastic cable, 7...Cable insulator, 10...Insulator tube, 11...Insulating oil, 13...
- Insulator, 15... stress cone or capacitor cone.

Claims (1)

[Claims] The reinforcing insulator, mainly consisting of a capacitor cone or stress cone, is vacuum dried and stored in a transport case, replaced with gas and sealed under positive pressure, and this transport case is transported to the site, and after opening, the transport case is A rubber or plastic cable, characterized in that the reinforcing insulator is taken out from inside and installed on the cable insulator of the rubber or plastic cable, the outer periphery of the reinforcement insulator is covered with an insulating tube, and after vacuum degassing, the insulating oil is filled inside the insulating tube. How to assemble the connections.