JPH0331774A - High voltage testing method for power cable - Google Patents

Abstract

PURPOSE:To easily perform a high voltage test even at the place with narrow space by filling up an insulating gas using a bag made of a plastic, etc. CONSTITUTION:One of terminal junction boxes 12 in gas of a power cable 11 is put in the atmosphere and a lead cable 19 connecting to a high voltage generating device 20 is connected directly to a conductor 13 at the top end of the box. Next, the part from the end part of cable 19 to the base part of box 12 is covered with an insulating bag 21. Then, an SF6 gas is filled in the bag 21 from a cylinder 22 after air in the bag 21 is discharged. When the bag 21 is in the swelling state, the box 12 is identified as being installed in the gas, and the high voltage test can be performed without generating a flashover at the surface along an insulating tube when the high voltage is impressed from the device 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high voltage testing method for power cables having a gas termination junction box.

[Prior art]

Conventionally, high voltage tests on power cables with gas termination junction boxes have been carried out as shown in Figure 2.

That is, the power cable 11 has a gas intermediate terminal junction box 12 at both ends, and each of these gas intermediate terminal junction boxes 12 is a gas container (filled with an insulating gas such as SF or gas).
GIS terminal box, etc.) 14.

When performing a high voltage test, a test adapter 15 is installed on the gas container 14. This test adapter 15 is S
A connecting conductor 17 and a bushing 18 are housed in a case 16 filled with an insulating gas such as P gas or the like. One end of the connecting conductor 17 is connected to the conductor 13 at the tip of the gas termination junction box 12 within the gas container 14, and the other end is connected to the high voltage generator 20 via a lead cable 19.

In this state, the high voltage generator 20 generates a high voltage,
This is applied to the power cable 11 to perform a high voltage test.

〔assignment〕

Conventional high voltage testing methods require test adapters as mentioned above, which has the disadvantage of increasing costs.
Also, depending on the installation location of the gas container, there may not be enough space to install the test adapter. If there is no space to install the test adapter, take the gas termination junction box outside the gas container and perform high voltage tests in the atmosphere. However, since the gas submerged terminal box is designed to be installed in an insulating gas such as SF or gas, the length of the guy tube is longer than that of the air submerged terminal box or the oil submerged terminal box. Therefore, if you try to install this in the atmosphere and perform a high voltage test, flange over tends to occur along the guy tube, making it virtually impossible to perform a high voltage test.

[Means for solving problems and their effects]

In order to solve the above-mentioned problems, the present invention provides a lead connected to a high voltage generator at the conductor at the tip of the gas termination junction box when performing a high voltage test on a power cable having a gas termination junction box. After connecting the cable, cover the area from the end of the lead cable to the base of the gas termination connection box with an insulating bag, fill the bag with insulating gas, and apply internal pressure to inflate the bag. This is characterized in that a high voltage is applied by the high voltage generator.

In this way, you can avoid using a test adapter.
High voltage tests can be easily performed using inexpensive bags made of plastic or the like.

〔Example〕

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

FIG. 2 shows an embodiment of the present invention, and the same parts as in FIG. 2 described above are given the same reference numerals.

In the test method of the present invention, one of the gas termination junction boxes 12 of the power cable 11 is placed in the atmosphere, and the lead cable 19 connected to the high voltage generator 20 is directly connected to the conductor 13 at the tip. The area from the end of the lead cable 19 to the base of the gas termination connection box 12 is covered with an insulating bag 21.

As the bag 21, it is preferable to use a bag made of polyethylene or polyvinyl chloride film formed into a cylindrical shape, with a hose 23 connected to the SFh gas cylinder 22 connected to the middle part. Such a cylindrical bag 21 is used. When connecting the lead cable 19, place it on the side of the lead cable 19 or on the side of the gas termination junction box 12, and after connecting the lead cable 19, remove the bag 21 from the end of the lead cable 19. It is pulled back to a position that covers up to the base of the gas intermediate terminal connection box 12.

Then, squeeze both ends as shown, wrap adhesive tape, etc., and apply a simple seal. This seal only needs to allow some gas to pass through. After squeezing the bag 21 in this state to expel the air inside, SF in the bag 21 from the cylinder 22,
Gas is supplied to inflate the bag 21. SP in this way in bag 21! It is convenient to set the gas pressure in the zero bag 21 to be filled with gas to be higher than the atmospheric pressure, and to allow the SPi gas to leak slightly into the atmosphere from the seals at both ends, since there is no risk of air entering the bag 21. It is.

When the bag 21 is inflated, the gas intermediate terminal connection box 12
is installed in SF & gas, so if high voltage is applied from the high voltage generator 20 in this state,
High voltage tests can be performed without causing flange over along the guide tube.

〔Effect of the invention〕

As explained above, according to the present invention, by covering the bag with an inexpensive bag made of plastic or the like and filling it with insulating gas, it is possible to conduct a high voltage test on a power cable having a terminal junction box in gas. This method eliminates the need for an adapter, is economical, and has the advantage of allowing high-voltage tests to be easily performed even in confined spaces.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a power cable high voltage testing method according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing a conventional power cable high voltage testing method. ll: Power cable, 12: Gas termination junction box, 13:
Conductor, 19: Lead cable, 20: High voltage generator,
21: Bag, 22: SP, gas cylinder, 23: Hose.

Claims (1)

[Claims] 1. In the high voltage test method for power cables having a gas termination junction box, a lead cable connected to a high voltage generator is connected to the conductor at the tip of the gas termination junction box, and then the gas is connected from the end of the lead cable. It is characterized by covering the intermediate terminal junction box up to the base with an insulating bag, filling the bag with insulating gas, applying internal pressure to inflate the bag, and applying high voltage from the high voltage generator mentioned above. High voltage test method for power cables.