JPS5815168A - Testing method of bushing - Google Patents

Abstract

PURPOSE:To simplify a replacement work of a sample bushing, to shorten a gas collecting time, and to elevate the test efficiency, by installing a gas tank to flange metallic fittings on a gas insulating medium side of a bushing in advance, immersing the whole body is an oil tank, and executing its test. CONSTITUTION:To a gas side of flange metallic fittings 5 of a sample bushing 1, a gas tank 13 is installed in advance, in a state that a gas insulating medium 12 has been sealed in its inside. Subsequently, a testing bushing 14 used for oil is prepared, and to flange metallic fittings 15, a fitting cover 4 of an oil tank 3 is installed. This testing bushing 14 is connected with the sample bushing 1 in one body. This unified bushing is immersed in the oil tank 3 filled with insulation oil 2, and the fitting cover 4 is installed to the oil tank 3. When a test is executed in this way, a gas connecting box becomes unnecessary, and the working time can be shortened remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bushing test method, and is particularly suitable for testing the dielectric strength of a bushing interposed between a gas-insulated switch and an oil-immersed transformer directly connected thereto. Concerning bushing test method.

Generally, when a gas-insulated switch and an oil-immersed transformer are directly connected, the sunrise wire of the transformer winding is connected to the switch via a bushing, insulated from the tongue or cover. . For this reason, the bushing has a center conductor that electrically connects the two, an insulator that is placed around the center conductor, and a flange fitting that connects to the gas-insulated switch and the oil-immersed transformer. It is something that Such bushings are tested for their dielectric strength.

Conventionally, tests on such bushings have been conducted as follows. That is, as shown in FIG. 1, one side of the flange fitting 5 of the test bushing 1 to be tested is joined to the mounting lid 4 of the oil tank 3, the inside of which is filled with insulating oil 2 in advance. Attach it. Next, a gas connection box 6 is fixed to the opposite side of the flange fitting 5 so as to surround the test bushing 1 protruding from the oil tank 3. In addition, a test bushing 7 is prepared, and the test bushing 7 is? The entire mounting lid 9 of the gas connection box 6 is attached to the lunge fitting 8. After that, the center conductor 10 of the test bushing 1 and the test bushing 7 are electrically connected with the connection lead 11 in the gas connection box 6, and then the gas mounting lid 9 is attached to the gas connection box 6. It is sealed and a gas insulator 12 is sealed inside to perform the test.

However, the conventional testing method described above has a problem in that the testing efficiency is extremely poor. That is, when testing a plurality of test bushings 1, in order to replace the test bushings 1, it is necessary to collect the gas insulating medium 12, remove the gas mounting lid 9 and the test bushing 7, and also remove the gas connection box 6. The procedure of removing the test bushing 1 had to be taken, and the replacement work of the test bushing 1 was complicated and had the drawback that the work required a long time. Furthermore, the test bushing 7 needs to be for gases with a higher insulation class than the test bushing 1, which leads to an increase in test costs.

The present invention focuses on the above-mentioned conventional problems and provides a bushing test method with improved test efficiency. A gas tank is attached to the 7-lunge fitting, and the entire bushing integrated with the gas tank is immersed in an oil tank filled with insulating oil to perform the test. This is designed to shorten collection time and thereby increase testing efficiency.

Embodiments of the present invention will be described in detail below with reference to the drawings.

A test apparatus to which this example is applied is shown in FIG. 2, and a bushing test method according to this example will be explained based on this figure.

The test bushing 1 to be tested is provided with a connecting flange fitting 5 at its center, but a gas tank 13 is attached in advance to the gas side of the flange fitting 5 to the test bushing 1. put. This gas tank 13 houses the gas side half of the test bushing 1, and has a gas insulating medium 12 sealed therein.

Next, a test bushing 14 to be used for oil is prepared, and the mounting lid 4 of the oil tank 3 is attached to the flange fitting 15 of this bushing 14. Such test bushing 14
In contrast, the test bushing 1 integrated with the gas tank 13 is electrically connected. The connection is made by electrically and mechanically connecting the center conductor 10 of the test bushing 14 protruding from the gas tank 13 and the test bushing 14 using a connection rule 16 having mechanical strength. , 14 are integral.

In this way, the test bushing 14, the mounting lid 4, and the test bushing 1 are integrated, and they are lifted together and the gas tank 13 is integrated into the oil tank 3 filled with insulating oil 2. The entire test bushing 1 is immersed, the mounting lid 4 is attached to the oil tank 3, and preparations are completed, and the test is conducted.

In the bushing test method configured in this way, when replacing the test bushing 1, the test bushing 14, the mounting lid 4, and the test bushing 1 that have been tested are lifted up as one body, as in the case where the test bushing 1 is replaced. After that, replace it with the next test bushing 1. In this case, since the gas tank 13 is immersed in the oil tank 3, it becomes smaller, and therefore the time for filling and collecting the gas insulating medium 12 can be shortened. In addition, the gas tank 13 can be attached to the test bushing 1 in advance and the gas insulating medium 12 can be filled in, and the test bushing 1 and the gas tank 13 can be assembled together, which greatly reduces the work time. In this example, a reduction of 50% compared to the conventional method was achieved. In particular, it is economical because a gas connection box is not required and the gas tank 13 can also be used as a container for gas tightness testing. Furthermore,
The test bushing 14 does not have to be for gas,
It can be tested in the same way as oil-to-oil wall-opening bushings. As a result, it became possible to reduce material costs by 30%.

FIG. 3 shows a test apparatus for applying another embodiment of the present invention. This is because, in the above embodiment, when the test bushing 1 is immersed in the oil tank 2 together with the gas tank 13, it is lifted together with the test bushing 14, whereas the test bushing 14 and the test bushing The difference is that 1 and 2 are attached to the oil tank 2 separately. For this reason, the test bushing 1 and the test bushing 14 were connected by a detachable contactor 17. This contactor 17 has a structure in which a length adjustment terminal 18 provided on the test bushing 14 can be inserted, and the contact piece is supported by a spring.

Therefore, the test bushing 1 with the gas tank 13 attached is immersed in insulating oil 2 in advance and placed on the bottom of the oil tank 3, and then the test bushing 14 is attached to the mounting lid 4 and electrically connected to the test bushing 1. It is connected to.

This embodiment has the advantage that the work of connecting and integrating the test bushing 14 with the test bushing 1 in advance can be omitted.

As explained above, according to the present invention, the complexity of the bathing/engineering test work can be eliminated, the work time can be significantly shortened, and the test efficiency can be significantly improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view of a test device applied to a conventional bushing test method, Fig. 2 is a schematic sectional view of a test device applied to a bushing test method according to this embodiment, and Fig. 3 is a schematic sectional view of a test device applied to a bushing test method according to the present embodiment. It is the same schematic sectional view applied to. 1... Test bushing, 2... Insulating oil, 3...
Oil tank, 5... Flange fitting, 10... Center conductor, 12... Gas insulating medium, 13... Gas tank, 1
4...Test bamboo grass 10th opening

Claims (1)

[Claims] 1. A center conductor that is interposed between a gas-insulated switchgear and an oil-immersed transformer that is directly connected to the same and electrically connects the two, an insulator placed around the center conductor, and the gas-insulated switchgear. In a bushing test method for testing the dielectric strength of a bushing equipped with a flange fitting for connection to an oil-immersed transformer, a gas tank is sealed with a gas insulating medium sealed on the gas contact surface side of the flange fitting. A bushing test method characterized by carrying out a bushing test by immersing the entire bushing, which is formed by installing the gas tank in advance and integrally attaching the gas tank, into an oil tank filled with insulating oil.