JPH0328123B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to gas insulated electrical equipment such as gas insulated switchgear and gas insulated transformer, in which electrical equipment and insulating gas are housed in a container. This invention relates to improvements to the equipment used.

[Prior art]

A conventional gas insulated switchgear of this type of device will be explained with reference to FIGS. 1 and 2. In Figures 1 and 2, 1 is a container of a gas insulated switchgear, 2
3 is the blind cover, 4 is the mounting bolt, and 5 is the part to which withstand voltage is applied, such as the cable charging part of the switchgear.
an internal space containing an insulating gas such as SF ₆ gas, 6
7 is a bushing for applying withstand voltage, 8 is a withstand voltage applying conductor embedded in the bushing 7, 81 is a contact attached to the tip of the withstanding voltage applying conductor 8, 9 is an O-ring, an opening 10 formed in the container 1 facing the withstand voltage application portion 2;
1 for gas sealing the bushing 7,
10 is a flange for holding down the bushing.

Next, the operation will be explained. First, FIG. 1 shows a normal state in which a gas insulated switchgear is assembled and used. Gas-insulated switchgear is always subjected to a withstand voltage test during installation and inspection. When applying a withstand voltage, first release the SF ₆ gas, then remove the blind cover 3 and insert the bushing 7 as shown in FIG. A withstand voltage applying conductor 8 is embedded in the bushing 7, and a contact 81 that can be connected to the withstand voltage applying portion 2 is attached to the tip facing the container 1. This bushing 7 is attached to the flange 1.
Fix with mounting bolt 4 so that it is held at 0.

After installing the bushing 7 in this way, the container 1
Evacuate the inside and then refill with SF ₆ gas.
Withstand voltage cannot be applied until gas filling is completed. After applying withstand voltage and completing the withstand voltage test, return to the original state as shown in Figure 1, but at this time, perform the reverse procedure to the above, i.e., vent the SF ₆ gas and remove the bushing 7. , attaching the blind lid 3, evacuation, and filling with SF ₆ gas.

As mentioned above, conventional equipment has disadvantages such as complicated and large-scale work, long power outages for testing, and the need to open the sealed insulating gas container many times. However, there was a high risk of contamination with foreign substances, and the reliability of gas-insulated electrical equipment decreased with each test.

[Summary of the invention]

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional ones, and by always having a test bushing that seals the container against the outside air, it is possible to easily test the container without opening it many times. The object of the present invention is to provide gas-insulated electrical equipment that can be subjected to voltage tests.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.
The diagram will be explained. FIG. 3 shows a normal state, and FIG. 4 shows a state during a withstand voltage test. In addition,
Throughout both figures, parts that are the same as or equivalent to those in FIGS. 1 and 2 are designated by the same reference numerals.

In FIG. 3, reference numeral 11 denotes a hollow bushing, which is fixed to the container 1 by a mounting bolt 4 and is connected to an opening 101 by an O-ring 9 to prevent the SF ₆ gas inside the container 1 from leaking to the outside. It is sealed. A cylindrical filler metal 111 is integrally molded on the inner wall of the hollow bushing 11, and its function will be described later. A withstand voltage applying conductor 8 is inserted into the hollow part of the filler metal 111 so as to be movable in the axial direction, and is sealed against the inner wall of the filler metal 111 by an O-ring 12 so that SF ₆ gas leaks to the outside. It is designed to prevent A shield 82 is fixed to the tip of the withstand voltage application conductor 8 on the side of the withstand voltage application part 2. A blade 83 is further held movably in the axial direction on this shield, and a spring 84 is used to connect the withstand voltage application part 2 to the shield 82. 2, ie, inwardly. The withstand voltage applying conductor 8 itself is pressed outward of the container 1 by a spring 13. 14 is a blind lid, O-ring 15,
It is attached to the container 1 by a mounting bolt 4 via a bolt 16. 141 is a ground electrode provided on the blind lid 14.

In FIG. 4, reference numeral 17 denotes a withstand voltage applying device that is assembled to the hollow bushing 11 and presses the withstand voltage applying conductor 8 into contact with the withstand voltage applying portion 2 during the withstand voltage test, and applies a withstand voltage to the withstand voltage applying conductor 8. In this embodiment, the electrode 171 protrudes forward.
The electrode is connected to a high voltage power source (not shown) through a cable 172.

Next, the operation will be explained. Normally, the blade 83 is in the state shown in FIG. 3, in which the ground electrode 141 of the blind lid 14 comes into contact with the rear end of the withstand voltage application conductor 8, so that the blade 83 is electrically grounded. Furthermore, even if some SF ₆ gas leaks through the O-ring 12, it is completely sealed by the O-rings 15 and 16 and is prevented from leaking to the outside.

When conducting a withstand voltage test, the blind cover 14 is removed and the withstand voltage applying device 17 is attached to the hollow bushing 11 with bolts 4. At this time, withstand voltage application conductor 8
is pushed out toward the withstand voltage application part 2 by the electrode 171, and after the blade 83 contacts the withstand voltage application part 2, the spring 84 is compressed, so that the blade 83 is completely in contact with the withstand voltage application part 2. . After mounting in this manner, a withstand voltage is applied to the withstand voltage applying conductor 8 by the withstand voltage applying device 17 to perform a withstand voltage test. When the test is completed, the withstand voltage applying device 17 is removed, and the withstand voltage applying conductor 8 automatically returns to the position shown in FIG. 3 by the action of the spring 13. Thereafter, when the blind cover 14 is attached, the normal state shown in FIG. 3 is restored.
Note that the filler metal 111 prevents discharge from occurring due to rattling between the withstand voltage applying conductor 8 and the hollow bushing 11 when the withstanding voltage applying conductor 8 is inserted directly into the hollow bushing 11. . Such a filler metal may be omitted if the withstand voltage to be applied is low, and in that case, the withstand voltage applying conductor 8 may be directly sealed to the hollow bushing 11 with an O-ring or the like.

Although the above embodiments have been described with respect to a gas insulated switchgear, the present invention can be similarly applied to other gas insulated electrical equipment such as a gas insulated transformer. Further, although the withstand voltage applying conductor 8 is configured to automatically return to its original position by the spring 13, it may be automatically restored by a pressure difference between the inside and outside of the container. Further, although FIG. 4 shows a plug-in cable head as the withstand voltage applying device, it may be a straight type, or a bushing that can perform the same function may be connected instead of a cable. Furthermore, a contact mechanism consisting of a shield 82, a blade 83, and a spring 84 provided at the tip of the withstand voltage applying conductor 8 is preferably provided in order to ensure good electrical contact, but may be omitted. .

〔Effect of the invention〕

As described above, in this invention, the bushing for withstanding voltage tests is always kept in the container in an airtight manner, and the withstanding voltage can be applied without breaking the airtightness during the withstanding voltage test. There is no need for any troublesome work such as removing the gas, evacuation, refilling with insulating gas, etc. Therefore, withstanding voltage tests can be performed extremely easily and in a short time, and there is no possibility of foreign matter getting into gas-insulated electrical equipment. Effects can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a normal state of a part of a conventional gas insulated switchgear, Fig. 2 is a sectional view showing the state of the device shown in Fig. 1 during a withstand voltage test, and Fig. 3 is an embodiment of the present invention. Sectional view showing the normal state of the example, No. 4
The figure is a diagram showing the state of the device shown in FIG. 3 during a withstand voltage test, and the same reference numerals in the figure indicate the same or equivalent parts. In addition, in the figure, 1 is a container, 101 is an opening, 2 is a withstand voltage application part, 8 is a withstand voltage application conductor, 9 is an O-ring, 11 is a hollow bushing, 12 is an O-ring, 1
7 is a withstand voltage application device.

Claims (1)

[Scope of Claims] 1. A gas-insulated electrical device containing an electrical device and an insulating gas in a container, wherein a withstand voltage applying conductor is provided from the outside facing a withstand voltage applying portion of the electrical device to which a withstand voltage is to be applied. is provided with an opening for inserting into the container, the container includes a hollow bushing fixed to the outer wall of the container in a sealed manner with respect to the opening, and the withstand voltage applying conductor is inserted in the hollow bushing in its axial direction. inserted so as to be movable into the hollow bushing and sealed against the inner wall of the hollow bushing;
The present invention further includes a withstand voltage applying device that is combined with the hollow bushing to press the withstand voltage applying conductor into contact with the withstand voltage applying portion and applies a withstand voltage to the withstand voltage applying conductor when applying a withstand voltage. gas insulated electrical equipment. 2. The gas-insulated electric device according to claim 1, wherein the voltage-withstanding voltage applying conductor is pressed toward the outside of the container by a spring provided between the withstanding voltage applying conductor and the hollow bushing. 3. The gas insulated electric device according to claim 1, wherein the withstand voltage application conductor has a blade at the tip thereof on the side of the withstand voltage application portion that is pressed by a spring toward the withstand voltage application portion. 4. The gas-insulated electrical equipment according to claim 1, wherein the hollow bushing has a cylindrical filler metal on its inner wall, and a withstand voltage applying conductor is inserted into the hollow portion of the filler metal.