JPH0683524B2 - Gas insulated electrical equipment - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to gas-insulated electrical equipment, and more particularly to gas-insulated electrical equipment configured to suppress surge voltage generated in substations.

[Background of the Invention]

In order to suppress the surge voltage generated in the substation, in particular, the surge voltage generated when the disconnector is opened and closed has a high frequency and a high frequency of occurrence, so that suppression is desired.

As a conventional suppression method, for example, as disclosed in Japanese Utility Model Laid-Open No. 55-40918, it has been proposed to open and close a disconnector via a resistor. However, this method has a new structural problem such that the moving distance of the movable electrode must be increased by adding a resistor. Further, as disclosed in Japanese Utility Model Laid-Open No. 58-27808, a method of mounting a magnetic ring around the vicinity of the contact has been proposed. The former is the case where the magnetic ring is used in the atmosphere, and the latter is the case where it is used on the low voltage ground side even though it is in a gas-insulated device.Therefore, consider the insulating structure of the magnetic ring itself. I didn't have to pay.

However, electrical equipment when used in disconnectors, etc. of the gas insulated electric device, a magnetic ring must be placed around the high voltage conductor in an atmosphere such as SF ₆ gas, using SF ₆ gas Then, relaxing the electric field concentration part as much as possible leads to improvement of insulation performance or downsizing of equipment. Therefore, when the magnetic ring is attached near the high voltage conductor, there is an important problem that the shield electrode, the magnetic body, etc. are damaged by the high frequency surge voltage.

[Object of the Invention]

An object of the present invention is to provide a gas-insulated electric device that prevents damage to a magnetic material, a shield electrode, etc. against surge voltage.

[Outline of Invention]

The present invention relates to a gas-insulated electric device in which a high-voltage conductor is arranged in a ground tank filled with an insulating gas, and a magnetic body is provided so as to surround the outer periphery of the high-voltage conductor, and at least an end portion of the magnetic body A shield electrode is arranged so as to cover the outer peripheral portion of the shield electrode, and the shield electrode is electrically connected to the high voltage conductor, and at least one end of the shield electrode and the magnetic body end portion corresponding to the shield electrode and the high voltage conductor. The gas-insulated electrical equipment is characterized in that an insulating distance is provided between the gas-insulated electrical equipment and the insulating material to prevent a discharge from occurring.

Example of Invention

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

FIG. 3 shows a cross-sectional view in which the present invention is applied to a gas-insulated busbar, in which a high-voltage conductor 2 is arranged in a grounding tank 1 in which an insulating gas is sealed, and a plurality of ring-shaped or A cylindrical magnetic body 10 is attached. When the disconnector 30 connected to the conductor 2 is opened and closed, a surge voltage is generated to some extent. FIG. 2 shows an example of the surge voltage V generated when the disconnecting switch 30 is turned on, where a is the case where the magnetic body 10 is not attached and b is the case where the magnetic body 10 is attached. As described above, the surge voltage is reduced from V ₁ to V ₂ by mounting the magnetic body 10, and the surge suppressing effect is obtained.

By the way, the end of the magnetic body 10 has a sharp shape, and the electric field strength E _e toward the ground tank 1 side is extremely higher than the electric field strength E _c on the side surface of the cylinder, and it is necessary to relax the electric field at this portion. Become.

Therefore, as shown in FIG. 4, a shield electrode 20 for relaxing the electric field is attached to the outer periphery of the magnetic body 10. Since the end portion of the shield electrode 20 can have a relatively large curvature, the electric field strength E _s can be significantly reduced as compared with the electric field strength E _e of the same portion in FIG.

The problem here is the influence of the shield electrode 20 on the effect of suppressing the surge voltage. As a result of various studies on this point, it was found that the electrical connection structure between the high-voltage conductor 2 and the shield electrode 20 is extremely important. That is, in FIG. 4, if one end B ₁ of the shield electrode 20 and the B ₂ point of the high voltage conductor are connected, and the other end C ₁ of the shield electrode 20 and the C ₂ point of the high voltage conductor 2 are connected, the surge voltage The suppression effect is impaired. On the other hand, if at least one end of the shield electrode 20 is separated from the high-voltage conductor 2 in a floating state, the surge voltage suppressing effect can be obtained with or without contact with the magnetic body 10.

FIG. 1 shows a cross-sectional view of a gas-insulated electric device constructed on the basis of these studies. A high-voltage conductor 2 is supported by an insulating material such as an insulating spacer 5 in a ground tank 1 containing an insulating gas. A plurality of annular or tubular magnetic bodies 10 are attached to the outer periphery of the high-voltage conductor 2,
A shield electrode 20 for relaxing an electric field is arranged on the outer periphery of the magnetic body 10. The left end of the shield electrode 20 is fixed to the high voltage conductor 2 and is also electrically connected. However, the right end of the shield electrode 20 is separated from the high voltage conductor 2 by a gap g. This gap g is a distance that can withstand the maximum surge expected in this gas-insulated electric device against a potential difference generated at both ends of the magnetic body 10 and maintain insulation.

Since the insulation distance, for example, g is provided in this way, the maximum surge voltage does not cause discharge between the magnetic body 10 and the shield electrode 20, and damage to the magnetic body 10, the shield electrode 20, etc. can be prevented. It was That is, the potential difference between both ends of the magnetic body 10, for example, one end side of the insulation distance g and the opposite end thereof, for example, if the opposite end is 1, a voltage of 2 is generated at one end side, so one end of the shield electrode 20. With the insulation distance g, it is possible to prevent discharge that occurs between the end of the magnetic material and the corresponding high-voltage conductor, and the shield electrode 20 can be used for the magnetic material 10. In addition, a gas-insulated electric device having a sufficient surge absorbing effect when a surge occurs and having no electric field concentration in the magnetic body 10 and having excellent insulation characteristics can be obtained.

5 to 7 show shield electrodes according to other different embodiments.

The shield electrode 20 in FIG. 5 is divided into two parts, and the magnetic material 10
The electric fields of the electric field concentration portions are relaxed. Also in this example, the lower ends, which are one ends of both shield electrodes 20, are connected to the high-voltage conductor 2, but the upper ends, which are the other ends, are separated from the high-voltage conductor 2 by a predetermined distance g, similar to the case of FIG. The effect of is obtained.

In the embodiment of FIG. 6, the lower end of the shield electrode 20 divided into two is sandwiched between the magnetic bodies 10. Meanwhile, the shield electrode 20
The upper part of the is curved so as to contain the magnetic substance 10 at both ends, and its end is separated from the high-voltage conductor 2 by a predetermined distance g. With this structure, the same effect as that of the previous embodiment can be obtained.

A support plate 4 is fixed to the shield electrode 20 shown in FIG. 7 at an intermediate portion, and by sandwiching the support plate 4 between the magnetic members 10, the shield electrode 20 is connected to the high voltage conductor via the support plate 4. 2 is electrically connected to the high voltage conductor 2 but is separated from the high voltage conductor 2 by a predetermined distance g. As described above, the shield electrode 20 may be separated from the high-voltage conductor 2 by the predetermined distance via the support plate 4, and is not limited to separating only one end from the high-voltage conductor 2.

FIG. 8 shows an example in which the present invention is applied to a disconnector which is a source of surge. The high-voltage conductor in the grounded tank 1 containing the insulating gas has a fixed electrode 40 and a movable electrode 41. On the outer periphery of the fixed electrode 40, a plurality of annular or cylindrical magnetic bodies are provided.
10 is attached, and the left end of the shield electrode 21 for electric field relaxation is fixed to the fixed electrode 40 which is a high-voltage conductor and electrically connected to the outer periphery thereof, but the right end thereof is fixed electrode 40. And a predetermined distance g between them. The movable electrode 41 slides and moves in the current collector 42 whose position is fixed, and is brought into contact with and separated from the fixed electrode 40. The shield electrode 22 is fixed to the current collector 42 so as to face the shield electrode 21.

When the movable electrode 41 is separated from the fixed electrode 40, a discharge 50 occurs and a high surge voltage is generated, but the magnetic body 10 suppresses this surge voltage. It becomes possible to prevent the discharge generated between one end of the shield electrode 21 and the corresponding end of the high-voltage conductor 2 and the magnetic body 10 by the insulation distance g, and cover at least the outer periphery of the end of the magnetic body. In addition, the shield electrode 21 can be used. The magnetic body 10 is made of permalloy,
Materials such as iron and ferrite can be used, but ferrite is most effective because the frequency band of the disconnector surge is several 100 KHz to several 10 MHz.

FIG. 9 shows a magnetic substance near the insulating spacer 5 of the gas-insulated bus bar.
The case where 10 is provided is shown. In this example, the conductor 25 at the center of the insulating material such as the insulating spacer 5 has a tubular shape having a bottom portion only at one end. The left and right high-voltage conductors 2 are connected at the bottom of the conductor 25. Therefore, a gap g having the same predetermined distance as that of the previous embodiment is formed between the cylindrical portion of the conductor 25 and the high-voltage conductor 2. A plurality of magnetic bodies 10 are mounted inside the conductor 25 on the outer periphery of the high-voltage conductor 2.

With such a configuration, the conductor 25 has the same function as the shield electrode, and the discharge is prevented by the gap provided between one end of the conductor 25 and the corresponding end of the high-voltage conductor 2 and the magnetic body 10. As a result, the shield electrode 25 can be used for the magnetic body.

In particular, the insulating spacer 5 and the like are weak points in insulation in this type of gas-insulated electric equipment, but surge voltage can be suppressed in the vicinity of the insulating spacer 5 and reliability can be improved.

〔The invention's effect〕

As described above, according to the present invention, the shield electrode for reducing the electric field of the magnetic substance is provided, and one end of the shield electrode is arranged at a predetermined distance from the high voltage conductor, so that the effect of suppressing the surge voltage is impaired. A gas-insulated electric device with improved insulation performance can be obtained. Also, due to the maximum surge voltage, discharge does not occur between the magnetic body and the shield electrode,
It is now possible to prevent damage to magnetic materials, shields, etc.

[Brief description of drawings]

FIG. 1 is a sectional view of a gas-insulated electric device according to an embodiment of the present invention, FIG. 2 is a waveform diagram of surge voltage, FIG. 3 and FIG.
FIG. 5 is a sectional view of a gas-insulated electric device showing the principle of the present invention, and FIGS. 5 to 9 are sectional views of a gas-insulated electric device according to different embodiments of the present invention. 1 ... Ground tank, 2 ... High-voltage conductor, 5 ... Insulating spacer, 10 ... Magnetic material, 20,21 ... Shield electrode, 40 ...
Fixed electrode, 41 …… Movable electrode.

Claims (4)

[Claims] 1. A gas-insulated electric device comprising a high-voltage conductor arranged in a ground tank filled with an insulating gas, wherein a magnetic body is provided so as to surround the outer periphery of the high-voltage conductor, and at least an end of the magnetic body. A shield electrode is arranged so as to cover the outer peripheral portion of the portion, and the shield electrode is electrically connected to the high-voltage conductor, and at least one end of the shield electrode and a magnetic body end portion corresponding to the shield electrode and the high-voltage conductor. A gas-insulated electric device, characterized in that an insulation distance is provided between the conductor and the conductor to prevent discharge. 2. The gas-insulated electric device according to claim 1, wherein the high-voltage conductor constitutes a disconnecting section having a pair of electrodes that come in contact with and separate from each other. 3. The high-voltage conductor according to claim 1, wherein the high-voltage conductor is supported by the ground tank by an insulator, and the magnetic body is arranged in the vicinity of the insulator. And gas-insulated electrical equipment. 4. A gas-insulated electric device according to claim 1, wherein ferrite is used as the magnetic material.