JPH02276404A - Compressed-gas-insulated switchgear - Google Patents

Abstract

PURPOSE:To miniaturize a compressed-gas-insulated switchgear by integrally forming a ring-shaped structure containing an insulating spacer magnetic substance and an insulating material. CONSTITUTION:Stepped high frequency surge voltage generated across disconnector electrodes reaches an insulating spacer 2, which is equipped with an insulating material 2b on the outside whose relative dielectric constant is 5 or 6. Consequently, in the steep rising part of the high frequency surge voltage it acts as an earth terminal and no high frequency component will be propagated to a ring-shaped structure 2a, so that no large voltage will be applied locally. This action is made striking by arranging the ring-shaped structure 2a at the position close to inductance component and capacitance component. By casting the ring-shaped structure 2a to such insulating material 2b, the spacer 2 can be acted as a short-circuit terminal and the high frequency surge voltage will be damped and effectively controlled without amplifying the voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a gas insulated switchgear having an insulating spacer that contributes to high frequency surge suppression.

(Prior Art) Insulating spacers are generally used as supports for insulating and supporting high voltage conductors such as gas insulated switchgear in metal containers.

In gas-insulated switchgear, it is known that high-frequency surges are generated and propagated by operating disconnectors and circuit breakers that are components of the gas-insulated switchgear.

In particular, when operating a disconnector, the rise of the wave crest is 3 to 5 nm.
At S, the surge voltage of the high frequency surge of several MH2 that follows this becomes more than twice the constant operating voltage.

This high-frequency surge has been reported to cause dielectric breakdown of oil bushings, ground faults, and control circuit breakdowns due to radio interference.

Furthermore, it is known that high frequency surges are reflected at discontinuities caused by insulating spacers.

Therefore, surge suppression measures as shown in FIG. 3 have been taken, for example, as known from Japanese Patent Application Laid-Open No. 81-227325. The figure shows countermeasures taken near the disconnector, which is a device that generates high-frequency surges. Both ends of the metal container 1 are sealed with insulating spacers 2, and an insulating gas 3 is filled inside.

Further, a pair of hollow fixed electrodes 4a and 4b are housed in the metal container 1 and are insulated and supported facing each other by an insulating spacer 2. Contactors 5a and 5b are fixed inside the fixed electrodes 4a and 4b, respectively. Further, inside the fixed electrode 4b, a movable electrode 6 is housed, which is in contact with the contactor 5b and can freely come into contact with and separate from the contactor 5a. An arc contact 8 is fixed to the tip of the movable electrode 6. and,
The movable electrode 6 is operated by an operating mechanism 10 via an operating rod 9. Further, both fixed electrodes 4a and 4b are connected to a high voltage conductor 11 via connecting conductors 2 supported by insulating spacers 2, respectively.

Furthermore, cylindrical structures lea and 16b made of magnetic material are arranged around both fixed electrodes 4a and 4b.

The large inductance of the cylindrical structures IGa and 16b absorbs high frequency surges and prevents their propagation.

By the way, the step-like high frequency surge generated at the contact point of the disconnector is propagated first to the cylindrical structure 16a.

16b. At this time, for high frequency components, this portion becomes an open end and a voltage twice the surge voltage is generated. Since the high frequency surge enters the cylindrical structures L6a and 16b while maintaining its steepness, the one-turn voltage here becomes large. Moreover, this becomes more noticeable as the frequency becomes higher.

Further, the cylindrical structures 16a and 16b are generally formed by laminating thin magnetic films in an insulating manner. Therefore, there is a possibility that dielectric breakdown may occur due to the local application of a large voltage due to a large high-frequency surge. To prevent this, it is necessary to increase the insulation distance between the magnetic films to a sufficiently large extent to improve insulation resistance. As a result, the cylindrical structures 16a and 18b become larger, which in turn leads to an increase in the size of the gas-insulated switchgear.

(Problems to be Solved by the Invention) As described above, in conventional high frequency surge suppression, a cylindrical structure formed by laminating insulating magnetic material films has been used. However, if the magnetic films are placed close to each other, dielectric breakdown occurs and the surge suppressing effect is lost, so it is necessary to ensure a sufficient insulation distance between the magnetic films. Therefore, it has not been possible to downsize the cylindrical structure and, by extension, the gas insulated switchgear.

The present invention has been made in consideration of the above points, and an object of the present invention is to provide an insulating spacer having a high-frequency surge suppressing effect and to downsize a gas-insulated switchgear.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, in the present invention, an insulating spacer is formed by integrally forming a ring-shaped structure containing a magnetic material with an insulating material.

(Function) With this configuration, the insulating spacer can work with the short-circuit end, and the ring-shaped structure does not require special insulation and the metal container does not need to be enlarged. Insulated switchgear may be provided.

(Example) An example of the present invention will be described below with reference to FIG. Incidentally, parts equivalent to those of the gas insulated switchgear shown in FIG. 3 are given the same reference numerals and detailed explanations are omitted.

In this embodiment, the insulating spacer 2 is formed by integrally casting a ring-shaped structure 2a containing a magnetic material with an insulating material 2b.

The ring-shaped structure 2a is made of, for example, a magnetic material formed by mixing amorphous alloy powder with conductive plastic.

Further, the insulating material 2b is made of an insulating material such as epoxy resin having a dielectric constant of 5 to 6.

Next, the composition effect of the configuration of this embodiment will be explained. The step-like high frequency surge generated between the disconnector electrodes reaches the insulating spacer 2. Since this insulating spacer 2 has an insulating material 2b having a dielectric constant of 5 to 6 on the outside thereof, the insulating spacer 2 acts as a ground fault terminal for a steep rising portion of a high frequency surge. Therefore, high frequency components are not propagated to the ring-shaped structure 2a.

Therefore, a large voltage is not locally applied to the ring-shaped structure 2a. This effect becomes remarkable when the ring-shaped structure 2a is provided at a position where the inductance component and the capacitance component are close to each other.

In this way, by casting the ring-shaped structure 2a on the insulating material 2b, the insulating spacer 2 can act as a short-circuit end. As a result, high-frequency surges are attenuated and effectively suppressed without amplifying the voltage. Moreover,
Since voltage with high frequency components is not applied to the ring-shaped structure 2a, there is no risk of dielectric breakdown and there is no need to take special insulation measures.

Therefore, it is possible to effectively suppress high frequency surges without increasing the size of the metal container 1.

Incidentally, as shown in FIG. 2, the ring-shaped structure 2a may be covered with a conductive plastic 2c. In this case, since the conductive plastic 2C and the insulating material 2b are made of the same material, casting between the two materials can be easily performed.

In addition, although the above-mentioned embodiment describes a high-frequency surge in a disconnector, a similar configuration can be applied to a lightning surge that can occur even without a contact portion, and the same effect can be obtained.

〔Effect of the invention〕

As explained above, in the present invention, since the insulating spacer and the ring-shaped structure containing a magnetic material are integrally formed with the insulating material, the insulating spacer can act as a short-circuit end, and the ring-shaped structure has special insulation. Therefore, it is possible to provide a small gas insulated switchgear that does not need to be enlarged and does not need to have a large metal container.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a gas insulated switchgear showing one embodiment of the present invention, Fig. 2 is a sectional view of a gas insulated switchgear showing another embodiment of the invention, and Fig. 3 is a sectional view of a conventional gas insulated switchgear. FIG. 2 is a sectional view showing the device. 1... Metal container, 2... Insulating spacer,
2a...Ring-shaped structure, 2b...Insulating material, 2c
... Conductive plastic, 3... Insulating gas, 4a, 4b... Fixed electrode, 5a, 5b... Contactor, 6... Movable electrode, 8... Arc contact, 9... Operating rod, lO... operating mechanism, 11
...High voltage conductor, 12...Connection conductor, lea
, 16b... Cylindrical structure. Figure 2

Claims (1)

[Claims] In a gas-insulated switchgear in which a high-voltage conductor is insulated and supported by an insulating spacer and housed in a metal container filled with an insulating gas, the insulating spacer is formed by integrally forming a ring-shaped structure containing a magnetic material with the insulating material. Gas insulated switchgear.