JPH07282630A - Insulating varnish for gas insulated equipment and gas insulated equipment using this insulating varnish - Google Patents

Abstract

PURPOSE:To provide an insulating varnish for a gas insulated equipment such as capable of maintaining a stable high withstanding voltage characteristic even in the case of providing fine foreign matter of metal powder or the like in the gas insulated equipment. CONSTITUTION:In a metal sealed vessel 3, a conductor 1 is stored, also to seal inside the metal sealed vessel 3 with insulating gas 2 of SF6 or the like. In an internal surface opposed to the conductor 1 of the metal sealed vessel 3, a uniform insulating film 9 is formed. The insulating film 9 is formed by applying an insulating varnish formed by mixing an insulation oxide, containing alumina of 5mum or less grain size by 71.6wt.% content ratio, in a resin. As the resin, an epoxy resin, phthalic acid resin, polyurethane resin, acrylic resin, melamine resin, silicone resin, phenol resin or vinyl chloride resin are selectively used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating paint for high-voltage equipment, and more particularly to an insulating paint for gas-insulated equipment containing an electrically negative insulating gas such as SF ₆ gas. Is.

[0002]

2. Description of the Related Art An electrically negative insulating gas such as SF ₆ gas is widely used as an insulating medium for various gas-insulated equipment such as circuit breakers because it has excellent arc extinguishing performance and insulating performance. Has been done. Such a gas-insulated device is a device configured by enclosing a conductor in a metal closed container and enclosing an insulating gas such as SF ₆ gas, and having a high insulating gas that is several times that of air. It is designed to reduce the distance between electrodes and the dimensions of insulators by taking advantage of its performance, and to obtain high withstand voltage characteristics.

In such a gas-insulated device, the insulating gas exhibits excellent characteristics of withstanding high voltage in a short distance, but on the other hand, there are small irregularities on the surface of a high-voltage conductor, metal powder, etc. When such a fine foreign substance adheres, the electric field is disturbed, and the withstand voltage value rapidly decreases, which is an inconvenient characteristic. The disadvantageous characteristics of this insulating gas will be described below with reference to FIG.

FIG. 5 is a principle diagram showing a case where foreign matter is mixed in a high-voltage gas-insulated device, where 1 is a conductor and 2 is S.
Insulating gas such as F ₆ gas, 3 is a metal closed container. As shown in FIG. 5, in a state where the conductor 1 is charged with a positive charge 4 and the metal closed container 3 is charged with a negative charge 5, fine particles such as metal powder are formed on the inner surface of the metal closed container 3. When the foreign matter 6 exists, electric charges are injected into the foreign matter 6 from the metal closed container 3, and the foreign matter 6 is charged with the negative charge 5 like the metal closed container 3. In this case, due to the electric field 7 generated between the metal closed container 3 charged with the negative charge 5 and the conductor 1 charged with the positive charge 4, the foreign matter 6 has an electrostatic force 8 that attracts the foreign matter 6 to the conductor 1. Occur. This electrostatic force 8
Is larger than the gravity of the foreign matter 6, the foreign matter 6 rises and floats, and the withstand voltage characteristic of the gas-insulated equipment is greatly deteriorated.

On the other hand, conventionally, in order to prevent the mixing of the foreign matter 6 as described above and maintain the original high withstand voltage characteristic of the insulating gas, the surface roughness of the electrode surface is made high in manufacturing the electrode. Therefore, the work is carried out in a dust-proof chamber which is controlled so as to eliminate irregularities and prevent foreign matter such as metal powder from entering the gas-filled portion even when assembling the equipment.

[0006]

However, the gas-insulated equipment is manufactured under the strict control system as described above.
When assembling, there is a problem that a great cost is required. Furthermore, even if the gas-insulated equipment is manufactured and assembled under such a strict control system, foreign matter may be mixed into the gas-insulated equipment for some reason. In addition, even if it is possible to completely prevent foreign matter from entering the gas-insulated equipment during manufacturing and assembly, in particular for switchgear such as circuit breakers and disconnectors, due to its structure,
It is impossible to avoid generation of fine metallic foreign matter from the sliding portion in the opening / closing operation, and it is impossible to completely prevent foreign matter from entering.

Therefore, in the prior art, the electric field strength should be kept low and the distance between the electrodes should be increased in consideration of the contamination of foreign matter during the manufacturing and assembling and the generation of the foreign matter inside the equipment due to the opening / closing operation. This makes it possible to maintain a sufficient withstand voltage characteristic even when the withstand voltage characteristic deteriorates due to the presence of foreign matter. However, in this case, a new problem arises that the device becomes large and heavy, and the cost also increases.

The present invention has been proposed in order to solve the above problems of the prior art. That is, an object of the present invention is to provide an insulating coating material for a gas insulation device that can maintain stable high withstand voltage characteristics even when fine foreign substances such as metal powder are present in the gas insulation device. It has stable and high withstand voltage characteristics and is small in size by using various insulating paints for gas insulation equipment.
It is to provide a lightweight and economical gas insulated device.

More specifically, the object of the present invention is to provide an insulating paint by using an insulating oxide containing alumina having a limited particle size in a limited content ratio. Is to improve the withstand voltage characteristics of the gas insulation device by forming an insulating film having a high relative dielectric constant when the is coated on the inner surface of the metal closed container of the gas insulation device.

It is an object of the present invention to provide an insulating coating material by mixing an insulating oxide containing alumina having a limited particle diameter in a limited content ratio into a resin which is easy to handle and has excellent insulating properties. This configuration makes it possible to easily apply this insulating paint to the inner surface of the metal closed container of gas insulation equipment, and when this easy coating is performed, a uniform insulating film with a high dielectric constant is formed. It is to improve the withstand voltage characteristics of the gas insulation device.

A third object of the present invention is to coat the inner surface of a metal closed container of a gas insulating device with an insulating paint for a gas insulating device having a high relative permittivity so that it has stable withstand voltage characteristics and is small in size. -To provide a lightweight and economical gas insulated device.

[0012]

The insulating coating material for gas insulation equipment according to claim 1 is made of alumina having a particle diameter of 5 μm or less.
It is characterized in that it contains an insulating oxide contained in a content ratio of up to 72% by weight. The insulating coating material for gas insulation equipment according to claim 2 is obtained by mixing the insulating oxide according to claim 1 into a resin, and the resin is an epoxy resin, a phthalic acid resin, a polyurethane resin, an acrylic resin, a melamine resin, It is characterized by being a silicone resin, a phenol resin, or a vinyl chloride resin.

According to a third aspect of the present invention, there is provided a gas-insulated device in which a conductor is housed in a metal hermetic container, and an insulating gas is sealed therein. It is characterized by being coated with insulating paint for gas insulation equipment.

[0014]

According to the present invention having the above structure, the following effects can be obtained. First, the insulating coating material for gas insulation equipment according to claim 1 comprises alumina having a particle diameter of 5 μm or less,
By including the insulating oxide contained in the content ratio of 1 to 72% by weight, the relative dielectric constant is increased.

Next, the insulating coating material for gas insulation equipment according to claim 2 contains the insulating oxide according to claim 1 in a resin which is easy to handle, thereby facilitating spray coating with a spray gun. It can be painted by the method. Further, each of the resins described in claim 2 has an excellent insulating property, and therefore does not impair the high dielectric constant action of alumina.

Further, the gas-insulated equipment according to claim 3 is:
By coating the inner surface of the metal closed container with the insulating paint having a high relative dielectric constant according to claim 1 or 2, it is possible to form an insulating film having a high relative dielectric constant. Even if there is a fine foreign substance such as metal powder, the sufficient withstand voltage characteristics can be maintained.

[0017]

EXAMPLES An example of an insulating coating material for a gas insulating device and a gas insulating device using the same according to the present invention will be specifically described below with reference to FIGS. The same parts as those in the conventional example shown in FIG. 5 are designated by the same reference numerals. [1] Configuration of Embodiment A configuration of a gas insulation device according to the present invention will be described with reference to FIG. This gas insulation device is configured such that a conductor 1 is housed in a metal closed container 3 and an insulating gas 2 such as SF ₆ gas is sealed. A uniform insulating film 9 is formed on the inner surface of the metal closed container 3 facing the conductor 1 by applying an insulating paint containing alumina. That is, the insulating film 9 is formed by coating an insulating paint containing an insulating oxide containing alumina having a particle diameter of 5 μm or less at a content ratio of 71.6% by weight in a resin. Epoxy resin, phthalic acid resin, polyurethane resin, acrylic resin, melamine resin, silicone resin, phenol resin, or vinyl chloride resin is selectively used as a specific resin of this insulating paint. [2] Operation of Embodiment In the gas-insulated equipment of this embodiment having the above-mentioned configuration, when fine foreign matter 9 such as metal powder is present,
Since the insulating film 9 acts as a dielectric or a resistor, it is possible to reliably prevent the foreign matter from rising and floating, and improve the withstand voltage characteristic.

First, FIG. 1 shows a fine foreign substance 9 such as metal powder.
Is present, which indicates the action of the insulating film 9 when the foreign matter 9 is charged. That is, as shown in FIG. 1, in a state where the conductor 1 is charged with a positive charge 4 and the metal closed container 3 is charged with a negative charge 5, fine foreign matter 6 such as metal powder exists, When the foreign matter 6 is charged, the insulating film 9 acts as a dielectric to generate a polarization positive charge 10 on the surface of the insulating film 9 on the side of the metal closed container 3 and the insulating film 9 on the foreign matter 6 side. Negative charge 11 on the surface of
Occurs. When the insulating film 9 is polarized in this way, a polarized positive charge 10 is applied to the surface of the charged foreign matter 6 on the insulating film 9 side.
The electrostatic attraction force 12 that attracts the foreign matter 6 to the insulating film 9 is generated on the foreign matter 6. Therefore, due to the electrostatic attraction force 12, the foreign matter 6 is generated by the electric field 7.
Since it is possible to cancel the electrostatic force 8 acting on, it is possible to prevent the foreign matter 6 from rising and floating, and as a result, it is possible to improve the withstand voltage characteristics of the gas-insulated equipment.

Next, FIG. 2 shows fine foreign matter 9 such as metal powder.
Is present, indicating the action of the insulating film 9 when the foreign matter 9 is not charged. That is, as shown in FIG. 2, in a state in which the conductor 1 is charged with a positive charge 4 and the metal closed container 3 is charged with a negative charge 5, fine foreign matter 6 such as metal powder exists, When the foreign matter 6 is not charged, the insulating film 9 acts as a resistor to generate a polarization positive charge 10 on the surface of the insulating film 9 on the side of the metal closed container 3 and the insulating film 9 on the foreign matter 6 side. A polarized negative charge 11 is generated on the surface of the metal and the charge injection from the metal closed container 3 into the foreign matter 6 is blocked. Therefore, the surface of the foreign matter 6 on the side of the insulating film 9 is charged with a positive charge 4, the surface of the foreign matter 6 on the side of the conductor 1 is charged with a negative charge 5, and the foreign matter 6 is electrically neutralized as a whole. Become. Therefore, since the electrostatic force 8 does not act on the foreign matter 6, it is possible to prevent the foreign matter 6 from rising and floating, and as a result, it is possible to improve the withstand voltage characteristics of the gas-insulated equipment.

Next, FIG. 3 is a graph showing the relationship between the relative permittivity of the insulating film 9 and the electrostatic force (electrostatic attraction force) generated by it. This relationship is derived from the following equation (1). Be done.

[0021]

[Number 1] ^{fe = (Q 2/4 ·} π · εo · R) × (εs-
1 / εs + 1) Equation (1) where fe: electrostatic force (N) Q: charge amount (C) εo: permittivity (vacuum state) (F / m) εs: relative permittivity R: radius of foreign matter ( m) From FIG. 3, the higher the relative permittivity εs of the insulating film 9 is,
It is clear that the electrostatic force fe generated thereby also becomes large, and as a result, the withstand voltage characteristic can be improved.

FIG. 4 is a graph showing the relationship between the content ratio of alumina in the insulating oxide used as a component of the insulating coating for the insulating film 9 and the withstand voltage characteristic obtained thereby. From FIG. 4, the content ratio of alumina is 7
It is clear that the highest withstand voltage characteristic is obtained when the amount is 1.6% by weight. [3] Effects of Examples As described above, in this example, the insulating coating material is obtained by mixing the insulating oxide containing the alumina having the particle diameter of 5 μm or less in the content ratio of 71.6% by weight into the resin. By forming the insulating film 9 on the inner surface of the metal closed container 3, the relative permittivity of the insulating film 9 can be increased, so that even if a fine foreign substance 6 such as metal powder is present, a stable high withstand voltage can be obtained. The characteristics can be maintained. In addition, since the withstand voltage characteristics can be improved in this way, the electric field strength of the device can be increased and the distance between the electrodes can be reduced,
The gas insulation equipment can be made as small and lightweight as possible to reduce the cost.

[0023]

As described above, in the present invention, the insulating coating material is used in which the insulating oxide containing the alumina having the particle size of 5 μm or less in the content ratio of 71 to 72% by weight is mixed in the resin. This makes it possible to provide a gas-insulated device that can maintain stable high withstand voltage characteristics even when fine foreign substances such as metal powder are present in the gas-insulated device, and that is small, lightweight, and economical. .

[Brief description of drawings]

FIG. 1 is a principle diagram showing the configuration and operation of an embodiment of a gas insulation device according to the present invention.

FIG. 2 is a principle view showing another operation of the gas insulation device of FIG.

FIG. 3 is a graph showing the relationship between the relative dielectric constant of the insulating film of FIG. 1 and the electrostatic force.

FIG. 4 is a graph showing the relationship between the content ratio of alumina in the insulating oxide and the withstand voltage characteristic.

FIG. 5 is a principle diagram showing a problem in a conventional gas insulation device.

[Explanation of symbols]

 1 ... Conductor 2 ... Insulating gas 3 ... Metal closed container 4 ... Positive charge 5 ... Negative charge 6 ... Foreign matter 7 ... Electric field 8 ... Electrostatic force 9 ... Insulating film 10 ... Polarization positive charge 11 ... Polarization negative charge 12 ... Electrostatic attraction Power

Claims (3)

[Claims] 1. Alumina having a particle size of 5 μm or less is made of 71 to 72.
An insulating coating material for gas insulation equipment, characterized in that it contains an insulating oxide contained in a weight percentage. 2. The insulating oxide is mixed in a resin, and the resin is an epoxy resin, a phthalic acid resin, a polyurethane resin, an acrylic resin, a melamine resin, a silicone resin, a phenol resin, or a vinyl chloride resin. The insulating coating material for gas insulation equipment according to claim 1. 3. A gas insulating device in which a conductor is housed in a metal hermetic container and an insulating gas is sealed therein, wherein an inner surface of the metal hermetic container is an insulating coating material for gas insulating device according to claim 1 or 2. Gas-insulated equipment characterized by being coated with.