JP2013258811A - Electric power device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric power device which maintains high insulation performance without using a SFgas having a high global warming coefficient while keeping the same size as a conventional device.SOLUTION: An electric power device, such as a gas-insulation switchgear, a cubicle type gas-insulation switchgear, and a gas filling type transformer, is formed including: a ground container in which an insulation gas is enclosed; an electric apparatus housed in the ground container and in which high voltage charging is performed; a power supply part for performing the high voltage charging to the electric apparatus; and an ionization gas supply part which ionizes the insulation gas and supplies an ionization gas to the ground container.

Description

  The present invention relates to a closed type power device in which an electric device is accommodated in a grounded container.

In general, as a closed-type power device used for power receiving and transformation equipment, gas-insulated switchgear that contains electrical devices such as circuit breakers, disconnectors, busbars, lightning arresters, etc. in a metal grounding container filled with insulating gas Devices (GIS: Gas Insulated Switch), cubicle type gas insulated switchgear (C-GIS), or gas-filled transformers are known. In such power equipment, sulfur hexafluoride (SF ₆ ) having excellent thermal stability, electrical stability, and high withstand voltage is used as an insulating gas (for example, Patent Documents 1 to 3). ).

Japanese Patent Laid-Open No. 10-257624 JP 2000-350317 A JP 2001-286015 A JP 2007-141692 A JP 2002-95731 A

By the way, SF ₆ gas has a global warming potential of 23,900 times that of carbon dioxide, and is designated as a greenhouse gas subject to emission reduction in the Kyoto Protocol. .
Therefore, an alternative gas for SF ₆ gas is being sought, but alternative gases (dry air, nitrogen gas, etc.) that are listed as candidates from the viewpoint of environmental adaptability (low global warming potential) and toxicity are SF Dielectric strength is lower than ₆ gas. Therefore, application of SF ₆ alternative gas in power equipment involves the following sacrifices.

For example, when the pressure is the same, the dielectric strength of nitrogen gas is about 1/3 compared to SF ₆ gas. For this reason, when nitrogen gas is used as an insulating gas in power equipment, a grounded container having a volume of about three times the insulation distance is required to make the pressure in the installation container the same. On the other hand, from the dielectric strength ratio of gas, it is difficult to make the grounded containers have the same volume even if the pressure is increased. However, in the existing power equipment, the volume of the ground container cannot be changed, and it is difficult to increase the pressure significantly.
As a result, countermeasures such as lowering the operating voltage are required, and the performance as a power device is reduced. Further, when the pressure is increased, the pressure resistance of the grounding container is also required, which causes an increase in equipment cost and is not preferable in terms of safety.

An object of the present invention is to provide a power device that has the same size as a conventional power device and can maintain high insulation performance without using SF ₆ gas having a high global warming potential.

A power device according to the present invention includes a ground container filled with an insulating gas,
Electrical equipment housed in the grounded container and subjected to high voltage power;
A power supply unit for applying high-voltage power to the electrical device;
An ionized gas supply unit that ionizes the insulating gas and supplies the ionized gas into the grounded container.

According to the present invention, since the high electric field portion in the grounded container is covered with the ionized gas, the charge charged in the high electric field portion is neutralized (static elimination) by positive ions or negative ions contained in the ionized gas. Therefore, since it is possible to effectively prevent discharge in the grounded container, high insulation performance can be maintained without using SF ₆ gas. Further, it is not necessary to increase the volume of the ground container in order to increase the dielectric strength.

It is a figure which shows schematic structure of the apparatus for electric power which concerns on 1st Embodiment. It is a figure which shows schematic structure of the apparatus for electric power which concerns on 2nd Embodiment. It is a figure which shows the modification of the apparatus for electric power which concerns on 1st Embodiment. It is a figure which shows the other modification of the electric power equipment which concerns on 1st Embodiment. It is a figure which shows the other modification of the electric power equipment which concerns on 1st Embodiment.

[First Embodiment]
FIG. 1 is a diagram illustrating a schematic configuration of a power device according to the first embodiment.
As shown in FIG. 1, the power device 1 is a gas insulated switchgear in which a charging unit 40 such as a circuit breaker 41, a disconnector 42, a bus line 43, and the like is housed in a ground container 10. The power device 1 is partitioned into a device housing unit 10A that houses the charging unit 40, and an elephant unit 10B in which a bushing 20 for drawing a power cable (not shown) for applying power to the charging unit 40 is provided.

The ground container 10 is a grounded metal container, and the inside of the ground container 10 is a sealed space. Insulating gas is sealed in the ground container 10. As the insulating gas, for example, dry air that does not contain moisture (nitrogen: about 80%, oxygen: about 20%), insulating gas such as nitrogen (excluding SF ₆ gas), or a gas that does not decompose during ionization can be applied. In particular, dry air does not contain moisture, has a higher insulating property than air in the atmosphere, and is also suitable as an insulating gas because it is applied to high-voltage electrical equipment such as a gas-insulated switchgear (GIS).

The bushing 20 includes an insulating cylinder 21 and a lead conductor 22.
The insulating cylinder 21 is a hollow molded body made of a hard insulator such as an epoxy resin. The insulating cylinder 21 is inserted into the ground container 10 and is airtightly fixed to the ground container 10 by tightening the ground container 10 with a plurality of bolts. That is, the insulating gas sealed in the grounding container 10 has a structure that does not leak outside through an opening formed in the grounding container 10 in order to attach the bushing 20.

  The lead conductor 22 is a metal member suitable for energization, such as copper, copper alloy, aluminum, or aluminum alloy. The lead conductor 22 is formed integrally with the insulating cylinder 21 by molding. The lead conductor 22 is connected to the other end of the connection conductor 50 whose one end is connected to the charging unit 40.

  The ionized gas supply unit 30 ionizes the insulating gas sealed in the ground container 10 and supplies the ionized gas from the ion discharge port 33 into the ground container 10 at a predetermined flow rate. The ionized gas supply unit 30 ionizes the insulating gas by discharge, for example, and generates an ionized gas containing positive ions or negative ions. As the ionized gas supply unit 30, a known ion generator can be applied (for example, Patent Documents 4 and 5).

  The ionized gas supply unit 30 is arranged so that the ionized gas is supplied to the high electric field portion in the grounded container 10 in an ionized state. Thereby, the insulation performance of the apparatus 1 for electric power improves. The high electric field portion is a tip portion of the conductor exposed in the ground container 10, a shielding layer end portion 23 of the bushing, a supporting insulator or an insulating spacer that supports the conductor while ensuring insulation between the ground.

Specifically, the ion discharge port 33 and the high electric field portion of the ionized gas supply unit 30 are arranged as close as possible. This is because, after the ionized gas is introduced into the grounded container 10, if it recombines with time and returns to the insulating gas, the effect of suppressing the occurrence of discharge is reduced.
In FIG. 1, an ionized gas supply unit 30 is disposed in the vicinity of the bushing 20 so that ionized gas is efficiently supplied to the connection portion between the lead conductor 22 and the connection conductor 50. Further, by arranging the ionized gas supply unit 30 in the grounded container 10, simplification around the power equipment can be achieved.

  In addition, since discharge tends to occur when the humidity in the ground container 10 is high, the ground container 10 is preferably filled with an ionized gas whose humidity is controlled.

  When the power device 1 is in operation, a power cable terminal that has been subjected to a corresponding termination process is connected to the bushing 20 in a locally assembled manner or a plug-in manner. High voltage power is applied to the charging unit 40 via a power cable (not shown), the bushing 20, and the connection conductor 50.

  As described above, the power device 1 includes the grounding container 10 in which the insulating gas is sealed, the charging unit 40 (electrical device) that is accommodated in the grounding container 10 and performs high-voltage charging, and the charging unit 40 is charged with high pressure. A bushing 20 (electric power supply unit) for performing electricity and an ionized gas supply unit 30 that ionizes the insulating gas and supplies the ionized gas into the grounded container 10 are provided.

In the power device 1, since the high electric field portion (for example, the connection portion of the connection conductor 50 and the lead conductor 22) in the ground container 10 is covered with the ionized gas, the charge charged in the high electric field portion is included in the ionized gas. Neutralization (static elimination) with ions or negative ions. Therefore, it is possible to effectively prevent the discharge from occurring in the grounded container 10, so that high insulation performance can be maintained without using SF ₆ gas. Further, it is not necessary to increase the volume of the ground container 10 in order to increase the dielectric strength.

[Second Embodiment]
FIG. 2 is a diagram illustrating a schematic configuration of the power device 2 according to the second embodiment. In FIG. 2, the same or corresponding components as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 2, in the power device 2, an ionized gas supply unit 30 is installed outside the ground container 10. The ionized gas generated by the ionized gas supply unit 30 is introduced into the grounded container 10 through the nonmetallic pipe 31. Further, the insulating gas generated by recombination in the ground container 10 is supplied to the ionized gas supply unit 30 through the pipe 32 in a circulating manner. If the non-metallic pipe 31 is made of a metal material, ions disappear, so the non-metallic pipe 31 is made of a non-metallic material. The pipe 32 may be made of either a metal material or a non-metal material.
By installing the ionized gas supply unit 30 outside the ground container 10, maintenance work of the ionized gas supply unit 30 is facilitated.

Further, similarly to the first embodiment, according to the power device 2, it is possible to effectively prevent discharge in the grounded container 10, so that high insulation performance can be achieved without using SF ₆ gas. Can be held. Further, it is not necessary to increase the volume of the ground container 10 in order to increase the dielectric strength.
If the ionized gas supply unit 30 is installed on the top surface of the grounded container 10, it is not necessary to expand the installation space for the ionized gas supply unit 30.

[Example]
In the example, the test vessel (not shown) simulating the elephant unit 10B of the power device 1 according to the first embodiment was operated with an applied voltage of 100 kV. As the insulating gas, air in the atmosphere or dry air was used. A case where air is ionized and supplied into the grounded container 10 is referred to as Example 1, and a case where dry air is ionized and supplied into the grounded container 10 is referred to as Example 2. The bushing of the same form was used for the bushing.
As a result, in both cases of Examples 1 and 2, it was possible to operate satisfactorily without causing discharge under an applied voltage of 100 kV.

[Comparative example]
In the comparative example, the test vessel (not shown) having the same size as that of the example was operated with an applied voltage of 100 kV without supplying ionized gas. As the insulating gas, dry air and SF ₆ gas were used. The case where the ground container is filled with dry air is referred to as Comparative Example 1, and the case where the test container is filled with SF ₆ gas is referred to as Comparative Example 2. The bushing of the same form as the example was used for the bushing.

  As a result, in Comparative Example 1, corona discharge occurred at 61 kV, making it impossible to continue the power application. In Comparative Example 2, it was possible to apply power satisfactorily without causing discharge under an applied voltage of 100 kV.

As described above, in the simulated electrical test according to the first embodiment, it was confirmed that the insulation performance equivalent to that of the conventional case in which SF ₆ gas was filled was ensured. Moreover, since the insulating property improves in Example 1 in which dry air is ionized compared to Example 2 in which air is ionized, it can be said that dry air is preferably used as the insulating gas.
Moreover, although description is abbreviate | omitted, the result similar to Example 1, 2 is obtained also in the test container (not shown) which simulated the elephant part 10B of the apparatus 2 for electric power which concerns on 2nd Embodiment.

As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and can be changed without departing from the gist thereof.
For example, as shown in FIGS. 3 and 4, the ion discharge port 33 of the ionized gas generated in the ionized gas supply unit 30 is preferably disposed at a position facing the high electric field portion in the ground container 10.
In the case where the ion discharge port 33 of the ionized gas supply unit 30 is provided at a position facing the high electric field portion (see, for example, FIG. 3), it is confirmed that the discharge of the high electric field portion is suppressed in the electric test. It is more preferable to obtain a power device having the electrical characteristics. In this case, the ionized gas supply unit 30 may be disposed either inside or outside the ground container 10.
As shown in FIG. 4, when the ionized gas is ejected through the non-metallic nozzle 34, the ionized gas can be easily supplied to the high electric field portion, and the ionized gas supply unit 30 can The degree of freedom of installation location is also increased.

In addition, by installing a plurality of ionized gas supply units 30, the ionized gas can be efficiently supplied to the high electric field portion in the ground container 10.
Further, a blower may be arranged in the ground container 10 or the structure in the ground container 10 may be devised so that the ionized gas is efficiently supplied to the high electric field portion. In the embodiment, the case where the ionized gas supply unit 30 is provided in the vicinity of the bushing 20 serving as the high electric field portion is described. An ionized gas supply unit 30 may be provided.

  The power equipment of the present invention can be applied to gas insulated high-voltage equipment in general, such as a gas-filled transformer, in addition to the GIS shown in the embodiment. In the above-described embodiment, the bushing 20 that supplies power to the power device by connecting the power cable is applied as the power supply unit. However, as shown in FIG. 5, the power cable is not connected. A so-called air bushing 20A may be applied to supply power to the charging unit 40 (electrical device). In this case, a lead-in wire or the like from an overhead wire is connected to the tip of the air bushing 20A on the air side (outside of the power device 1A).

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1, 2 Power equipment 10 Grounding container 20, 20A Bushing (power supply unit)
21 Insulating cylinder 22 Lead conductor 23 Shielding layer end 30 Ionized gas supply part 31 Non-metallic pipe 32 Pipe 40 Charging part 41 Breaker 42 Disconnector 43 Bus line 50 Connection conductor

Claims (6)

A grounded container filled with insulating gas;
Electrical equipment housed in the grounded container and subjected to high voltage power;
A power supply unit for applying high-voltage power to the electrical device;
And an ionized gas supply unit that ionizes the insulating gas and supplies the ionized gas into the grounded container.   The power device according to claim 1, wherein the ionized gas supply unit supplies the ionized gas to a high electric field portion in the grounded container.   The power device according to claim 2, wherein a discharge port of the ionized gas generated in the ionized gas supply unit is disposed at a position facing a high electric field portion in the ground container.   The power device according to claim 1, wherein the insulating gas is dry air.   5. The power device according to claim 1, wherein the ionized gas supply unit is disposed in the grounded container.   5. The electric power according to claim 1, wherein the ionized gas supply unit is disposed outside the grounded container and supplies the ionized gas into the grounded container through a non-metallic pipe. Equipment.

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