JP2000059935A - Gas filling method of gas-insulated electric apparatus, and its foreign-matter inspecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas filling method wherein two or more kinds of insulating gases are filled into a metallic container as mixing them with each other uniformly. SOLUTION: A gas filling method of a gas-insulated electric apparatus wherein a conductor 3 of applying thereto a high voltage and insulators 4 for supporting the conductor 3 thereby in an insulating way are stored and two or more kinds of insulating gases having different partial-pressure ratios from each other are filled into a grounded metallic container 1. Hereupon, the foregoing insulating gases are so filled into the grounded metallic container 1 that the gas having the low partial-pressure ratio precedes always the gas having the high partial-pressure ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for filling gas in a gas-insulated electric device and a method for detecting foreign matter.

[0002]

2. Description of the Related Art FIG. 10 is a structural view showing a gas insulated container of a conventional gas insulated switchgear. In FIG. 10, a metal container 1 is grounded, and an insulating gas of about several atmospheres is sealed in the inside thereof through a valve 2. Further, the conductor 3 is housed in the metal container 1, and a high voltage is applied to the conductor 3. The conductor 3 is insulated and supported by an insulating spacer 4, and a high-voltage embedded conductor 5 is provided inside the insulating spacer 4.
Is embedded. In the metal container 1, linear metallic foreign matter 6 is mixed or generated due to vibration during assembly, an opening / closing test of an opening / closing device, and transportation.

At present, gas-insulated switchgear using SF ₆ as an insulating medium is widely used in power systems. Since SF ₆ has excellent insulation performance, it greatly contributes to the realization of a compact gas insulated switchgear having good performance. However, SF ₆ has a high liquefaction temperature, by the use in cold climates, the liquefaction occurs, there is a possibility that the insulating performance is significantly decreased, serious accidents may occur.

[0004] In order to avoid this problem, a gas-insulated electric device for cold regions is filled with SF ₆ reduced to a pressure that does not liquefy at the lowest temperature used and mixed with CF ₄ gas or N _2. A method for compensating for a decrease in insulation performance has been proposed (JP-A-53-86473, JP-A-5-86473).
5-76520).

[0005] In addition, amid recent years growing awareness of global environmental protection, SF ₆ is noted that a high gas global warming potential, in the Kyoto Conference on has been the prevention of global warming held in December 1997, SF ₆ has been designated as a greenhouse gas for reduction. At present, SF ₆ has a small total usage compared to CO ₂ gas,
It is an effective measure to reduce the emission of SF _{6 into} the atmosphere. However, the global warming potential of SF ₆ is
It is said to be 24900 times as large as CO ₂ , and it is desired to reduce the total amount used.

From the above, a gas-insulated electric device using an alternative gas without using SF ₆ as an insulating gas in the metal container 1 or mixing SF ₆ with another insulating gas to form SF ₆ Gas insulated electrical devices have been proposed that reduce total usage.

[0007]

However, in a gas insulated electric device using a mixture of a plurality of insulating gases,
Since the specific gravities of the respective insulating gases are different, the insulating gases may be separated at the time of filling the insulating gases and may not be mixed uniformly.

For example, in the case of a mixed gas of SF ₆ and N ₂ , the molecular weight is 148 for the former and 28 for the latter, and has a specific gravity difference of 5 times or more at the same temperature and the same pressure. Therefore, SF ₆ tends to stay in the lower part of the metal container 1 and N ₂
Tends to stay at the top. As described above, when the insulating gas is separated, the metal container 1 in which N ₂ having a low dielectric strength is retained.
Insulation failure may occur at the upper part.

FIGS. 11A and 11B show an example in which an insulating gas having a high partial pressure is filled first. Since the insulating gas having a high partial pressure is filled first, when the insulating gas is sealed later, the absolute amount of sealing is small, and the sealing time is short. Furthermore, the flow rate of the insulating gas to be sealed is reduced by the pressure of the insulating gas having a high partial pressure previously sealed, so that the effect of mixing is reduced.

Therefore, when the insulating gas to be charged later is larger than the specific gravity of the insulating gas already charged, the insulating gas to be charged later is placed below the metal container 1 as shown in FIG. An on-going quiet gas flow 7a is formed.

On the other hand, when the insulating gas to be sealed later is smaller than the specific gravity of the insulating gas already sealed, FIG.
As shown in FIG. 2B, the insulating gas to be sealed later forms a quiet gas flow 7b toward the upper part of the metal container 1. As described above, if an insulating gas having a high partial pressure is sealed beforehand, there is a problem that the insulating gas is not efficiently mixed.

In the gas-insulated electric device, the metallic foreign matter 6
There is a risk of dielectric breakdown due to That is, as described above, the metal foreign matter 6 may be mixed or generated by the vibration during the assembly, the opening / closing test of the switchgear, and the transportation, and the metal foreign matter 6 causes the dielectric breakdown during the withstand voltage test or the normal operation. It can also cause For this reason, withstand voltage test,
Before the normal operation, a method for detecting the metal foreign material 6 existing inside the metal container 1 was required.

The present invention has been made in view of the above circumstances, and provides a method of filling a gas insulated electric device for uniformly filling two or more kinds of insulating gases in a metal container while mixing. With the goal.

Another object of the present invention is as follows.
An object of the present invention is to provide a method for detecting foreign matter in a gas-insulated electric device, which detects foreign matter present in the gas-insulated electric device with high sensitivity.

[0015]

In order to achieve the above object, according to the present invention, a conductor to which a high voltage is applied and an insulator for insulating and supporting the conductor are housed and grounded. A gas filling method for a gas-insulated electric device in which two or more kinds of insulating gases having different partial pressure ratios are filled in a metal container, wherein the insulating gas is supplied to the metal container first from an insulating gas having a low partial pressure ratio. It is characterized by being enclosed.

According to the first aspect of the present invention, since the pressure of the insulating gas previously filled is smaller than the total pressure of the insulating gas, the pressure of the insulating gas in the metal container at that time is reduced. The difference between the pressure of the supplied gas and the insulating gas is large, and the time for filling the insulating gas with a larger partial pressure is long, and the filling flow rate is also fast, so that it mixes well with the previously filled insulating gas, Two or more insulating gases can be efficiently mixed.

According to a second aspect of the present invention, a conductor to which a high voltage is applied and an insulator for insulating and supporting the conductor are housed, and two or more types of insulating materials having different specific gravities are accommodated in a grounded metal container. What is claimed is: 1. A gas charging method for a gas-insulated electric device for charging a gas, comprising: installing a valve for sucking and discharging the insulating gas at an upper portion of the metal container; It is characterized in that an insulating gas having a higher specific gravity is sealed.

According to the second aspect of the present invention, when two or more kinds of insulating gases having different specific gravities are used, when the insulating gas to be filled later has a higher specific gravity than the insulating gas filled earlier, Convection occurs due to the difference in specific gravity of the insulating gas, and it becomes possible to uniformly mix two or more types of insulating gas having different specific gravities.

According to a third aspect of the present invention, at least two types of insulating materials having different specific gravities are accommodated in a grounded metal container while accommodating a conductor to which a high voltage is applied and an insulator for insulating and supporting the conductor. What is claimed is: 1. A gas charging method for a gas-insulated electric device for charging a gas, comprising the steps of: installing a valve for sucking and discharging the insulating gas at a lower portion of the metal container; An insulating gas having a lower specific gravity is sealed.

According to the third aspect of the present invention, when two or more kinds of insulating gases having different specific gravities are used, when the insulating gas to be filled later is smaller in specific gravity than the insulating gas filled earlier, Convection occurs due to the difference in specific gravity of the insulating gas, and it becomes possible to uniformly mix two or more types of insulating gas having different specific gravities.

According to a fourth aspect of the present invention, a conductor to which a high voltage is applied and an insulator for insulating and supporting the conductor are housed, and two or more types of insulating materials having different specific gravities are accommodated in a grounded metal container. What is claimed is: 1. A gas filling method for a gas-insulated electric device for filling a gas, wherein an upper valve and a lower valve for sucking and discharging the insulating gas are respectively installed at an upper part and a lower part of the metal container, and the gas is already installed in the metal container. An insulating gas having a specific gravity higher than that of the filled insulating gas is sealed from the upper valve, and an insulating gas having a lower specific gravity is sealed from the lower valve.

According to the fourth aspect of the present invention, a convection is generated due to a difference in specific gravity of the insulating gas by selecting a valve for filling the insulating gas from an upper valve or a lower valve, and the specific gravity differs. Two or more insulating gases can be uniformly mixed.

According to a fifth aspect of the present invention, a conductor to which a high voltage is applied and an insulator which insulates and supports the conductor are housed, and two or more types having different partial pressure ratios and specific gravities are provided in a grounded metal container. A gas filling method for a gas insulated electric device that fills an insulating gas according to claim 1, wherein an upper valve and a lower valve for sucking and discharging the insulating gas are installed at upper and lower portions of the metal container, respectively. When the gas is sealed in the metal container, the two kinds of insulating gases are sealed first from the lower partial pressure ratio, and the larger one of the two kinds of insulating gases is further separated from the upper valve by the upper valve. ,
The lower specific gravity is simultaneously sealed from each of the lower valves.

According to the fifth aspect of the present invention, since the insulating gas is sealed from the upper and lower two valves,
The time required to fill the insulating gas can be reduced,
Due to the difference in specific gravity of the insulating gas to be enclosed, convection occurs in the metal container and the insulating gases are mixed, so that the two types of insulating gases are uniformly mixed. In addition, since the insulating gas with a lower partial pressure is charged first, the insulating gas with a higher partial pressure is charged when the insulating gas with a higher partial pressure is charged. Since the pressure difference between the insulating gas and the pressure increases, the flow rate of the sealing gas increases, and the flow rate of the insulating gas to be sealed later increases. As a result, it is possible to mix well with the previously-filled insulating gas and efficiently mix two or more types of insulating gas.

According to a sixth aspect of the present invention, in the gas filling method of the gas insulated electric device according to the fifth aspect, a flow meter for measuring a gas flow rate is provided in each of the upper valve and the lower valve, and two kinds of low partial pressure ratios are provided. When filling the insulating gas,
It is characterized in that the flow rate of the insulating gas is adjusted to be the inverse ratio of the partial pressure ratio.

According to the sixth aspect of the present invention, since the charging of the insulating gas is completed almost simultaneously, the insulating gas having a different specific gravity always generates a convection with the insulating gas sealed from the two valves. While mixing, two or more insulating gases can be efficiently mixed.

According to a seventh aspect of the present invention, a conductor to which a high voltage is applied and an insulator for insulating and supporting the conductor are housed, and two or more different insulating gases are placed in a grounded metal container. What is claimed is: 1. A gas filling method for a gas-insulated electric device, wherein a pressure vessel is connected to a gas intake / exhaust valve attached to the metal container, and the insulating gas is filled in the pressure container at a predetermined mixing ratio. Thereafter, the insulating gas is sealed in the metal container.

According to the seventh aspect of the present invention, in the pressure vessel, two or more kinds of insulating gases are uniformly mixed in advance at a predetermined mixing ratio, so that the mixed gas sealed in the metal vessel is also uniform. It becomes a mixed gas mixture.

[0029] The invention according to claim 8 is a gas insulated electric device which accommodates a conductor to which a high voltage is applied and an insulator which insulates and supports the conductor, and detects foreign matter contained in a grounded metal container. Foreign material detection method, factory test,
In the on-site test, a gas having a small electron adhesion is sealed in the metal container, a corona discharge is measured by applying a voltage lower than the withstand voltage test, and then the inside of the metal container is replaced with the insulating gas. A withstand voltage test is performed and normal operation is started.

According to the eighth aspect of the present invention, the presence or absence of an abnormality in a metal container such as a foreign substance causing dielectric breakdown in a withstand voltage test or normal operation is measured with high sensitivity by measuring a corona. Becomes possible.

According to a ninth aspect of the present invention, in the method for detecting foreign matter in a gas insulated electric device according to the eighth aspect, 100% SF ₆ is used as an insulating gas and N ₂ is used as a gas having a small electron-adhering property. It is characterized by having been.

According to the ninth aspect of the present invention, the presence or absence of an abnormality in the metal container such as a foreign substance which causes insulation breakdown in a withstand voltage test or normal operation is measured by measuring the corona in an N ₂ atmosphere where corona is easily generated. By doing so, measurement can be performed with high sensitivity. In addition, since N ₂ is inexpensive and has a small environmental load, it can be released into the atmosphere, and the time and effort for gas recovery can be saved.

According to a tenth aspect of the present invention, in the gas insulated electric device foreign matter detection method according to the eighth aspect, a mixed gas of SF ₆ and N ₂ is used as the insulating gas, and It is characterized by using 100% N ₂ .

According to the tenth aspect of the present invention, the presence or absence of an abnormality in the metal container such as a foreign substance causing dielectric breakdown in a withstand voltage test or normal operation is measured with high sensitivity by measuring a corona. Becomes possible. After the corona measurement is completed, N ₂ is further filled in, or SF ₆ is filled out after discharging, and a predetermined mixing ratio and a mixed gas pressure are set so that the metal container is quickly evacuated without evacuation. The operation can be shifted to the withstand voltage test corresponding to the operating voltage and the normal operation. In addition, since N ₂ is inexpensive and has a small environmental load, it can be released into the atmosphere, and the time and effort for gas recovery can be saved.

[0035]

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

[First Embodiment of Gas Filling Method] FIG. 1 is a configuration diagram showing a gas insulating container applied to a first embodiment of a gas filling method for a gas insulated electric device according to the present invention. In FIG. 1, the same or corresponding parts as those in FIGS. 10 and 11 are denoted by the same reference numerals and described.

In FIG. 1, a metal container 1 is grounded, and two or more different types of insulating gas of about several atmospheres are sealed therein through a valve 2. Further, the conductor 3 is housed in the metal container 1, and a high voltage is applied to the conductor 3. The conductor 3 is insulated and supported by an insulating spacer 4 as an insulator, and a high-voltage embedded conductor 5 is embedded in the insulating spacer 4.

In the present embodiment, an insulating gas having a relatively low partial pressure ratio is first sealed in the metal container 1 through the valve 2, and an insulating gas having a relatively high partial pressure ratio is sealed later. Then, the insulating gas having the highest partial pressure ratio is filled last, and the filling of the insulating gas into the metal container 1 is completed. In addition, in FIG. 1, the code | symbol 7 has shown the gas flow when the insulating gas with a high partial pressure ratio is enclosed later.

Next, the operation of the present embodiment will be described.

First, when the inside of the metal container 1 is evacuated and the first insulating gas is filled therein, only one kind of insulating gas is used, so that the inside of the metal container 1 is uniformly filled. Since the insulating gas to be filled next tends to stay at the upper or lower part of the metal container 1 depending on the magnitude of the specific gravity of the insulating gas filled first, the insulating gas to be filled later is filled vigorously. However, it is necessary to mix well with the insulating gas previously sealed.

The sealing of the insulating gas is performed via the valve 2
Performed by the differential pressure between the pressure in the container 1 and the pressure of a cylinder (not shown),
The insulating gas sealed in the metal container 1 becomes a turbulent flow, and is sealed while being mixed with the insulating gas already sealed as shown in FIG. Since the insulating gas with a high partial pressure ratio to be filled later has a large absolute amount, the filling time is long and the insulating gas can be efficiently mixed.

That is, in this embodiment, since the pressure of the insulating gas previously sealed is smaller than the pressure of the entire insulating gas, the insulating gas pressure and the insulating gas in the metal container 1 are supplied at that time. The difference between the pressure of the cylinder and the pressure of the insulating gas is large, the time to fill the insulating gas with a larger partial pressure is long, and the filling flow rate is fast. The above insulating gases can be efficiently mixed.

As described above, according to the present embodiment, when two or more kinds of insulating gases having different partial pressure ratios are filled in the metal container 1, the insulating gas having the lower partial pressure ratio is firstly sealed in the metal container 1. Thereby, the insulating gas can be filled while being uniformly mixed.

[Second Embodiment of Gas Filling Method] FIG. 2 is a structural view showing a gas insulating container applied to a second embodiment of the gas filling method of the gas insulated electric device according to the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The same applies to the following embodiments.

As shown in FIG. 2, in this embodiment, an upper valve 2a for supplying and discharging an insulating gas is provided above a metal container 1.
Is installed, and an insulating gas having a higher specific gravity than the insulating gas already filled in the metal container 1 is sealed from the upper valve 2a.

Next, the operation of the present embodiment will be described.

In a gas insulated electric device using two or more kinds of insulating gases having different specific gravities, when the insulating gas is sealed in the metal container 1, the insulating gas having a higher specific gravity than the insulating gas already filled in the metal container 1 is used. An inert gas is sealed from the upper valve 2a.

Then, the insulating gas having a large specific gravity has a property of staying in the lower portion of the metal container 1, but the insulating gas has a higher specific gravity.
Since it is sealed from a, it flows into the lower part of the metal container 1 and mixes with the already filled insulating gas.

That is, in the present embodiment, when two or more kinds of insulating gases having different specific gravities are used, when the insulating gas to be filled later has a higher specific gravity than the insulating gas previously filled, the insulating gas is used. A convection is generated due to the difference in specific gravity, and two or more insulating gases having different specific gravities can be uniformly mixed.

As described above, according to the present embodiment, when an insulating gas having a large specific gravity is sealed later, the upper valve 2a
By filling the insulating gas, the insulating gas can be filled while being uniformly mixed.

[Third Embodiment of Gas Filling Method] FIG. 3 is a configuration diagram showing a gas insulating container applied to a third embodiment of the gas filling method of the gas insulated electric device according to the present invention.

As shown in FIG. 3, in the present embodiment, a lower valve 2b for gas supply / exhaust is provided below the metal container 1, and from the lower valve 2b, the insulating gas already filled in the metal container 1 is used. An insulating gas having a small specific gravity is sealed.

Next, the operation of the present embodiment will be described.

In a gas insulated electric device using two or more kinds of insulating gases having different specific gravities, when the insulating gas is sealed in the metal container 1, the insulating gas having a lower specific gravity than the insulating gas already filled in the metal container 1 is used. An inert gas is sealed from the lower valve 2b. The insulating gas having a small specific gravity is supplied to the metal container 1
Although it has the property of staying in the upper part, it is sealed from the lower valve 2b, so that it mixes with the already filled insulating gas in the process of floating above the metal container 1.

That is, in the present embodiment, when two or more types of insulating gases having different specific gravities are used, when the insulating gas to be sealed later is smaller in specific gravity than the insulating gas previously sealed, the insulating gas is used. A convection is generated due to the difference in specific gravity, and two or more insulating gases having different specific gravities can be uniformly mixed.

As described above, according to the present embodiment, when the insulating gas having a small specific gravity is later filled, the lower valve 2b
By filling the insulating gas, the insulating gas can be filled while being uniformly mixed.

[Fourth Embodiment of Gas Filling Method] FIG. 4 is a structural view showing a gas insulating container applied to a gas filling method for a gas insulated electric device according to a fourth embodiment of the present invention.

As shown in FIG. 4, in the present embodiment, an upper valve 2a and a lower valve 2b for gas supply / exhaust are respectively installed at two locations, an upper portion and a lower portion, of the metal container 1. An insulating gas having a higher specific gravity than the filled insulating gas is sealed from the upper valve 2a, and an insulating gas having a lower specific gravity is sealed from the lower valve 2b.

Next, the operation of the present embodiment will be described.

In a gas-insulated electric device using two or more kinds of insulating gases having different specific gravities, when the insulating gas is sealed in the metal container 1, the insulating gas having a higher specific gravity than the insulating gas already filled in the metal container 1 is used. Insulating gas is filled from the upper valve 2a and insulating gas having a small specific gravity is filled from the lower valve 2b, and so on. .

Although the insulating gas having a large specific gravity has a property of stagnating in the lower portion of the metal container 1, it is sealed from the upper valve 2a. Will mix. Similarly, although the insulating gas having a small specific gravity has a property of staying in the upper portion of the metal container 1, it is sealed from the lower valve 2b. Will mix.

That is, in the present embodiment, the valve for charging the insulating gas is replaced with the upper valve 2a or the lower valve 2b.
By selecting the above, convection occurs due to the difference in specific gravity of the insulating gas, and it becomes possible to uniformly mix two or more types of insulating gas having different specific gravities.

As described above, according to the present embodiment, when two or more kinds of insulating gases having different specific gravities are filled in the metal container 1, the insulating gas having a larger specific gravity than the insulating gas already filled in the metal container 1 is used. By filling the insulating gas from the upper valve 2a and the insulating gas having a small specific gravity from the lower valve 2b, the insulating gas can be filled while being uniformly mixed.

[Fifth Embodiment of Gas Filling Method]
This embodiment will be described with reference to FIG. 4 as in the fourth embodiment.

In the metal container 1, an upper valve 2a and a lower valve 2b for gas supply / exhaust are respectively installed at two places, an upper part and a lower part. When two or more kinds of insulating gases having different partial pressure ratios and specific gravities are sealed in the metal container 1, two kinds of insulating gases having the lowest partial pressure ratio are simultaneously sealed first, and the two kinds of insulating gases are sealed. Among the gases, the gas having a higher specific gravity is sealed from the upper valve 1a, and the gas having a lower specific gravity is sealed from the lower valve 1b.

Next, the operation of the present embodiment will be described.

In a gas insulated electric device using two or more kinds of insulating gases having different partial pressure ratios and specific gravities, when the insulating gas is sealed in the metal container 1, an upper valve 2a and a lower valve 2b provided at two upper and lower positions are provided. Therefore, the sealing time of the insulating gas can be shortened by simultaneously filling the two types of insulating gases in the order of the lower partial pressure ratio. At the same time, among the insulating gases to be simultaneously filled, one having a higher specific gravity is supplied from the upper valve 1a, and one having a lower specific gravity is supplied from the lower valve 1b.
, The mixing of the insulating gas in the metal container 1 is efficiently performed.

When three types of insulating gas are used, two types of insulating gas having a small partial pressure ratio are first filled, and
By filling the insulating gas having the large partial pressure ratio last, the mixing of the insulating gas is efficiently performed by the operation described in the first embodiment.

Further, when the insulating gas having a high partial pressure ratio is larger than the specific gravity of the mixed insulating gas already sealed, the insulating gas is sealed from the upper valve 1a, and when the insulating gas is lower than the specific gravity, it is sealed from the lower valve 1b. With the action
Mixing of the insulating gas is performed efficiently.

Even when four or more kinds of insulating gases are sealed, two kinds of insulating gases are simultaneously sealed from the upper valve 2a and the lower valve 2b provided at the upper and lower two places in the same manner as described above. It is possible to efficiently fill the insulating gas with time.

That is, in this embodiment, since the insulating gas is sealed from the upper and lower two valves 2a and 2b, the time required for sealing the insulating gas can be shortened, and the insulating gas to be sealed can be shortened. Convection occurs in the metal container 1 due to the difference in specific gravity of
The types of insulating gas are mixed uniformly.

Further, since the insulating gas having a lower partial pressure is filled first, when the insulating gas having a higher partial pressure is charged, the insulating gas pressure and the insulating gas in the metal container 1 are supplied. Since the pressure difference from the gas pressure of the cylinder increases, the sealing flow rate increases, and the flow rate of the insulating gas to be sealed later increases. As a result, it is possible to mix well with the previously-filled insulating gas and efficiently mix two or more types of insulating gas.

As described above, according to the present embodiment, when filling two or more kinds of insulating gases into the metal container 1, the two kinds of insulating gases having the lowest partial pressure ratio are simultaneously sealed first.
Of the two kinds of insulating gases, the one having a higher specific gravity is sealed from the upper valve 1a and the lower one having a lower specific gravity is sealed from the lower valve 1b, so that the insulating gas can be uniformly and quickly filled. .

[Sixth Embodiment of Gas Filling Method] FIG. 5 is a configuration diagram showing a gas insulating container applied to a sixth embodiment of the gas filling method of the gas insulated electric device according to the present invention.

As shown in FIG. 5, in the present embodiment, an upper valve 2a and a lower valve 2b for gas supply / exhaust are respectively installed at upper and lower portions of the metal container 1, and the respective valves 2a, 2b Is provided with a gas flow meter 8 for measuring a gas flow rate.

In the present embodiment, two metal containers 1
When filling more than two kinds of insulating gases, two kinds of insulating gases are filled first from the lower partial pressure ratio, and the larger one of the two kinds of insulating gases is used as the specific gravity from the upper valve 1a. While simultaneously filling the smaller one from the lower valve 1b and measuring the sealed gas flow rate with the gas flow meter 8.
The flow rate of the insulating gas to be sealed is adjusted so as to be the inverse ratio of the partial pressure.

Next, the operation of the present embodiment will be described.

In this embodiment, in addition to the operation of the fifth embodiment, two upper and lower valves 2a and two lower valves 2b are provided.
By setting the filling flow rates of the two kinds of insulating gases to be filled simultaneously as the inverse ratio of the filling partial pressure, the time required for filling becomes almost equal as shown in FIG.

Therefore, two kinds of insulating gases are always sealed in the metal container 1 at the same time, and further, are mixed so as to be mixed in the metal container 1 due to a difference in specific gravity, so that the insulating gas is efficiently mixed. .

That is, in the present embodiment, the filling of the insulating gas is completed almost at the same time, so that the insulating gas having different specific gravities is always mixed with the insulating gas filled from the two upper and lower valves 2a and 2b. Since they are mixed while generating convection, two or more types of insulating gases can be efficiently mixed.

As described above, according to the present embodiment, when two or more kinds of insulating gases are filled in the container, the two kinds of insulating gases having the lower partial pressure ratio are first sealed, and the two kinds of insulating gases are filled. Of the insulating gas having a higher specific gravity is used as the upper valve 1a.
From the lower valve 1b at the same time, while the gas flow meter 8 measures the sealed gas flow rate,
By adjusting the flow rate of the insulating gas to be sealed so as to be the inverse ratio of the partial pressure, the insulating gas can be uniformly and quickly filled.

[Seventh Embodiment of Gas Filling Method] FIG. 7 is a structural view showing a gas insulating container applied to a gas filling method for a gas insulated electric device according to a seventh embodiment of the present invention.

As shown in FIG. 7, in this embodiment, a pressure vessel 9 is connected to the valve 2 of the metal vessel 1, and two or more kinds of insulating gases are uniformly mixed in the pressure vessel 9 at a predetermined mixing ratio. After mixing, the mixed gas is sealed in the metal container 1.

Next, the operation of the present embodiment will be described.

In the pressure vessel 9, two or more types of insulating gases are uniformly mixed in advance at a predetermined mixing ratio, so that the mixed gas sealed in the metal container 1 also becomes a uniformly mixed insulating gas. .

As described above, according to the present embodiment, after two or more kinds of insulating gases are uniformly mixed at a predetermined mixing ratio in the pressure vessel 9, the mixed gas is sealed in the metal vessel 1. When enclosing more than one type of insulating gas in the metal container 1, the insulating gas can be uniformly mixed and sealed.

[First Embodiment of Foreign Object Detection Method] In the first embodiment of the foreign object detection method of the gas insulated electric device, in the factory test and the on-site test, the first step is to have no or no electron adhesion. Only a small gas is sealed in the metal container 1, a voltage lower than the withstand voltage test is applied to the conductor 3, a partial discharge is measured, and an abnormality such as the presence of the metal foreign material 6 is detected. Thereafter, the insulating gas in the metal container 1 is replaced with one or more kinds of insulating gases, a withstand voltage test corresponding to the operating voltage is performed, and the normal operation is started.

Next, the operation of the present embodiment will be described.

In the test at the time of shipment from the factory and the test after the on-site assembly, defects in the assembly and the like are confirmed. In particular, it is known that, when gaseous foreign matter 6 is mixed in the metal container 1 in a gas insulated device, the insulation performance is greatly reduced, and it is important to detect the metal foreign matter 6 mixed in at the time of assembly. A major problem is to detect and eliminate the metal foreign matter 6 with high sensitivity.

In a mixed gas insulating device, a gas having no or low electron adhesion (N ₂ , C
Although a gas having a high electron-adhesion property (a material such as SF ₆ ) is mixed with an inert gas such as O ₂ and Air to provide a predetermined insulating performance, the electron-adhesive substance has a corona phenomenon. It also has the effect of suppressing, which is disadvantageous for detecting a defect such as a foreign substance.

[0091] Figure 8 is a SF ₆ mixture ratio dependence of positive and negative polarity corona onset voltage of SF ₆ / N ₂ mixed gas, 9 SF
_The figure shows a corona starting voltage when a metallic foreign matter adheres to the surface of an insulator in a ₆ / N ₂ mixed gas. As described above, the corona starting voltage increases in the atmosphere where the conventional SF ₆ is mixed, and it is possible to detect a foreign substance, which has been difficult, with high sensitivity using an insulating gas such as N _{2 having} a small electron-adhering property.

That is, in the present embodiment, the presence or absence of an abnormality in the metal container 1 such as the metal foreign material 6 causing the dielectric breakdown in the withstand voltage test or the normal operation is measured with high sensitivity by measuring the corona. Becomes possible.

As described above, according to the present embodiment, in the factory test and the on-site test, a gas having a small electron adhesion is sealed in the metal container 1 and the corona is measured by applying a voltage lower than the withstand voltage test. Thereafter, the inside of the metal container 1 is replaced with an insulating gas, a withstand voltage test is performed, and normal operation is started, whereby abnormalities such as foreign substances can be detected with high sensitivity.

[Second Embodiment of Foreign Object Detecting Method] In the second embodiment of the foreign object detecting method of the gas insulated electric device, a corona measurement test is performed by using N ₂ as a gas having a small electron-adhering property, and the insulating gas is measured. 100% SF ₆ is used.

Next, the operation of the present embodiment will be described.

In a conventional gas-insulated electric device using 100% SF ₆ , it is possible to detect foreign substances with high sensitivity by corona measurement as shown in the first embodiment. That is,
The presence or absence of an abnormality in the metal container 1 such as a foreign substance that causes insulation breakdown in a withstand voltage test or a normal operation is determined by determining whether a corona is easily generated.
By measuring corona in _two atmospheres, it is possible to measure with high sensitivity.

Since N ₂ is inexpensive and has a low environmental load, it can be released into the atmosphere.
The trouble of performing gas recovery can be saved.

As described above, according to this embodiment, 100% SF ₆ is used as the insulating gas and N ₂ is used as the gas having a small electron-adhering property, so that abnormalities such as foreign substances can be reduced in a short time at low cost. It can be detected with high sensitivity.

[Third Embodiment of Foreign Substance Detection Method] In the third embodiment of the foreign matter detection method of the gas insulated electric device, a corona measurement test was performed using 100% N ₂ as a gas having a small electron-adhering property, and the insulating property was measured. A mixed gas of SF ₆ and N ₂ is used as the gas.

Next, the operation of the present embodiment will be described.

SF ₆ is a gas having a very high withstand voltage performance, and N ₂ is inexpensive. Therefore, as a mixed gas insulated electric device in which the amount of SF ₆ used is reduced, SF ₆ and N _{2 are used.}
Is believed to be the most promising. In such a mixed gas insulated electric device, it is possible to detect foreign substances with high sensitivity by corona measurement as described in the second embodiment.

After completion of the corona measurement with 100% N ₂ , N ₂ is further enclosed or discharged, and S 2
Sealed F _6, by setting the predetermined mixing ratio and gas mixture pressure, vacuum quickly operating voltage equivalent withstand voltage test without the metallic container 1, it is possible to shift to the normal operation. Furthermore, N ₂ is inexpensive and has a low environmental load, so it can be released to the atmosphere.
The trouble of performing gas recovery can be saved.

As described above, according to the present embodiment, a mixed gas of SF ₆ and N ₂ is used as an insulating gas, and 100% N ₂ is used as a gas having a small electron-adhesiveness, thereby being inexpensive and short. An abnormality such as a foreign substance can be detected with high sensitivity in a short time.

[0104]

As described above, according to the first to seventh aspects of the present invention, in a gas-insulated electric device using two or more kinds of insulating gases, the order of filling the insulating gases and the valves to be filled are described. By adjusting the position, two or more types of insulating gas can be uniformly filled in a short time.

According to the eighth to tenth aspects of the present invention, before the withstand voltage test, a gas having a small electron adhesion is sealed, a voltage lower than that in the withstand voltage test is applied, and the corona discharge is measured. This makes it possible to detect the presence of foreign matter with high sensitivity before the withstand voltage test.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a gas insulated container applied to a first embodiment of a gas filling method for a gas insulated electric device according to the present invention.

FIG. 2 is a configuration diagram showing a gas-insulated container applied to a second embodiment of the gas filling method for a gas-insulated electric device according to the present invention.

FIG. 3 is a configuration diagram showing a gas-insulated container applied to a third embodiment of a gas filling method for a gas-insulated electric device according to the present invention.

FIG. 4 is a configuration diagram showing a gas insulated container applied to a fourth embodiment of a gas filling method for a gas insulated electric device according to the present invention.

FIG. 5 is a configuration diagram showing a gas-insulated container applied to a sixth embodiment of the gas filling method for a gas-insulated electric device according to the present invention.

FIG. 6 is a graph showing a relationship between a filling time of an insulating gas and a partial pressure of a gas-insulated electric device according to a sixth embodiment of the present invention.

FIG. 7 is a configuration diagram showing a gas insulated container applied to a gas insulated electric device according to a seventh embodiment of the present invention.

FIG. 8 is a graph showing the SF ₆ mixing ratio dependency of the positive / negative corona starting voltage in the SF ₆ / N ₂ mixed gas.

FIG. 9 is a graph showing the amount of corona discharge charge when a metal foreign matter adheres to the surface of an insulator in an SF ₆ / N ₂ mixed gas.

FIG. 10 is a configuration diagram showing a gas-insulated container of a conventional gas-insulated electric device.

11A is a configuration diagram of a gas insulated electric device showing a gas flow when an insulating gas to be sealed later has a low partial pressure ratio and a large specific gravity, and FIG. 11B is a diagram showing an insulating gas to be sealed later. FIG. 4 is a configuration diagram of a gas-insulated electric device showing a gas flow when the partial pressure ratio is low and the specific gravity is low.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal container 2 Valve 2a Upper valve 2b Lower valve 3 Conductor 4 Insulating spacer (insulator) 5 Embedded conductor 6 Foreign metal 7 Gas flow 7a Gas flow 7b Gas flow 8 Gas flowmeter 9 Pressure vessel

Claims (10)

[Claims] A gas for housing a conductor to which a high voltage is applied, an insulator for insulating and supporting the conductor, and enclosing two or more types of insulating gases having different partial pressure ratios in a grounded metal container. What is claimed is: 1. A gas charging method for an insulated electric device, comprising: charging the insulating gas in the metal container first with the insulating gas having a low partial pressure ratio. 2. A gas insulation for housing a conductor to which a high voltage is applied and an insulator for insulating and supporting the conductor, and enclosing two or more kinds of insulating gases having different specific gravities in a grounded metal container. What is claimed is: 1. A gas filling method for an electric device, comprising: installing a valve for sucking and discharging the insulating gas at an upper portion of the metal container; and providing an insulating material having a higher specific gravity than the insulating gas already filled into the metal container from the valve. A gas filling method for a gas-insulated electric device, comprising filling a gas. 3. A gas insulation for housing a conductor to which a high voltage is applied and an insulator for insulating and supporting the conductor, and enclosing two or more types of insulating gases having different specific gravities in a grounded metal container. What is claimed is: 1. A gas filling method for an electric device, comprising: installing a valve for sucking and discharging said insulating gas at a lower portion of said metal container; and said insulating valve having a lower specific gravity than said insulating gas already filled in said metal container from said valve. A gas filling method for a gas-insulated electric device, comprising filling a gas. 4. A gas insulation for housing a conductor to which a high voltage is applied and an insulator for insulating and supporting the conductor, and enclosing two or more types of insulating gases having different specific gravities in a grounded metal container. A gas filling method for an electric device, wherein an upper valve and a lower valve for sucking and discharging the insulating gas are respectively installed at an upper portion and a lower portion of the metal container, and an insulating gas already filled in the metal container is provided. A gas filling method for a gas insulated electric device, wherein an insulating gas having a large specific gravity is filled from the upper valve and an insulating gas having a small specific gravity is filled from the lower valve. 5. A conductor to which a high voltage is applied and an insulator for insulating and supporting the conductor are housed, and two or more insulating gases having different partial pressure ratios and specific gravities are sealed in a grounded metal container. A gas filling method for a gas insulated electric device, comprising: an upper valve and a lower valve for sucking and discharging the insulating gas, respectively, at an upper portion and a lower portion of the metal container, and the insulating gas is placed in the metal container. When sealing the two, the two types of insulating gases are first filled in the order from the lower partial pressure ratio, and of the two types of insulating gases, the one with the higher specific gravity is removed from the upper valve, and the one with the lower specific gravity is changed from the upper valve. A gas sealing method for a gas insulated electric device, wherein the gas is sealed simultaneously from the lower valves. 6. An upper valve and a lower valve each provided with a flow meter for measuring a gas flow rate. When two kinds of insulating gases having a low partial pressure ratio are filled, the flow rate of the insulating gas is set to the inverse ratio of the partial pressure ratio. 6. The method according to claim 5, wherein the adjustment is performed so as to satisfy the following conditions. 7. A gas insulated electric device which accommodates a conductor to which a high voltage is applied and an insulator for insulating and supporting the conductor, and encloses two or more different insulating gases in a grounded metal container. A gas filling method, wherein a pressure vessel is connected to a gas intake / exhaust valve attached to the metal container, and the insulating gas is filled into the pressure container at a predetermined mixing ratio, and then the metal container is filled with the insulating gas. A gas charging method for a gas insulated electric device, comprising charging the insulating gas. 8. A foreign matter detection method for a gas-insulated electrical device for housing a conductor to which a high voltage is applied and an insulator for insulating and supporting the conductor, and detecting foreign matter in a grounded metal container. In a factory test and a field test, a gas having a small electron-adhesive property was sealed in the metal container, and a corona discharge was measured by applying a voltage lower than the withstand voltage test. A method for detecting foreign matter in a gas-insulated electrical device, wherein a gas is replaced, a withstand voltage test is performed, and normal operation is started. 9. The method for detecting foreign matter in a gas-insulated electric device according to claim 8, wherein 100% SF ₆ is used as the insulating gas, and N ₂ is used as the gas having low electron adhesion. 10. A mixed gas of SF ₆ and N ₂ is used as an insulating gas, and 100
Foreign substance detecting method of the% N ₂ gas insulated electric apparatus according to claim 8, wherein the using.