JP5771564B2 - Electrical test apparatus and electrical test method - Google Patents

Description

  The present invention relates to an electrical test apparatus and electrical test method used for testing electrical characteristics of high-voltage equipment.

  In general, for electrical components (bushings, epoxy seats, etc.) used in high-voltage electrical equipment such as cable termination connections, commercial frequency withstand voltage tests, commercial frequencies are used to confirm safety before use. Various electrical tests such as partial discharge test and lightning impulse withstand voltage test are conducted. When such an electrical test is performed in air, air discharge and surface flashing occur from the charging section, sample protrusions, corners, or adhering foreign matter, so in general, in an insulating gas atmosphere with high dielectric strength. The test is performed in a state where the sample is arranged (for example, Patent Document 1).

  In addition, as a partial discharge measuring device for measuring a partial discharge generated in a gas-insulated electric device, the gas flow rate of the insulating gas generated by collision of ions generated by ionization of the insulating gas with neutral molecules that are not ionized There is known a partial discharge measuring device capable of measuring partial discharge by detecting with a detection element (for example, Patent Document 2).

Further, in the conventional electric test apparatus, sulfur hexafluoride (SF ₆ ) is mainly used as the insulating gas. SF ₆ gas has a dielectric strength superior to natural gas such as dry air (oxygen: about 20%, nitrogen: about 80%) and nitrogen (N ₂ ) gas that does not contain moisture. This is because it is suitable as an insulating gas.

Japanese Unexamined Patent Publication No. 7-140197 Japanese Examined Patent Publication No. 6-46209 JP-A-10-230124 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, and reduction in use is also required in the field of electrical testing. Therefore, the conventional electrical test apparatus is devised so that SF ₆ gas does not leak out from the test container as much as possible during the test (during high voltage application and sample exchange).

For example, in the electrical test apparatus described in Patent Document 1, an inner container containing SF ₆ gas is arranged so as to be movable up and down in the test container, and when applying a high voltage, the inner container is raised to remove the sample from SF _6. While being placed in a gas atmosphere, the inner container is lowered when exchanging the sample. The SF ₆ gas is heavier than air, and the SF ₆ gas is stored in the lower part of the test container when the sample is exchanged. Therefore, the SF ₆ gas can be prevented from leaking from the upper opening of the test container.

However, since it is difficult to completely prevent the SF ₆ gas from leaking out during the sample exchange, the SF ₆ gas in the test container is generally collected and reused in advance during the sample exchange (for example, Patent Documents). 3).
Thus, when SF ₆ gas is used as the insulating gas, a recovery facility for recovering SF ₆ gas after the test and a separation facility for reusing SF ₆ gas are required, and gas recovery / separation time is also required. As a result, the test cycle time becomes longer. In addition, a large space is required for installing a recovery / separation facility for recovering SF ₆ gas.
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 _In some cases, the dielectric strength is lower than that of ₆ gases, and the characteristics required for insulating gases for electrical tests are not fully satisfied, especially when the applied voltage is high.

An object of the present invention is to provide an electrical test apparatus and an electrical test method capable of performing an electrical test without using SF ₆ gas having a high global warming potential and greatly reducing the test cycle time. It is.

An electrical test apparatus according to the present invention is an electrical test apparatus for conducting an electrical test of electrical components used in high-voltage electrical equipment,
An insulating container for containing the sample;
A voltage application unit for applying a voltage to the sample housed in the container;
An ionized gas supply unit that ionizes insulating gas and supplies ionized gas into the container;
With
The ionized gas supply is disposed in the container and covered with a grounded metal shield having a through hole;
The sample is disposed on the shield part via an insulating member,
The ionized gas is filled in the container so that the periphery of the sample is covered with the ionized gas by the ionized gas supply unit,
A high voltage is applied to the sample by the voltage application unit , and any one of a commercial frequency partial discharge test, a commercial frequency withstand voltage test, and a lightning impulse test is performed.

An electrical test method according to the present invention is an electrical test method for conducting an electrical test of electrical components used in high voltage electrical equipment,
A sample, which is an electrical component used in high-voltage electrical equipment, is placed on a grounded metal shield part having a through hole covering an ionized gas supply part placed in an insulating container via an insulating member. A first step of:
A second step of ionizing an insulating gas and introducing the ionized gas into the container so as to cover the periphery of the sample;
And applying a voltage to the sample to measure the electrical characteristics of any one of a commercial frequency partial discharge test, a commercial frequency withstand voltage test, and a lightning impulse test .

According to the present invention, since the periphery of the sample, which becomes a high electric field portion when a high voltage is applied, is covered with the ionized gas, the air discharge is neutralized (discharged) by positive ions or negative ions contained in the ionized gas. The Therefore, the occurrence of air discharge and surface flashing can be effectively prevented, so that an electrical test can be performed without using SF ₆ gas. In addition, since a complicated operation such as a gas recovery operation using SF ₆ gas is not required, the test cycle time can be greatly shortened.

It is a figure which shows schematic structure of the electrical test apparatus which concerns on 1st Embodiment. It is a figure which shows the modification of the electrical test apparatus which concerns on 1st Embodiment. It is a figure which shows the other modification of the electrical test apparatus which concerns on 1st Embodiment. It is a figure which shows schematic structure of the electrical test apparatus which concerns on 2nd Embodiment.

[First Embodiment]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of an electrical test apparatus according to the first embodiment. An electrical test apparatus 1 shown in FIG. 1 includes, for example, a known bushing including a high voltage electrode, an insulator made of epoxy resin or the like, and an embedded metal fitting, or an insulator and embedded metal fitting made of an epoxy resin or the like. This is a facility for performing a commercial frequency partial discharge test using a known electrical part such as an epoxy seat as a sample TS.

As shown in FIG. 1, the electrical test apparatus 1 includes a test container 10, a voltage application unit 20, an ionized gas supply unit 30, and a measurement device 40.
The test container 10 is a container made of polycarbonate, for example. The test container 10 includes a storage portion 11 that stores the sample TS and a lid portion 12 that closes the opening of the storage portion 11. When performing an electrical test, the inside of the test vessel 10 is filled with an ionized gas supplied from the ionized gas supply unit 30 and an insulating gas generated by recombination of the ionized gas.

The lid portion 12 is placed on the housing portion 11 via a seal member 13 such as a rubber packing so that a predetermined humidity in the test container 10 can be maintained.
Moreover, since the inside of the test container 10 does not need to be airtight if insulation is ensured, the accommodating part 11 and the cover part 12 do not need to be airtightly fixed by bolting or the like. Thereby, since the cover part 12 can be opened and closed easily, the exchange work of sample TS is facilitated and test efficiency improves.

A grounded shield portion 14 is disposed in the lower half of the test container 10. The shield part 14 is made of, for example, stainless steel and is a pedestal formed in a covered and bottomless cylindrical shape. An ionized gas supply unit 30 is disposed in the space covered with the shield unit 14. By covering the periphery of the ionized gas supply unit 30 with the shield unit 14, it is possible to reduce the influence of noise caused by the ionized gas supply unit 30 itself (in this embodiment, the ion generator itself). In the commercial frequency partial discharge test, since it is necessary to detect a small amount of charge due to partial discharge, noise removal is extremely important.
If the ionized gas supply unit 30 itself has a shield function, the shield unit 14 may not be provided.

  An insulating member 15 made of, for example, polyacetal, which is formed in a plate shape, is disposed on the upper surface of the shield portion 14. A sample TS is placed on the insulating member 15. In order to reduce the influence of noise caused by the ionized gas supply unit 30, it is preferable that the insulating member 15 has a predetermined thickness or more (for example, 20 mm or more).

  A through hole 14 a is formed in the shield part 14, and ionized gas is introduced into the test container 10 through the through hole 14 a. Although FIG. 1 shows a case where a plurality of through holes 14a are formed on the upper surface of the shield part 14, the formation mode (position, size, shape, number, etc.) of the through holes in the shield part 14 is not particularly limited. .

  In the case of the withstand voltage test, since it is not necessary to remove noise, the shield part 14 and the insulating member 15 may or may not be provided. However, since the commercial frequency partial discharge test and the withstand voltage test are normally performed continuously, it is preferable to have the shield part 14 and the insulating member 15 in consideration of the test cycle time. Here, the test cycle time is the time taken from preparation of the electrical test to clean-up to perform the necessary electrical test on one or a plurality of samples, and includes working time such as charging time and sample replacement. It's time.

  The ionized gas supply unit 30 ionizes the insulating gas and supplies the ionized gas into the test 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 in the vicinity of the surface of the sample TS where air discharge or surface flashing may occur so that the ionized gas is supplied in an ionized state. Specifically, the gas supply port (not shown) of the ionized gas supply unit 30 and the sample TS are arranged as close as possible. This is because if the ionized gas is introduced into the test vessel 10 and then recombines with time to return to the insulating gas, the effect of suppressing the occurrence of air discharge and surface flashing is reduced.

  In addition, by disposing the ionized gas supply unit 30 in the test container 10, the ionized gas can be efficiently supplied around the sample TS, and simplification around the test facility can be achieved.

An insulating gas supply unit 31 is connected to the ionized gas supply unit 30. The insulating gas supply unit 31 is a gas cylinder that supplies an insulating gas to the ionized gas supply unit 30. As the insulating gas, for example, dry air containing no moisture (nitrogen: about 80%, oxygen: about 20%) or an insulating gas such as nitrogen (excluding SF ₆ gas) 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 insulating gas supply unit 31 supplies the insulating gas to the ionized gas supply unit 30 through, for example, a pipe 32 inserted through a through hole formed in the side surface of the housing unit 11. The pipe 32 is provided with a flow meter 33 so that the insulating gas is supplied from the insulating gas supply unit 31 to the ionized gas supply unit 30 at a predetermined flow rate.

An exhaust port 11 a is formed in the upper part of the side surface of the housing part 11. While ionized gas is supplied into the test container 10 by the ionized gas supply unit 30, the insulating gas generated by recombination of the ionized gas or the ionized gas is exhausted from the exhaust port 11a. Since the pressure in the test container 10 is kept substantially constant (does not rise too much), the ionized gas can be efficiently supplied around the sample TS.
If the supplied ionized gas is exhausted as it is, the effect of suppressing the occurrence of air discharge and surface flashing is reduced, so the gas supply port of the ionized gas supply unit 30 and the exhaust port 11a are arranged as far apart as possible. The

  In the first embodiment, air in the atmosphere whose water content is not adjusted to be constant can be used as the insulating gas. Specifically, as in the electrical test apparatus 1A shown in FIG. 2, it is sufficient that air is taken in from an intake port (not shown) of the ionized gas supply unit 30, and there is no need to provide the insulating gas supply unit 31. . Further, the lid 12 may be omitted and the upper part of the test container 10 may be opened.

  In the first embodiment, the test container 10 may be filled with an insulating gas in advance. Specifically, as in the electrical test apparatus 1B shown in FIG. 3, the housing part 11 and the lid part 12 are fixed in an airtight manner so that the insulating gas does not leak out. And while introducing insulating gas (for example, dry air) by the insulating gas supply part 31, air is exhausted from the exhaust port 11a, and the test container 10 is filled with insulating gas. After the filling of the insulating gas is completed, the valves 17 and 18 are closed to seal the test container 10. In this case, the insulating gas supply part 31 can also be removed. The ionized gas supply unit 30 cyclically sucks the insulating gas filled in the test container 10 and ionizes it to supply the ionized gas.

The voltage application unit 20 includes a test transformer that can adjust the applied voltage. The test lead wire TL is drawn out from the voltage application unit 20, and this test lead wire TL is connected to one end of the high voltage electrode of the sample TS. A measuring device 40 is connected to the other end (flange portion) of the sample TS.
In the case of a sample TS without a high voltage electrode such as an epoxy seat, the shield electrode 16 is attached to the sample TS. In this case, the test lead wire TL is connected to the shield electrode 16. The voltage application unit 20 applies a voltage to the sample TS via the test lead wire TL.

In addition, a hygrometer 50 is arranged in the test container 10 so that the humidity in the test container 10 can be measured. When performing an electrical test, it is preferable to start when the measured value by the hygrometer 50 falls below a predetermined humidity. This is because if the humidity in the test container 10 is high, air discharge and surface flashing are likely to occur during the test.
Therefore, for example, in the case of the electrical test apparatus 1 in which the insulating gas supply unit 31 (gas cylinder or the like) is connected to the ionized gas supply unit 30 by the pipe 32 as in the electrical test apparatus 1 of FIG. It is preferable that the ionized gas supply unit 30 adjust the supply amount of the ionized gas according to (measurement humidity). Specifically, the ionized gas supply unit 30 increases the supply amount of the ionized gas when the detection result of the hygrometer 50 is higher than a reference value (for example, humidity 3%). Thereby, the humidity in the test container 10 can be controlled to a humidity suitable for the electrical test.

  When the insulating gas supply unit 31 (gas cylinder or the like) is not connected to the ionized gas supply unit 30 as in the electrical test apparatuses 1A and 1B in FIGS. 2 and 3, the humidity control is performed as in the electrical test apparatus 1 in FIG. However, since the humidity can be managed by the hygrometer 50 (humidity detection unit), if the detection result of the hygrometer 50 is lower than a reference value (for example, 3% humidity), an electrical test can be performed. is there. In particular, in the case of FIG. 3, since the insulating gas such as dry air is filled in the test container 10 and is hermetically fixed, the humidity in the test container 10 is more stable than in the case of FIG.

  When a commercial frequency partial discharge test is performed using the electrical test apparatus 1, the sample TS is placed in the test vessel 10 in which the ionized gas supply unit 30, the shield unit 14, and the insulating member 15 have been placed (first step). ). Then, the test lead wire TL is connected to one end (shield electrode 16) of the sample TS, the measuring device 40 is connected to the other end (flange portion), and the lid portion 12 of the test container 10 is closed. At this time, the inside of the test container 10 is filled with air.

  Next, the ionized gas supply unit 30 is operated to generate the ionized gas while the insulating gas supply unit 31 is opened to supply the insulating gas to the ionized gas supply unit 30 (second step). The test vessel 10 is filled with an ionized gas, and a part thereof is recombined with time to become an insulating gas.

  As the test container 10 is filled with the ionized gas, the air initially filled in the test container 10 is exhausted from the exhaust port 11a. When the insulating gas whose water content is adjusted to be equal to or lower than air is used, the humidity in the test container 10 is lowered according to the filling rate of the insulating gas. It waits until the measured value by the hygrometer 50 becomes below predetermined humidity (for example, 3% or less).

  Then, after the humidity in the test container 10 becomes equal to or lower than the predetermined humidity, a voltage is applied to the sample TS by the voltage application unit 20, and the electrical characteristics (in this example, the commercial frequency partial discharge voltage) are measured (first). Step 3). At the time of the test, since the ionized gas is supplied around the sample TS, the electric test can be stably performed without causing an air discharge or a surface flash.

  As described above, the electrical test apparatus 1 includes the test container 10 that accommodates the sample TS, the voltage application unit 20 that applies a voltage to the sample TS accommodated in the test container 10, and the inside of the test container 10 by ionizing the insulating gas. And an ionized gas supply unit 30 for supplying an ionized gas to the battery.

  In addition, the electrical test method using the electrical test apparatus 1 includes a first step of placing the sample TS in the test container 10 and a second step of ionizing the insulating gas and introducing the ionized gas into the test container 10. And a third step of measuring the electrical characteristics by applying a voltage to the sample TS.

According to the electrical test apparatus 1 and the electrical test method using the electrical test apparatus, when the electrical test is performed by applying a high voltage, the periphery of the sample TS is covered with an ionized gas to form a plasma space. Neutralization (static elimination) by positive ions or negative ions contained in the gas.
That is, according to the electrical test apparatus 1 and the electrical test method using the same, since the air discharge generation voltage and the surface flashover voltage are improved, the high voltage section can be applied without using SF ₆ gas having a high global warming potential. Electricity tests can be performed.
In addition, since troublesome work such as gas recovery work in the case of SF ₆ gas is not required, the test time can be greatly shortened.

[Second Embodiment]
FIG. 4 is a diagram showing a schematic configuration of the electrical test apparatus 2 according to the second embodiment. In FIG. 4, 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. 4, in the electrical test apparatus 2, an ionized gas supply unit 30 is installed outside the test container 10. The ionized gas generated by the ionized gas supply unit 30 is introduced into the test container 10 through the nonmetallic pipe 34. If the non-metallic pipe 34 is made of a metal material, ions disappear, so the non-metallic pipe 34 is made of a non-metallic material.
Thereby, it is not necessary to provide the shield part 14 and the insulating member 15 in the first embodiment, and the test container 10 itself can be reduced in size and simplified. Further, the ionized gas supply unit 30 is installed outside the test container 10, thereby facilitating maintenance work of the ionized gas supply unit 30.

Further, similarly to the first embodiment, according to the electrical test apparatus 2, the air discharge generation voltage and the surface flashover voltage are improved, so that the SF ₆ gas having a high global warming potential is not used. Electrical tests can be performed by applying voltage.
In addition, since troublesome work such as gas recovery work in the case of SF ₆ gas is not required, the test cycle time can be greatly shortened.
As in FIG. 1, according to the electrical test apparatus 2 of FIG. 4 in which an insulating gas supply unit 31 (gas cylinder or the like) is connected to the ionized gas supply unit 30 by a pipe 32, the ionized gas supply unit 30 has a humidity When the detection result of the total 50 is higher than a reference value (for example, humidity 3%), the supply amount of ionized gas can be increased. Thereby, the humidity in the test container 10 can be controlled to a humidity suitable for the electrical test.

[Example]
In the examples, in the electrical test apparatus 1 according to the first embodiment, the bushing was used as the sample TS, the pressure was increased to 100 kV, and the air discharge voltage or the surface flash voltage was measured. As the insulating gas, air in the atmosphere or dry air was used. A case where air is ionized and supplied into the test container 10 is referred to as Example 1, and a case where dry air is ionized and supplied into the test container 10 is referred to as Example 2.

As a result, in both cases of Examples 1 and 2, it was possible to satisfactorily charge up to 100 kV without causing air discharge or surface flashing.
Further, when the pressure was increased to 100 kV or more, air discharge or surface flashing occurred at 120 kV in Example 1, whereas air discharge or surface flashing did not occur even at 120 kV in Example 2.

[Comparative example]
In the comparative example, in a conventional electrical test apparatus (without supplying ionized gas), the bushing was used as a sample in the same manner as in the example, the pressure was increased to 100 kV, and the air discharge voltage or the surface flash voltage was measured. As the insulating gas, dry air and SF ₆ gas were used. The case where the test 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.

  As a result, in Comparative Example 1, air discharge or surface flashing occurred at 61 kV. In Comparative Example 2, it was possible to satisfactorily charge up to 100 kV without causing air discharge or surface flashover.

Thus, in the electrical test apparatus 1 according to the first embodiment, it was possible to ensure the necessary insulation performance without using SF ₆ gas. Moreover, since the dielectric strength improves in Example 2 using dry air compared with Example 1 using air, it can be said that it is preferable to use dry air as the insulating gas.
Moreover, although description is abbreviate | omitted, also when using the electrical test apparatus 2 which concerns on 2nd Embodiment, the result similar to an Example is obtained.

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, in the electrical test apparatus 1 according to the first embodiment and the electrical test apparatus 2 according to the second embodiment, the insulating gas exhausted from the exhaust port 11a is circulated and supplied to the ionized gas supply unit 30. You may make it do.
Alternatively, a nozzle may be connected to the ionized gas supply unit 30 so that the ionized gas is ejected to a site where air discharge or surface flashing is likely to occur.

A plurality of ionized gas supply units 30 may be installed. Thereby, ionized gas can be efficiently supplied into the test container 10.
Further, a plurality of samples TS may be connected to the test lead wire TL so that the electrical test can be performed on the plurality of samples TS simultaneously.

  The present invention can be applied to an electrical test for measuring various electrical characteristics such as a commercial frequency withstand voltage test and a lightning impulse withstand voltage test in addition to the commercial frequency partial discharge test shown in the embodiment.

  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.

DESCRIPTION OF SYMBOLS 1, 2 Electrical test apparatus 10 Test container 11 Housing | casing part 12 Cover part 13 Seal member 14 Shield part 15 Insulating member 16 Shield electrode 20 Voltage application part 30 Ionized gas supply part 31 Insulated gas supply part 32 Piping 33 Flow meter 34 Non-metallic piping 40 Measuring device 50 Hygrometer (humidity detector)
TL test lead TS sample

Claims (7)

An electrical testing device for conducting electrical testing of electrical components used in high voltage electrical equipment,
An insulating container for containing the sample;
A voltage application unit for applying a voltage to the sample housed in the container;
An ionized gas supply unit that ionizes insulating gas and supplies ionized gas into the container;
With
The ionized gas supply is disposed in the container and covered with a grounded metal shield having a through hole;
The sample is disposed on the shield part via an insulating member,
The ionized gas is filled in the container so that the periphery of the sample is covered with the ionized gas by the ionized gas supply unit,
An electrical test apparatus, wherein a high voltage is applied to the sample by the voltage application unit, and an electrical test of a commercial frequency partial discharge test, a commercial frequency withstand voltage test, or a lightning impulse test is performed.   The electrical test apparatus according to claim 1, further comprising a humidity detection unit that detects humidity in the container.   The electrical test apparatus according to claim 1, wherein an insulating gas supply unit is connected to the ionized gas supply unit by a pipe.   The electrical test apparatus according to claim 1, wherein the insulating gas is dry air. An electrical testing method for conducting electrical testing of electrical components used in high voltage electrical equipment,
A sample, which is an electrical component used in high-voltage electrical equipment, is placed on a grounded metal shield part having a through hole covering an ionized gas supply part placed in an insulating container via an insulating member. A first step of:
A second step of ionizing an insulating gas and introducing the ionized gas into the container so as to cover the periphery of the sample;
A third step of applying a voltage to the sample and measuring an electrical characteristic of any one of a commercial frequency partial discharge test, a commercial frequency withstand voltage test, and a lightning impulse test . In the second step, the humidity in the container is measured,
The electrical test method according to claim 5 , wherein the third step is started after the humidity in the container becomes equal to or lower than a predetermined humidity. As the insulating gas, electrical test method according to claim 5 or 6, wherein the use of dry air.

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