JPH0533612U - Gas insulated switchgear - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a cable retractable gas insulated switchgear capable of easily performing AC and DC withstand voltage tests without opening a rectangular container. [Structure] A cable connection portion CHd in which an electric power cable 3 is detachably connected to a main circuit charging portion in a rectangular container 2 in which an insulating gas is sealed and a main circuit charging portion is housed together.
And a terminal portion 9 having the same structure as the terminal portion for the aerial pull-in bushing, which is connected to the main circuit charging portion and to which the voltage-applying bushing is detachably connected at the time of the withstand voltage test, are provided in an airtight manner,
The terminal portion 9 is hermetically housed in an end container 10 in which an insulating gas is sealed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cubicle type gas insulated switchgear in which a main circuit charging unit is housed in a rectangular container.

[0002]

[Prior Art]

Conventionally, in this type of gas insulated switchgear (hereinafter referred to as GIS), there are a cable lead-in type and an overhead lead-in type depending on a power receiving system. The cable pull-in type GIS has a configuration as shown in FIGS. 4 and 5, in which a rectangular container 2 is placed on an operation box 1 accommodating an operation device, and the container 2 is placed in the underground pit. For connecting to the cable connection part CHd to which the power cable 3 is detachably connected, the power receiving disconnector DS ₁ , the gas circuit breaker GCB, the busbar disconnecting switch DS ₂ , and the external power supply / demand instrument transformer MOF. Main circuit charging part consisting of the reciprocating conductor 4, and the disconnecting switch DS _{3 for the} transformer, various earthing switches ES _{1 to} ES ₄ for maintenance and inspection, the arrester LA and the arrester for opening and closing between this and the main circuit The disconnecting section 5 is housed together, and an insulating gas such as SF ₆ gas is sealed in this container.

The transformer disconnecting switch DS ₃ is connected to a transformer (not shown) through a transformer connecting container 6. CT ₁ is a current transformer attached to the power cable 3, and VD is a voltage detector for detecting the main circuit voltage. In addition, as shown in FIGS. 6 and 7, in the GIS of the aerial retracting system, instead of the cable connecting portion CHd, a terminal portion 7 is airtightly provided on the upper left side of the rectangular container 2 and the instrument is provided there. It has an aerial retractable bushing 8 in which a current transformer CT ₂ is installed. Other than that, the configuration is the same as that of the cable retractable GIS.

[0004]

[Problems to be solved by the device]

 By the way, in the case of the above-mentioned GIS, it is necessary to carry out an AC withstanding voltage test of the main circuit charging part after the installation is completed at the time of on-site installation. Especially, in the case of the cable pull-in method, the DC of the power cable 3 is required. It is necessary to carry out a pressure resistance test at the same time.

In the case of the overhead lead-in system of FIG. 6, an AC withstand voltage test can be carried out by using the overhead wire connecting terminal portion of the overhead lead-in bushing 8 and applying a test voltage from this portion. Although there is no problem, in the case of the cable pull-in method of FIG. 4, since there is no voltage-carrying terminal portion for the DC withstanding voltage test and the AC withstanding voltage test, the GIS side is not used for the DC withstanding voltage test. There is a problem that voltage cannot be applied.

When performing the AC withstanding voltage test of GIS with this structure, it is necessary to open a part of the rectangular container 2, perform a large amount of gas treatment, and attach a test bushing to carry out the test. The work becomes very complicated, and furthermore, there is a risk that foreign materials and water may be mixed into the container 2 when the container 2 is opened, which causes a problem of quality deterioration.

The present invention has been made in view of the above problems of the conventional technology, and the purpose thereof is to carry out AC and DC withstand voltage tests without opening the rectangular container. The object is to provide a cable pull-in type GIS that can be easily implemented.

[0008]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, in the GIS of the present invention, a rectangular container in which an insulating gas is filled and which houses a main circuit charging section is connected to the main circuit charging section and a power cable is detachably connected. The cable connection part and the aerial retractable type terminal part that is connected to the main circuit charging part and to which the voltage-applying bushing is detachably connected at the time of the withstand voltage test, are installed in an airtight manner, and this terminal part is insulated with an insulating gas. It is hermetically enclosed in an end container that encloses.

[0009]

In the GIS having the above-described structure, the end container is opened, the terminal is connected to the charging bushing, and the disconnector or the like provided in the main circuit charging section is operated to open the terminal cable. By connecting only to the connection part, the voltage-imparting bushing can be connected to the power cable via the terminal part and the cable connection part, and power can be supplied from the voltage-imparting bushing for DC withstanding voltage test. The DC withstand voltage test of the cable can be performed from the GIS side. Also, since this terminal part has the same structure as that of the aerial pull-in type, as in the case of the aerial pull-in type GIS, the voltage is applied by the voltage-applying bushing connected to the terminal part, and the AC withstanding voltage test is performed. Can also be implemented.

Here, when the charging bushing is attached, only the end container accommodating the terminal part needs to be opened, so that the gas treatment amount is extremely small and the work is short compared with the case of opening the rectangular container. Only time is required, and no foreign matter or water is mixed into the rectangular container. Further, since the terminal portion for the aerial pull-in bushing is used, it is possible to commonly use the parts such as the rectangular container and the terminal portion in the aerial pull-in type GIS, and the standardization in design and manufacture can be achieved.

[0011]

【Example】

 An example will be described with reference to FIGS. 1 to 3. FIG. 1 shows a cable pull-in type GIS in a normal use state. What is different from the conventional one shown in FIG. 4 is that the aerial pull-in type GIS is installed above the left side of the rectangular container 2. The point is that a terminal portion 9 having the same structure as the terminal portion for the retractable bushing is provided in an airtight manner.

The terminal portion 9 is composed of a pipe portion 9a communicating with the rectangular container 2, a conductor portion 9b connected to the main circuit charging portion, and an insulating spacer 9c that hermetically closes the end portion of the pipe portion 9a. The end portion of the conductor portion 9b is airtightly drawn out from the insulating spacer 9c, and the end portion is airtightly housed in a separately prepared end portion container 10 in which an insulating gas such as SF ₆ gas is sealed. The inside of the rectangular container 2 and the inside of the end container 10 are gas-divided by the insulating spacer 9c.

When an AC / DC withstand voltage test is to be performed after the GIS is installed on site, the terminal portion 9 is used as a charging terminal. That is, first, the insulating gas in the end container 10 is evacuated, the end container 10 is removed, and then, as shown in FIG. 9b is connected and attached.

Then, in the case of the DC withstanding voltage test of the power cable 3, the power receiving disconnector DS ₁ is opened, the lightning arrester disconnecting unit 5 is opened, and the DC voltage is applied from the power application bushing 11. Can be implemented by Furthermore, the disconnector DS ₁ and the disconnector 5 are closed, the power cable 3 is removed, and an AC voltage is applied from the charging bushing 11 to perform an AC withstanding voltage test in GIS.

[0015]

[Effect of the device]

 Since the present invention is configured as described above, it has the following effects. The terminal part provided in the rectangular container is always sealed with the end container, and only the end container is opened at the time of the withstand voltage test, and the voltage-imparting bushing is attached to this, and the DC withstand voltage test of the power cable and the inside of the rectangular container are performed. Since the AC withstanding voltage test can be performed by a voltage-applying bushing, there is no need to open the rectangular container and perform the withstanding voltage test as in the conventional case, and the gas treatment amount during the withstanding voltage test is significantly reduced. The work time can be greatly shortened, and there is no risk of foreign matter or water being mixed into the rectangular container, and quality can be improved.

Moreover, since the rectangular container provided with the cable connection portion is provided with the terminal of the aerial pulling-in method, and the two power receiving methods of the aerial pulling-in and the cable pulling-in are possible, the structure depending on the difference of the power receiving method is provided. There is almost no difference between the two, making it possible to use common parts such as rectangular containers and conductors, achieve standardization in design and manufacturing, and reduce costs.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a gas insulated switchgear according to the present invention.

FIG. 2 is a single line connection diagram of FIG.

FIG. 3 is a schematic cross-sectional view at the time of a withstand voltage test of an example.

FIG. 4 is a schematic cross-sectional view of a conventional example (cable retractable type).

5 is a single line connection diagram of FIG. 4. FIG.

FIG. 6 is a schematic cross-sectional view of a conventional example (imaginary retractable type).

FIG. 7 is a single line connection diagram of FIG.

[Explanation of symbols]

2 rectangular container 3 power cables 9 terminal unit 10 ends the container 11 Section conductive bushing CHd cable connection DS ₁ to DS ₃ disconnector GCB gas circuit breaker

Claims (1)

[Scope of utility model registration request] 1. A gas-insulated switchgear in which a main circuit charging unit is housed together in a rectangular container in which an insulating gas is sealed, in which a power cable is detachably connected to the main circuit charging unit. The connected cable connection part and the aerial retractable type terminal part, which is connected to the main circuit charging part and to which the charging bushing is detachably connected at the time of the withstand voltage test, are hermetically pierced respectively, and the terminal part is hermetically sealed. A gas-insulated switchgear in which an end container for accommodating is provided and an insulating gas is sealed in the end container.