JPS58171681A - Withstand voltage tester for switching device of gas insulation - Google Patents

Abstract

PURPOSE:To impress testing voltage simply from the external by airtightly fixing a movable rod on the inside of an insulated cylinder gastightly fitted to the back of an opening part of a cover and fitting a contact to one end of the rod. CONSTITUTION:The movable rod 14 is airtightly fixed on the inside of the insulated cylinder 13 gastightly fitted to the back of the opening part 11a of the cover 11, the contact 15 is attached to one end of the rod 14 and a dish-like contact board 16 is elastically supported by the other end through springs 17. In said constitution, testing voltage can be simply impressed from the external without disassembling operation or the like and be quickly switched after testing, so that a stable and small-sized with-stand voltage tester for gas insulation switching device can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for performing a withstand voltage test by applying a test voltage from the outside to an internal circuit of a gas insulated switchgear.

General electrical equipment, not just gas insulated equipment, is installed on-site.
A pressure test based on electrical equipment technical standards is required. In this withstand voltage test, in the case of air-insulated electrical equipment, which is commonly used, the voltage application point does not cause any inconvenience to the air-drain test voltage application, but the situation is completely different for gas-insulated equipment. That is, in the case of a gas-insulated switchgear, all of the live parts are housed in a grounded container, and there is no risk that the live parts will come into direct contact with personnel.

However, even if you try to apply the full test voltage on-site, the application point is not exposed to the air, so testing cannot be performed as with air-insulated electrical equipment. Therefore, conventionally, voltage application points for on-site testing are generally provided in advance when manufacturing equipment.

FIG. 1 shows an example in which a voltage application point is provided on the connection side of a gas insulated switchgear to a transformer. To explain the figure, the gas insulated switchgear 1 is provided with a connection case 3 filled with insulating gas on the side connected to the transformer, and the transformer bushing/plug 4 is connected to the bottom surface of this case 3 via the partition plate 5. Oil-gas bushings 6 for three phases of the transformer are installed through the partition plate 5. The bushing 6 of each phase has a connecting conductor 7 attached vertically to the gas side terminal, and a conductor 2 extending from the switchgear 1 is connected to the connecting conductor 7, and a connecting conductor of each phase is connected to the connecting conductor 7. Reference numeral 7 includes test terminals 7a' formed at the upper end so as to have the same height. 8 is a test bushing in which the adapter 9 is attached to the upper part of the connection case 3 after installation on site, and the contact plate IO attached to the lower terminal of this bushing 8 is connected to the test terminal 7a for the three phases indicated by L. The structure is such that the withstand voltage test of the internal electric circuit can be carried out for three phases at once by contacting and applying the full test voltage through the bushing 8 during the withstand voltage test.

However, since the above-mentioned device has a configuration in which the test bushing 8 is attached during the pressure test, a part of the internal space of the switchgear is exposed to the atmosphere when the bushing is attached or disassembled, and the insulation is required each time. It is necessary to refill the gas.

This requires a lot of effort and work time, and in order to install all the test bushings, it is necessary to prepare a space in advance in the switchgear that takes into account all the air insulation space.
There were problems such as restrictions on the configuration of the device.

An object of the present invention is to make it possible to apply a test voltage from the outside while maintaining the gas-tightness of the switchgear without any complicated work during a withstand voltage test, and to easily switch to the operating state after the test. Our goal is to provide all possible pressure test equipment for gas insulated switchgear.

An embodiment of the present invention will be described below with reference to the drawings. Second
3, 1 is a gas-insulated switchgear, 2 is a current-carrying conductor of the device, 3 is a connection case, 4 is a transformer plug, 5 is a partition plate, and 6 is an oil-gas bushing of a transformer. , 7 is a connecting conductor, 7a is a test terminal, and each part below corresponds to the part shown with the same reference numeral in FIG. Reference numeral 11 designates a soil cover of the connection case 3, and reference numeral 12 designates a cable connection device that is attached to the upper cover 11 and is detachable from the test cable 21 that is inserted from the outside. The cable connection device 12 is connected to the opening 11a of the cover 11 as shown in FIGS. 4 and 5.
A rod 14 which is movable in an airtight state is installed in an insulating tube 13 which is gas-tightly attached to the back side of the rod 14, a contact 15 is attached to one end of the rod 14, and a two-shaped contact plate 16 is attached to the other end by a spring. It is elastically supported through 17.

When the test cable 21 is inserted from the outside, the rod 14 moves the contact 1 to a predetermined lowered position as shown in FIG.
5. The contact plate 16 is automatically connected to the cable terminal 22 for all the three phases, and at the same time, the contact plate 16 is pressed into contact with the test terminal 7a for three phases.

The internal circuit provided with this terminal 7a is connected to an external test power source. When the test cable 21 is in the inserted state, the opening 11a of the cover 11 is closed by the cable sheath 23. Further, insulation of the cable end portion within the jacket 23 is ensured by the insulating collar 25 pressed against the spring holder being pressed into contact with the inner surface of the insulating tube 13.

On the other hand, after the pressure test and after the cable 21 is pulled out, the rod 14 is pulled up to a predetermined raised position by the stud 26 attached to the screw hole at its end from one side, as shown in FIG. The inserted insulating stand 27 is supported in that position through the spring 28, and the cover 1 is supported through the grounding member (not shown) in the cap 29 attached to the opening 11a.
Grounded to the same potential as 1. When the rod 14 moves to the raised position, the contact plate 16 separates the test insulator 7a and holds it at a position where a predetermined insulation distance is maintained. The center part of the contact plate 16 is elastically supported by the rod 14 via several springs 17, and even if there is a slight misalignment in the position of the test terminal 7a, it can be freely displaced according to the position. Reliably contacts the phase terminals 7a. Note that 18 is a flexible conductor that connects the rod 14 and the contact plate 16.

According to the configuration described in 1-, during a pressure test, the internal space of the switchgear is opened to the entire atmosphere by inserting the test cable 21 from the outside into the cable connection device 12 provided in the gas-insulated switchgear 1. While maintaining this gas-tight state, the rod 14 and contact plate 16 of this device 12 are
Since it can be automatically connected to the test terminal 7a of the three phases of the internal electric circuit through the terminal, there is no need for any work such as gas refilling as in the conventional method, and the work is extremely simple and the withstand voltage test can be performed quickly. be able to. Furthermore, even after the test cable 2'' is pulled out after the pressure test, the rod 14 is not pulled up to the specified position and grounded without opening the switchgear to the atmosphere, and the contact plate 16 is also grounded. Since the potential is reached and the test terminal 7a is opened at a position where a predetermined insulation distance is maintained, there is no problem with steady operation and the operating state can be quickly switched.Also, one cable common to three phases is used. Since the connection device 12e is used as the test voltage application point, it can be installed in a small space and there is no need to provide a special air insulation space at the installation part. The entire device can be downsized without suffering any damage.

As described above, according to the present invention, it is possible to easily apply a test voltage from the outside without any disassembly work or the like, and it is possible to quickly switch to the operating state after the test, and it is safe and compact. It is possible to provide a pressure test device for gas-insulated switchgear.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional pressure test device for gas insulated switchgear, and FIGS. 2 and 3 show test and non-test conditions of a pressure test device for gas insulated switchgear according to an embodiment of the present invention. The cross-sectional views shown in FIGS. 4 and 5 are detailed cross-sectional views showing the cable connection device of the same device in a voltage-proof test state and a non-test state. ■...Gas insulated switchgear, 3...Case, 7a...
・Test terminal, 12... Cable connection device, 14...
- Rod, 16... Contact plate, 21... Test cable. Application agent: Patent attorney Kikuchi Gobuhata Yama 1) Akira Nobuo L/Zuo 4 Zuo 5 Figure 1-, J w”

Claims (1)

[Claims] A three-phase test terminal formed in a part of the inter-case electrical circuit of a gas-insulated switchgear, and an airtight insulating tube attached gas-tightly to the opening of the case opposite to the tip of the test terminal. It is provided so as to be movable in the holding state, and one end is connected to a test cable inserted into the insulating cylinder from the outside at a predetermined lowered position, and when the cable is removed, it is pulled up to a predetermined raised position and is universally grounded. a rod elastically held at the other end of the rod, and a contact plate that contacts the test terminals for the three phases in the lowered position of the rod and separates from the test terminals in the raised position. A pressure test device for a gas insulated switchgear, comprising a cable connection device.