JPH07118862B2 - Gas insulated electrical equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to gas-insulated electrical equipment using an insulating gas such as a gas-insulated switchgear, and more particularly to mitigating an electric field of an insulating spacer supporting a conductive portion thereof. Is.

[Conventional technology]

Regarding the electric field relaxation of the insulating spacer, for example, IEEE TRA
NSACTIONS (Bulletin of the Institute of Electrical and Electronics Engineers), Vol.PAS-102, N
There is a paper described in o.1, January 1983, P, 250-255. FIG. 7 is a cross-sectional view showing a conventionally known gas-insulated electric device in which a groove for electric field relaxation is provided on the contact surface between the peripheral portion of the insulating spacer and the flange portion of the metal container, and FIG. Then
It is sectional drawing which shows the condition of vibration of the electroconductive minute foreign material in a metal container. (1) is a conductive part to which a high voltage is applied, (2)
(3) is a metal container which accommodates this conductive part inside and is filled with an insulating gas, and is grounded. (4) is an insulating spacer that supports the conductive portion and is sandwiched between the flange portions of the metal containers (2) and (3), and (5) is the peripheral portion of the insulating spacer and the flange portion of the metal container (2). A groove (6) provided on the contact surface for relaxing electric field concentration, and (6) are conductive minute foreign matters remaining inside the metal container (2).

The conventional gas-insulated electric equipment is configured as described above, and for example, conductive fine foreign matters (6) such as metal chips and welding spatters remain inside the metal container (2) or are generated during operation. Sometimes. In this case, when a high voltage is applied to the conductive portion (1), charges having the opposite polarity to the applied voltage are induced in the metal container (2) and the minute foreign matter (6) existing therein, and the minute foreign matter (6) In addition to the attraction force acting in the direction of the electric field, when the minute foreign matter (6) has an asymmetrical shape, repulsive force acts between the metal container (2) and the metal container (2) because it is charged with the same polarity. . When the resultant force of the attraction force and the repulsive force becomes larger than the resultant force of the gravity acting on the minute foreign matter (6) and the viscous force of the metal container (2), the minute foreign matter (6) floats and has a true charge. The floating fine foreign matter (6) receives the electrostatic force that acts on this true charge and the electrostatic force that is polarized by the electric field and that acts on the polarized charge. Therefore, the floating fine foreign matter (6) vibrates in the gas space according to the instantaneous value of the voltage when the voltage applied to the conductive portion (1) is alternated, and in some cases, as shown by the dotted line in FIG. It enters into the groove (5) for electric field relaxation provided on the contact surface between the peripheral portion of the spacer (4) and the flange portion of the metal container (2).

[Problems to be solved by the invention]

In the conventional gas-insulated electric device as described above, the conductive fine foreign matter (6) is driven by the electrostatic force due to the alternating electric field and enters the electric field relaxation groove (5) to impair the electric field relaxation effect,
There is a problem in that the insulating spacer (4) causes a dielectric breakdown.

[Object of the Invention]

The present invention has been made to solve the above problems, and conductive minute foreign matter remaining inside the metal container (2) or generated during operation is driven toward the insulating spacer by electrostatic force due to an alternating electric field. It is an object of the present invention to obtain a gas-insulated electric device that does not enter the groove for alleviating an electric field even if it is carried out.

[Means for solving problems]

In the gas-insulated electric device according to the present invention, the insulating spacer is provided with a projection for preventing the entry of conductive fine foreign matter into the groove for electric field relaxation provided on the contact surface between the peripheral portion of the insulating spacer and the flange portion of the metal container. It is provided.

[Action]

According to the present invention, the protrusion provided on the insulating spacer prevents the conductive minute foreign matter driven by the electrostatic force due to the alternating electric field from entering the groove for electric field relaxation.

〔Example〕

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing an enlarged main part thereof and showing a state of vibration of a conductive minute foreign substance in a metal container. 1-2,
(1) to (6) are exactly the same as the above conventional devices.
(21) (31) is the same metal container as that of the above conventional equipment except that the shape of the flange portion is different, and is provided on the contact surface between the peripheral portion of the insulating spacer and the flange portion of the metal container (21). The electric field relaxation groove (52) is provided adjacent to the electric field relaxation groove in the flange portion of the metal container (21) for catching the conductive minute foreign matter (6), and (41)
1) is the insulating spacer (41) for preventing the conductive minute foreign matter (6) from entering the electric field relaxing groove (51).
Is a protrusion that is integrally formed on the.

In the gas-insulated electric device configured as described above, conductive minute foreign matter (6) existing inside the metal container (21)
When a high alternating voltage is applied to the conductive part (1), it receives an electrostatic force and levitates as in the case of the above-mentioned conventional equipment, and vibrates in the gas space according to the instantaneous value of the alternating voltage. As shown by the dotted line in Fig. 2, it moves toward the insulating spacer (41), but it does not enter the electric field mitigating groove (51) because it is blocked by the protrusion (411) of the insulating spacer (41). It will enter the foreign matter capturing groove (52).

FIG. 3 shows another embodiment of the present invention, in which the insulating spacer (42) is in contact with the flange portions of the metal containers (21) and (31) so that the peripheral portion thereof is thinner than the other portions, and the protrusions (421 ) Is provided, the same effect as in the above embodiment can be expected.

In each of the above embodiments, the conductive portion (1) is arranged horizontally, but FIG. 4 shows the embodiment of the present invention when the conductive portion (1) is arranged vertically. 43)
Only the upper side of the metal container (21) is provided with a protrusion (431) by making the peripheral edge portion abutting the flange portion thinner than the other portions, and the minute foreign matter (6) dropped on the upper surface of the insulating spacer (43). Slide down the slope of the insulating spacer (43),
It will be blocked by 1) and enter the groove (52) for capturing minute foreign matter.

In each of the above-mentioned embodiments, in order to form the electric field relaxation groove (51), the flange portions of the metal containers (21) (31) are cut out so as to contact with the peripheral portions of the insulating spacers (41) (42) (43). Although they are in contact with each other, the insulating spacer (44) may be cut out to make contact with the flange portion of the metal container (22) (Fig. 5), or the peripheral portion of the insulating spacer (45) and the metal. Both of the flange portions of the container (23) may be cut out so as to abut (FIG. 6).

Further, in the above embodiment, the insulating spacers (41) (42) (44)
Although (45) is conical in shape, it is disk-shaped and similarly provided with a protrusion, or the periphery of the metal container (21) (31) that comes into contact with the flange is thinned to make a protrusion. May be provided.

By the way, in the above description, the case where the conductive minute foreign matter (6) is inside the one metal container (21) has been described.
It goes without saying that it may be inside the other metal container (31).

〔The invention's effect〕

As described above, according to the present invention, the insulating spacer is provided with the protrusion for preventing the entry of the conductive foreign matter into the groove for electric field relaxation provided on the contact surface between the flange portion of the metal container and the peripheral portion of the insulating spacer. There is an effect that the electric field relaxation effect is not impaired by the entry of the minute foreign matter.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, FIG. 2 is an enlarged view of a main portion thereof, and a cross-sectional view showing a vibration state of a conductive minute foreign substance in a metal container, and FIG. FIG. 4 is a cross-sectional view showing another embodiment of the present invention, FIG. 4 is a cross-sectional view showing one embodiment of the present invention when the conductive portions are arranged vertically, and FIGS. 5 and 6 are schematic views of still another embodiment of the present invention. 7 is a cross-sectional view showing a conventional gas-insulated electric device, and FIG. 8 is a cross-sectional view showing the vibration of conductive minute foreign matter in a metal container. Is. In the figure, (1) is a conductive part, (6) is a minute conductive foreign substance, (21) (22) (23) are metal containers, (41) (42)
(43), (44) and (45) are insulating spacers, (51) is a groove for mitigating an electric field, (52) is a groove for capturing conductive minute foreign matter, and (41)
1) (421) (431) are protrusions of the insulating spacer. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. An insulating spacer for supporting a conductive portion, a metal container filled with an insulating gas for sandwiching a peripheral portion of the insulating spacer, and provided on a contact surface between a flange portion of the metal container and the peripheral portion of the insulating spacer. Gas insulated electrical equipment, characterized in that it is provided with a groove for electric field relaxation that opens toward the inside of the metal container, and a protruding portion that is provided in the insulating spacer to prevent the entry of conductive minute foreign matter into the groove. machine.