KR19990023397A - Gas Insulation Bus and Gas Insulation Switch - Google Patents

Abstract

An object of the present invention is to provide a compact gas insulated bus and a gas insulated switchgear having the same, which can improve the insulation performance and the reliability of operation even if the phase shift converter is present.

In the present invention, as shown in FIG. 1, three three-phase conductors 3 to which three-phase AC high voltage is applied, three-phase conductors 3, and a container 1 sealed and grounded with an insulating gas are provided, and three three-phase conductors ( (3) A gas insulated bus bar having a phase shift converter for converting positions in the circumferential direction of (3), wherein in the converter of one conductor (31) closest to the bottom of the container (1) among the three high voltage conductors (3), Is formed in a substantially straight line shape, and the shape in the conversion section of the remaining two conductors 32 is formed to be convex outward in the radial direction.

Description

Gas Insulation Bus and Gas Insulation Switch

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas insulated switchgear, and more particularly, to a gas insulated bus having a phase shift converter of three phase high voltage.

The gas insulated switchgear (hereinafter referred to as GIS) is disposed between a three-phase high voltage power supply and an airborne transmission line in a substation, and detects an abnormal voltage such as a lightning surge to cut off the current. The GIS is composed of a bushing receiving power from a three-phase high voltage power supply, a gas insulating bus (hereinafter referred to as GIB) from the bushing to a gas insulated circuit breaker (hereinafter referred to as GCB), and a GCB to cut off current.

In recent years, the compactness of the device and the reduction of the area are progressed, and when wiring conductors from the bushing to the GIB, or when wiring conductors from the GIB to the GCB, it is necessary to batch convert the three-phase conductors in the GIB and to wire each phase in one direction. There is. The inside of the container of the GIB is filled with sulfur hexafluoride (SF ₆ ) as an insulating gas, and the gas dielectric breakdown electric field strength is different depending on the type of gas. Between the conductors of the three-phase conductor, and between the conductor and the container, the electric field strength of the conductor surface and the container surface is lower than the gas dielectric breakdown electric field strength.

In recent years, metal foreign matters mixed in containers have become a problem as a cause of deterioration of the insulation strength. Metallic foreign matter tends to gather at the bottom of the container under the influence of gravity, and is charged by the electric field of the bottom of the container, and floats due to the electric field force acting on the charged electric charge. If the electric field strength of the bottom of a container becomes high, the charge amount of a metal foreign material may increase, the floating height may increase, and it may contact a conductor. When a metal foreign material comes into contact with the conductor, the metal foreign material is welded to the conductor by the discharge generated between the conductor and the metal foreign material, which significantly lowers the insulation strength. Therefore, the electric field strength of the bottom of a container needs to be less than the electric field strength (the permissible electric field strength of a metal foreign material) which a metal foreign material does not contact a conductor.

As described above, when the arrangement of conductors in a container is determined, the surface electric field strength between the conductors, the surface electric field strength between the conductor and the container is less than the gas dielectric breakdown electric field strength, and the electric field strength at the bottom of the container is allowed to float the metal foreign material. It is necessary to under the field strength. In addition, since the allowable electric field strength of the foreign material of metal is lower than that of the gas breakdown electric field, the bottom of the container becomes a weak part in the insulation strength.

The conventional method of performing the phase shift transformation in a container is demonstrated using FIG. 6 thru | or FIG. The side view of the container 1 is shown in FIG. 6, the figure seen from the B-B line before phase shift transformation of FIG. 6, and FIG. 7 is the figure seen from the C-C line after phase shift transformation of FIG. Since the bottom part of the container 1 is a weak part in insulation strength, as shown in FIG. 7, the arrangement of the three-phase conductors 3 in the container 1 is one of the triangle peaks connecting the centers of the respective conductors of the three-phase conductors 3. Has an arrangement that comes above in the vertical direction.

If the inner diameter of the container 1 is large and the distance between the bottom of the container 1 and the conductor which is the shortest distance is sufficient in the space for converting the top arrangement, the electric field strength of the bottom of the container 1 is the incidence of metallic foreign matter. It can fall below the allowable field strength. Accordingly, the three-phase conductor 3 is moved in the same direction by the acute angle θ around the central axis O so that the surface electric field strength between the three-phase conductors 3 is less than the gas dielectric breakdown electric field strength. The conductor after the movement was connected to the linear conductor, and this was repeated to perform the phase shift transformation.

In this method, as the apparatus becomes more compact and the inner diameter of the container becomes smaller, the electric field strength of the bottom of the container increases, which exceeds the allowable electric field strength of the metal foreign matter. In addition, many members are used for the phase shift conversion unit, and the distance in the long (axial) direction of the container from the start position of the phase shift conversion to the end position of the phase shift is increased, resulting in a large apparatus.

An object of the present invention is to provide a compact gas insulated bus and a gas insulated switchgear having the same, which can improve the insulation performance and the reliability of operation even if the phase shift converter is present.

1 is a side view of a first embodiment of a gas insulated switchgear according to the present invention;

FIG. 2 is a view seen from line B-B of FIG. 1;

3 is a view seen from the line C-C of FIG.

4 is a side view showing a schematic configuration of a first embodiment of a gas insulated switchgear according to the present invention;

5 is a top view of FIG. 4;

6 is a side view of a conventional container,

7 is a view seen from the line B-B of FIG.

8 is a view seen from the line C-C of FIG.

9 is a side view of a comparative example,

10 is a view seen from the line B-B of FIG.

FIG. 11 is a view taken along the line C-C of FIG. 9;

12 is a diagram showing an example of analysis of the electric field strength distribution at the bottom of the container;

13 is a side view of a second embodiment of a gas insulated switchgear of the present invention;

14 is a view seen from the line B-B of FIG. 13,

FIG. 15 is a view taken along the line C-C of FIG. 13;

16 is a side view of a third embodiment of a gas insulated switchgear of the present invention;

17 is a view seen from the line B-B of FIG. 16,

FIG. 18 is a view taken along the line C-C of FIG. 16;

19 is a side view of a fourth embodiment of a gas insulated switchgear of the present invention;

20 is a view seen from the line B-B of FIG. 19,

FIG. 21 is a view taken along the line C-C in FIG. 19; FIG.

In order to achieve the above object, the present invention provides a gas insulated bus bar comprising three high voltage conductors to which a three-phase AC high voltage is applied, and a container in which the high voltage conductor and the insulating gas are sealed and grounded. In the gas insulated bus bar having a phase shift converter for converting a position in the circumferential direction, the shape of one of the three high voltage conductors closest to the bottom of the container is formed in a substantially straight line, and the rest The shapes at the two conversion sections of are formed to be convex outward in the radial direction.

According to the present invention, the distance between the high voltage conductor closest to the bottom of the container and the bottom of the container can be kept longer than before, without making the distance between the high voltage conductors too short. It may be lower than the allowable field strength of metal foreign objects. Therefore, insulation performance and operation reliability can be improved. In addition, since there are fewer members used for phase shift conversion, the gas insulation busbar can be made more compact.

A first embodiment of a GIS according to the present invention will be described with reference to FIGS. 1 to 5. 4 is a side view showing a schematic configuration of a first embodiment of a GIS, FIG. 5 is a top view of FIG. 4, FIG. 1 is a side view of a first embodiment of a GIB, and FIG. 2 is a view taken from the BB line before the phase shift arrangement of FIG. 1. 3 is a view seen from the CC line after the phase shift transformation in FIG.

The present GIS includes a bushing 100 for receiving power from a three-phase high voltage power supply, a GIB 101 for distributing power from the bushing 100 to the GCB 102, and a GCB 102 for interrupting current for each phase. The GIB 101 is an insulating spacer for supporting a grounded container 1, a container flange 2 joining the containers 1 together, a three-phase conductor 3, and a three-phase conductor 3 within the container 1. (4) is provided. In the space (area) of the phase shifting conversion, the conductors, which are the shortest distance from the bottom of the vessel in the three-phase conductor 3, are denoted by 31 and two conductors other than the conductor 31 are denoted by the numeral 32.

In this embodiment, the arrangement of the three-phase conductors 3 is disposed at positions rotated by 120 ° about the central axis O, and as shown in FIG. 2, a triangle connecting the centers of the respective conductors of the three-phase conductors 3 is shown. One of the vertices of is arranged in the vertical direction (up and down direction) to come up. The phase shift conversion in the phase shift conversion unit shown in FIG. 1 is converted in the circumferential direction by an angle smaller than 120 ° with respect to the central axis O. As shown in FIG.

In the space of the phase shift transformation, two conductors 32 of the three conductors 3 move the center axis O while maintaining the relative distance from the start position of the phase shift transformation to the end position of the phase shift transformation. The phase shift is performed by rotating in a helical shape around the center, and the conductor 31 performs the phase shift by following the start position of the phase shift and the end position of the phase shift in a substantially straight line.

By having such a structure of phase shift conversion, the distance between the conductor 31 and the bottom of a container can be made longer than before, without making the distance between the conductor 31 and the conductor 32 too short. Therefore, the surface electric field strength between the conductors and the surface electric field strength between the conductor and the container can be lower than the gas dielectric breakdown electric field strength, and the electric field strength of the bottom of the container weak in insulation strength can be lower than the allowable field strength of the metal foreign matter. Compared with this, insulation performance and operation reliability can be improved. Moreover, since there are fewer members used for phase shift conversion than before, a GIB can be made compact.

In order to confirm the effect of this embodiment, the conductor 3 is spirally rotated about the central axis O while maintaining the relative distance between the start position of the phase shift transformation and the end position of the phase shift transformation. Comparative examples (see Figs. 9 to 11) in which the phase shifting conversion was performed, and the electric field strength distributions of the bottom of the container of this example were analytically determined. The analysis results are shown in FIG. In FIG. 12, the vertical axis | shaft is a relative value of the electric field intensity distribution of the bottom part of a container, and has shown the allowable electric field strength of metal foreign material as 1E [% / mm]. The horizontal axis represents the axial distance between the container flanges. 9 is a side view of the comparative example, FIG. 10 is a view seen from line B-B of FIG. 9, and FIG. 11 is a view seen from line C-C of FIG.

In Fig. 12, the area of the left end with the shorter distance corresponds to the phase shift conversion unit, the area of the right end with the larger distance corresponds to the phase shift conversion unit, after the phase shift conversion. As shown in the figure, the electric field strength at the bottom of the container is about 1.6 times the allowable electric field strength of the metal foreign material in the comparative example, but in the present embodiment, it is found that the electric field strength is less than the allowable electric field strength of the metal foreign material. . That is, according to this embodiment, even with the gas insulated busbar of the compact structure shown in FIGS. 1-3, the insulation performance can be improved and operation reliability can also be improved. In addition, although not shown, the surface field strength between conductors and the surface field strength between a conductor and a container are less than the gas dielectric breakdown field strength in both this Example and a comparative example.

Next, a second embodiment of a GIB according to the present invention will be described with reference to FIGS. 13 to 15. FIG. 13 is a side view of the second embodiment, FIG. 14 is a view seen from the line B-B before the phase shift transformation in FIG. 13, and FIG. 15 is a view seen from the line C-C after the phase shift transformation in FIG. The configuration of this embodiment is almost the same as that of the first embodiment, except that the phase shift transformation is converted to about 120 degrees about the central axis O.

Also in this embodiment, in the space of the phase shift transformation, two conductors 32 of the three conductors 3 maintain their relative distances from the start position of the phase shift transformation to the end position of the phase shift transformation. The phase shift is performed by rotating about 120 ° around the axis O in a spiral shape, and the conductor 31 performs the phase shift transformation after the start position of the phase shift transformation and the end position of the phase shift transformation are almost linear. have.

Also in this embodiment, the same effects as in the first embodiment can be achieved. In addition, in the case of the present embodiment, the distance between the conductor 31 and the bottom of the container is longer than in the first embodiment, so that the electric field strength of the bottom of the container can be further lowered than in the first embodiment.

Next, a third embodiment of a GIB according to the present invention will be described with reference to FIGS. 16 to 18. FIG. 16 is a side view of the third embodiment, FIG. 17 is a view seen from line B-B before the phase shift transformation in FIG. 16, and FIG. 18 is a view seen from a line C-C after the phase shift transformation in FIG. The configuration of the present embodiment is substantially the same as that of the second embodiment, and the phase shift conversion method of the conductor 31 is different.

That is, in the space of the phase shift transformation, two conductors 32 of the three conductors 3 maintain their relative distances from the start position of the phase shift transformation to the end position of the phase shift transformation. Phase shift transformation is performed by rotating about 120 ° around (O) in a spiral shape. On the other hand, the conductor 31, the second of the small angle (θ ₂₎ of the previous from and between, the end position of the arrangement conversion to the first intermediate position of the small angle (θ ₁₎ from the starting position of the arranged transform Between the intermediate positions, phase shifting is performed by rotating in a spiral around the central axis O while maintaining a relative distance from the conductor 32, and a substantially straight line between the first intermediate position and the second intermediate position. Phase shifting is performed following the shape.

Also in this embodiment, the same effects as in the second embodiment can be achieved. In addition, in the present embodiment, since the distance between conductors can be made larger than that of the second embodiment, the surface electric field strength between conductors can be lowered as compared with the second embodiment.

Next, a fourth embodiment of a GIB according to the present invention will be described with reference to FIGS. 19 to 21. FIG. 19 is a side view of the fourth embodiment, FIG. 20 is a view seen from line B-B before the phase shift transformation in FIG. 19, and FIG. 21 is a view seen from a line C-C after the phase shift transformation in FIG. The configuration of this embodiment is almost the same as that of the third embodiment, and the method of phase shift conversion of the conductor 32 is different.

That is, in the space of the phase shift transformation, two conductors 32 of the three conductors 3 are connected in a substantially straight line from the start position of the phase shift transformation to an intermediate position of an angle of about 60 °, and the angle is from the intermediate position. The phase shift transformation is performed in a substantially straight line up to the end position of the phase shift transition of about 60 degrees. Also in this embodiment, the same effects as in the third embodiment can be achieved.

According to the present invention, the distance between the high voltage conductor closest to the bottom of the container and the bottom of the container can be made longer than before, without making the distance between the high voltage conductors too short. It may be lower than the allowable field strength of metal foreign objects. Therefore, insulation performance and operation reliability can be improved. In addition, since there are fewer members used for phase shift conversion, the gas insulation busbar can be made more compact.

Claims (6)

A phase insulated converting unit having three high voltage conductors to which a three-phase AC high voltage is applied, and a container in which the high voltage conductor and the insulating gas are sealed and grounded, wherein the phase shift converter converts positions of the three high voltage conductors in the circumferential direction. In the gas insulated bus bar, The shape in one said conversion part which is closest to the bottom part of the said container among the said three high voltage conductors is formed in substantially linear form, A gas insulated bus bar, characterized in that the shape of the remaining two conversion sections is convex outward in the radial direction. The method of claim 1, The gas insulated busbars of the said two remaining said conversion parts are formed in spiral form centering on the center axis of the said container. The method according to claim 1 or 2, A gas insulated bus, characterized in that the conversion angle of the three high voltage conductors in the circumferential direction is smaller than 120 °. The method according to claim 1 or 2, A gas insulated bus, characterized in that the conversion angle in the circumferential direction of the three high voltage conductors is about 120 °. A phase insulated converting unit having three high voltage conductors to which a three-phase AC high voltage is applied, and a container in which the high voltage conductor and the insulating gas are sealed and grounded, wherein the phase shift converter converts positions of the three high voltage conductors in the circumferential direction. In the gas insulated bus bar, One of the three high voltage conductors closest to the bottom of the container is phase-converted after the start position and end position of the phase shift transformation in a substantially straight line, And the other two high voltage conductors are rotated in a phased configuration by rotating in a spiral around the center axis of the vessel between the start position and end position of the phase shift transformation. A gas insulated switchgear comprising a bushing for receiving a three-phase high voltage, a gas insulated circuit breaker for interrupting current for each phase, and a gas insulated bus line for power distribution from the bushing to the gas insulated circuit breaker. A gas insulated switchgear according to any one of claims 1 to 5, wherein the gas insulated bus is used.