JP4146249B2 - Switchgear - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a switch gear using a vacuum valve.
[0002]
[Prior art]
In a conventional switchgear using a vacuum valve, a mounting member such as a support insulator is installed on the inner wall of the tank in order to fix the bus-side conductor to the inner wall of the tank sealed with insulating gas (see, for example, Patent Document 1). ).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-185577 (page 6, FIG. 3)
[0004]
[Problems to be solved by the invention]
In such a conventional switchgear, an installation member such as a support insulator is provided on the inner wall of the tank, so that there is creepage on the insulator, and the dielectric strength is lower than a simple gas gap. Therefore, it is necessary to provide an insulation distance larger than the gas gap, and there is a problem that it is difficult to further downsize the apparatus.
[0005]
An object of the present invention is to provide a switchgear that can eliminate the need for a support insulator for fixing the bus-side conductor to the tank, and can further reduce the size of the tank.
[0006]
[Means for Solving the Problems]
A switchgear according to the present invention includes an insulating cylinder housed in a tank filled with an insulating gas and having one axial end fixed to the tank, and a movable side energizing shaft disposed substantially coaxially within the insulating cylinder. A vacuum valve oriented in the direction of one end of the insulating cylinder, and a busbar fixing portion provided in the direction intersecting the axial direction of the insulating cylinder in the vicinity of the other end of the insulating cylinder and insulatingly supporting the busbar-side conductor. It is intended to provide.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
1 and 2 schematically show a switchgear according to Embodiment 1 of the present invention. FIG. 1 is a side sectional view, and FIG. 2 is a sectional view taken along the line II-II in FIG. is there. The casing 1 constituting the switchgear is configured such that the left side of the figure is used as a front part and the right side as a rear part, a tank 2 in which an insulating gas is filled in a rear (back side) upper part, and a control chamber in a front upper part. 3, an operation mechanism chamber 4 is provided at the front center portion of the lower portion, and a cable chamber 5 is provided at the lowermost portion, and the inside is partitioned.
[0008]
In the lower part of the tank 2, three insulating cylinders 8 each housing a vacuum valve 7 for each phase are juxtaposed in the horizontal direction, and each insulating cylinder 8 is on the front (left side in the figure) side which is one end. A flange-like mounting portion 8 a provided at the end is fixed to a mounting plate 6 as a mounting portion that also serves as a partition with the operation mechanism chamber 4. The insulating cylinder 8 is made of, for example, a solid insulator such as an epoxy resin, and in the direction intersecting with the central axis of the insulating cylinder 8 in the vicinity of the rear (right side in the drawing) side end which is the other end. The protruding busbar fixing portion 8b is integrally formed. In addition, a through hole 8c is provided at a substantially central portion in the axial direction, and a blade support portion 8d is integrally formed on an outer peripheral portion near the through hole 8c.
[0009]
The vacuum valve 7 includes a fixed electrode and a movable electrode (not shown in detail) housed in a vacuum vessel. The fixed electrode has a fixed energizing shaft 7a, and the movable electrode has a movable energizing shaft 7b. Are connected to each other and protrude from the vacuum valve end plate 7c to opposite sides in the axial direction. Then, the fixed-side energizing shaft 7a is arranged on the rear (right side in the figure) side which is the other end of the insulating cylinder 8, and the one end, that is, the fixed part (left side in the figure) side of the insulating cylinder 8 in the tank 2. The stationary energizing shaft 7a is electrically and physically connected and fixed to the load side conductor 9 fixed to the other end of the insulating cylinder 8.
[0010]
The movable side energizing shaft 7 b is connected to a vacuum valve operating member 10 penetrating the mounting plate 6 via an insulating rod 11. Further, a portion in front of the substantially central portion of the insulating tube 8 extending in the direction of the central axis of the vacuum valve 7 (leftward in the drawing) serves to secure an insulation distance between the vacuum valve 7 and the mounting plate 6. ing.
[0011]
Next, the structure of the disconnector / ground switch part of the first embodiment will be described. A blade support member 20 is fixed to the blade support portion 8d provided at the substantially outer peripheral portion of the insulating cylinder 8. For example, the blade 12 is fixed to the blade support member 20 by directly embedding it as a buried metal during casting or by embedding a nut member (not shown) and screwing the nut member. It is pivotally supported. Further, the blade 12 is electrically connected to the movable side energizing shaft 7b of the vacuum valve 7 by a flexible connecting conductor 13 provided through a through hole 8c provided in the insulating cylinder 8.
[0012]
In addition, the bus bar fixing portion 8b provided on the other end side of the insulating cylinder 8 protrudes a predetermined length in the vertical direction in the drawing in order to secure a creeping insulation distance between the load side conductor 9 and the bus side conductor 14. The lower end portion of the bus-side conductor 14 is fixed to the tip portion.
[0013]
A predetermined portion of the bus-side conductor 14 is provided with a bus terminal 14a that comes into contact with the blade 12 when energized, and a predetermined terminal inside the tank 2 of the mounting plate 6 has a ground terminal 15 that contacts the blade 12 when grounded. Is provided. The blade 12 is rotated by a blade operation member 16 made of an insulating rod from the operation mechanism chamber 4 in front of the tank 2 as indicated by a broken line, and the tip portion contacts the bus terminal 14a as indicated by a solid line in FIG. At the position where the current is energized, and at the position where the tip of the blade 12 is in contact with the ground terminal 15 indicated by the broken line A, the ground is in the grounded state. When it is held at the position shown, it becomes a disconnected state.
[0014]
In addition, the integrated mechanism of the disconnecting switch and the earthing switch configured by using the vacuum valve 7, the insulating cylinder 8, the blade 12, and the like as described above is configured in the same manner for each phase, and one set for three phases. Are operated in a batch. The load-side conductor 9 that fixes the vacuum valve 7 is connected to a cable 19 via a bushing 18. The bus bar side conductor 14 is connected to the bus bar 17.
[0015]
Next, the operation of the first embodiment configured as described above will be described. In the switchgear, the contact point between the blade 12 configured to serve as both a disconnector and a ground switch and the bus terminal 14a is not shown in order to prevent the contact point from being separated by an electromagnetic force repulsive force when a short-circuit current is applied. Sufficient contact pressure is applied by the spring. Therefore, when the disconnector is opened and closed, a considerable force is applied to the bus terminal 14a and the bus-side conductor 14 by the frictional force of the contacts.
[0016]
Further, since a large electromagnetic force is generated in the bus-side conductor 14 and the blade 12 used for disconnection / grounding when the short-circuit current is energized, if the fixing of the bus-side conductor 14 and the blade 12 is insufficient, these cause deformation. However, in the switchgear according to this embodiment, since the bus-side conductor 14 is directly fixed to the insulating cylinder 8, it can sufficiently withstand the mechanical force and electromagnetic force as described above.
[0017]
Further, when the bus bar side conductor 14 and the bus bar terminal 14a are fixed to the inner wall of the tank 2 using a support insulator as in the prior art, the creeping insulator enters between the conductor and the tank inner wall by using the support insulator. Since the dielectric strength is reduced, it is necessary to increase the insulation distance. However, in the switchgear configuration according to the present invention, since the support insulator is not used, the distance between the bus-side conductor 14 and the tank 2 can be reduced. .
[0018]
As described above, according to the first embodiment, by disposing the disconnector, bus-side conductor, and load-side conductor in the insulating cylinder that houses the vacuum bulb, partial discharge and insulation at the end of the vacuum bulb where the electric field is high Breaking is suppressed by the discharge barrier effect of the insulating cylinder, and the function of the disconnector is compactly arranged to make the switch gear compact and to fix the bus side conductor 14 and the bus terminal 14a to the tank 1 Since it is possible to obtain a bus-side conductor support method that can withstand the electromagnetic force due to the insertion / extraction force of the disconnector and energizing current without a support insulator, the number of parts can be reduced and the switchgear can be made compact by reducing the insulation distance. Furthermore, the effect that the cost can be reduced can be obtained.
[0019]
Embodiment 2. FIG.
3 and 4 are diagrams schematically illustrating the switch gear according to the second embodiment. FIG. 3 is a side cross-sectional view showing main components inside the tank. FIG. 4 is a line IV-IV in FIG. FIG. In the second embodiment, the insulating cylinder 81 has an inner diameter from the mounting portion 8a side to the inside of the tank 2 which is one end portion (left side in the figure) to the opposite mounting portion side which is the other end portion (right side in the figure). The inner wall is inclined so as to gradually become smaller toward the direction. Since other configurations are the same as those of the first embodiment, description thereof is omitted.
[0020]
The insulating cylinder 81 is manufactured by casting a thermosetting resin such as an epoxy resin. Explaining the case of an epoxy resin, the epoxy resin changes from a liquid to a solid by a chemical reaction when the main agent and the curing agent are mixed to a certain temperature or higher. In this curing reaction, the epoxy resin is cured and contracted. Also, during casting, in order to increase the initial fluidity of the resin and promote the curing reaction, the mold temperature is heated to, for example, 100 degrees Celsius or more. The epoxy resin undergoes thermal shrinkage because of a slight decrease.
[0021]
Due to such curing shrinkage during casting and thermal shrinkage when the temperature decreases, stress is generated in the direction in which the resin clamps the mold surface that cuts out the insulating cylinder 81. Therefore, when the inner diameter of the insulating cylinder 81 is uniform in the axial direction, it is difficult for the casting to come off from the mold. However, in the second embodiment, the inner wall of the insulating cylinder 8 is directed from one axial end to the other end. Since the inner diameter gradually decreases, it is easy to remove it from the mold during manufacturing.
[0022]
As described above, according to the second embodiment, as shown in the drawing, the inner diameter of the insulating cylinder 81 gradually increases from the attachment portion 8a side as one end portion to the opposite attachment portion side as the other end portion. By providing an inclination so that the inner diameter of the insulating cylinder is pulled out in the direction of the larger diameter, the solid insulation material of the insulating cylinder can be removed from the mold even if it undergoes curing shrinkage or heat shrinkage during manufacturing. It becomes easy to come off, the workability at the time of manufacture improves, and the effect that the manufacturing cost can be reduced is obtained. Further, since the vertical span in the mounting portion 8a can be increased, it is advantageous in terms of strength in the mounted state.
[0023]
Embodiment 3 FIG.
FIGS. 5 and 6 illustrate a switchgear according to Embodiment 3 of the present invention. FIG. 5 is an enlarged side sectional view showing a main part of a vacuum valve and a grounding / disconnector, and FIG. It is arrow sectional drawing in the VI-VI line of FIG. As shown in the figure, in the third embodiment, the insulating cylinder 82, which is a solid insulator for fixing the vacuum valve 7, has the smallest inner diameter in the central portion in the axial direction, and the inner diameter gradually increases toward both ends. It is formed to be large. Since other configurations are the same as those of the first embodiment, description thereof is omitted.
[0024]
In this switchgear having a configuration in which the vacuum valve 7 is fixed to the insulating cylinder 82 in a metal tank and arranged in three phases in the horizontal direction, the end plate 7c of the vacuum valve 7 adjacent to the tank inner wall faces the inner wall of the tank 2. The electric field of the part and the part where the adjacent vacuum valve end plates 7c face each other is the highest. The insulating cylinder 82 has an effect of barrier insulation that suppresses dielectric breakdown where the electric field concentration portion of the vacuum valve end plate 7c is a base point. Since it rises as it approaches 7c, it is necessary to provide a gap of a certain distance or more between the inner wall of the insulating cylinder 82 and the vacuum valve end plate 7c.
[0025]
In the insulating cylinder 81 of the second embodiment shown in FIGS. 3 and 4, the inner diameter of the end portion of the vacuum valve fixed side (right side in the figure) is the smallest, so the fixed end of the vacuum valve 7 and the rear side of the insulating cylinder 81 Since the inner wall is closest to the inner wall and the inner diameter of the insulating cylinder 81 increases toward one end (the mounting portion 8a side), the radial dimension of the insulating cylinder 81 is the minimum inner diameter on the rear end side and the inclination of the inner wall. Determined by angle and axial dimensions. On the other hand, in the insulating cylinder 82 according to the third embodiment shown in FIGS. 5 and 6, since the inner diameter of the central portion is the smallest, the movable end of the vacuum valve 7 and the inner wall of the insulating cylinder 82 are closest to each other to insulate The inner diameter of the cylinder 82 increases as it goes to both ends.
[0026]
Therefore, the dimension in the radial direction of the insulating cylinder 82 is determined by the minimum inner diameter at the center, the inclination angle of the inner wall, and the half dimension in the axial direction. In view of the above, even if the withstand voltage performance is the same, the shape of the insulating cylinder 82 shown in FIGS. 5 and 6 reduces the radial dimension, and the switchgear configuration is arranged horizontally for three phases in the panel width direction. Then, it is possible to secure the workability of manufacturing the insulating cylinder 82 and to make the panel width W compact.
[0027]
The insulating cylinder 82 supports the vacuum valve 7 and functions as an insulating barrier that increases the dielectric strength between the adjacent vacuum valves 7 and between the vacuum valve 7 and the tank inner wall (not shown). If it is too close to the bulb, the local electric field increases and the dielectric strength decreases, so there is a limit to reducing the inner diameter of the insulating cylinder. On the other hand, by inclining the inner wall of the insulating cylinder, the maximum diameter of the insulating cylinder becomes large, and it becomes difficult to make the switch gear compact. Therefore, by setting the position of the minimum inner diameter of the insulating cylinder to the substantially central portion in the axial direction, both the inclined shape of the side wall and the compactness can be realized.
[0028]
As described above, according to the third embodiment, the workability at the time of manufacturing the insulating cylinder is improved and the radial dimension of the insulating cylinder is reduced, so that the panel width W is reduced and the switch gear is made more compact. I can do it.
[0029]
By the way, in the description of the above embodiment, the case where the busbar fixing portion 8b is provided in a direction substantially orthogonal to the axial direction of the insulating cylinder 8 is illustrated, but it is not necessarily limited to a right angle. Moreover, although the case where the bus-bar fixing part 8b is cast integrally with the insulating cylinder 8 has been described, it does not necessarily have to be integrated. Also, the casting resin is not particularly limited to the epoxy resin, and other similar insulating resins can be used without any particular limitation. Furthermore, it goes without saying that various modifications and changes such as the shape of the mounting portion 8a of the insulating cylinder 8 and the connection method between the blade 12 and the movable-side conductive shaft 7b are possible.
[0030]
【The invention's effect】
As described above, the present invention insulates and supports the bus-side conductor provided in the vicinity of the other end portion of the insulating cylinder accommodating the vacuum valve in a direction intersecting the axial direction of the insulating cylinder with respect to the tank. by which is adapted comprises a bus fixing portion, and reliably insulated supports the bus side conductor by bus fixing portion while maintaining the dielectric strength, eliminating the need for installation of the support insulator for fixing the bus side conductor to the tank, In addition to being able to be configured more compactly, it is possible to provide an effect that can provide a switchgear that can ensure resistance to electromagnetic force acting on a bus-side conductor or the like when a short-circuit current is applied.
[Brief description of the drawings]
FIG. 1 is a side sectional view of an essential part schematically showing a switchgear according to a first embodiment.
FIG. 2 is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 is a side sectional view showing main constituent members inside a tank, which is a main part of a switchgear according to a second embodiment.
4 is a cross-sectional view taken along the line IV-IV in FIG. 3;
FIG. 5 is a side cross-sectional view of an essential part showing, in an enlarged manner, portions of a vacuum valve and a ground / disconnector of a switchgear according to a third embodiment.
6 is a cross-sectional view taken along line VI-VI in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Case, 2 Tank, 4 Operation mechanism room, 6 Mounting part (mounting plate), 7 Vacuum valve, 7a Fixed side energizing shaft, 7b Movable side energizing shaft, 7c Vacuum valve end plate, 8, 81, 82 Insulating cylinder, 8a mounting portion, 8b busbar fixing portion, 8d blade support portion, 9 load side conductor, 10 vacuum valve operation member, 12 blade, 20 blade support member, 13 connection conductor, 14 busbar side conductor, 14a busbar terminal, 15 ground terminal, 16 blade operation member, 17 busbar, 20 blade support member.

Claims (3)

An insulating cylinder housed in a tank filled with insulating gas and having one end in the axial direction fixed to the tank, and a movable energizing shaft disposed substantially coaxially inside the insulating cylinder is directed toward one end of the insulating cylinder. One end is fixed to the other end of the insulating cylinder in a direction in which the axial direction intersects the axial direction of the insulating cylinder, and is electrically and physically connected to the vacuum valve fixed side energizing shaft. A load-side conductor fixed to a bushing penetrating the tank, and a bus bar formed so as to protrude a predetermined length in the direction intersecting the axial direction of the insulating cylinder in the vicinity of the other end of the insulating cylinder A fixed portion and a bus-side conductor that is insulated and supported by the bus-bar-fixed portion fixed in a direction in which the axial direction intersects the axial direction of the insulating tube And the blade on the outer periphery of the axial center A holding member, and a bus terminal provided in a predetermined portion of the bus side conductor, a ground terminal provided in a predetermined portion inside the tank, and a blade support member that is pivotally supported by the blade support member. A blade provided to contact the bus terminal when energized, to contact the ground terminal when grounded, and to be held at a position between the bus terminal and the ground terminal when disconnected. Switch gear. An insulating cylinder housed in a tank filled with insulating gas and having one end in the axial direction fixed to the tank, and a movable energizing shaft disposed substantially coaxially inside the insulating cylinder is directed toward one end of the insulating cylinder. comprising a vacuum valve which is directed, and a bus fixing portion for insulating support provided bus side conductor in a direction crossing the axial direction of the insulating cylinder to the vicinity of the other end of the insulating cylinder, the said insulating cylinder, said It has a gap between the vacuum valve, the inner diameter of the central portion in the axial direction is the narrowest, and the inner wall is inclined so that the inner diameter becomes wider as it approaches both ends. Switch gear. An insulating cylinder housed in a tank filled with insulating gas and having one end in the axial direction fixed to the tank, and a movable energizing shaft disposed substantially coaxially inside the insulating cylinder is directed toward one end of the insulating cylinder. And a busbar fixing portion provided in the direction intersecting the axial direction of the insulating cylinder in the vicinity of the other end portion of the insulating cylinder and insulatingly supporting the busbar-side conductor. It is formed integrally with the busbar fixing portion, and a blade support member is provided on the outer periphery of the central portion in the axial direction, and a busbar terminal provided at a predetermined portion of the busbar side conductor, and a predetermined portion inside the tank A grounding terminal provided on the blade support member and pivotally supported by the blade support member so as to contact the bus terminal when energized, contact the ground terminal when grounded, and between the bus terminal and the ground terminal when disconnected. Provided to be held in position And a blade, moreover, the insulating cylinder has a gap between the vacuum valve, the most narrow substantially axial central portion inner diameter, such that each wider internal diameter than closer to both end portions A switchgear characterized in that its inner wall is inclined.

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