JP2004153953A - Gas-insulated switchgear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems of the heat radiation, dispersion in each phase of cutoff performance, an yield in manufacturing, the security of airtightness, the standardization of a bushing, and the hindrance of production efficiency. <P>SOLUTION: For this gas-insulated switchgear, an insulating frame for supporting a vacuum breaker is an insulating cylinder, and an opening which pierces the insulating cylinder vertically is provided in the vicinity of the mobile part of a vacuum valve. Moreover, a main circuit of the breaker provided with a grounding switch is arranged, so that a positional relation with the vacuum value is the same, at either the top or the bottom of the insulating cylinder of each phase, and three-phase insulating spacers at the topside of a tank made individually for each phase are arranged, being slid back and forth/right and left centering upon a second phase of a bushing, and the bushing at the bottom of the tank has a sufficient length for arranging a current transformer outside the tank. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to the structure of a gas insulated switchgear.
[0002]
[Prior art]
In a conventional gas insulated switchgear, a tank is provided on a base via a gantry. The tank has a shape in which a lower portion on the front side is cut out, and an opening is formed on the front side of the tank, and the opening is closed by a mounting plate. The inside of the tank is airtightly configured and filled with an insulating gas. One end of an insulating frame made of a solid insulator and having a substantially U-shaped cross section is mounted inside the mounting plate, and a vacuum circuit breaker is mounted inside the insulating frame as a switch. A disconnecting switch with a ground switch as a switch is provided above the insulating frame. An operation unit for operating the vacuum circuit breaker and an operation unit for operating the disconnector with a grounding switch are provided outside the mounting plate.
[0003]
The bus is located above the tank. An opening is formed on the upper surface of the tank, and a three-phase insulating spacer is provided as an insulating member for airtightly closing the opening. The three-phase insulating spacer is obtained by molding an internal conductor for three phases with a solid insulator. The upper end of this internal conductor is connected to the bus, and the lower part is connected to a disconnecting switch with a ground switch.
At the lower part of the tank, there are provided three-phase composite bushings in which an internal conductor and a current transformer are embedded in a bushing made of a solid insulator. This bushing is hermetically attached to the opening of the tank via an O-ring from inside. A cable head is attached to this bushing from the front side of the gas insulated switchgear. The vacuum circuit breaker and the inner conductor of the bushing are connected via a conductor, and a power cable is connected to the cable head. (For example, see Patent Document 1)
[0004]
[Patent Document 1]
JP-A-11-185577
[Problems to be solved by the invention]
The conventional gas insulated switchgear requires a reinforcing measure such as increasing the thickness of the end portion because the cross section of the insulating frame supporting the vacuum circuit breaker is U-shaped. There is a problem that heat is difficult to radiate.
[0006]
In addition, the main circuit part of each phase of the disconnecting switch with grounding switch is arranged in the depth direction in the vicinity of the circuit breaker, so that the electromagnetic field accompanying the fault current for each phase is cut off between the vacuum switches. There was a question that the breaking performance of the vacuum circuit breaker varied depending on each phase due to the different effects.
[0007]
In addition, the three-phase insulating spacer mounted on the top of the tank has a complicated shape, resulting in poor production yield, and the wide flange surface has a wide flatness on the tank side to maintain airtightness. It was expensive to secure.
[0008]
Further, the bushing provided at the lower part of the tank has a complicated and large size because the current transformer is buried therein, resulting in poor production yield and poor workability. In addition, it was necessary to cope with the specifications of the current transformer that changed for each customer, which hindered the standardization of the bushing and the production efficiency.
[0009]
[Means for Solving the Problems]
According to the gas insulated switchgear of the present invention for solving the above-mentioned problems, a metal container filled with an insulating gas, a bus-side bushing supported by the metal container and to be connected to an external circuit, An insulating frame supported at one end on the container wall, a movable terminal supported by the insulating frame and connected to an insulating rod extending through one end of the insulating frame, and fixed at the other end of the insulating cylinder; A vacuum circuit breaker having a side terminal, a rotatable blade provided on an insulating frame, a disconnector connected between the busbar bushing and the vacuum circuit breaker, and an electric power connected to the vacuum circuit breaker. In a gas insulated switchgear provided with a cable head connectable to a cable and a current transformer for measuring a current flowing through the cable head, a cross section of the insulating frame whose surface perpendicular to the axial direction is an annular tube A body, a gas insulated switchgear, characterized in that with an opening for connecting the movable terminal of the vacuum circuit breaker to the disconnector is obtained.
[0010]
In addition, even if the main circuit conductor including the bus-side bushing and the disconnecting switch includes a flexible conductor that penetrates through the insulating cylinder and connects the movable terminal to the blade, the main circuit conductor including the axis of the vacuum circuit breaker is substantially vertical. In-plane, bus-side bushings are offset from each other in the depth and width directions of the gas insulated switchgear, or the current transformer is a separate component from the cable head. Is also good.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
As shown in FIG. 1, in the gas insulated switchgear of the present invention, a tank 3 is provided on a gantry 2 made of a thin sheet metal. The front surface of the tank 3 has a notched shape. An opening is formed in the front surface of the tank 3, the opening is closed by the mounting plate 4, the inside of the tank 3 is airtightly configured, and is filled with an insulating gas.
[0012]
Inside the mounting plate 4, one side of an insulating cylinder 18 made of a solid insulator is attached so as to have a gap of 5 mm or more with the main circuit portion of the circuit breaker 6, and inside the insulating cylinder 18, a vacuum valve 19 and a vacuum A circuit breaker main circuit section such as a flexible conductor 23 for connecting the movable shaft 20 of the valve 19 and the blade support terminal 21 for the disconnector with a grounding switch so as not to impair the operation of the movable shaft 20; A mechanical part such as an insulating rod 23 that insulates the movable shaft 20 from the circuit breaker operating section 8 and an adapter 24 that connects the insulating rod 23 and the movable shaft 20 of the vacuum valve 19 are housed therein. The disconnecting switch 7 with a ground switch is provided on the insulating tube 18. Outside the mounting plate 4, an operation unit 8 for a breaker and an operation unit 9 for a disconnector with a grounding switch are provided as in the conventional case.
[0013]
On the opposite side of the insulating cylinder 18 from the mounting plate 4, a fixed terminal 25 of a vacuum valve is mounted via a fixed terminal 26, and the upper insulating cylinder 18 protrudes upward and is an input terminal of a disconnector with a grounding switch. 27 is mounted, and a blade support terminal 21 of a disconnector with a grounding switch, which protrudes smaller than the protruding portion, is mounted above the vacuum valve movable shaft 20 of the insulating cylinder 18. An opening 28 is provided on the mounting plate 4 side of the small protrusion so as to penetrate the insulating cylinder 18. The movable shaft 20 of the vacuum valve is grounded by a flexible conductor 22 penetrating the opening 28. It is connected to the blade support terminal 21 of the disconnector with switch.
[0014]
Openings are formed at the same pitch as the insulating cylinder 18 for each phase above the insulating cylinder 18 of the mounting plate 4, and a test terminal / ground terminal 29 as an insulating member for airtightly closing the opening is provided. I have. The test terminal / grounding terminal 29 has an inner conductor 29a embedded at the center, and a mounting bracket 30 for mounting to the tank is buried on a circumference around the inner conductor 29a. A recess 31 is provided around the inner conductor 29a for mounting a packing for airtight attachment to the tank. The inner end of the inner conductor 29a is connected to the ground terminal 32 of the disconnector with a ground switch, and the outer end of the tank is connected to the ground terminal. Around the opening above the insulating cylinder 18 of the mounting plate 4, a small hole for attaching a test terminal and ground terminal 29 is provided on a circle having the same center as the center of the opening. The grounding terminal 29 is inserted into the opening from the inside of the tank, and a bolt 33 penetrating the mounting hole from the outside of the tank is inserted into the mounting bracket 30 and fastened.
[0015]
On the upper surface of the tank 3, an opening is formed above the insulating cylinder 18 for each phase at a pitch substantially equal to that of the insulating cylinder 18 and at a position slightly larger than the outer diameter of the bus bar 10 in the front-rear direction. A bus single-phase bushing 34 is provided as an insulating member for airtightly closing the opening. This single-phase bushing 34 has an inner conductor 34a embedded at the center, and a mounting bracket 35 for mounting to the tank 3 is buried on a circumference around the inner conductor 34a. A recess 36 for mounting a packing for airtight mounting is provided around the inner conductor 34a. An inner end of the inner conductor 34a is connected to the input terminal 27 of the disconnector with a grounding switch via a connection conductor 38, and an outer end of the tank is connected to the bus 10. Around the opening on the upper surface of the tank, there is a small hole for attaching a single-phase bushing 34 on a circumference having the same center as the center of the opening, and the single-phase bushing 34 is provided from the inside of the tank to the opening. The bolt 37 is inserted, and the bolt 37 penetrating the mounting hole from the outside of the tank is inserted into the mounting bracket and fastened.
[0016]
An opening is formed at the same pitch as the insulating cylinder 18 below the insulating cylinder 18 for each phase at the lower portion of the front surface of the tank 3, and a single-phase bushing for cable connection as an insulating member that air-tightly closes the opening. 39 are provided. This single-phase bushing 39 has an inner conductor 39a embedded at the center, and a mounting bracket 40 for mounting to the tank 3 is buried on a circumference around the inner conductor 39a. A concave portion 41 for mounting a packing for airtight mounting is provided around the inner conductor 39. An inner end of the inner conductor 39 is connected to the fixed terminal 26 of the circuit breaker via a connection conductor 42, and an outer end of the tank is connected to the power cable 17 via the cable head 15. Around the opening at the lower part of the front surface of the tank 3, there is a small hole for attaching a single-phase bushing 39 on a circumference having the same center as the center of the opening. A bolt 42 inserted into the opening and penetrating the mounting hole from the outside of the tank is inserted into the mounting bracket and fastened.
[0017]
In the gas insulated switchgear of this embodiment, since the insulating frame supporting the vacuum circuit breaker is a cylindrical body and has an opening, reinforcement such as increasing the thickness of the end as in the conventional case is provided. No measures are required, and the heat generated in the vacuum circuit breaker can be efficiently radiated. Further, since the main circuit conductors including the bus-side bushing and the disconnector are in a substantially vertical plane including the axis of the vacuum circuit breaker, the breaking performance of the vacuum circuit breaker for each phase is equivalent. Furthermore, since the bus-side bushings are shifted from each other in the depth direction and the width direction of the gas insulated switchgear, the shape of the insulating spacer mounted on the tank upper surface can be simplified, and the production yield and airtight performance can be maintained. Easy. Furthermore, since the current transformer is a separate component from the above-mentioned cable head, the production yield is good, the workability is good, and it is possible to easily cope with the specifications of the current transformer that changes for each customer. it can.
[0018]
Embodiment 2 FIG.
Next, a second embodiment will be described with reference to FIG. As can be seen from a comparison between FIG. 2 and FIG. 1, there is no circuit breaker inside the insulating cylinder, and the short-circuit conductor 45 connects the blade support terminal 21 and the fixed terminal 26 of the disconnector with ground switch without passing through the switch. ing.
[0019]
Embodiment 3 FIG.
Next, a third embodiment will be described with reference to FIG. As can be seen from a comparison between FIG. 3 and FIG. 2, the positions of the insulating cylinder 18 and the disconnecting switch 7 with a grounding switch are turned upside down without changing the mutual positional relationship. The connection conductor 46 is connected to the single-phase bushing 34 on the upper surface of the tank, and the input terminal 27 of the disconnector with a ground switch is connected to the single-phase bushing 39 at the lower part of the front surface of the tank via the connection conductor 47. Also, although a state is shown in which the instrument transformer 47 is connected to the single-phase bushing 39 at the lower part of the front surface of the tank instead of the power cable 17, a power cable, a lightning arrestor, and the like can be connected in a similar structure.
[0020]
Embodiment 4 FIG.
Next, a fourth embodiment will be described with reference to the drawings. As can be seen by comparing FIG. 4 with FIG. 1, the single-phase bushing 39 at the lower part of the tank is mounted on the rear side, and the power cable 17 is connected to the single-phase bushing 39 from the rear side of the gas-insulated switchgear. Although the power cable 17 is drawn from above the gas insulated switchgear in the figure, it can be connected even when the power cable 17 is drawn from below.
[0021]
As described above, according to the gas insulated switchgear of the present invention, the stress in the insulator is dispersed by making the insulator housing the main circuit portion of the circuit breaker circular or elliptical, and the insulator is thinned. Can be realized. Also, by providing a protruding portion on the insulator, it is possible to reduce the assembly time without requiring extra hardware for mounting each terminal of the disconnector with the earthing switch, and a through hole is provided in a part of the insulating cylinder. Is provided, heat generated in the insulating cylinder can be easily radiated to the outside of the insulating cylinder, and a large current can be supplied even with the same conductor size.
[0022]
【The invention's effect】
The gas insulated switchgear according to the present invention is provided with an insulating frame in which the cross section of a surface perpendicular to the axial direction is an annular tubular body, and includes an opening for connecting the movable terminal of the vacuum circuit breaker to the disconnector. Since the stress in the insulation frame can be dispersed, the insulation frame can be made thinner, a disconnector with a grounding switch can be attached to the insulation frame, and a through hole must be provided in a part of the insulation frame. Accordingly, heat generated in the insulating frame can be easily radiated to the outside, and a large current can be supplied even with the same conductor size.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a first embodiment of a gas insulated switchgear of the present invention.
FIG. 2 is a side sectional view showing a second embodiment of the gas insulated switchgear of the present invention.
FIG. 3 is a side sectional view showing a third embodiment of the gas insulated switchgear of the present invention.
FIG. 4 is a side sectional view showing a fourth embodiment of the gas insulated switchgear of the present invention.
[Explanation of symbols]
Reference Signs List 3 metal container (tank), 7 disconnector, 15 cable head, 17 power cable, 18 insulating frame, 19 vacuum circuit breaker (vacuum valve), 20 movable terminal, 22 flexible conductor, 23 insulating rod, 25 fixed terminal , 28 opening, 34 busbar bushing, 48 current transformer.

Claims (9)

A metal container filled with an insulating gas,
A busbar bushing supported by the metal container and to be connected to an external circuit,
An insulating frame supported at one end on the container wall in the metal container,
A vacuum circuit breaker having a movable terminal connected to an insulating rod extending through the one end of the insulating frame and a fixed terminal supported at the other end of the insulating cylinder;
A disconnector having a rotatable blade provided on the insulating frame and connected between the busbar-side bushing and the vacuum circuit breaker,
A cable head connected to the vacuum circuit breaker and connectable to a power cable;
In a gas-insulated switchgear having a current transformer for measuring a current flowing through the cable head,
A gas characterized in that the insulating frame is a tubular body having a cross section of a surface perpendicular to the axial direction, and an opening for connecting a movable terminal of the vacuum circuit breaker to the disconnector. Insulated switchgear. 2. The gas insulated switchgear according to claim 1, further comprising a flexible conductor that penetrates through the insulating cylinder and connects the movable terminal to the blade. A metal container filled with an insulating gas,
A busbar bushing supported by the metal container and to be connected to an external circuit,
An insulating frame supported at one end on the container wall in the metal container,
A vacuum circuit breaker having a movable terminal connected to an insulating rod extending through the one end of the insulating frame and a fixed terminal supported at the other end of the insulating cylinder;
A disconnector having a rotatable blade provided on the insulating frame and connected between the busbar-side bushing and the vacuum circuit breaker,
A cable head connected to the vacuum circuit breaker and connectable to a power cable;
In a gas-insulated switchgear having a current transformer for measuring a current flowing through the cable head,
A gas insulated switchgear, wherein a main circuit conductor including the bus-side bushing and the disconnector is in a substantially vertical plane including an axis of the vacuum circuit breaker. A metal container filled with an insulating gas,
A busbar bushing supported by the metal container and to be connected to an external circuit,
An insulating frame supported at one end on the container wall in the metal container,
A vacuum circuit breaker having a movable terminal connected to an insulating rod extending through the one end of the insulating frame and a fixed terminal supported at the other end of the insulating cylinder;
A disconnector having a rotatable blade provided on the insulating frame and connected between the busbar-side bushing and the vacuum circuit breaker,
A cable head connected to the vacuum circuit breaker and connectable to a power cable;
In a gas-insulated switchgear having a current transformer for measuring a current flowing through the cable head,
A gas-insulated switchgear characterized in that the bus-side bushings are shifted from one another in the depth direction and the width direction of the gas-insulated switchgear. A metal container filled with an insulating gas,
A busbar bushing supported by the metal container and to be connected to an external circuit,
An insulating frame supported at one end on the container wall in the metal container,
A vacuum circuit breaker having a movable terminal connected to an insulating rod extending through the one end of the insulating frame and a fixed terminal supported at the other end of the insulating cylinder;
A disconnector having a rotatable blade provided on the insulating frame and connected between the busbar-side bushing and the vacuum circuit breaker,
A cable head connected to the vacuum circuit breaker and connectable to a power cable;
In a gas-insulated switchgear having a current transformer for measuring a current flowing through the cable head,
A gas insulated switchgear wherein the current transformer is a separate component from the cable head. The gas-insulated switchgear according to any one of claims 3 to 5, wherein the insulating frame is a tubular body having a cross section of a surface perpendicular to the axial direction, and a movable terminal of the vacuum circuit breaker. A gas-insulated switchgear comprising an opening for connecting the switch to the disconnector. 7. The gas insulated switchgear according to claim 6, further comprising a flexible conductor that penetrates the insulating cylinder and connects the movable terminal to the blade. 6. The gas-insulated switchgear according to claim 1, wherein the main circuit conductor including the bus-side bushing and the disconnector is substantially vertical including an axis of the vacuum circuit breaker. A gas insulated switchgear characterized by being in the plane. The gas-insulated switchgear according to any one of claims 1 to 3, and 5, wherein the bus-side bushings are shifted from each other in the depth direction and the width direction of the gas-insulated switchgear. And gas insulated switchgear.

Images