Electric power supply and demand instrument transformers and gas-insulated switchgear

Abstract

To provide an instrument transformer for power supply and demand and a gas-insulated switchgear that can be made compact.SOLUTION: An instrument transformer for power supply and demand has an instrument pressure transformer for power supply and demand, a plurality of current transformers for power supply and demand, and a tank unit. The tank unit accommodates a conductor extending in a first direction. The tank unit is connected to the instrument pressure transformer for power supply and demand and the plurality of current transformers for power supply and demand. At least one first pair of devices of devices included in the instrument pressure transformer for power supply and demand and the plurality of current transformers for power supply and demand is connected to one first tank included in the tank unit. The pair of first devices is arranged with at least a portion of each device overlapping each other in the first direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to an instrument transformer for power supply and demand and a gas-insulated switchgear. [Background technology]

[0002] Gas insulated switchgear (GIS) is used in power receiving facilities such as factories. To measure the amount of electricity being traded, a voltage and current transformer (VCT) is built into the gas insulated switchgear. The voltage and current of the gas insulated switchgear are transformed into voltage and current suitable for measuring the amount of electricity. There is a demand for miniaturization of power supply and demand instrument transformers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-101510 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide an instrument transformer for power supply and demand and a gas-insulated switchgear that can be made compact. [Means for solving the problem]

[0005] An electric power supply and demand instrument transformer according to an embodiment includes an electric power supply and demand potential transformer, a plurality of electric power supply and demand current transformers, and a tank unit. The tank unit houses a conductor extending in a first direction. The electric power supply and demand potential transformer and the plurality of electric power supply and demand current transformers are connected to the tank unit. At least a pair of first devices among the devices included in the electric power supply and demand potential transformer and the plurality of electric power supply and demand current transformers are connected to one first tank included in the tank unit. The pair of first devices are arranged such that at least a portion of each of them overlaps with each other in the first direction. A second device, different from the pair of first devices among the devices included in the power supply and demand potential transformer and the multiple power supply and demand current transformers, is connected to the first tank. A third device, any one of the potential transformer, earthing switch, voltage detector, and power supply and demand current transformers, is connected to the first tank. At least a portion of the second device and at least a portion of the third device are arranged to overlap each other in the first direction. [Brief description of the drawings]

[0006] [Figure 1] 1 is a side view of a gas-insulated switchgear including an instrument transformer for power supply and demand according to a first embodiment. FIG. [Diagram 2] FIG. 2 is a side cross-sectional view of the electric power supply and demand instrument transformer of the first embodiment. [Diagram 3] FIG. 4 is a side view of an instrument transformer for power supply and demand according to a first modified example of the first embodiment. [Figure 4] FIG. 13 is a plan view of an instrument transformer for power supply and demand according to a second modified example of the first embodiment. [Diagram 5] FIG. 13 is a side view of an instrument transformer for power supply and demand according to a second modified example of the first embodiment. [Figure 6] FIG. 4 is a side view of an instrument transformer for electric power supply and demand according to a second embodiment. [Figure 7] FIG. 11 is a side view of an instrument transformer for electric power supply and demand according to a third embodiment. [Figure 8] FIG. 11 is a side cross-sectional view of an instrument transformer for electric power supply and demand according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, an electric power supply and demand instrument transformer and a gas-insulated switchgear according to an embodiment will be described with reference to the drawings. (First embodiment) FIG. 1 is a side view of a gas-insulated switchgear GIS including a power supply and demand potential transformer VCT of the first embodiment. FIG. 2 is a side cross-sectional view of the power supply and demand potential transformer of the first embodiment. As shown in FIG. 1, the gas-insulated switchgear GIS has a cable head CH and a transformer junction TR-J. The cable head CH is connected to an external power transmission line. The transformer junction TR-J is connected to a transformer of a power receiving facility. The gas-insulated switchgear GIS has a line from the cable head CH to the transformer junction TR-J.

[0008] In this application, the Z direction, X direction, and Y direction of the Cartesian coordinate system are defined as follows. The Z direction is the vertical direction, and the +Z direction is the upward direction. The X direction and the Y direction are horizontal directions. The X direction (first direction) is the direction in which the lines of the gas-insulated switchgear GIS extend. The +X direction is the direction from the cable head CH to the transformer junction TR-J. The +X direction may be called the transformer side, and the -X direction may be called the transmission line side. The Y direction is perpendicular to the Z and X directions.

[0009] As shown in FIG. 2, the circuit of the gas-insulated switchgear GIS including the power supply and demand instrument transformer VCT is formed by a grounded tank T and a conductor 10 housed inside the tank T. From the viewpoint of layout efficiency, a three-phase integrated system is adopted for the circuit of the gas-insulated switchgear GIS. In the circuit of the three-phase integrated system, the conductors 10 of the first phase 11, the second phase 12, and the third phase 13 corresponding to three-phase AC are housed inside the same tank T. An insulating gas such as SF6 is sealed inside the tank T. The circuit of the gas-insulated switchgear GIS is separated into a plurality of gas sections by insulating spacers 30. The insulating spacers 30 support the conductors 10 and divide the inside of the tank T in the extension direction of the conductors 10.

[0010] As shown in Figure 1, the gas-insulated switchgear GIS includes, along the line from the cable head CH to the transformer junction TR-J, a lightning arrester LA, a transmission line side disconnecting switch / earthing switch DS / ES, a voltage transformer VT, a current transformer CT, a circuit breaker GCB, a power supply and demand instrument transformer VCT, and a transformer side earthing switch ES.

[0011] The transmission line side disconnecting switch / earthing switch DS / ES opens and closes the line, and earths the line which becomes voltage-free during an outage. The potential transformer VT transforms the line voltage to a voltage suitable for measurement. The current transformer CT transforms the line current to a current suitable for measurement. The voltage measured using the potential transformer VT and the current measured using the current transformer CT are used to control the gas-insulated switchgear GIS. The circuit breaker GCB connects and disconnects the line of the gas-insulated switchgear GIS. The transformer side earthing switch ES earths the line which becomes voltage-free during an outage.

[0012] In order to measure the amount of electricity being traded, the power supply and demand potential transformer (VCT) transforms the voltage and current of the line of the gas-insulated switchgear (GIS) into a voltage and current suitable for measuring the amount of electricity. For example, the power supply and demand potential transformer (VCT) is the property of the power company, while the gas-insulated switchgear (GIS) excluding the power supply and demand potential transformer (VCT) is the property of the electricity consumer. The replacement cycle for power supply and demand potential transformers (VCT) is shorter than that of the gas-insulated switchgear (GIS). The power supply and demand potential transformers (VCT) are assembled into the gas-insulated switchgear (GIS) in a united state to allow for easy replacement.

[0013] As shown in FIG. 2, the electric power supply and demand instrument transformer VCT has a tank unit 20, an electric power supply and demand instrument transformer VT (VCT), and a plurality of electric power supply and demand current transformers CT (VCT).

[0014] The tank unit 20 houses the conductor 10 extending in the X direction. Insulating spacers 30 are arranged at both ends of the tank unit 20 in the X direction. An insulating gas such as SF6 is sealed inside the tank unit 20. A power supply and demand instrument transformer VT (VCT) and a plurality of power supply and demand current transformers CT (VCT) are connected to the tank unit 20. The tank unit 20 has a first tank 21. The first tank 21 is formed in a cylindrical shape. The central axis of the first tank 21 is parallel to the X direction.

[0015] The power supply and demand voltage transformer VT (VCT) and the multiple power supply and demand current transformers CT (VCT) are covered by the VCT tank 25. An insulating gas such as SF6 is sealed inside the VCT tank 25. The power supply and demand voltage transformer VT (VCT) and the multiple power supply and demand current transformers CT (VCT) are separated from the tank unit 20 by insulating spacers 35 into independent gas sections.

[0016] The power supply voltage transformer VT (VCT) transforms the line voltage of the gas insulated switchgear GIS into a voltage suitable for measurement. The power supply voltage transformer VT (VCT) is connected to the first phase 11, the second phase, and the third phase 13 of the conductor 10. The power supply voltage transformer VT (VCT) transforms the voltage between the first phase 11 and the second phase 12, and also transforms the voltage between the first phase 11 and the third phase 13.

[0017] The multiple power supply and demand current transformers (CTs) transform the current of the line of the gas insulated switchgear GIS into a current suitable for measurement. The multiple power supply and demand current transformers (CTs) (VCTs) include a second power supply and demand current transformer (CT) (VCT) 2 and a third power supply and demand current transformer (CT) (VCT) 3. The second power supply and demand current transformer (CT) (VCT) 2 is connected to a second phase 12 of the conductor 10 and transforms the current of the second phase 12. The third power supply and demand current transformer (CT) (VCT) 3 is connected to a third phase 13 of the conductor 10 and transforms the current of the third phase 13.

[0018] A connection point V3 of the power supply and demand voltage transformer VT (VCT) for the third phase 13 of the conductor 10 is disposed in the -X direction from a connection point C3 of the third power supply and demand current transformer CT (VCT) 3 for the third phase 13. A connection point V2 of the power supply and demand voltage transformer VT (VCT) for the second phase 12 of the conductor 10 is disposed in the -X direction from a connection point C2 of the second power supply and demand current transformer CT (VCT) 2 for the second phase 12. In other words, the connection points V2, V3 of the power supply and demand voltage transformer VT (VCT) for the conductor 10 are disposed in the -X direction (one side in the X direction) from the connection points C2, C3 of the multiple power supply and demand current transformers CT (VCT) for the conductor 10. A power supply and demand voltage transformer VT (VCT) is connected to the transmission line side (upstream side) of the conductor 10, and multiple power supply and demand current transformers CT (VCT) are connected to the transformer side (downstream side). Since the power supply and demand voltage transformer VT (VCT) is not connected between multiple power supply and demand current transformers CT (VCT), the accuracy of the power supply and demand instrument transformer VCT is improved.

[0019] Among the devices included in the power supply and demand voltage transformer VT (VCT) and the multiple power supply and demand current transformers CT (VCT), the power supply and demand voltage transformer VT (VCT) and the third power supply and demand current transformer CT (VCT) 3 are an example of a pair of first devices 41. At least a pair of first devices 41 are connected to one first tank 21. Among the devices included in the power supply and demand voltage transformer VT (VCT) and the multiple power supply and demand current transformers CT (VCT), a second power supply and demand current transformer CT (VCT) 2 different from the pair of first devices 41 is an example of a second device 42. In the first embodiment, in addition to the pair of first devices 41, the second device 42 is also connected to the first tank 21. That is, all devices included in the power supply and demand voltage transformer VT (VCT) and the multiple power supply and demand current transformers CT (VCT) are connected to the first tank 21.

[0020] At least a pair of first devices 41 are connected to one first tank 21, thereby making the power supply and demand potential transformer VCT smaller. There are cases where a plurality of single-phase circuits are branched off from a three-phase integrated circuit, and a plurality of power supply and demand current transformers CT (VCT) are connected to each tank. Compared to this case, in the first embodiment, the space occupied by the power supply and demand potential transformer VCT is smaller.

[0021] When viewed from the X direction, the pair of first devices 41 are at different positions from each other. The pair of first devices 41 are disposed on opposite sides of the first tank 21. When viewed from the X direction, the pair of first devices 41 are disposed 180° apart in the circumferential direction of the first tank 21. This allows the power supply and demand instrument transformer VCT to be miniaturized in the YZ directions. The pair of first devices 41 may be disposed at an angle less than 180° apart.

[0022] The pair of first devices 41 are disposed so that at least a portion of each of them overlaps with each other in the X direction. In the example of Fig. 1 and Fig. 2, a portion of the power supply and demand instrument transformer VT (VCT) and substantially the entirety of the third power supply and demand current transformer CT (VCT) 3 are disposed so as to overlap with each other in the X direction. This reduces the size of the power supply and demand instrument transformer VCT in the X direction. Compared to a case in which the power supply and demand voltage transformer VT (VCT) and the third power supply and demand current transformer CT (VCT) 3 are arranged side by side in the X direction, the length of the power supply and demand instrument transformer VCT in the X direction is shorter.

[0023] Of the pair of first devices 41, the power supply and demand voltage transformer VT (VCT) is disposed in the +Z direction (above) of the first tank 21. Of the pair of first devices 41, the third power supply and demand current transformer CT (VCT) 3 is disposed in the -Z direction (below) of the first tank 21. The second power supply and demand current transformer CT (VCT) 2, which is the second device 42, is also disposed in the -Z direction (below) of the first tank 21. The second power supply and demand current transformer CT (VCT) 2 is disposed next to the third power supply and demand current transformer CT (VCT) 3 in the +X direction.

[0024] When viewed from the X direction, the second power supply and demand current transformer CT (VCT) 2 and the pair of first devices 41 may be located at different positions. In this case, it is desirable that at least a part of the second power supply and demand current transformer CT (VCT) 2 and at least a part of the pair of first devices 41 are arranged to overlap each other in the X direction. This reduces the size of the power supply and demand instrument transformer VCT in the X direction.

[0025] 3 is a side view of a power supply and demand instrument transformer VCT of a first modified example of the first embodiment. In the first modified example, the power supply and demand voltage transformer VT (VCT) of the pair of first devices 41 is disposed in the -Z direction (below) of the first tank 21. The third power supply and demand current transformer CT (VCT) 3 of the pair of first devices 41 is disposed in the +Z direction (above) of the first tank 21. The second power supply and demand current transformer CT (VCT) 2, which is the second device 42, is also disposed in the +Z direction (above) of the first tank 21. The second power supply and demand current transformer CT (VCT) 2 is disposed next to the third power supply and demand current transformer CT (VCT) 3 in the +X direction.

[0026] In the first embodiment and its first modified example, one of the pair of first devices 41 is disposed above the first tank 21, and the other of the pair of first devices 41 is disposed below the first tank 21. That is, the pair of first devices 41 are disposed on opposite sides of each other in the Z direction (up-down direction) with the first tank 21 in between. This reduces the size of the power supply and demand instrument transformer VCT in the Y direction. The area occupied by the power supply and demand instrument transformer VCT is reduced.

[0027] Fig. 4 is a plan view of an electric power supply and demand instrument transformer VCT of a second modified example of the first embodiment, and Fig. 5 is a side view. In the second modified example, the electric power supply and demand voltage transformer VT (VCT) of the pair of first devices 41 is disposed in the +Y direction (one side in the horizontal direction) of the first tank 21. The third electric power supply and demand current transformer CT (VCT) 3 of the pair of first devices 41 is disposed in the -Y direction (the other side in the horizontal direction) of the first tank 21. The second electric power supply and demand current transformer CT (VCT) 2, which is the second device 42, is also disposed in the -Y direction of the first tank 21. The second electric power supply and demand current transformer CT (VCT) 2 is disposed next to the third electric power supply and demand current transformer CT (VCT) 3 in the +X direction.

[0028] In the second modified example, the pair of first devices 41 are disposed on opposite sides in the Y direction across the first tank 21. This reduces the size of the power supply and demand instrument transformer VCT in the Z direction (up and down direction).

[0029] The gas-insulated switchgear GIS of the embodiment has a miniaturized power supply and demand instrument transformer VCT, which allows the gas-insulated switchgear GIS to be miniaturized.

[0030] Second embodiment 6 is a side view of an electric power supply and demand potential transformer VCT of the second embodiment. The electric power supply and demand potential transformer VCT of the second embodiment differs from the first embodiment in that a third device 43 is connected to the first tank 21. Descriptions of the second embodiment that are similar to the first embodiment may be omitted.

[0031] The third device 43 is a device that constitutes the gas-insulated switchgear GIS. For example, the third device 43 is a voltage transformer VT, an earthing switch ES, or a voltage detector. The voltage detector detects the presence or absence of a voltage in the conductor 10. The third device 43 may be a first power supply and demand current transformer CT (VCT) 1. The first power supply and demand current transformer CT (VCT) 1 is connected to the first phase 11 (see FIG. 2) of the conductor 10 and transforms the current of the first phase 11.

[0032] The third device 43 is connected to the first tank 21. The third device 43 is arranged in the +Z direction of the first tank 21. The third device 43 is arranged alongside the power supply and demand voltage transformer VT (VCT) in the +X direction space of the power supply and demand voltage transformer VT (VCT). The second power supply and demand current transformer CT (VCT) 2, which is the second device 42, and the third device 43 are arranged on opposite sides of the first tank 21. At least a part of the second device 42 and at least a part of the third device 43 are arranged to overlap each other in the X direction. In the example of FIG. 6, substantially the entire second power supply and demand current transformer CT (VCT) 2 and a part of the third device 43 are arranged to overlap each other in the X direction.

[0033] The third device 43, which is a component of the gas-insulated switchgear GIS, is placed in a space vacant in the power supply and demand instrument transformer VCT and is connected to the first tank 21. The second device 42 and the third device 43 are placed on opposite sides of the first tank 21. At least a part of the second device 42 and at least a part of the third device 43 are placed overlapping each other in the X direction. This reduces the size of the gas-insulated switchgear GIS.

[0034] (Third embodiment) Fig. 7 is a side view of the electric power supply and demand instrument transformer VCT of the third embodiment, and Fig. 8 is a side cross-sectional view. The electric power supply and demand instrument transformer VCT of the third embodiment differs from the second embodiment in that the second device 42 and the third device 43 are connected to the second tank 22. Descriptions of the third embodiment that are similar to the second embodiment may be omitted.

[0035] The tank unit 20 has a second tank 22 in addition to the first tank 21. The second tank 22 is formed in a cylindrical shape. The central axis of the second tank 22 is parallel to the X direction. The second tank 22 is disposed in the +X direction of the first tank 21. The length in the X direction of the first tank 21 of the third embodiment is approximately half the length in the X direction of the first tank 21 of the second embodiment. The length in the X direction of the second tank 22 is approximately the same as the length in the X direction of the first tank 21. The sum of the lengths in the X direction of the first tank 21 and the second tank 22 of the third embodiment is approximately the same as the length in the X direction of the first tank 21 of the second embodiment. The pair of first devices 41 are connected to the first tank 21. The second device 42 and the third device 43 are connected to the second tank 22.

[0036] An insulating spacer 33 is disposed between the first tank 21 and the second tank 22. The second tank 22 is disposed adjacent to the first tank 21 in the X direction via the insulating spacer 33. The first tank 21 and the second tank 22 are separated into different gas compartments by the insulating spacer 33. The insulating spacer 33 is formed of an insulating material such as resin. As shown in FIG. 8, the insulating spacer 33 supports the conductor 10. The conductor 10 is supported by the pair of insulating spacers 30 disposed at both ends in the X direction of the power supply and demand instrument transformer VCT, as well as the insulating spacer 33 disposed at the center in the X direction.

[0037] When a ground fault occurs in the gas-insulated switchgear GIS, a large current flows through the conductor 10. An electromagnetic force acts between each phase 11-13 of the conductor 10. The electromagnetic force acts in the YZ directions perpendicular to the X direction in which the conductor 10 extends. This may damage a pair of insulating spacers 30 that support the conductor 10 at both ends in the X direction. The power supply and demand potential transformer VCT is required to withstand a large fault current (short-time current withstand specification). Since the insulating spacer 33 is added to the center, the force acting on the insulating spacers 30 at both ends is dispersed. This improves the resistance of the power supply and demand potential transformer VCT.

[0038] In the embodiment, as an example, the power supply and demand voltage transformer VT (VCT) and the third power supply and demand current transformer CT (VCT) 3 are a pair of first devices 41, and the second power supply and demand current transformer CT (VCT) 2 is a second device 42. Alternatively, the power supply and demand voltage transformer VT (VCT) and the second power supply and demand current transformer CT (VCT) 2 may be a pair of first devices 41, and the third power supply and demand current transformer CT (VCT) 3 may be the second device. Also, the second power supply and demand current transformer CT (VCT) 2 and the third power supply and demand current transformer CT (VCT) 3 may be a pair of first devices 41, and the power supply and demand voltage transformer VT (VCT) may be the second device 42. In the embodiment, the second device 42 is disposed in the +X direction of the pair of first devices 41. In contrast, the second device 42 may be disposed in the -X direction of the pair of first devices 41.

[0039] According to at least one of the embodiments described above, at least a portion of each of the pair of first devices 41 is disposed so as to overlap with each other in the X direction. This makes it possible to reduce the size of the power supply and demand instrument transformer VCT.

[0040] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0041] ES...earthing switch, GIS...gas-insulated switchgear, CT (VCT)...current transformer for power supply and demand, C2, C3...connection point, VCT...electrical power supply and demand instrument transformer, VT...voltage transformer, VT (VCT)...electrical power supply and demand instrument transformer, V2, V3...connection point, 10...conductor, 20...tank unit, 21...first tank, 22...second tank, 33...insulating spacer, 41...first device, 42...second device, 43...third device.

Claims

1. an electric power supply and demand potential transformer and a plurality of electric power supply and demand current transformers; a tank unit that houses a conductor extending in a first direction and to which the power supply and demand potential transformer and the plurality of power supply and demand current transformers are connected; At least a pair of first devices among the devices included in the power supply and demand potential transformer and the plurality of power supply and demand current transformers are connected to one first tank included in the tank unit, The pair of first devices are disposed so that at least a portion of each of them overlaps with each other in the first direction, a second device, which is different from the pair of first devices among devices included in the power supply and demand potential transformer and the plurality of power supply and demand current transformers, is connected to the first tank; A third device, which is any one of an instrument transformer, a grounding switch, a voltage detector, and a current transformer for power supply and demand, is connected to the first tank; At least a portion of the second device and at least a portion of the third device are arranged to overlap each other in the first direction. Instrument transformer for power supply and demand.

2. The pair of first devices are disposed on opposite sides of the first tank.

2. The electric power supply and demand instrument transformer according to claim 1.

3. one of the pair of first devices is disposed above the first tank; The other of the pair of first devices is disposed below the first tank.

3. The electric power supply and demand instrument transformer according to claim 2.

4. one of the pair of first devices is disposed on one side of the first tank in a horizontal direction; The other of the pair of first devices is disposed on the other side of the first tank in the horizontal direction.

3. The electric power supply and demand instrument transformer according to claim 2.

5. the power supply and demand potential transformer and all of the plurality of power supply and demand current transformers are connected to the first tank; a connection point of the power supply and demand instrument transformer to the conductor is disposed on one side in the first direction with respect to connection points of the plurality of power supply and demand current transformers to the conductor; The electric power supply and demand instrument transformer according to any one of claims 1 to 4.

6. the tank unit includes a second tank disposed adjacent to the first tank in the first direction with an insulating spacer interposed therebetween, A second device, which is different from the pair of first devices among the devices included in the power supply and demand instrument transformer and the plurality of power supply and demand current transformers, is connected to the second tank. The electric power supply and demand instrument transformer according to any one of claims 1 to 4.

7. A power supply and demand instrument transformer according to any one of claims 1 to 6, Gas insulated switchgear.

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