Instrument transformer, gas-insulated switchgear, and removal method
The instrument transformer design addresses the challenge of removing inner conductors by ensuring a specific distance between inner conductor ends, enabling easy and cost-effective busbar removal without disturbing connected components.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2024-02-01
- Publication Date
- 2026-05-18
AI Technical Summary
Existing methods do not provide an efficient way to remove the inner conductor or inner bus from a transformer for instruments in a gas-insulated switchgear where the bus connection pipe and VCT connection pipe are connected.
The instrument transformer design includes a first return busbar with a first inner conductor and a first outer conductor, and contacts that allow the distance between the ends of the inner conductors to exceed the length of the inserted portion, enabling easy removal by moving the outer conductors toward the center and pulling the inner conductor out of the contact.
This design facilitates easy removal of the busbar from the instrument transformer, reducing man-hours, effort, and cost by allowing independent removal without affecting connected devices.
Smart Images
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Abstract
Description
Technical Field
[0001] One aspect of the present invention relates to a transformer for instruments and gas-insulated switchgear including the transformer for instruments.
Background Art
[0002] Patent Document 1 discloses a gas-insulated switchgear including a transformer for instruments (VCT, Voltage Current Transformer). In the gas-insulated switchgear of Patent Document 1, the inner bus of the coaxial bus arranged in the bus connection pipe and the inner conductor of the coaxial connection conductor arranged in the VCT connection pipe are connected via a contact.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In Patent Document 1, a method for removing the inner conductor or the inner bus in a state where the bus connection pipe and the VCT connection pipe are connected is not disclosed.
[0005] One aspect of the present invention aims to easily remove the bus from the transformer for instruments.
Means for Solving the Problems
[0006] An instrument transformer according to one aspect of the present invention comprises an instrument transformer that transforms voltage and current; a first return busbar electrically connected to the instrument transformer and having a first inner conductor and a first outer conductor located around the first inner conductor; and contacts located at each end of the first return busbar and electrically connecting the second inner conductor of a second return busbar having (1) the first inner conductor and (2) a second inner conductor and a second outer conductor located around the second inner conductor, wherein, when the first inner conductor and the second inner conductor are inserted into and fixed inside the contacts, the distance between the end of the first inner conductor and the end of the second inner conductor inside the contacts is greater than the length of the portion of the first inner conductor inserted into the contacts.
[0007] A removal method according to one aspect of the present invention comprises a first moving step of moving the first outer conductors located at each end of the first reciprocating busbar toward the center of the first reciprocating busbar along the first inner conductor, in a first reciprocating busbar which is electrically connected to an instrument transformer that transforms voltage and current and has a first inner conductor and a plurality of first outer conductors located around the first inner conductor, and a second inner conductor in a second reciprocating busbar which is located at each end of the first reciprocating busbar and has (1) the first inner conductor and (2) a second inner conductor and a second outer conductor located around the second inner conductor The process includes a second moving step of moving one of the contacts that electrically connect the first and second inner conductors in a direction that pulls the end of the first inner conductor out of the contact, wherein the second moving step pulls the end of the first inner conductor out of the contact by moving the first inner conductor by a distance greater than the length of the portion of the first inner conductor inserted into the contact, which is the distance between the end of the first inner conductor and the end of the second inner conductor inside the contact when the first inner conductor and the second inner conductor are inserted into and fixed inside the contact. [Effects of the Invention]
[0008] According to one aspect of the present invention, the busbar can be easily removed from the instrument transformer. [Brief explanation of the drawing]
[0009] [Figure 1] This is a side view showing a schematic configuration of a gas-insulated switchgear according to one embodiment. [Figure 2] This is a schematic cross-sectional view showing the terminal conductor configuration of a single-phase circuit in the internal structure of a three-phase circuit in an instrument transformer and its peripheral components according to one embodiment. [Figure 3] This is a schematic cross-sectional view showing the region containing the contactor. [Figure 4] This is a flowchart showing a method for removing a first busbar and an instrument transformer according to one embodiment. [Figure 5] This is a cross-sectional view schematically showing each region including the contact, and depicts the state in which the outer end conductor is moved toward the center of the first busbar. [Figure 6] This is a cross-sectional view schematically showing each region including the contact, and depicts the state in which one of the first inner conductor ends is drawn out from inside the contact. [Figure 7] This is a schematic side view of a gas-insulated switchgear as a comparative example, illustrating the removal of the first return busbar. [Modes for carrying out the invention]
[0010] Hereinafter, one embodiment of the present invention will be described in detail with reference to Figures 1 to 7. For the sake of explanation, the right side of the figure will be referred to as the right direction, the left side as the left direction, and the front side of the figure will be referred to as the front direction.
[0011] [Gas-insulated switchgear 100] Figure 1 is a side view showing the schematic configuration of a gas-insulated switchgear 100. The gas-insulated switchgear 100 is equipment installed in a substation. The inside of the container of the gas-insulated switchgear 100 is filled with insulating gas. As the insulating gas, for example, an environmentally friendly gas may be used. Environmentally friendly gases may be, for example, fluoronitrile, dry air, N2, CO2, O2, CF4, fluoroketones, or gases mixed therewith. In addition, for example, SF6 may be used as the insulating gas.
[0012] As shown in Figure 1, the gas-insulated switchgear 100 includes, for example, an instrument transformer 1, a connecting conduit 6, and a gas-insulated switchgear 7. In the gas-insulated switchgear 100 shown in Figure 1, two gas-insulated switchgears 7 are positioned opposite each other with respect to the instrument transformer 1. Each of the two gas-insulated switchgears 7 is electrically connected to the instrument transformer 1 via the connecting conduit 6. The gas-insulated switchgear 100 can be configured such that the instrument transformer 1 is positioned between the two gas-insulated switchgears 7, and each of the two gas-insulated switchgears 7 is electrically connected to the instrument transformer 1.
[0013] The instrument transformer 1 is a device that transforms the voltage and current of an AC circuit into low voltage and low current, respectively. The gas-insulated switchgear 7 is a device that electrically protects the substation and includes, for example, busbars, circuit breakers, disconnectors, grounding switches, and lightning arresters. The connecting conduit 6 is located in the gap between the instrument transformer 1 and the gas-insulated switchgear 7 and connects the instrument transformer 1 and the gas-insulated switchgear 7.
[0014] [Instrumental transformer 1 and its peripheral components] The internal structure of the instrument transformer 1 and its surrounding components will be explained using Figure 2. Figure 2 is a schematic cross-sectional view showing the terminal conductor configuration of a single-phase circuit in the three-phase circuit internal structure of the instrument transformer 1 and its surrounding components.
[0015] <Instrumental transformer 1> As shown in FIG. 2, the instrument transformer 1 includes, for example, an instrument transformer 10, a first reciprocating bus 11, a contact 16, a first connection conductor 17, and a second connection conductor 18.
[0016] The instrument transformer 10 is a member that transforms voltage and current. The instrument transformer 10 is composed of, for example, an instrument voltage transformer and a current transformer. The instrument transformer 10 is electrically connected to the first reciprocating bus 11.
[0017] The first reciprocating bus 11 is electrically connected to the second reciprocating bus 30 provided in the connection pipeline 6. The first reciprocating bus 11 includes a first inner conductor 12 and a first outer conductor 13.
[0018] The first inner conductor 12 may have a shape that is inserted into the contacts 16 located at both ends thereof and is electrically connected to the contacts 16. For example, it may be a cylindrical rod-shaped member. Further, the first inner conductor 12 may have a shape that is movable in the insertion and extraction direction when both ends thereof are inserted into the inside of each contact 16. Further, the first inner conductor 12 may have flexibility.
[0019] The first inner conductor 12 is electrically connected to the instrument transformer 10 by the second connection conductor 18. The first inner conductor 12 and the second connection conductor 18 are fixed by a second bolt 20 via the first outer conductor 13 (specifically, the central outer conductor 132 and the pipe 133). However, the second connection conductor 18 is electrically insulated from the first outer conductor 13. By removing the second bolt 20, the first inner conductor 12 can move in the left-right direction.
[0020] The first outer conductor 13 is a conductor that is arranged coaxially with the first inner conductor 12 and is positioned to cover the periphery of the first inner conductor 12. That is, the first inner conductor 12 is inserted through the inside of the first outer conductor 13. The first outer conductor 13 is, for example, a cylindrical member and may be, for example, a substantially cylindrical member. [[ID=In this embodiment, the first busbar 11 comprises a plurality of first outer conductors 13. Each of the plurality of first outer conductors 13 functions as an end outer conductor 131, a central outer conductor 132, and a pipe 133.
[0022] The end outer conductors 131 are conductors located at both ends of the first busbar 11, among a plurality of first outer conductors 13. The end outer conductors 131 are physically connected and fixed to connecting conductors 8 (described later), which are provided inside the insulating spacer 5, by bolts (not shown). When the bolts are removed and the fixing to the connecting conductors 8 is released, the end outer conductors 131 are installed so as to be movable toward the center of the first busbar 11.
[0023] The central outer conductor 132 is a conductor located in the center of the first return busbar 11 in the axial direction. The central outer conductor 132 is electrically connected to the instrument transformer 10 by the first connecting conductor 17. The central outer conductor 132 does not have to be located in the center of the first return busbar 11 in the axial direction. The central outer conductor 132 may be located at any position between the two end outer conductors 131, as long as it is electrically connected to the instrument transformer 10 by the first connecting conductor 17.
[0024] The central outer conductor 132 and the first connecting conductor 17 are fixed together by a first bolt 19. The central outer conductor 132 is composed of two conductors, and these two conductors are fixed together by bolts (not shown). After removing the first bolt 19 and the second bolt 20, the central outer conductor 132 can be disassembled and removed from the instrument transformer 1 by removing these bolts.
[0025] The pipe 133 is positioned to cover the first inner conductor 12 and is located on the side of the first inner conductor 12 that is greater than the end outer conductor 131 and the central outer conductor 132. The pipe 133 allows for the electrical connection between the end outer conductor 131 and the central outer conductor 132.
[0026] The contactor 16 is a component that electrically connects the first inner conductor 12 and the second inner conductor 31, which constitutes the second reciprocating busbar 30. The contactor 16 is located at each of the two ends of the first inner conductor 12. The positional relationship between the first inner conductor 12 and the second inner conductor 31 is fixed in the state in which the contactor 16 is inserted inside. The contactor 16 is, for example, a cylindrical member, and may be, for example, a substantially cylindrical member. In this case, the inner surface of one opening side of the contactor 16 is in contact with the outer surface of the first inner conductor 12, and the inner surface of the other opening side of the contactor 16 is in contact with the outer surface of the second inner conductor 31. In this way, the first inner conductor 12 and the second inner conductor 31 are electrically connected via the contactor 16.
[0027] <Adapter 4, insulating spacer 5, and connecting conduit 6> As shown in Figure 2, the gas-insulated switchgear 100 includes an adapter 4, an insulating spacer 5, and a connecting conduit 6 as peripheral components of the instrument transformer 1.
[0028] The connecting conduit 6 contains a portion of the second return busbar 30. In Figure 2, the second return busbar 30 is electrically connected to the first return busbar 11, which is electrically connected to the instrument transformer 10. The second return busbar 30 is also electrically connected to a busbar (not shown) provided by the gas-insulated switchgear 7. Therefore, the instrument transformer 10 and the gas-insulated switchgear 7 are electrically connected via the first return busbar 11 and the second return busbar 30.
[0029] The second busbar 30 comprises a second inner conductor 31 and a second outer conductor 32. The second inner conductor 31 only needs to have a shape that allows it to be inserted into the contact 16 and electrically connected to the contact 16, and may be, for example, a cylindrical rod-shaped member. The second inner conductor 31 is fixed by a positioning retaining ring 53, and is movable toward the connecting conduit 6 when the fixing with the positioning retaining ring 53 is released. The second outer conductor 32 is a conductor arranged coaxially with the first inner conductor 12 and positioned to surround the second inner conductor 31. In other words, the second inner conductor 31 is inserted inside the second outer conductor 32. The second outer conductor 32 is, for example, a cylindrical member, and may be, for example, a substantially cylindrical member. The second outer conductor 32 is physically connected and fixed to a connecting conductor 8 provided inside the insulating spacer 5 by a bolt (not shown).
[0030] The busbar (not shown) of the gas-insulated switchgear 7 is also a return busbar comprising an inner conductor and an outer conductor located around it. The second return busbar 30 is electrically connected to the busbar of the gas-insulated switchgear 7 by the second inner conductor 31 being electrically connected to the inner conductor of the gas-insulated switchgear 7 via a contact 16.
[0031] The insulating spacer 5 is located between the instrument transformer 1 and the connecting conduit 6 and is a member (insulator) that blocks the electrical connection between the outer wall of the instrument transformer 1 and the outer wall of the connecting conduit 6 and the connecting conductor 8. The connecting conductor 8 is located between the instrument transformer 1 and the connecting conduit 6 (in this embodiment, inside the insulating spacer 5) and is a conductor that electrically connects the first outer conductor 13 and the second outer conductor 32. The connecting conductor 8 has a through hole through which the second inner conductor 31 can be inserted. The through hole is larger than the diameter of the second inner conductor 31 and smaller than the diameters of the first outer conductor 13 and the second outer conductor 32. As a result, the first inner conductor 12 and the second inner conductor 31 are electrically connected.
[0032] Furthermore, the insulating spacer 5 has a protrusion 51 on a part of its surface facing the instrument transformer 1, which protrudes relative to the instrument transformer 1. In addition, the insulating spacer 5 has a protrusion 52 on a part of its surface facing the connecting conduit 6, which protrudes relative to the connecting conduit 6.
[0033] The protrusion 51 protrudes from the surrounding surface by a length L. The protrusion 52 also protrudes from the surrounding surface by a length L. However, the protrusion amounts of the protrusions 51 and 52 may be different from each other. In addition, although the protrusions 51 and 52 are located in the center of the insulating spacer 5, the positions of the protrusions 51 and 52 are not particularly limited, and the protrusions 51 and 52 should be formed in a position that can insulate the outer wall of the instrument transformer 1 and the outer wall of the connecting conduit 6 from the connecting conductor 8. The presence of the protrusions 51 and 52 in the insulating spacer 5 improves the insulation between the outer wall of the instrument transformer 1 and the outer wall of the connecting conduit 6 and the connecting conductor 8.
[0034] The adapter 4 is located between the instrument transformer 1 and the insulating spacer 5 and has a housing space MR capable of accommodating the protrusion 51 of the insulating spacer 5. The adapter 4 is, for example, a cylindrical member, and may be, for example, a substantially cylindrical member. The length M is the length between the two openings in the adapter 4. This length M is the length of the housing space MR in the direction of protrusion of the protrusion 51 (the direction of insertion of the protrusion 51 into the housing space MR) when the adapter 4 is located between the instrument transformer 1 and the insulating spacer 5.
[0035] When the protrusion 51 is housed in the housing space MR, the length M of the housing space MR is greater than the length L of the protruding protrusion 51. As a result, when the insulating spacer 5 is placed between the instrument transformer 1 and the connecting conduit 6, the protrusion 51 does not enter the interior of the instrument transformer 1. Therefore, when removing only the instrument transformer 1 in the forward direction, the insulating spacer 5 does not interfere with the instrument transformer 1.
[0036] Therefore, the adapter 4 only needs to be placed if the insulating spacer 5 has a protrusion 51 on at least a part of the surface on the instrument transformer 1 side. For example, even if the insulating spacer 5 does not have a protrusion 52, if it has a protrusion 51, the adapter 4 may be placed between the instrument transformer 1 and the insulating spacer 5. On the other hand, if the insulating spacer 5 does not have a protrusion 51 on the instrument transformer 1 side, the adapter 4 does not need to be placed between the instrument transformer 1 and the insulating spacer 5, regardless of the presence or absence of a protrusion 52.
[0037] [Positional relationship between the first reciprocating busbar 11 and the second reciprocating busbar 30 inside the contactor 16] The positional relationship between the contactor 16, the first busbar 11, and the second busbar 30 will be explained using Figure 3. Figure 3 is a schematic cross-sectional view showing the right-hand region AR1, which includes the contactor 16. The left-hand region AR2 has the same structure.
[0038] As shown in Figure 3, the first inner conductor 12 and the second inner conductor 31 are fixed with the first inner conductor end 121 and the second inner conductor end 311 inserted inside the contact 16. The first inner conductor end 121 is the end of the first inner conductor 12, and the second inner conductor end 311 is the end of the second inner conductor 31.
[0039] In this state, if we let distance X be the distance between the first inner conductor end 121 and the second inner conductor end 311 inside the contact 16, and length Y be the length of the portion of the first inner conductor 12 inserted into the contact 16, then distance X is greater than length Y. The length of the first busbar 11 and the positional relationship between the first busbar 11, the second busbar 30, and the contact 16 are defined such that distance X is greater than length Y.
[0040] In each of the two contacts 16, the positional relationship between the first busbar 11 and the second busbar 30 is defined such that the distance X is greater than the length Y. Therefore, it becomes possible to pull out the first inner conductor end 121 from inside one of the contacts 16. After pulling out the first inner conductor end 121 from inside one contact 16, the first inner conductor end 121 of the other contact 16 can be pulled out from inside the other contact 16, thereby making it possible to remove the first inner conductor 12 from the instrument transformer 1.
[0041] In this way, the first inner conductor 12 can be drawn out from the contact 16 using a simple method, making it possible to easily remove the first return busbar 11 from the instrument transformer 1. The fact that the distance X is greater than the length Y makes it possible to draw out the end 121 of the first inner conductor from inside the contact 16 will be explained in detail below.
[0042] [Method for removing the first busbar 11 and the instrument transformer 1] The removal method for the first return busbar 11 and the instrument transformer 1 will be explained using Figures 4 to 6. Figure 4 is a flowchart of the removal method for the first return busbar 11 and the instrument transformer 1. Figure 5 is a schematic cross-sectional view showing each region AR1 and AR2 including the contact 16, and shows the state in which the outer end conductor 131 has been moved toward the center of the first return busbar 11. Figure 6 is a schematic cross-sectional view showing each region AR1 and AR2 including the contact 16, and shows the state in which one of the first inner conductor ends 121 has been pulled out from inside the contact 16.
[0043] First, the worker removes conductors other than the first busbar 11 from the instrument transformer 1 (S1). Specifically, the worker removes components other than the first connecting conductor 17 and the second connecting conductor 18, which are fixed to the first busbar 11 by the first bolt 19 and the second bolt 20. As a result of step S1, as shown in Figure 2, the first busbar 11 remains inside the instrument transformer 1 without being removed from it.
[0044] Next, the worker removes the first bolt 19 that secures the first inner conductor 12 and the second bolt 20 that secures the central outer conductor 132 (S2). By removing the second bolt 20, the first inner conductor 12 can be moved in its axial direction. Also, by removing the first bolt 19 and the second bolt 20, the central outer conductor 132 can be disassembled.
[0045] Next, the worker removes the bolts (not shown) that secure the end outer conductors 131 to the connecting conductor 8 at each end of the first reciprocating busbar 11 (S3). This allows each of the two end outer conductors 131 to move towards the center of the first reciprocating busbar 11 along the first inner conductor 12.
[0046] Next, the operator moves each of the two outer end conductors 131 toward the center of the first reciprocating busbar 11 along the first inner conductor 12 (S4; first moving step). By moving the outer end conductors 131 toward the center of the first reciprocating busbar 11, the outer end conductors 131 that protrude outside the instrument transformer 1 can be retracted into the instrument transformer 1 beyond the contactor 16, as shown in Figure 5.
[0047] Next, the worker moves the first inner conductor 12 in either the left or right direction, thereby drawing out the first inner conductor end 121 from inside one of the contactors 16 (S5; second movement step). In S5, the worker moves in a direction that draws out the first inner conductor end 121 from inside one of the contactors 16. As described above, the distance X is greater than the length Y. Therefore, this movement allows the first inner conductor end 121 to be drawn out from one of the contactors 16.
[0048] Figure 6 shows an example of moving the first inner conductor end 121 in a direction that pulls it out from inside the contactor 16. As shown in Figure 6, when the first inner conductor 12 is moved to the left, the first inner conductor 12 can be moved to the left by a distance X. Since the distance X is greater than the length Y, in the right region AR1, the first inner conductor end 121 is pulled out to the outside of the contactor 16 before it comes into contact with the second inner conductor end 311 in the left region AR2. When the first inner conductor 12 is moved to the right, the first inner conductor end 121 is also pulled out to the outside of the contactor 16 in the left region AR2.
[0049] Next, the worker pulls out the first inner conductor end 121 from inside the other contact 16 (S6). In Figure 6, the worker tilts the first inner conductor end 121, which has been pulled out from inside the contact 16 in the right-hand region AR1, toward the front of the instrument transformer 1, while moving the first inner conductor 12 to the right. As a result, the first inner conductor end 121 is also pulled out from inside the contact 16 in the left-hand region AR2. In this way, the worker can remove the first reciprocating busbar 11 from the instrument transformer 1.
[0050] Next, the worker removes the contactor 16 and the positioning retaining ring 53 (S7; removal process). This allows the second inner conductor 31 to be moved toward the connecting conduit 6. Next, the worker moves the second inner conductor 31 toward the connecting conduit 6 and pulls out the second inner conductor end 311 from the instrument transformer 1 (S8; pull-out process). This allows the second inner conductor end 311 to fit into the housing space MR defined by length M. In this way, the worker can remove the first reciprocating busbar 11 from the instrument transformer 1 and eliminate the protrusions in the cut-out section of the instrument transformer 1. The protrusions in the cut-out section refer to the parts that protrude from the outer wall of the instrument transformer 1 (contactor 16, end outer conductor 131, and second inner conductor end 311).
[0051] Next, the worker moves only the instrument transformer 1 without moving the external devices that were electrically connected to the instrument transformer 1, namely the connecting conduit 6 and the gas-insulated switchgear 7 (S9; third moving step). This allows the instrument transformer 1 to be removed towards the worker without moving the connecting conduit 6 and the gas-insulated switchgear 7.
[0052] [Comparison with gas-insulated switchgear 700] The gas-insulated switchgear 100 will be explained in comparison with the gas-insulated switchgear 700. Figure 7 is a schematic side view of the gas-insulated switchgear 700 as a comparative example, and is a diagram for explaining the removal of the first return busbar 711.
[0053] The gas-insulated switchgear 700 comprises an instrument transformer 701, a connecting conduit 706, and gas-insulated switchgear 707. The gas-insulated switchgear 700 has two gas-insulated switchgear 707 positioned opposite each other with respect to the instrument transformer 701. Each of the two gas-insulated switchgear 707 is electrically connected to the instrument transformer 701 via the connecting conduit 706.
[0054] The instrument transformer 701 is equipped with a first return busbar 711. The first return busbar 711 protrudes from inside the instrument transformer 701 toward the connecting conduit 706. The gas-insulated switchgear 707 is equipped with a return busbar 771. The return busbar 771 also protrudes from the gas-insulated switchgear 707 toward the connecting conduit 706. The connecting conduit 706 is equipped with a second return busbar (not shown). The first return busbar 711 and the return busbar 771 are electrically connected via the second return busbar.
[0055] Here, when removing the instrument transformer 701 for maintenance, it would be ideal to pull only the instrument transformer 701 forward. However, because the first return busbar 711 protrudes, it interferes with the connecting conduit 706, making it impossible to pull the instrument transformer 701 forward.
[0056] Furthermore, in the instrument transformer 701, similar to the instrument transformer 1, the first inner conductor constituting the first return busbar 711 and the second inner conductor constituting the second return busbar are electrically connected via a contact. However, in the instrument transformer 701, the distance X between the end of the first inner conductor and the end of the second inner conductor inside the contact is less than or equal to the length Y of the portion of the first inner conductor inserted into the contact. Therefore, even if the first inner conductor is moved in the left-right direction, the end of the first inner conductor cannot be pulled out from inside the contact, and the first return busbar 711 cannot be removed from the instrument transformer 701.
[0057] Therefore, in order to remove the instrument transformer 701, for example, it is necessary to first move the right-side gas-insulated switchgear 707 to the right, then move the right-side connecting conduit 706 to the right, and then move the instrument transformer 701 to the right. Alternatively, it is necessary to move the right-side gas-insulated switchgear 707 to the right, then move the right-side connecting conduit 706 to the right, while simultaneously moving the left-side gas-insulated switchgear 707 to the left, and then move the left-side connecting conduit 706 to the left.
[0058] Thus, in the gas-insulated switchgear 700, the instrument transformer 701 cannot be removed independently, requiring the removal of the gas-insulated switchgear 707 and the connecting conduit 706, which incurs considerable time and effort. Furthermore, such removal requires a significant amount of time and expense.
[0059] On the other hand, in the gas-insulated switchgear 100, the positional relationship between the first inner conductor 12 and the second inner conductor 31 is defined such that the distance X is greater than the length Y. Therefore, by moving the first inner conductor 12 and the end outer conductor 131 along the first reciprocating busbar 11, it becomes possible to remove the first reciprocating busbar 11 from the instrument transformer 1. Then, by moving the second inner conductor 31 towards the connecting conduit 6, the end 311 of the second inner conductor can be placed in the accommodation space MR defined by length M. Consequently, the instrument transformer 1 can be removed in the forward direction without moving the connecting conduit 6 and the gas-insulated switchgear 7 as described above. This reduces the man-hours, effort, time, and cost of removing the instrument transformer 1.
[0060] 〔summary〕 An instrument transformer according to Embodiment 1 of the present disclosure comprises: an instrument transformer for transforming voltage and current; a first return busbar electrically connected to the instrument transformer and having a first inner conductor and a first outer conductor located around the first inner conductor; and contacts located at each end of the first return busbar and electrically connecting the second inner conductor of a second return busbar having (1) the first inner conductor and (2) a second inner conductor and a second outer conductor located around the second inner conductor, wherein, in a state in which the first inner conductor and the second inner conductor are inserted into and fixed inside the contacts, the distance between the end of the first inner conductor and the end of the second inner conductor inside the contacts is greater than the length of the portion of the first inner conductor inserted into the contacts.
[0061] In the instrument transformer according to Embodiment 2 of the present disclosure, in Embodiment 1, the first busbar comprises a plurality of first outer conductors, and of the plurality of first outer conductors, the first outer conductors located at each end of the first busbar are installed to be movable toward the center of the first busbar in an unfixed state.
[0062] A gas-insulated switchgear according to Embodiment 3 of the present disclosure comprises an instrument transformer as in Embodiment 1 or 2, a second reciprocating busbar, and a gas-insulated switchgear electrically connected to the instrument transformer via the first reciprocating busbar and the second reciprocating busbar.
[0063] The gas-insulated switchgear according to Embodiment 4 of the present disclosure, in Embodiment 3, comprises: a connecting conduit that connects the instrument transformer and the gas-insulated switchgear, with a portion of the second reciprocating busbar located inside; a connecting conductor located between the instrument transformer and the connecting conduit, which electrically connects the first outer conductor and the second outer conductor; an insulating spacer located between the instrument transformer and the connecting conduit, which interrupts the electrical connection between the outer wall of the instrument transformer and the outer wall of the connecting conduit and the connecting conductor, and which has a protrusion on at least a portion of the surface on the instrument transformer side; and an adapter located between the instrument transformer and the insulating spacer, which has a housing space capable of accommodating the protrusion, wherein the length of the housing space in the direction of protrusion of the protrusion is greater than the length of the protrusion in the direction of protrusion of the protrusion.
[0064] A removal method according to aspect 5 of the present disclosure is a first moving step of moving a first outer conductor located at each end of the first reciprocating bus toward the center of the first reciprocating bus along the first inner conductor, in a first reciprocating bus having a first inner conductor and a plurality of first outer conductors located around the first inner conductor, which is electrically connected to an instrument transformer that transforms voltage and current, and a second inner conductor in a second reciprocating bus having (1) the first inner conductor and (2) a second inner conductor and a second outer conductor located around the second inner conductor The process includes a second moving step of moving one of the contacts that electrically connect the first and second inner conductors in a direction that pulls the end of the first inner conductor out of the inside of the contact, wherein the second moving step pulls the end of the first inner conductor out of the inside of the contact by moving the first inner conductor by a distance greater than the length of the portion of the first inner conductor inserted into the contact, where the first inner conductor and the second inner conductor are inserted into and fixed inside the contact.
[0065] A removal method according to aspect 6 of the present disclosure, in aspect 5, includes a removal step of removing the contact from an instrument transformer comprising the instrument transformer, the first reciprocating busbar, and the contact; a pull-out step of pulling out the end of the second inner conductor to the outside of the instrument transformer; and a third moving step of moving only the instrument transformer without moving any external devices that were electrically connected to the instrument transformer.
[0066] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]
[0067] 100 Gas-insulated switchgear 1. Instrument transformer 10 Instrument transformers 11 1st round trip busbar 12 First inner conductor 121 First inner conductor end (end of the first inner conductor) 13. First outer conductor 131 End outer conductor (first outer conductor) 132 Central outer conductor (first outer conductor) 16 Contactor 30 2nd round trip busbar 31 Second inner conductor 311 End of second inner conductor (end of second inner conductor) 32 Second outer conductor 4 adapters 5. Insulating spacer 51 Convex part 6. Connecting conduits 7. Gas-insulated switchgear 8 connecting conductors X Distance between the first inner conductor end and the second inner conductor end Y Length of the portion of the first inner conductor that is inserted into the contact MR accommodation space M Length of the storage space Length of the protruding portion L
Claims
1. Instrument transformers that change voltage and current, A first round-trip busbar is electrically connected to the instrument transformer and has a first inner conductor and a first outer conductor located around the first inner conductor, The first busbar is located at each end of the first busbar and comprises contacts that electrically connect (1) the first inner conductor and (2) the second inner conductor of the second busbar, which has a second inner conductor and a second outer conductor located around the second inner conductor, An instrument transformer in which, in a state in which the first inner conductor and the second inner conductor are inserted and fixed inside the contact, the distance between the end of the first inner conductor and the end of the second inner conductor inside the contact is greater than the length of the portion of the first inner conductor inserted inside the contact.
2. The first busbar comprises a plurality of the first outer conductors, The instrument transformer according to claim 1, wherein, among the plurality of first outer conductors, the first outer conductors located at each end of the first return bus are installed in a non-fixed state so as to be movable toward the center of the first return bus.
3. An instrument transformer according to claim 1 or 2, The aforementioned second round-trip busbar, A gas-insulated switchgear comprising a gas-insulated switchgear electrically connected to the instrument transformer via the first and second busbars.
4. A portion of the second reciprocating busbar is provided internally, and a connecting conduit connects the instrument transformer and the gas-insulated switchgear, A connecting conductor located between the instrument transformer and the connecting conduit, electrically connecting the first outer conductor and the second outer conductor, An insulating spacer located between the instrument transformer and the connecting conduit, which interrupts the electrical connection between the outer wall of the instrument transformer and the outer wall of the connecting conduit and the connecting conductor, wherein the insulating spacer has a protrusion on at least a part of the surface on the instrument transformer side, The adapter is located between the instrument transformer and the insulating spacer and has a housing space capable of accommodating the protrusion, The gas-insulated switchgear according to claim 3, wherein the length of the housing space in the direction of protrusion of the protrusion is greater than the length of the protrusion in the direction of protrusion.
5. A first reciprocating busbar is electrically connected to an instrument transformer that transforms voltage and current, and has a first inner conductor and a plurality of first outer conductors located around the first inner conductor, wherein a first moving step is performed to move the first outer conductors located at each end of the first reciprocating busbar toward the center of the first reciprocating busbar along the first inner conductor, The method includes a second moving step of moving one of the contacts located at each end of the first busbar, which electrically connects the second inner conductor of a second busbar having (1) the first inner conductor and (2) the second inner conductor and a second outer conductor located around the second inner conductor, in a direction that pulls out the end of the first inner conductor from inside the contact, In the second moving step, the removal method involves moving the first inner conductor by a distance greater than the length of the portion of the first inner conductor inserted into the contact, which is the distance between the end of the first inner conductor and the end of the second inner conductor inside the contact, while the first inner conductor and the second inner conductor are inserted into and fixed inside the contact, thereby pulling out the end of the first inner conductor from inside the contact.
6. A removal step of removing the contact from an instrument transformer comprising the instrument transformer, the first reciprocating busbar, and the contact, A drawing-out step of leading the end of the second inner conductor to the outside of the instrument transformer, The removal method according to claim 5, comprising a third moving step of moving only the instrument transformer without moving any external devices that were electrically connected to the instrument transformer.