An external independent CT unit structure of a power transformer current transformer

Abstract

The utility model relates to electric appliance technical field mainly discloses a kind of external independent CT unit structure of power transformer current transformer, including CT casing, first epoxy cover and second epoxy cover, the middle part of first epoxy cover is equipped with first center insert, the middle part of second epoxy cover is equipped with second center insert, the inside of CT casing is equipped with the electrically conductive rod of coaxial heart arrangement, and the both ends of electrically conductive rod are respectively fixedly installed with first contact seat and second contact seat.The external structure of the transformer body of the current transformer of the application is stripped, and the installation limitation of the transformer is separated, is not affected by the temperature drift generated by the temperature change of transformer body, only needs to hit the air chamber where it is when overhauling, and can be filled after overhauling, greatly reduce the outline dimension of transformer, save installation space, save installation cost.

Description

Technical Field

[0001] This utility model relates to the technical field of electrical equipment, and in particular to an external independent CT unit structure for power transformer current transformers. Background Technology

[0002] Currently, conventional power transformers use bushing-type current transformers. The current transformer is installed in the riser bracket at the tail of the bushing, with a baffle welded inside. After the current transformer is placed, a pressure plate is installed on top for fixation. If there are many transformer groups, high-precision current transformers, and large dimensions, and the bushings must all be placed in the riser bracket, the riser bracket will become very large, increasing not only the manufacturing and installation difficulty but also the overall size of the transformer.

[0003] Current transformers are installed inside the riser of the transformer's side oil tank. If maintenance, inspection, or replacement is required, the transformer must be drained and the relevant bushings and riser must be disassembled before any operation can be carried out. Furthermore, the installation of this type of transformer is limited by the transformer's installation environment and schedule. In the past, current transformers were installed inside GIL pipes, but due to inconsistent insulation levels, the gas chamber pressure was not uniform. In addition, current transformers are usually installed in power supply equipment, which is often in a high-temperature, high-humidity, and highly corrosive environment. These extreme conditions can damage the internal parts and insulation materials of the current transformer.

[0004] No effective solutions have yet been proposed to address the problems in the relevant technologies. Utility Model Content

[0005] To address the problems mentioned in the background art, this application provides an external independent CT unit structure for power transformer current transformers.

[0006] This application provides an external independent current transformer (CT) unit structure for a power transformer, which adopts the following technical solution: An external independent current transformer (CT) unit structure for a power transformer includes a CT housing. A first epoxy cover and a second epoxy cover are fixedly installed at both ends of the CT housing. A first mounting hole is formed in the middle of the first epoxy cover, and a first central insert is fixedly installed within the first mounting hole. A second mounting hole is formed in the center of the second epoxy cover, and a second central insert is fixedly installed within the second mounting hole. A conductive rod is coaxially arranged inside the CT housing. A first contact and a second contact are fixedly installed at both ends of the conductive rod. The end of the first contact away from the conductive rod is fixedly connected to the first central insert, and the end of the second contact away from the conductive rod is connected to the second central insert. The conductive rod acts as a current-carrying conductor. The current transformer is cast integrally within the conductive rod, eliminating the need for installation. This unit structure is installed at the transformer outlet and connected to the transformer bushing or bushing via a metal conductor to monitor the current. The SF6 in the independent unit busbar provides better insulation protection, and it does not share a gas chamber with the current transformer (GIL), using an independent gas chamber without affecting the operation of the GIL.

[0007] Furthermore, a transition block is fixedly installed at the end of the second contact away from the conductive rod, and the second contact is fixedly connected to the second central insert through the transition block.

[0008] Furthermore, the CT housing has a first mounting port and a second mounting port on its side wall. A cover plate is fixedly installed on the outside of the first mounting port, and an adsorbent cover is fixedly installed on the end face of the cover plate facing the inside of the first mounting port. The adsorbent cover can be filled with desiccant or the like to ensure the dryness of the inside of the CT housing.

[0009] Furthermore, a wiring terminal is fixedly installed on the outside of the second mounting port, a wiring cover is fixedly installed on the outside of the wiring terminal, and a wiring cap is fixedly installed on the end of the wiring cover away from the second mounting port.

[0010] Furthermore, a support block is fixedly installed on the inner wall of the CT housing, the support block is located close to the first epoxy mask, and a shielding cylinder is also provided inside the CT housing. An annular plate is fixedly installed at one end of the shielding cylinder close to the first epoxy mask, the annular plate is fixedly installed on the support block, the shielding cylinder is sleeved on the outside of the conductive rod, and a shielding ring is fixedly installed at the end of the shielding cylinder away from the annular plate.

[0011] Furthermore, a first flange ring is fixedly installed on the outside of the first epoxy mask, and a first assembly ring is integrally provided on the outer side wall of the CT housing near the first epoxy mask. The first epoxy mask is fixedly installed on the first assembly ring through the first flange ring, and a first nameplate is installed on the outer wall of the first flange ring.

[0012] Furthermore, a second flange ring is fixedly installed on the outside of the second epoxy cover, and a second assembly ring is integrally provided on the inner wall of the CT housing near the second epoxy cover. The second epoxy cover is fixedly connected to the second assembly ring through the second flange ring, and a second nameplate is installed on the outer wall of the second flange ring.

[0013] Furthermore, both the first epoxy mask and the second epoxy mask have a protrusion at their center. The protrusion on the first epoxy mask is located away from the CT housing, while the protrusion on the second epoxy mask is located towards the inside of the CT housing.

[0014] Compared with the prior art, this application has the following beneficial effects: This application separates the instrument transformer from the transformer body and installs it in a separate housing. This housing is not limited by the transformer structure or the transformer installation schedule. It does not require oil filling or bushing installation. It adopts a cast-in-place method, which can also eliminate the need for later installation of the instrument transformer. The SF6 in the independent unit busbar of the instrument transformer provides better insulation performance protection. It does not share a gas chamber with the GIL and uses an independent gas chamber, which does not affect the operation of the GIL.

[0015] By separating the current transformer from the transformer body and placing it externally, the transformer is freed from installation limitations and is not affected by temperature drift caused by changes in the transformer body's temperature. During maintenance, only the air chamber where the current transformer is located needs to be vented, and air can be replenished after maintenance. This greatly reduces the transformer's external dimensions, saves installation space, and reduces installation costs. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of an external independent CT unit structure for a power transformer current transformer according to an embodiment of this application; Figure 2 This is a cross-sectional structural schematic diagram of an external independent CT unit structure for a power transformer current transformer according to an embodiment of this application; Figure 3 This is a schematic diagram of the CT housing in an external independent CT unit structure for a power transformer current transformer according to an embodiment of this application; Figure 4 This is a schematic diagram of the shielding cylinder in an external independent CT unit structure for a power transformer current transformer according to an embodiment of this application; Figure 5This is a schematic diagram of the conductive rod in an external independent CT unit structure for a power transformer current transformer according to an embodiment of this application; Figure 6 This is a schematic diagram of the structure of the first epoxy cover in an external independent CT unit structure for a power transformer current transformer according to an embodiment of this application; Figure 7 This is a schematic diagram of the structure of the second epoxy cover in an external independent CT unit structure for a power transformer current transformer according to an embodiment of this application; Figure 8 This is a schematic diagram of the wiring cover in an external independent CT unit structure for a power transformer current transformer according to an embodiment of this application; Figure 9 This is a schematic diagram of the adsorbent cover in an external independent CT unit structure for a power transformer current transformer according to an embodiment of this application; Figure 10 This is a schematic diagram of an external independent CT unit structure for a power transformer current transformer installed on a transformer, according to an embodiment of this application.

[0018] Figure label: 1. CT housing; 101. First assembly ring; 102. Second assembly ring; 2. First mounting port; 3. Second mounting port; 4. Cover plate; 5. Adsorbent cover; 6. Terminal block; 7. Wiring cover; 8. Wiring cap; 9. First epoxy cover; 10. Second epoxy cover; 11. Support block; 12. Shielding cylinder; 13. Annular plate; 14. Shielding ring; 15. Conductive rod; 16. First contact seat; 17. Second contact seat; 18. Transition block; 19. First mounting hole; 20. First center insert; 21. First flange ring; 22. First nameplate; 23. Second mounting hole; 24. Second center insert; 25. Second flange ring; 26. Second nameplate; 100. Oil tank assembly; 200. Tank cover; 300. Cable outlet device. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] This application discloses an external independent CT unit structure for a power transformer current transformer, referring to... Figure 1-9The CT housing includes a CT shell 1. A first epoxy cover 9 and a second epoxy cover 10 are fixedly installed at both ends of the CT shell 1. A first mounting hole 19 is opened in the middle of the first epoxy cover 9. A first central insert 20 is fixedly installed in the first mounting hole 19. A second mounting hole 23 is opened in the center of the second epoxy cover 10. A second central insert 24 is fixedly installed in the second mounting hole 23. A conductive rod 15 is coaxially arranged inside the CT shell 1. A first contact seat 16 and a second contact seat 17 are fixedly installed at both ends of the conductive rod 15. The end of the first contact seat 16 away from the conductive rod 15 is fixedly connected to the first central insert 20. The end of the second contact seat 17 away from the conductive rod 15 is connected to the second central insert 24.

[0021] The conductive rod 15 acts as a current-carrying conductor. The current transformer is cast into the conductive rod 15 as a whole, which can achieve installation-free operation. This unit structure is installed at the transformer outlet and connected to the transformer outlet bushing or basin through a metal conductor to achieve the purpose of monitoring the current. The SF6 in the independent unit busbar of the current transformer provides better insulation performance protection. It does not share a gas chamber with the GIL and uses an independent gas chamber, which does not affect the operation of the GIL.

[0022] A transition block 18 is also fixedly installed at the end of the second contact 17 away from the conductive rod 15, and the second contact 17 is fixedly connected to the second central insert 24 through the transition block 18. In summary, the external structure of the instrument transformer, which is separated from the transformer body, eliminates the installation limitations of the transformer and is not affected by temperature drift caused by changes in the temperature of the transformer body. During maintenance, only the air chamber where it is located needs to be vented, and the air can be replenished after maintenance. This greatly reduces the external size of the transformer, saves installation space, and reduces installation costs.

[0023] The CT housing 1 has a first mounting port 2 and a second mounting port 3 on its side wall. A cover plate 4 is fixedly installed on the outside of the first mounting port 2, and an adsorbent cover 5 is fixedly installed on the end face of the cover plate 4 facing the inside of the first mounting port 2. The adsorbent cover 5 can be filled with desiccant or the like to ensure the dryness of the inside of the CT housing 1.

[0024] A wiring terminal 6 is fixedly installed on the outside of the second mounting port 3, a wiring cover 7 is fixedly installed on the outside of the wiring terminal 6, and a wiring cap 8 is fixedly installed on the outside of the end of the wiring cover 7 away from the second mounting port 3.

[0025] A support block 11 is fixedly installed on the inner wall of the CT housing 1, and the support block 11 is located close to the first epoxy cover 9. A shielding cylinder 12 is also provided inside the CT housing 1. An annular plate 13 is fixedly installed at one end of the shielding cylinder 12 near the first epoxy cover 9. The annular plate 13 is fixedly installed on the support block 11. The shielding cylinder 12 is fitted over the conductive rod 15, and a shielding ring 14 is fixedly installed at the end of the shielding cylinder 12 away from the annular plate 13. The shielding cylinder 12 provides protection for the conductive rod 15, preventing it from being affected by external factors.

[0026] A first flange ring 21 is fixedly mounted on the outside of the first epoxy cover 9. A first assembly ring 101 is integrally formed on the outer side wall of the CT housing 1 near the first epoxy cover 9. The first epoxy cover 9 is fixedly mounted on the first assembly ring 101 via the first flange ring 21. The first epoxy cover 9 can be easily fixedly mounted by assembling the first flange ring 21 with the first assembly ring 101. A first nameplate 22 is mounted on the outer wall of the first flange ring 21, and relevant information can be laser-engraved on the first nameplate 22.

[0027] The second epoxy cover 10 is externally fixedly mounted with a second flange ring 25. A second assembly ring 102 is integrally provided on the inner wall of the CT housing 1 near the second epoxy cover 10. The second epoxy cover 10 is fixedly connected to the second assembly ring 102 by the second flange ring 25. The assembly of the second flange ring 25 and the second assembly ring 102 facilitates the fixed installation of the second epoxy cover 10. A second nameplate 26 is installed on the outer wall of the second flange ring 25. The second nameplate 26 can be laser-engraved with relevant information.

[0028] Both the first epoxy cover 9 and the second epoxy cover 10 have a protrusion at their center. The protrusion on the first epoxy cover 9 is located away from the CT housing 1, while the protrusion on the second epoxy cover 10 is located towards the inside of the CT housing 1.

[0029] Through the above-described scheme of this application, the instrument transformer is separated from the transformer body and installed separately in a housing. This housing is not limited by the transformer structure or the transformer installation schedule. It does not require oil filling or bushing installation. It adopts a casting type, which can also eliminate the need for later installation of the instrument transformer. The SF6 in the independent unit busbar of the instrument transformer provides better insulation performance protection. It does not share a gas chamber with the GIL and uses an independent gas chamber, which does not affect the operation of the GIL.

[0030] In actual installation, the bottom of the transformer is the oil tank assembly 100, the top of the oil tank assembly 100 is equipped with a tank cover 200, the top of the tank cover 200 is equipped with multiple sets of outgoing line devices 300, and the outlet end of the outgoing line device 300 is equipped with the CT unit structure set in this application. The central protruding part of the first epoxy cover 9 of the CT unit structure is assembled into the outlet end of the outgoing line device 300, thus completing the overall installation and assembly, which is very convenient for subsequent replacement and installation.

[0031] In summary, the external structure of the instrument transformer, which is separated from the transformer body, eliminates the installation limitations of the transformer and is not affected by temperature drift caused by changes in the temperature of the transformer body. During maintenance, only the air chamber where it is located needs to be vented, and the air can be replenished after maintenance. This greatly reduces the external size of the transformer, saves installation space, and reduces installation costs.

[0032] In this application, unless otherwise expressly specified and limited, the terms "installation", "setting", "connection", "fixing", "screw connection", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise expressly limited, those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0033] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0034] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0035] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A structure for an external independent CT unit for a power transformer current transformer, characterized in that, The CT housing (1) includes a first epoxy cover (9) and a second epoxy cover (10) fixedly installed at both ends of the CT housing (1). The first epoxy cover (9) has a first mounting hole (19) in the middle and a first central insert (20) fixedly installed in the first mounting hole (19). The second epoxy cover (10) has a second mounting hole (23) in the center and a second central insert (24) fixedly installed in the second mounting hole (23). The CT housing (1) has a conductive rod (15) arranged coaxially inside. The two ends of the conductive rod (15) are fixedly installed with a first contact seat (16) and a second contact seat (17). The end of the first contact seat (16) away from the conductive rod (15) is fixedly connected to the first central insert (20), and the end of the second contact seat (17) away from the conductive rod (15) is connected to the second central insert (24).

2. The structure of an external independent CT unit for a power transformer current transformer according to claim 1, characterized in that, A transition block (18) is fixedly installed at the end of the second contact (17) away from the conductive rod (15), and the second contact (17) is fixedly connected to the second center insert (24) through the transition block (18).

3. The structure of an external independent CT unit for a power transformer current transformer according to claim 2, characterized in that, The CT housing (1) has a first mounting port (2) and a second mounting port (3) on its side wall. A cover plate (4) is fixedly installed on the outside of the first mounting port (2). An adsorbent cover (5) is fixedly installed on one end face of the cover plate (4) facing the inside of the first mounting port (2).

4. The structure of an external independent CT unit for a power transformer current transformer according to claim 3, characterized in that, A wiring terminal (6) is fixedly installed on the outside of the second mounting port (3), a wiring cover (7) is fixedly installed on the outside of the wiring terminal (6), and a wiring cap (8) is fixedly installed on the outside of the end of the wiring cover (7) away from the second mounting port (3).

5. The structure of an external independent CT unit for a power transformer current transformer according to claim 4, characterized in that, A support block (11) is fixedly installed on the inner wall of the CT housing (1). The support block (11) is located close to the first epoxy cover (9). The CT housing (1) is also provided with a shielding cylinder (12). A ring plate (13) is fixedly installed at one end of the shielding cylinder (12) close to the first epoxy cover (9). The ring plate (13) is fixedly installed on the support block (11). The shielding cylinder (12) is sleeved on the outside of the conductive rod (15). A shielding ring (14) is fixedly installed at the end of the shielding cylinder (12) away from the ring plate (13).

6. The structure of an external independent CT unit for a power transformer current transformer according to claim 5, characterized in that, The first epoxy cover (9) is fixedly mounted on the outside of the first flange ring (21). The CT housing (1) is integrally provided with a first assembly ring (101) on the outer side wall of one end near the first epoxy cover (9). The first epoxy cover (9) is fixedly mounted on the first assembly ring (101) by the first flange ring (21).

7. The structure of an external independent CT unit for a power transformer current transformer according to claim 6, characterized in that, A first nameplate (22) is installed on the outer wall of the first flange ring (21).

8. The structure of an external independent CT unit for a power transformer current transformer according to claim 7, characterized in that, The second epoxy cover (10) is fixedly mounted with a second flange ring (25). The CT housing (1) is integrally provided with a second assembly ring (102) on the inner wall of one end near the second epoxy cover (10). The second epoxy cover (10) is fixedly connected to the second assembly ring (102) by the second flange ring (25).

9. The structure of an external independent CT unit for a power transformer current transformer according to claim 8, characterized in that, A second nameplate (26) is installed on the outer wall of the second flange ring (25).

10. The structure of an external independent CT unit for a power transformer current transformer according to claim 9, characterized in that, Both the first epoxy mask (9) and the second epoxy mask (10) have protrusions at their centers. The protrusions on the first epoxy mask (9) are located away from the CT housing (1), while the protrusions on the second epoxy mask (10) are located towards the inside of the CT housing (1).

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