An inverted current transformer winding structure

Abstract

The utility model relates to an inverted current transformer winding structure, including oil conservator and be equipped with primary coil subassembly and secondary coil subassembly in the oil conservator, wherein the oil conservator one side is equipped with P1 side terminal board, the other side is equipped with P2 side terminal board, primary coil subassembly includes primary coil stranded wire A and primary coil stranded wire B, and primary coil stranded wire A passes through the middle part of secondary coil subassembly and is surrounded by the outside of secondary coil subassembly and returns P1 side, and the both ends of primary coil stranded wire A are electrically connected with corresponding P1 side terminal board respectively, and one end of primary coil stranded wire B is electrically connected with corresponding P1 side terminal board, and the other end passes through the middle part of secondary coil subassembly and is electrically connected with P2 side terminal board. The utility model realizes the application of primary tap and multiple primary current values, can be suitable for the accurate level of current ratio, and does not need to change the connection of primary terminal board.

Description

Technical Field

[0001] This utility model relates to the field of power equipment, specifically to an inverted current transformer winding structure. Background Technology

[0002] Oil-immersed inverted current transformers are electrical measuring devices primarily used for current measurement, metering, and protection in high-voltage power systems. Unlike upright current transformers, the secondary winding of an inverted current transformer is located at the top. Compared to oil-immersed upright current transformers, inverted current transformers offer advantages such as lower leakage reactance, better dynamic and thermal stability, compatibility with multi-turn primary structures, better heat dissipation, smaller size, lighter weight, and lower cost. However, traditional inverted current transformers still have the following problems: I. Traditional oil-immersed inverted current transformers have two primary coil structures. One involves an aluminum or copper rod passing through the middle of the oil conservator and separated from it by an aluminum tube. This method is simple, but the primary coil can only be connected in series or parallel to achieve 1, 2, or 4 turns, which cannot meet the accuracy requirements of low current ratio coils. The other method uses copper wire wound around the transformer body and sealed in the oil conservator. However, this structure is only used for low current ratio transformers and cannot meet the requirements of large primary current parameters.

[0003] Second, in the existing technology, the primary coil can often only achieve two numbers of turns through series and parallel connection. However, since the connecting plates are different when connecting in series and parallel, it is often necessary to remove the original connecting plate and replace it with a new one when switching between series and parallel connections. In the field, after a long period of operation, the connecting plate for the primary connection is often lost, which leads to the need to replace the connecting plate with a new one from the manufacturer. Utility Model Content

[0004] The purpose of this utility model is to provide an inverted current transformer winding structure, whose primary coil can realize the application of a primary tap and multiple primary current values, can be used for accuracy levels of large and small current ratios, and does not require replacement of the primary terminal block.

[0005] The objective of this utility model is achieved through the following technical solution: An inverted current transformer winding structure includes an oil conservator and a primary coil assembly and a secondary coil assembly disposed within the oil conservator. The oil conservator has a P1 side terminal plate on one side and a P2 side terminal plate on the other side. The primary coil assembly includes a primary coil strand A and a primary coil strand B. The primary coil strand A passes through the middle of the secondary coil assembly and wraps around the P1 side from the outside of the secondary coil assembly. Both ends of the primary coil strand A are electrically connected to the corresponding P1 side terminal plate. One end of the primary coil strand B is electrically connected to the corresponding P1 side terminal plate, and the other end passes through the middle of the secondary coil assembly and is electrically connected to the P2 side terminal plate.

[0006] The oil tank has a first mounting hole on one side, and the P1 side terminal plate is mounted on the corresponding first mounting hole through a transition terminal plate. The transition terminal plate includes a connecting part, a shaft insert part, and a coil wire connecting plate. The P1 side terminal plate has a first mounting plate on one side, and the first mounting plate is fixedly connected to the connecting part. The rear end of the shaft insert part is connected to the connecting part, and the front end passes through the first mounting hole and has a threaded section. A nut is fitted on the threaded section, and a coil wire connecting plate is provided at the front end of the threaded section.

[0007] The insert shaft is provided with an insulating sleeve, an insulating ring, a first washer, a second washer and a nut in sequence. The insulating sleeve is located between the connecting part and the oil tank, the insulating ring is located in the first mounting hole, and sealing washers are provided at both ends of the insulating ring.

[0008] A coil connecting plate is provided on one side of the inner wall of the oil tank, and a second mounting plate is provided on one side of the P2 side terminal plate. The second mounting plate is fixed to the oil tank by connecting bolts, and the connecting bolts are in contact with the coil connecting plate.

[0009] The oil storage tank includes an upper oil storage tank body and a lower oil storage tank body. The lower oil storage tank body has a first mounting part on one side and a second mounting part on the other side. The first mounting part has a first mounting hole for mounting the P1 side terminal board, and the second mounting part has a second mounting hole for mounting the P2 side terminal board.

[0010] An expander assembly is provided at the upper end of the upper oil storage tank. The expander assembly includes an expander cover, and an expander is provided inside the expander cover, which communicates with the interior of the upper oil storage tank. An equipotential bonding plate is provided on the expander. An equipotential threaded hole is provided on the inner wall of the upper end of the upper oil storage tank. One end of the equipotential bonding line is connected to the equipotential bonding plate by a first bolt, and the other end is fixed to the equipotential threaded hole by a second bolt. An expander bracket is provided inside the expander.

[0011] The lower oil tank body is provided with an outer insulating sleeve on its lower side, and a base is provided at the lower end of the outer insulating sleeve; a metal tube is provided on the lower side of the secondary coil assembly, and the metal tube is located in the outer insulating sleeve. The lead wire of the secondary coil assembly passes through the metal tube and is connected to the secondary terminal box provided on the base. A measuring terminal is provided on the base, and the lower end of the metal tube is connected to the measuring terminal through a measuring terminal connection wire. An equipotential bonding plate is provided on the outer end of the measuring terminal and is electrically connected to the base.

[0012] The secondary coil assembly includes a secondary coil, a metal shell, and a main insulation arranged sequentially from the inside to the outside, wherein the upper end of the metal tube is welded and fixed to the metal shell; the base has a terminal box connection part on one side and a measuring terminal seat on the other side, wherein the secondary terminal box is fixed on the terminal box connection part, the measuring terminal has a terminal flange, and the terminal flange is fixed on the measuring terminal seat, and a sealing element is provided between the terminal flange and the measuring terminal seat.

[0013] The lower end of the metal tube is fixed to the base via a connecting assembly, which includes a pull-down bolt, an insulating flange, a support rod, and an upper bolt. Two insulating flanges are stacked and fitted onto the lower end of the metal tube and connected together by the pull-down bolt. The lower end of the pull-down bolt is fixed to the upper flange of the base at the upper end of the base. The support rod passes horizontally through the lower end of the metal tube, and both ends of the support rod are clamped and fixed by two insulating flanges. The upper bolt is located on the upper flange of the base, and the upper end of the upper bolt abuts against the insulating flange.

[0014] The pull-down bolt is fitted with a first locking nut and a second locking nut. The two insulating flanges are clamped and positioned by the nut of the pull-down bolt and the first locking nut. The inner side of the insulating flange is provided with a groove to accommodate the end of the support rod. The second locking nut is located on the lower side of the upper flange of the base.

[0015] The advantages and positive effects of this utility model are as follows: 1. The winding structure of this utility model has a P1 side terminal plate on one side of the oil tank and a P2 side terminal plate on the other side. The primary coil includes a primary coil stranded wire A that wraps around the secondary coil assembly from the inside to the outside and a primary coil stranded wire B that passes through the secondary coil assembly. The two ends of the primary coil stranded wire A1 are electrically connected to the corresponding P1 side terminal plate, and one end of the primary coil stranded wire B is electrically connected to the corresponding P1 side terminal plate, and the other end is electrically connected to the P2 side terminal plate. In this way, this utility model can realize the application of a single tap and multiple primary current values, and can be used for accuracy levels of large and small current ratios. In field applications, this utility model only needs to connect the terminal plate corresponding to the primary current value as needed, without the need to replace the terminal plate.

[0016] 2. The P1 side terminal board of this utility model is installed on the oil tank through a transition terminal board. The direction (vertical or horizontal) of the front coil wire connecting plate can be adjusted as needed to facilitate connection. At the same time, suitable washers and other components can be set on the insertion shaft part of the transition terminal board as needed to ensure sealing and insulation. Then, the positions of each component are locked by nuts, and the purpose of installing the transition terminal board on the oil tank is completed.

[0017] 3. The present invention designs the oil tank as a split structure. The expander in the expander assembly is connected to the upper oil tank through an equipotential line to achieve equipotentiality, which can effectively prevent the expander from discharging. The P1 side terminal board, P2 side terminal board and other structures of the present invention are all concentrated on the lower oil tank, which facilitates the winding and installation of the primary coil. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of an inverted current transformer using the structure of this utility model. Figure 2 This is a schematic diagram of the P1 side terminal board, primary coil, and P2 side terminal board of this utility model. Figure 3 for Figure 2 A schematic diagram showing the connection status of the P1 side terminal block, the primary coil, and the P2 side terminal block. Figure 4 for Figure 3 A schematic diagram showing the connection status of the P1 side terminal board, the primary coil, and the P2 side terminal board after removing the secondary coil assembly. Figure 5 for Figure 2 Schematic diagram of the intermediate transition terminal block. Figure 6 for Figure 5 Front view of the intermediate transition terminal block. Figure 7 This is a schematic diagram of the electrical principle of this utility model.

[0019] Figure 8 for Figure 1 A schematic diagram of the structure of the expansion unit. Figure 9 for Figure 1 Schematic diagram of the upper and middle oil storage tanks. Figure 10 for Figure 9 Another structural diagram of the upper and middle oil storage tanks. Figure 11 for Figure 1 Schematic diagram of the lower oil storage tank. Figure 12 for Figure 11 Another structural diagram of the lower oil storage tank. Figure 13 for Figure 1 A schematic diagram showing the connection between the lower end of the middle metal tube and the base. Figure 14 for Figure 13 A schematic diagram of the structure of the connecting component. Figure 15 for Figure 13 A schematic diagram of the structure at the lower end of the central metal tube.

[0020] Wherein, 1 is the expander assembly, 101 is the expander housing, 102 is the expander, 103 is the equipotential bonding piece, 104 is the first bolt, 105 is the equipotential bonding wire, 106 is the expander bracket, and 107 is the second bolt; 2 is the secondary coil assembly, 201 is the secondary coil, 202 is the metal shell, and 203 is the main insulation; 3 is the oil conservator, 301 is the upper oil conservator body, 3011 is the first upper flange, 3012 is the equipotential threaded hole, and 30... 13 is the lifting plate, 3014 is the lifting hole, 3015 is the first lower flange, 302 is the lower oil tank body, 3021 is the second mounting part, 3022 is the first mounting hole, 3023 is the first mounting part, 3024 is the second upper flange, 3025 is the second lower flange, and 3026 is the coil connection plate; 4 is the P1 side terminal plate, 401 is the first mounting plate, 402 is the transition terminal plate, 4021 is the connecting part, 4022 is the threaded section, and 4023 is... Coil wire connecting plate, 403 is nut, 404 is first washer, 405 is isolation ring, 406 is sealing washer, 407 is second washer, 408 is isolation insulating sleeve; 5 is P2 side terminal plate, 501 is second mounting plate, 502 is connecting bolt; 6 is measuring terminal connection; 7 is connecting assembly, 701 is pull-down bolt, 702 is insulating flange, 703 is support rod, 704 is top bolt, 705 is first locking nut, 706 is... Second locking nut; 8 is a metal tube, 801 is an equipotential bonding hole, 802 is a support rod insertion hole; 9 is an outer insulating sleeve; 10 is a base, 1001 is a terminal box connection part, 1002 is a measuring terminal base, 1003 is a flange on the base; 11 is a secondary terminal box; 12 is a measuring terminal, 1201 is a terminal equipotential plate, 1202 is a terminal flange; 13 is a primary coil, 1301 is primary coil stranded wire A, 1302 is primary coil stranded wire B. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings.

[0022] like Figures 1-2 As shown, this utility model includes an oil tank 3 and a primary coil 13 and a secondary coil assembly 2 disposed within the oil tank 3. The oil tank 3 has a P1 side terminal plate 4 on one side and a P2 side terminal plate 5 on the other side. Figures 2-4 As shown, the primary coil 13 includes a primary coil stranded wire A1301 and a primary coil stranded wire B1302. The primary coil stranded wire A1301 passes through the middle of the secondary coil assembly 2 and wraps around the P1 side from the outside of the secondary coil assembly 2. The two ends of the primary coil stranded wire A1301 are electrically connected to the corresponding P1 side terminal plate 4, and one end of the primary coil stranded wire B1302 is electrically connected to the corresponding P1 side terminal plate 4, and the other end passes through the middle of the secondary coil assembly 2 and is electrically connected to the P2 side terminal plate 5.

[0023] like Figures 2-4 As shown in this embodiment, the oil tank 3 has three P1-side terminal blocks 4 on one side and one P2-side terminal block 5 on the other side. The electrical connection principle is as follows: Figure 7 As shown, this embodiment can achieve one tap and three primary current values ​​(i.e., I1, I2, I3), applicable to various current ratios. In field applications, this invention only requires connecting the terminal blocks corresponding to the primary current values ​​(i.e., I1, I2, I3) as needed, without the need for reconnection. It should also be noted that, for clarity of the invention's structure, Figures 3-4 Each primary coil strand is shown as having only one turn, but in actual production, it will be wound according to the required number of turns.

[0024] like Figure 1 As shown, in this embodiment, the oil storage tank 3 includes an upper oil storage tank body 301 and a lower oil storage tank body 302, wherein... Figures 11-12 As shown, the lower oil storage tank 302 has a first mounting part 3023 on one side and a second mounting part 3021 on the other side. The first mounting part 3023 has a first mounting hole 3022 for mounting the P1 side terminal plate 4, and the second mounting part 3021 has a second mounting hole for mounting the P2 side terminal plate 5.

[0025] like Figures 2-4 As shown, in this embodiment, the P1 side terminal plate 4 is mounted at the corresponding first mounting hole 3022 via a transition terminal plate 402, as... Figures 5-6 As shown, the transition terminal plate 402 includes a connecting part 4021, a shaft insert, and a coil wire connecting plate 4023. A first mounting plate 401 is provided on one side of the P1 side terminal plate 4, and the first mounting plate 401 is fixedly connected to the connecting part 4021. The rear end of the shaft insert is connected to the connecting part 4021, and the front end passes through the first mounting hole 3022 and is provided with a threaded section 4022. A nut 403 is fitted on the threaded section 4022. The front end of the threaded section 4022 is provided with a coil wire connecting plate 4023, and the coil wire connecting plate 4023 is electrically connected to the corresponding coil strand in the primary coil 13.

[0026] In this embodiment, as Figure 6 As shown, the connecting part 4021 of the transition terminal plate 402 has a square structure, which allows the installation angle to be adjusted as needed, thereby adjusting the direction (vertical or horizontal) of the front coil wire connecting plate 4023 for easy connection. And as... Figure 2As shown, the insert shaft can also be equipped with appropriate washers and other components as needed to ensure sealing and insulation. Then, the positions of each component are locked by the nut 403, which also achieves the purpose of fixing the transition terminal plate 402 to the first mounting hole 3022.

[0027] like Figure 2 As shown, in this embodiment, the insert shaft portion is sequentially provided with an insulating sleeve 408, an insulating ring 405, a first washer 404, a second washer 407, and a nut 403. The insulating sleeve 408 is disposed between the connecting portion 4021 and the first mounting portion 3023 to provide insulation. The insulating ring 405 is disposed in the first mounting hole 3022, and both the end of the insulating ring 405 located on the outer wall side of the first mounting portion 3023 and the end located on the inner wall side of the first mounting portion 3023 are provided with sealing washers 406 to provide sealing. In this embodiment, the first washer 404 is an insulating washer, and the second washer 407 is an elastic washer. This invention, through the above-described washer combination design, can fully guarantee the sealing and insulation performance of the transition terminal board 402.

[0028] like Figures 2-4 As shown, in this embodiment, a second mounting plate 501 is provided on one side of the P2 side terminal board 5, and a coil connecting plate 3026 is provided on the inner side of the upper end of the lower oil tank 302 to connect with the corresponding coil strand in the primary coil 13. The second mounting plate 501 is fixed to the lower oil tank 302 by connecting bolts 502, and the connecting bolts 502 contact the coil connecting plate 3026, thereby realizing the electrical connection between the P2 side terminal board 5 and the corresponding coil strand.

[0029] like Figure 1 As shown, in this embodiment, the secondary coil assembly 2 includes a secondary coil 201, a metal shell 202 (an aluminum shell in this embodiment) and a main insulation 203 arranged sequentially from the inside to the outside. The structure of the secondary coil assembly 2 is a technology known in the art.

[0030] like Figure 1 As shown, the upper end of the upper oil storage tank 301 is provided with an expander assembly 1, and as... Figure 8 As shown, in this embodiment, the expander assembly 1 includes an expander housing 101, and an expander 102 is disposed inside the expander housing 101, communicating with the interior of the upper oil storage tank 301. An equipotential bonding plate 103 is disposed on the expander 102, and one end of the equipotential bonding line 105 is connected to the equipotential bonding plate 103 via a first bolt 104. Figure 10As shown, the upper inner wall of the upper oil tank 301 is provided with an equipotential threaded hole 3012, and the other end of the equipotential connecting line 105 is fixed to the equipotential threaded hole 3012 by a second bolt 107, thereby achieving equipotential between the expander 102 and the upper oil tank 301, which can effectively prevent the expander 102 from discharging or other situations.

[0031] Other examples Figure 8 As shown in this embodiment, the expander 102 is provided with an arched expander bracket 106 inside, which is used to prevent the expander 102 from being flattened when the current transformer is vacuumed and oiled, and plays a limiting role for the expander 102.

[0032] like Figures 9-11 As shown, in this embodiment, the upper oil storage tank 301 has a first upper flange 3011 fixedly connected to the lower end of the expander assembly 1, and the lower end of the upper oil storage tank 301 has a first lower flange 3015 fixedly connected to the second upper flange 3024 at the upper end of the lower oil storage tank 302. Additionally, a lifting plate 3013 is provided on the outer side of the upper oil storage tank 301, and the lifting plate 3013 has lifting holes 3014 to facilitate the lifting and transfer of the current transformer of this utility model.

[0033] like Figure 1 As shown, the lower oil storage tank 302 has an outer insulating sleeve 9 on its lower side, and a base 10 is provided at the lower end of the outer insulating sleeve 9. The secondary coil assembly 2 has a metal tube 8 (an aluminum tube in this embodiment) on its lower side, and the metal tube 8 is located within the outer insulating sleeve 9. The lead wires of the secondary coil assembly 2 pass through the metal tube 8 and connect to the secondary terminal box 11 located on the base 10. The base 10 has measuring terminals 12, and as shown... Figure 13 As shown, the lower end of the metal tube 8 is connected to the measuring terminal 12 via the measuring terminal connection line 6.

[0034] like Figures 11-12 As shown, the lower oil storage tank 302 is provided with a second lower flange 3025 at the lower end, which is fixedly connected to the upper end of the outer insulating sleeve 9.

[0035] like Figure 13As shown, in this embodiment, the base 10 has a terminal box connecting part 1001 on one side and a measuring terminal base 1002 on the other side. The secondary terminal box 11 is fixed to the terminal box connecting part 1001, and the secondary terminal box 11 contains a secondary terminal plate connected to the lead wire of the secondary coil assembly 2. The measuring terminal 12 has a terminal flange 1202, and the terminal flange 1202 is fixed to the measuring terminal base 1002. A sealing element (such as a sealing ring) is provided between the terminal flange 1202 and the measuring terminal base 1002 to ensure a seal. In addition, the outer end of the measuring terminal 12 has a terminal equipotential bonding plate 1201 that is electrically connected to the base 10.

[0036] In this embodiment, the upper end of the metal tube 8 is welded and fixed to the metal shell 202 of the secondary coil assembly 2, together serving as the final screen of the transformer body. The secondary coil assembly 2, the metal shell 202, the metal tube 8, and the external main insulation 203 constitute the transformer body. The high-voltage screen of the transformer body is electrically connected to the oil conservator 3. The lower end of the metal tube 8 is connected to the measuring terminal 12 through the measuring terminal connection 6. Thus, the measuring terminal 12 measures the dielectric loss between the primary terminal plate and the measuring terminal 12, which is also the main dielectric loss tanδ of the transformer body. In addition, when the transformer is running, the outer end of the measuring terminal 12 needs to be connected to the base 10 through the terminal equipotential bonding plate 1201 to ground the final screen of the transformer body. The terminal equipotential bonding plate 1201 is removed when measuring tanδ.

[0037] like Figure 13 As shown, the lower end of the metal tube 8 is fixedly connected to the base 10 via a connecting assembly 7, as... Figure 14 As shown, in this embodiment, the connecting assembly 7 includes a pull-down bolt 701, an insulating flange 702, a support rod 703, and an upper bolt 704. Two insulating flanges 702 are stacked and fitted onto the lower end of the metal tube 8 and connected together by the pull-down bolt 701. The lower end of the pull-down bolt 701 is fixed to the upper flange 1003 of the base 10. The support rod 703 horizontally passes through the lower end of the metal tube 8, and both ends of the support rod 703 are clamped and fixed by the two insulating flanges 702. The upper bolt 704 is located on the upper flange 1003 of the base, and the upper end of the upper bolt 704 abuts against the insulating flange 702. This utility model, through the above-mentioned connecting assembly 7, can ensure insulation between the metal tube 8 and the base 10, and can effectively prevent the device body from shaking.

[0038] like Figure 14As shown, in this embodiment, a first locking nut 705 and a second locking nut 706 are fitted on the pull-down bolt 701. The two insulating flanges 702 are clamped and positioned by the nut of the pull-down bolt 701 and the first locking nut 705. The inner side of the insulating flange 702 is provided with a groove to accommodate the end of the support rod 703. The second locking nut 706 is located on the lower side of the flange 1003 on the base and limits the displacement of the pull-down bolt 701.

[0039] like Figure 15 As shown, in this embodiment, the lower end of the metal tube 8 is provided with an equipotential bonding hole 801 and a support rod insertion hole 802. The equipotential bonding hole 801 is used to connect with the measuring terminal connection line 6, and the support rod insertion hole 802 is for the support rod 703 to pass through.

[0040] The working principle of this utility model is as follows: This utility model has a P1 side terminal plate 4 on one side of the oil tank 3 and a P2 side terminal plate 5 on the other side. The primary coil 13 includes a primary coil stranded wire A1301 that surrounds the secondary coil assembly 2 from the inside out and a primary coil stranded wire B1302 that passes through the secondary coil assembly 2. Figures 2-4 As shown, the two ends of the primary coil stranded wire A1301 are electrically connected to the corresponding P1 side terminal plate 4, and one end of the primary coil stranded wire B1302 is electrically connected to the corresponding P1 side terminal plate 4, and the other end is electrically connected to the P2 side terminal plate 5. In this embodiment, there are a total of three P1 side terminal plates 4 and one P2 side terminal plate 5, which are arranged according to... Figures 2-4 Once the structure shown is connected, it forms... Figure 7 The winding structure shown in this embodiment enables the application of one tap and three primary current values ​​(i.e., I1, I2, I3), and is applicable to the accuracy level of large and small current ratios. In field applications, this utility model only needs to connect the terminal blocks corresponding to the primary current values ​​(i.e., I1, I2, I3) as needed, without the need for reconnection.

[0041] Secondly, as Figures 2-6 As shown, the P1 side terminal plate 4 of this utility model is installed on the oil tank 3 via a transition terminal plate 402. The transition terminal plate 402 has a square structure, and its installation angle can be adjusted as needed, thereby adjusting the direction (vertical or horizontal) of the front coil wire connecting plate 4023 for convenient connection. Figure 2 As shown, the insert shaft can also be equipped with appropriate washers and other components as needed to ensure sealing and insulation. Then, the positions of each component are locked by the nut 403, which also achieves the purpose of fixing the transition terminal plate 402 to the first mounting hole 3022.

[0042] Furthermore, this utility model designs the oil storage tank 3 as a split structure, which includes two parts: an upper oil storage tank body 301 and a lower oil storage tank body 302, wherein, as shown in the figure... Figure 8 As shown, the expander 102 in the expander assembly 1 is connected to the upper oil tank 301 via an equipotential bonding line 105 to achieve equipotentiality, which can effectively prevent the expander 102 from discharging. The P1 side terminal plate 4, P2 side terminal plate 5, and other structures of this utility model are all concentrated on the lower oil tank 302, which facilitates the winding and installation of the primary coil 13.

[0043] Other examples Figure 1 and Figures 13-15 As shown, the inverted current transformer using this invention has its upper end of the metal tube 8 welded and fixed to the metal shell 202 of the secondary coil assembly 2, together forming the final screen of the transformer body. The secondary coil assembly 2, metal shell 202, metal tube 8, and external main insulation 203 constitute the transformer body. The high-voltage screen of the transformer body is electrically connected to the oil conservator 3. The lower end of the metal tube 8 is connected to the measuring terminal 12 via the measuring terminal connection line 6. Thus, the measuring terminal 12 measures the dielectric loss between the primary terminal plate and the measuring terminal 12, which is also the main dielectric loss tanδ of the transformer body, thereby realizing the function of intuitively monitoring the insulation performance on site. At the same time, the lower end of the metal tube 8 is connected to the base 10 via the connecting assembly 7 including the insulating flange 702, which can ensure the insulation between the metal tube 8 and the base 10 and effectively prevent the transformer body from shaking.

Claims

1. An inverted current transformer winding structure, characterized in that: The system includes an oil tank (3) and a primary coil assembly (13) and a secondary coil assembly (2) disposed within the oil tank (3). The oil tank (3) has a P1 side terminal plate (4) on one side and a P2 side terminal plate (5) on the other side. The primary coil assembly (13) includes a primary coil strand A (1301) and a primary coil strand B (1302). The primary coil strand A (1301) passes through the middle of the secondary coil assembly (2) and wraps around the P1 side from the outside of the secondary coil assembly (2). The two ends of the primary coil strand A (1301) are electrically connected to the corresponding P1 side terminal plate (4) respectively. One end of the primary coil strand B (1302) is electrically connected to the corresponding P1 side terminal plate (4), and the other end passes through the middle of the secondary coil assembly (2) and is electrically connected to the P2 side terminal plate (5).

2. The inverted current transformer winding structure according to claim 1, characterized in that: The oil tank (3) has a first mounting hole (3022) on one side, and the P1 side terminal plate (4) is installed at the corresponding first mounting hole (3022) through the transition terminal plate (402); the transition terminal plate (402) includes a connecting part (4021), a shaft part and a coil wire connecting plate (4023), wherein the P1 side terminal plate (4) has a first mounting plate (401) on one side, and the first mounting plate (401) is fixedly connected to the connecting part (4021), the rear end of the shaft part is connected to the connecting part (4021), the front end passes through the first mounting hole (3022) and has a threaded section (4022), a nut (403) is fitted on the threaded section (4022), and a coil wire connecting plate (4023) is provided at the front end of the threaded section (4022).

3. The inverted current transformer winding structure according to claim 2, characterized in that: The insert shaft is provided with an insulating sleeve (408), an insulating ring (405), a first washer (404), a second washer (407) and a nut (403) in sequence. The insulating sleeve (408) is located between the connecting part (4021) and the oil tank (3). The insulating ring (405) is located in the first mounting hole (3022). Both ends of the insulating ring (405) are provided with sealing washers (406).

4. The inverted current transformer winding structure according to claim 1, characterized in that: The inner wall of one side of the oil tank (3) is provided with a coil connecting plate (3026), and the side of the P2 side terminal plate (5) is provided with a second mounting plate (501). The second mounting plate (501) is fixed to the oil tank (3) by connecting bolts (502), and the connecting bolts (502) are in contact with the coil connecting plate (3026).

5. The inverted current transformer winding structure according to claim 1, characterized in that: The oil storage tank (3) includes an upper oil storage tank body (301) and a lower oil storage tank body (302). The lower oil storage tank body (302) has a first mounting part (3023) on one side and a second mounting part (3021) on the other side. The first mounting part (3023) has a first mounting hole (3022) for mounting the P1 side terminal plate (4), and the second mounting part (3021) has a second mounting hole for mounting the P2 side terminal plate (5).

6. The inverted current transformer winding structure according to claim 5, characterized in that: The upper oil storage tank (301) is provided with an expander assembly (1) at its upper end. The expander assembly (1) includes an expander cover (101), and the expander cover (101) is provided with an expander (102) inside, which communicates with the interior of the upper oil storage tank (301). The expander (102) is provided with an equipotential bonding plate (103). The upper inner wall of the upper oil storage tank (301) is provided with an equipotential threaded hole (3012). One end of the equipotential connecting line (105) is connected to the equipotential bonding plate (103) by a first bolt (104), and the other end is fixed to the equipotential threaded hole (3012) by a second bolt (107). The expander (102) is provided with an expander bracket (106) inside.

7. The inverted current transformer winding structure according to claim 5, characterized in that: The lower oil storage tank (302) is provided with an outer insulating sleeve (9) on its lower side, and a base (10) is provided at the lower end of the outer insulating sleeve (9); the secondary coil assembly (2) is provided with a metal tube (8) on its lower side, and the metal tube (8) is located in the outer insulating sleeve (9). The lead wire of the secondary coil assembly (2) passes through the metal tube (8) and is connected to the secondary terminal box (11) on the base (10). The base (10) is provided with a measuring terminal (12), and the lower end of the metal tube (8) is connected to the measuring terminal (12) through the measuring terminal connection line (6). The measuring terminal (12) is provided with a terminal equipotential plate (1201) at its outer end and is electrically connected to the base (10).

8. The inverted current transformer winding structure according to claim 7, characterized in that: The secondary coil assembly (2) includes a secondary coil (201), a metal shell (202) and a main insulation (203) arranged sequentially from the inside to the outside. The upper end of the metal tube (8) is welded and fixed to the metal shell (202). The base (10) has a terminal box connection part (1001) on one side and a measuring terminal seat (1002) on the other side. The secondary terminal box (11) is fixed on the terminal box connection part (1001). The measuring terminal (12) is provided with a terminal flange (1202) and the terminal flange (1202) is fixed on the measuring terminal seat (1002). A sealing element is provided between the terminal flange (1202) and the measuring terminal seat (1002).

9. The inverted current transformer winding structure according to claim 7, characterized in that: The lower end of the metal tube (8) is fixed to the base (10) through a connecting assembly (7). The connecting assembly (7) includes a pull-down bolt (701), an insulating flange (702), a support rod (703), and an upper bolt (704). Two insulating flanges (702) are stacked and fitted on the lower end of the metal tube (8) and connected together by the pull-down bolt (701). The lower end of the pull-down bolt (701) is fixed to the upper flange (1003) of the base at the upper end of the base (10). The support rod (703) passes horizontally through the lower end of the metal tube (8), and both ends of the support rod (703) are clamped and fixed by the two insulating flanges (702). The upper bolt (704) is provided on the upper flange (1003) of the base, and the upper end of the upper bolt (704) abuts against the insulating flange (702).

10. The inverted current transformer winding structure according to claim 9, characterized in that: The pull-down bolt (701) is fitted with a first locking nut (705) and a second locking nut (706). The two insulating flanges (702) are clamped and positioned by the nut of the pull-down bolt (701) and the first locking nut (705). The inner side of the insulating flange (702) is provided with a groove to accommodate the end of the support rod (703). The second locking nut (706) is located on the lower side of the flange (1003) on the base.

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