A windowed bushing connection structure for an extra-high voltage transformer

Abstract

This invention relates to a window-type bushing connection structure for ultra-high voltage transformers. The bushing riser has an upper outlet device inside and an equalizing ball assembly at its lower end. The lower end of the bushing is inserted into the bushing riser and passes through the upper outlet device. The upper outlet device includes multiple layers of cardboard tubes, with a first window on one side and a rotatable cardboard ring on the outside. A second window is located on one side of the cardboard ring, and the second window rotates to coincide with the corresponding first window. The support assembly of the upper outlet device includes interlocking support bars and supporting support bars arranged staggered from the inside out, with cardboard tubes between adjacent interlocking and supporting support bars. The inner sides of the interlocking and supporting support bars are grooved in the cardboard ring, and the lower end of the cardboard ring has a limiting slot that fits into the lower wall of the corresponding cardboard ring groove. This invention exposes the observation and operation window of the upper outlet device by rotating the cardboard ring, without affecting the safety margin and ensuring wiring quality.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, specifically to a window-type bushing connection structure for ultra-high voltage transformers. Background Technology

[0002] With the development of ultra-high voltage direct current (UHVDC) transmission technology, the insulation levels of UHV transformers on the grid and valve sides have been increasing, from ±500kV to ±1100kV. This increase in voltage level leads to a greater number of insulation layers in the outgoing line equipment, making bushing wiring increasingly difficult. The connection between insulation layers in UHV outgoing line equipment typically uses an overlapping structure, resulting in a longer outgoing line length. When using bushings with a guide rod terminal structure, the connection of the lead cable at the bushing tail usually needs to be completed inside the equalizing sphere. However, to improve voltage distribution within the riser, UHV outgoing line equipment typically uses a thin paper tube with small oil gaps; that is, the outgoing line equipment inside the riser is basically made of multiple layers of cardboard or shaped corners, achieving a uniform distribution of oil gaps. Due to the structural limitations of the outgoing line equipment and its long length, operators cannot access the equalizing sphere area, making it impossible to complete the tail-end wiring of the guide rod type bushing. Using other bushing structures, such as tie rod bushings, has significant limitations in applicability. Summary of the Invention

[0003] The purpose of this invention is to provide a window-type bushing connection structure for ultra-high voltage transformers, which exposes the observation and operation window of the upper outgoing line device by rotating the cardboard rings of each layer, without affecting the safety margin of the upper outgoing line device, and at the same time can meet the installation requirements of connecting the lead cable at the tail end of the bushing.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] A window-type bushing connection structure for ultra-high voltage transformers, characterized in that: it includes a bushing riser base, wherein the bushing riser base is provided with an upper outlet device and a lower equalizing ball assembly, the lower end of the bushing is inserted into the bushing riser base and passes through the upper outlet device; the upper outlet device includes multiple layers of cardboard tubes, and the cardboard tubes have a first window on the side facing the hand hole of the bushing riser base, a cardboard ring is fitted on the outside of the cardboard tubes, and a second window is provided on one side of the cardboard ring, the second window being rotated and moved by the cardboard ring to coincide with the corresponding first window; the upper outlet device includes a support. The component comprises a support strip assembly, and the support strip assembly includes interlocking support strips and supporting support strips arranged alternately from the inside out, with a cardboard tube between adjacent interlocking support strips and supporting support strips; both the inner side of the interlocking support strip and the inner side of the supporting support strip are provided with cardboard tube ring grooves for accommodating cardboard rings, and the lower end of the cardboard ring is provided with a limiting slot, and the limiting slot is fitted into the lower end groove wall of the corresponding cardboard tube ring groove; the pressure equalizing ball assembly includes multiple outer forming parts with exposed upper ends, and the lower end of the interlocking support strip is provided with a first lower fitting, and the first lower fitting is fitted into the upper end of the corresponding outer forming part.

[0006] Each layer of cardboard tube has an upper window support strip assembly on the upper side of the first window and a lower window support strip assembly on the lower side.

[0007] The window support strip assembly includes multiple window support strips, and cardboard tubes are provided between adjacent window support strips. The lower side of the window support strip is provided with an upper limit groove, and the upper side of each layer of cardboard ring is respectively provided in the corresponding upper limit groove.

[0008] The window lower support strip assembly includes a mating lower support strip and a supporting lower support strip arranged alternately from the inside to the outside. The mating lower support strip has a first limiting groove at its upper end that supports the corresponding cardboard ring, and the bottom of the first limiting groove is fitted with the corresponding limiting slot. The supporting lower support strip has a second limiting groove at its upper end that supports the corresponding cardboard ring, and the bottom of the second limiting groove is fitted with the corresponding limiting slot.

[0009] The lower end of the fitting support bar is provided with a second lower fitting opening, and the second lower fitting opening is fitted with the upper end of the corresponding outer forming part in the pressure equalizing ball assembly.

[0010] The support strip assembly includes an inner support strip located on the innermost side, the lower window support strip assembly includes an inner lower support strip located on the innermost side, and the upper window support strip assembly includes an inner upper support strip located on the innermost side. The inner sides of the inner support strip and the inner lower support strip are both fixedly connected to an inner cardboard tube, and the outer sides of the inner support strip, the inner lower support strip, and the inner upper support strip are all fixedly connected to an adjacent first layer cardboard tube.

[0011] The lower end of the inner support strip is provided with a third lower inlet, and the lower end of the inner layer lower support strip is provided with a fourth lower inlet. The third lower inlet and the fourth lower inlet are respectively fitted into the upper end of the corresponding outer forming part in the pressure equalizing ball assembly.

[0012] The equalizing ball assembly includes a metal equalizing ball and an external forming assembly disposed on the outside of the metal equalizing ball. The external forming assembly includes outer support strips and outer forming parts arranged alternately from the inside to the outside. The lower end of the external forming assembly is provided with an opening. The lower end of the metal equalizing ball is provided with a flange plate with a through hole in the middle. The end of the lead wire shielding tube passes through the lower end opening of the external forming assembly and is fixedly connected to the flange plate.

[0013] The metal equalizing ball has an equalizing ball coating layer on its outer side, and a first layer of outer support strip is provided between the equalizing ball coating layer and the outer forming part of the adjacent first layer. The metal equalizing ball has an equalizing ball protective plate at its upper end, and the lower end of the equalizing ball protective plate contacts the first layer of outer support strip and is located between the equalizing ball coating layer and the first layer of outer forming part. The upper wire outlet device has an inner layer cardboard tube inside, and the upper ends of the equalizing ball protective plate and the outer forming part of the first layer are inserted into the inner layer cardboard tube. The upper end of the outer support strip contacts the lower end of the support strip assembly.

[0014] The upper end of the sleeve riser is provided with an upper flange and the lower end is provided with a lower flange. The sleeve is provided with a sleeve flange fixed to the upper flange, and the lower end of the upper cable outlet device is fixed to the lower flange.

[0015] The advantages and positive effects of this invention are as follows:

[0016] 1. The present invention forms an observation and operation window by rotating the cardboard rings of each layer, without damaging the structure of each cardboard tube. Therefore, it can ensure the safety margin of the upper wire outlet device, and at the same time meet the installation requirements of connecting the lead cable at the end of the sleeve.

[0017] 2. In the upper cable exit device of the present invention, each layer of cardboard tubes is supported and fixed by a set of support strip assemblies arranged along the circumferential direction. The inner side of the interlocking support strip and the inner side of the supporting support strip in the support strip assembly are provided with a cardboard tube ring groove for accommodating the cardboard ring. This can ensure that the cardboard tube is reliably fixed while also ensuring that the cardboard ring can be smoothly rotated and adjusted, thereby realizing the opening and closing operation of the upper cable exit device.

[0018] 3. The present invention has a limiting slot at the lower end of the cardboard ring that engages with the groove wall at the lower end of the corresponding paper tube ring groove. When the cardboard ring needs to rotate, the operator can lift the cardboard ring so that the limiting slot disengages from the groove wall at the lower end of the corresponding paper tube ring groove. After the cardboard ring rotates to the correct position, the limiting slot will re-engage with the corresponding paper tube ring groove, thereby ensuring that the cardboard ring will not rotate.

[0019] 4. In order to ensure that the window of the upper cable outlet device has sufficient area and obtains reliable support, the present invention provides an upper support strip assembly for the window on the upper side of the first window of each layer of cardboard tube, and a lower support strip assembly for the window on the lower side of the first window of each layer of cardboard tube. The upper support strip assembly and the lower support strip assembly form a spatial distance for exposing the window of the upper cable outlet device. At the same time, the upper side of the cardboard ring is placed in the upper limit groove at the lower end of the corresponding upper support strip, and the lower side of the cardboard ring is placed in the first limit groove at the upper end of the corresponding fitting lower support strip or the second limit groove at the upper end of the corresponding supporting lower support strip, so as not to affect the normal rotation and adjustment of the cardboard ring.

[0020] 5. The present invention provides a first lower insertion port at the lower end of the fitting support bar in the support bar assembly, and a second lower insertion port at the lower end of the fitting lower support bar in the lower window support bar assembly. The first lower insertion port and the second lower insertion port can fit and connect with the exposed outer molded part end of the upper end of the equalizing ball assembly. This enables the connection between the support bar assembly or the lower window support bar assembly and the equalizing ball assembly, thereby enabling the connection between the upper wire outlet device and the equalizing ball assembly. On the other hand, it also ensures reliable sealing at the connection point.

[0021] 6. This invention utilizes the innermost inner support strip of the support strip assembly, the innermost inner lower support strip of the lower window support strip assembly, and the innermost inner upper support strip of the upper window support strip assembly to connect the inner cardboard tube inside the upper cable exit device with the adjacent first layer cardboard tube. This not only defines the position of the first layer cardboard tube inside the upper cable exit device and the position of the first window above it, facilitating the assembly and positioning of subsequent layers of cardboard tubes and cardboard rings, but also ensures the support strength inside the upper cable exit device. Furthermore, the number of cardboard tube layers and cardboard ring layers can be set as needed, allowing for flexible installation.

[0022] 7. The present invention has a voltage equalization ball protective plate inside the voltage equalization ball assembly. When wiring, the lead cable can be inserted into the lead shield tube along the inclined surface of the voltage equalization ball protective plate. This can prevent the lead cable from getting stuck outside the voltage equalization ball and causing insulation discharge. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of the structure of the present invention.

[0024] Figure 2 for Figure 1 A sectional view of the upper and middle part of the cable outlet device.

[0025] Figure 3 for Figure 2 A three-dimensional sectional view of the upper and middle cable outlet device.

[0026] Figure 4 for Figure 3 Enlarged view of the middle section of the upper-middle cable outlet device.

[0027] Figure 5 for Figure 1 A schematic diagram showing the state of the upper middle cable outlet device when the window is closed.

[0028] Figure 6 for Figure 5 Enlarged view of point A in the image.

[0029] Figure 7 for Figure 1 A schematic diagram showing the state of the upper middle cable outlet device window when it is open.

[0030] Figure 8 for Figure 7 A three-dimensional sectional view of the upper and middle cable outlet device.

[0031] Figure 9 for Figure 8 Enlarged view of the middle section of the upper-middle cable outlet device.

[0032] Figure 10 for Figure 2 Main view of the interlocking support strip structure.

[0033] Figure 11 for Figure 2 The main view showing the interaction between the upper support strip of the middle window and the corresponding lower support strip.

[0034] Figure 12 for Figure 2 Front view of the cardboard ring.

[0035] Figure 13 for Figure 1 A cross-sectional view of the structure of the equalizing pressure ball assembly.

[0036] Figure 14 for Figure 1 Enlarged view of point K in the image.

[0037] Wherein, 1 is a sleeve, 2 is an upper cable exit device, 201 is an inner cardboard tube, 202 is a support strip assembly, 2021 is an inner support strip, 2022 is an interlocking support strip, 2023 is a supporting support strip, 2024 is a first lower inlet, 2025 is a cardboard tube groove, 2026 is a first upper mounting hole, 2027 is a first lower mounting hole, 203 is a cardboard tube, 204 is a window upper support strip assembly, 2041 is an inner upper support strip, 2042 is a window upper support strip, 2043 is an upper limit groove, 2044 is a second upper mounting hole, 205 is a window lower support strip assembly, 2051 is an inner lower support strip, 20... 52 is the interlocking lower support bar, 2053 is the supporting lower support bar, 2054 is the second limiting groove, 2055 is the second lower insert, 2056 is the second lower mounting hole, 206 is the cardboard ring, 2061 is the limiting bayonet, 2062 is the second window, 3 is the sleeve riser, 301 is the hand hole, 302 is the upper flange, 303 is the lower flange, 4 is the equalizing ball assembly, 401 is the metal equalizing ball, 402 is the equalizing ball slurry layer, 403 is the equalizing ball protective plate, 404 is the external forming assembly, 4041 is the external forming part, 4042 is the external support bar, 405 is the flange plate, and 5 is the lead wire shielding tube. Detailed Implementation

[0038] The invention will now be described in further detail with reference to the accompanying drawings.

[0039] like Figure 1 As shown, the present invention includes a sleeve riser 3, and the sleeve riser 3 is provided with an upper cable outlet device 2 and a lower pressure equalizing ball assembly 4. The lower end of the sleeve 1 is inserted into the sleeve riser 3 and passes through the upper cable outlet device 2; as shown Figures 2-9 As shown, the upper cable outlet device 2 includes multiple layers of cardboard tubes 203, and each layer of cardboard tube 203 has a first window on the side facing the handhole 301 of the sleeve riser 3. Each layer of cardboard tube 203 has a rotatable cardboard ring 206 fitted on its outer side, and a second window 2062 is provided on one side of the cardboard ring 206. Figure 7 As shown, when connecting sleeve 1, the second window 2062 is moved by the cardboard ring 206 to a position coinciding with the corresponding first window; as Figures 2-3 As shown, the upper cable exit device 2 includes a support strip assembly 202, and the support strip assembly 202 includes interlocking support strips 2022 and supporting support strips 2023 arranged alternately from the inside to the outside, wherein a cardboard tube 203 is provided between adjacent interlocking support strips 2022 and supporting support strips 2023, as shown. Figure 10 As shown, both the inner side of the fitting support bar 2022 and the inner side of the supporting support bar 2023 are provided with paper tube grooves 2025 for accommodating the corresponding cardboard rings 206, such as... Figures 5-6 and Figure 12As shown, the lower end of the cardboard ring 206 is provided with a limiting slot 2061, and the limiting slot 2061 is embedded in the lower end groove wall of the corresponding paper tube ring groove 2025; as Figures 13-14 As shown, the equalizing ball assembly 4 includes multiple externally formed parts 4041 with exposed upper ends, such as... Figure 10 As shown, the lower end of the fitting support bar 2022 is provided with a first lower fitting opening 2024, and the first lower fitting opening 2024 is fitted with the upper end of the corresponding outer forming part 4041.

[0040] When wiring this invention, the operator first lifts the outermost cardboard ring 206 so that its lower end limiting slot 2061 disengages from the lower end groove wall of the corresponding paper tube ring groove 2025. At this time, the operator can rotate the cardboard ring 206 so that the second window 2062 on this layer of cardboard ring 206 rotates to coincide with the first window on the inner corresponding paper tube 203. Then the operator repeats the above process, rotating each layer of cardboard ring 206 in turn until... Figure 7 The window shown is in the open state. However, for ease of operation, the heights of the first window on each layer of cardboard tube 203 and the second window 2062 on each layer of cardboard ring 206 differ, specifically as follows: Figure 7 As shown, the height of the first window and the second window 2062 on each layer gradually decreases from the outside to the inside, which facilitates the workers to lift the cardboard rings 206 on each layer sequentially from the outside to the inside. And when the upper cable outlet device 2... Figure 7 After the window is opened, the operator's hand reaches through the handhole 301 of the sleeve riser 3, and through each of the first and second windows 2062 to the inside of the upper cable outlet device 2 to complete the connection of the lead cable at the lower end of the sleeve 1, or to observe the internal condition of the upper cable outlet device 2. After completing the relevant work, the operator then rotates each layer of cardboard rings 206 from the inside out to close the first window on each layer of cardboard tube 203 until... Figure 5 All the windows shown are closed.

[0041] like Figures 2-5 As shown, in order to ensure operation, the window of the upper cable outlet device 2 needs to have a sufficient area. In order to ensure the support strength at the window, the upper side of the first window of each layer of cardboard tube 203 is provided with an upper window support strip assembly 204 and the lower side is provided with a lower window support strip assembly 205.

[0042] like Figures 2-4 and Figure 11 As shown, in this embodiment, the window upper support strip assembly 204 includes multiple window upper support strips 2042, and a cardboard tube 203 is provided between adjacent window upper support strips 2042. The lower side of the window upper support strip 2042 is provided with an upper limit groove 2043, and the upper side of each layer of cardboard ring 206 is respectively provided in the corresponding upper limit groove 2043.

[0043] like Figures 2-3 and Figure 11 As shown, in this embodiment, the window lower support strip assembly 205 includes a fitted lower support strip 2052 and a supporting lower support strip 2053 arranged alternately from the inside to the outside. The fitted lower support strip 2052 has a first limiting groove at its upper end that supports the corresponding cardboard ring 206, and the bottom of the first limiting groove is fitted with the corresponding limiting slot 2061. The supporting lower support strip 2053 has a second limiting groove 2054 at its upper end that supports the corresponding cardboard ring 206, and the bottom of the second limiting groove 2054 is fitted with the corresponding limiting slot 2061.

[0044] like Figures 2-3 and Figure 11 As shown, in this embodiment, the lower end of the fitting lower support bar 2052 is provided with a second lower fitting opening 2055, and the second lower fitting opening 2055 is fitted with the upper end of the corresponding outer forming part 4041 in the pressure equalizing ball assembly 4.

[0045] like Figures 2-3 As shown, in this embodiment, the support strip assembly 202 includes an inner support strip 2021 located on the innermost side, the lower window support strip assembly 205 includes an inner lower support strip 2051 located on the innermost side, and the upper window support strip assembly 204 includes an inner upper support strip 2041 located on the innermost side. The inner sides of the inner support strip 2021 and the inner lower support strip 2051 are both fixedly connected to an inner cardboard tube 201. The outer sides of the inner support strip 2021, the inner lower support strip 2051, and the inner upper support strip 2041 are all fixedly connected to an adjacent first cardboard tube 203. A spatial distance is formed between the inner upper support strip 2041 and the inner lower support strip 2051 to expose the first window on the first cardboard tube 203.

[0046] like Figures 2-3 As shown, in this embodiment, the inner support strip 2021 differs from the other support strips in the support strip assembly 202 in that: the inner support strip 2021 does not have a paper tube ring groove 2025, and the upper end of the inner lower support strip 2051 does not have a limiting groove, and the lower end of the inner upper support strip 2041 does not have an upper limit groove 2043. The inner cardboard tube 201, inner support strip 2021, inner lower support strip 2051, and inner upper support strip 2041 together support and define the position of the first layer cardboard tube 203 inside the upper cable outlet device 2 and the position of the first window thereon. This facilitates the subsequent assembly and positioning of each layer of cardboard tube 203 and each layer of cardboard ring 206. At the same time, the number of layers of cardboard tube 203 and cardboard ring 206 can be set according to actual needs, making installation flexible.

[0047] like Figures 2-3As shown, in this embodiment, the lower end of the inner support strip 2021 is provided with a third lower inlet, and the lower end of the inner lower support strip 2051 is provided with a fourth lower inlet. The third lower inlet and the fourth lower inlet are respectively fitted into the upper end of the corresponding outer forming part 4041 in the pressure equalizing ball assembly 4.

[0048] like Figures 2-3 As shown, in this embodiment, the upper ends of the inner support strip 2021, the upper ends of the fitting support strip 2022, and the upper ends of the supporting support strip 2023 of the support strip assembly 202 are all provided with first upper mounting holes 2026, and the lower ends of the inner support strip 2021, the lower ends of the fitting support strip 2022, and the lower ends of the supporting support strip 2023 of the support strip assembly 202 are all provided with first lower mounting holes 2027. The first upper mounting holes 2026 and the first lower mounting holes 2027 are used to connect each layer of cardboard tube 203 and each layer of support strips. Additionally, as shown... Figure 14 As shown, the first lower mounting hole 2027 is also used to connect with the outer molded part 4041 exposed at the upper end of the pressure equalizing ball assembly 4.

[0049] like Figures 2-3 As shown in this embodiment, the upper ends of the inner upper support strip 2041 and the upper ends of the window upper support strip 2042 of the window upper support strip assembly 204 are provided with second upper mounting holes 2044 for connecting with the cardboard tube 203. The lower ends of the inner lower support strip 2051, the lower ends of the fitting lower support strip 2052 and the lower ends of the supporting lower support strip 2053 of the window lower support strip assembly 205 are provided with second lower mounting holes 2056 for connecting with the cardboard tube 203 and the equalizing ball assembly 4.

[0050] like Figures 13-14 As shown, in this embodiment, the equalizing ball assembly 4 includes a metal equalizing ball 401 and an external forming assembly 404 disposed outside the metal equalizing ball 401. The external forming assembly 404 includes outer support strips 4042 and outer forming parts 4041 arranged alternately from the inside to the outside. Figure 14 As shown, the upper end of the outer support strip 4042 contacts the lower end of the corresponding support strip in the support strip assembly 202, and also contacts the lower end of the corresponding support strip in the window lower support strip assembly 205. The main body of the outer forming part 4041 is in the shape of a circular sleeve to mate with the corresponding cardboard tube 203. In addition, the lower end of the outer forming assembly 404 is provided with an opening, and the lower end of the metal equalizing ball 401 is provided with a flange plate 405 with a through hole in the middle. The end of the lead wire shielding tube 5 passes through the opening at the lower end of the outer forming assembly 404 and is welded and fixed to the flange plate 405. The lead cable connected to the lower end of the sleeve 1 is placed in the lead wire shielding tube 5.

[0051] like Figure 13As shown, in this embodiment, the outer side of the metal equalizing ball 401 is provided with an equalizing ball pulp coating layer 402 (pulp coating), and a first layer outer support strip 4042 is provided between the equalizing ball pulp coating layer 402 and the adjacent first layer outer forming part 4041. The upper end of the metal equalizing ball 401 is provided with an equalizing ball protective plate 403, and the lower end of the equalizing ball protective plate 403 contacts the first layer outer support strip 4042 and is provided between the equalizing ball pulp coating layer 402 and the first layer outer forming part 4041. Figure 1 As shown, the upper ends of the equalizing ball protective plate 403 and the outer forming part 4041 of the first layer are both inserted into the inner cardboard tube 201 of the upper cable outlet device 2. Figure 1 As shown, after the end of the sleeve 1 is connected to the lead cable, the sleeve 1 will descend a set distance. During this process, the lead cable can slide into the metal equalizing ball 401 along the inclined surface of the equalizing ball protective plate 403, thereby preventing the lead cable from getting stuck outside the metal equalizing ball 401 and causing insulation discharge.

[0052] like Figure 1 As shown, in this embodiment, the upper end of the sleeve riser 3 is provided with an upper flange 302 and the lower end is provided with a lower flange 303. The sleeve 1 is provided with a sleeve flange fixed to the upper flange 302, and the lower end of the upper cable outlet device 2 is fixed to the lower flange 303.

[0053] The working principle of this invention is as follows:

[0054] The wiring process of this invention includes the following steps:

[0055] Step 1: As Figures 5-6 As shown, the operator puts their hand into the hand hole 301 and lifts the outermost cardboard ring 206 so that the limiting slot 2061 at the lower end of the cardboard ring 206 disengages from the lower end groove wall of the corresponding paper tube ring groove 2025 in the support strip assembly 202. Then the operator rotates the outermost cardboard ring 206 so that the second window 2062 on the cardboard ring 206 coincides with the position of the first window on the inner corresponding cardboard tube 203.

[0056] Step Two: The operator repeats Step One to ensure that the second window on each layer of cardboard ring 206 coincides with the first window on the corresponding cardboard tube 203, thus achieving the desired effect. Figure 7 As shown, all the windows on the upper cable outlet device 2 are opened to expose the inner cardboard tube 201 inside.

[0057] Step 3: The sleeve 1 is placed in the upper cable outlet device 2 by hoisting, and the position of the lead wire connection at the lower end of the sleeve 1 corresponds to the position of the window opened in the upper cable outlet device 2. The operator's hand is inserted through the hand hole 301 on one side of the sleeve lifting seat 3 and enters the device through the window of the upper cable outlet device 2 to complete the connection between the lower end of the sleeve 1 and the lead cable.

[0058] Step 4: After completing the lead cable connection, as follows Figure 1 As shown, the operator controls the hoisting equipment to lower the sleeve 1 by a set distance so that the lower end of the sleeve 1 enters the equalizing ball assembly 4. During this process, the lead cable can slide along the equalizing ball protective plate 403 into the metal equalizing ball 401, thereby preventing the lead cable from getting stuck outside the metal equalizing ball 401 and causing insulation discharge.

[0059] Step 5: The operator fixes the sleeve flange on sleeve 1 to the upper flange 302 of sleeve riser 3, thereby completing the installation of sleeve 1.

[0060] Step Six: The operator inserts their hand into the handhole 301 and lifts and rotates the innermost cardboard ring 206 to close the first window on the innermost cardboard tube 203. This operation is repeated until each layer of cardboard ring 206 closes the cardboard tube 203 in sequence, until... Figure 5 The windows of each layer of the upper cable outlet device 2 shown are in the closed state.

[0061] During the aforementioned wiring and installation process, each time the cardboard ring 206 rotates to its final position and is lowered, the various limiting latches 2061 at its lower end re-engage and reposition themselves with the lower groove wall of the corresponding paper tube ring groove 2025, thereby preventing the cardboard ring 206 from rotating. Furthermore, this invention forms an observation and operation window for the upper cable exit device 2 by rotating each layer of cardboard rings 206, without damaging the structure of each layer of cardboard tubes 203. Therefore, it does not affect the safety margin of the upper cable exit device 2 and reduces reliance on significant adjustments to the position of the sleeve 1 or the tie rod structure sleeve, ensuring the quality and reliability of the wiring installation of the sleeve 1.

Claims

1. A window-type bushing connection structure for ultra-high voltage transformers, characterized in that: The device includes a sleeve riser (3), and the sleeve riser (3) is provided with an upper cable outlet device (2) inside and a pressure equalizing ball assembly (4) at the lower end. The lower end of the sleeve (1) is inserted into the sleeve riser (3) and passes through the upper cable outlet device (2). The upper cable outlet device (2) includes a multi-layer cardboard tube (203), and the cardboard tube (203) is provided with a first window on the side facing the hand hole (301) of the sleeve riser (3). A cardboard ring (206) is sleeved on the outside of the cardboard tube (203), and a second window (2062) is provided on one side of the cardboard ring (206). The second window (2062) is rotated and moved by the cardboard ring (206) to a position that coincides with the corresponding first window. The upper cable outlet device (2) includes a support bar assembly (202), and the support bar assembly (202) is provided with a support bar assembly (202). The assembly includes interlocking support strips (2022) and supporting support strips (2023) arranged alternately from the inside to the outside, with cardboard tubes (203) provided between adjacent interlocking support strips (2022) and supporting support strips (2023); both the inner side of the interlocking support strip (2022) and the inner side of the supporting support strip (2023) are provided with cardboard tube grooves (2025) for accommodating cardboard rings (206), the lower end of the cardboard ring (206) is provided with a limiting slot (2061), and the limiting slot (2061) is embedded in the lower end groove wall of the corresponding cardboard tube groove (2025); the pressure equalizing ball assembly (4) includes multiple outer forming parts (4041) with exposed upper ends, the lower end of the interlocking support strip (2022) is provided with a first lower insert (2024), and the first lower insert (2024) is fitted with the upper end of the corresponding outer forming part (4041).

2. The open-window bushing connection structure for ultra-high voltage transformers according to claim 1, characterized in that: Each layer of cardboard tube (203) has an upper window support strip assembly (204) on the upper side of the first window and a lower window support strip assembly (205) on the lower side.

3. The open-window bushing connection structure for ultra-high voltage transformers according to claim 2, characterized in that: The window support strip assembly (204) includes multiple window support strips (2042), and cardboard tubes (203) are provided between adjacent window support strips (2042). The lower side of the window support strip (2042) is provided with an upper limit groove (2043), and the upper side of each layer of cardboard ring (206) is respectively provided in the corresponding upper limit groove (2043).

4. The open-window bushing connection structure for ultra-high voltage transformers according to claim 2, characterized in that: The window support strip assembly (205) includes a mating support strip (2052) and a supporting support strip (2053) arranged alternately from the inside to the outside. The mating support strip (2052) has a first limiting groove at its upper end that supports the corresponding cardboard ring (206), and the bottom of the first limiting groove is fitted with the corresponding limiting slot (2061). The supporting support strip (2053) has a second limiting groove (2054) at its upper end that supports the corresponding cardboard ring (206), and the bottom of the second limiting groove (2054) is fitted with the corresponding limiting slot (2061).

5. The open-window bushing connection structure for ultra-high voltage transformers according to claim 4, characterized in that: The lower end of the fitting lower support bar (2052) is provided with a second lower fitting (2055), and the second lower fitting (2055) fits into the upper end of the corresponding outer forming part (4041) in the pressure equalizing ball assembly (4).

6. The open-window bushing connection structure for ultra-high voltage transformers according to claim 2, characterized in that: The support strip assembly (202) includes an inner support strip (2021) located on the innermost side. The lower support strip assembly (205) includes an inner lower support strip (2051) located on the innermost side. The upper support strip assembly (204) includes an inner upper support strip (2041) located on the innermost side. The inner sides of the inner support strip (2021) and the inner lower support strip (2051) are both fixedly connected to an inner cardboard tube (201). The outer sides of the inner support strip (2021), the inner lower support strip (2051), and the inner upper support strip (2041) are all fixedly connected to an adjacent first layer cardboard tube (203).

7. The open-window bushing connection structure for ultra-high voltage transformers according to claim 6, characterized in that: The lower end of the inner support strip (2021) is provided with a third lower inlet, and the lower end of the inner layer lower support strip (2051) is provided with a fourth lower inlet. The third lower inlet and the fourth lower inlet are respectively fitted into the upper end of the corresponding outer forming part (4041) in the pressure equalizing ball assembly (4).

8. The open-window bushing connection structure for ultra-high voltage transformers according to claim 1, characterized in that: The equalizing ball assembly (4) includes a metal equalizing ball (401) and an external forming assembly (404) disposed outside the metal equalizing ball (401). The external forming assembly (404) includes an outer support strip (4042) and an outer forming part (4041) arranged alternately from the inside to the outside. The lower end of the external forming assembly (404) is provided with an opening. The lower end of the metal equalizing ball (401) is provided with a flange plate (405) with a through hole in the middle. The end of the lead wire shielding tube (5) passes through the lower end opening of the external forming assembly (404) and is fixedly connected to the flange plate (405).

9. The open-window bushing connection structure for ultra-high voltage transformers according to claim 8, characterized in that: The metal equalizing ball (401) is provided with an equalizing ball slurry layer (402) on its outer side, and a first layer outer support strip (4042) is provided between the equalizing ball slurry layer (402) and the adjacent first layer outer forming part (4041). The metal equalizing ball (401) is provided with an equalizing ball protective plate (403) at its upper end, and the lower end of the equalizing ball protective plate (403) contacts the first layer outer support strip (4042) and is located between the equalizing ball slurry layer (402) and the first layer outer forming part (4041). The upper wire outlet device (2) is provided with an inner layer cardboard tube (201), and the upper ends of the equalizing ball protective plate (403) and the first layer outer forming part (4041) are inserted into the inner layer cardboard tube (201). The upper end of the outer support strip (4042) contacts the lower end of the support strip assembly (202).

10. The open-window bushing connection structure for ultra-high voltage transformers according to claim 1, characterized in that: The upper end of the sleeve riser (3) is provided with an upper flange (302) and the lower end is provided with a lower flange (303). The sleeve (1) is provided with a sleeve flange fixed on the upper flange (302), and the lower end of the upper cable outlet device (2) is fixed on the lower flange (303).

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