Vacuum casting spacer, mold and manufacturing method for 110kV dry-type transformer

Abstract

This application relates to the field of transformer spacer technology, and provides a vacuum casting spacer, mold, and manufacturing method for a 110kV dry-type transformer. The spacer includes a resin spacer body; a first top surface is provided on the top of the resin spacer body; the first top surface is provided with a first platform, a second platform, and a first slot; the first slot is located between the first platform and the second platform; the first slot is used to install a high-voltage insulating cylinder located between the low-voltage coil and the high-voltage coil; a protrusion is provided at the front end of the resin spacer body; a second top surface is provided on the top of the protrusion; the second top surface is provided with a second slot; the second slot is used to install a low-voltage insulating cylinder located between the core and the low-voltage coil. By adding a second slot for the low-voltage insulating cylinder, insulation failure is effectively avoided. The mold is cast under vacuum or negative pressure environment, resulting in high casting quality and good molding quality of the resin spacer body.

Description

Technical Field

[0001] This invention belongs to the field of transformer pad technology, specifically relating to a vacuum casting pad, mold, and manufacturing method for a 110kV dry-type transformer. Background Technology

[0002] Dry-type transformers are mainly composed of an iron core made of silicon steel sheets and coils cast with epoxy resin. An insulating cylinder is placed between the high-voltage and low-voltage coils to increase electrical insulation, and the coils are supported and constrained by pads. The pads are bolted to the metal clamps of the transformer. The function of the pads is to support and fasten the high-voltage and low-voltage coils, and at the same time to provide insulation between the coils and the metal clamps at both ends.

[0003] In existing dry-type transformers, the coils are first supported by pads during assembly. Then, the safe distances between the low-voltage coil and the core column, and between the high-voltage coil and the low-voltage coil are adjusted. Finally, the pads are pressed between the high-voltage and low-voltage coils to ensure the safe distances. For example, the insulating pads proposed in patent document CN217181983U are equipped with slots for installing high-voltage insulating cylinders located between the high-voltage and low-voltage coils.

[0004] In previous designs, epoxy fiberglass boards or similar materials were used as support components between the low-voltage coil and the core column. However, for 110kV dry-type transformers, the withstand voltage performance between the core and the low-voltage coil also needs to be considered. Therefore, a low-voltage insulating cylinder needs to be added between the low-voltage coil and the core; otherwise, discharge from the low-voltage coil to the core will break down the insulation layer between them, causing insulation failure. However, existing spacers only have slots for installing the high-voltage insulating cylinder between the high-voltage and low-voltage coils, and cannot accommodate the low-voltage insulating cylinder. If a new, separate spacer is used to support the low-voltage coil and the core, it would result in too many spacers arranged circumferentially between the high-voltage and low-voltage coils of the transformer, affecting the heat dissipation performance of the heat dissipation channel between the high-voltage and low-voltage coils.

[0005] In addition, previous designs used epoxy fiberglass boards to support the low-voltage coil and the core, lacking vibration elasticity margin. This caused electromagnetic resonance between the low-voltage coil and the core, significantly increasing the overall noise of the transformer. Furthermore, dry-type transformers vibrate continuously during use, causing the core pads to shift and the core to loosen, ultimately leading to increased noise during operation.

[0006] Therefore, there is a need for a pad suitable for 110kV dry-type transformers that can simultaneously install high and low voltage insulating cylinders and effectively reduce noise. Summary of the Invention

[0007] To address the problems in the prior art, this application proposes a vacuum casting pad, mold, and manufacturing method for a 110kV dry-type transformer. By adding a slot for the low-voltage insulating cylinder, insulation failure is effectively avoided. At the same time, an offset monitoring component is set to effectively monitor the offset of the pad installed on the transformer, so as to correct and tighten the pad in time and avoid increased noise.

[0008] In a first aspect, the present invention proposes a vacuum casting pad for a 110kV dry-type transformer, wherein the 110kV dry-type transformer includes an iron core, a low-voltage coil, a high-voltage coil, and metal clamps; the vacuum casting pad includes a resin pad body and an offset monitoring component.

[0009] The resin pad body has a first top surface on its top; the first top surface has a first platform, a second platform, and a first slot; the first slot is located between the first platform and the second platform; the first slot is used to install a high-voltage insulating cylinder located between the low-voltage coil and the high-voltage coil; the front end of the resin pad body has a protrusion; the top of the protrusion has a second top surface; the second top surface is lower than the first top surface; the second top surface has a second slot; the second slot is used to install a low-voltage insulating cylinder located between the iron core and the low-voltage coil; the rear end and two sides of the resin pad body have umbrella skirts; the bottom of the resin pad body is connected to the metal clamp.

[0010] The offset monitoring component includes: a pad cantilever plate, a clamp cantilever plate, a calibration post, a calibration disk, and a concentric marking ring group; one end of the pad cantilever plate is connected to the resin pad body, and the other end is a cantilever end, with a reference through hole provided on the pad cantilever plate; a circular concentric marking ring group is nested within the reference through hole; one end of the clamp cantilever plate is connected to the metal clamp, and the other end is a cantilever end; a vertical calibration post is provided on the clamp cantilever plate; the calibration post passes through the center of the concentric marking ring group; a circular calibration disk is provided on the calibration post, the calibration disk is located inside the concentric marking ring group, and the outer edge of the calibration disk and the inner edge of the concentric marking ring are radially spaced; the center of the calibration disk coincides with the center of the concentric marking ring group; a height scale line is provided on the calibration post along its height direction.

[0011] Furthermore, the surface of the pad cantilever plate is also concentrically provided with an annular azimuth disk outside the concentric marking ring group; the azimuth disk is provided with a plurality of azimuth scale lines pointing to the center of the circle along the circumference; the surface of the pad cantilever plate is provided with a reference pointer pointing to the azimuth scale line outside the azimuth disk; the calibration disk is provided with a measuring pointer pointing radially to the azimuth scale line.

[0012] By combining the reference pointer, the measuring pointer, and the azimuth scale, the angle of rotation of the pad cantilever plate relative to the calibration plate on the horizontal plane can be monitored, so as to determine whether the resin pad body has deflected and the specific deflection angle, so as to promptly reset and tighten the resin pad body.

[0013] Furthermore, the calibration plate is provided with an L-shaped cantilever rod, which includes a vertical rod and a horizontal rod; the vertical rod is connected to the calibration plate, one end of the vertical rod is connected to the horizontal rod, and the other end of the horizontal rod is cantilevered above the concentric marking ring group and connected to the measuring pointer.

[0014] By mounting the measuring pointer above the concentric marking ring group via an L-shaped cantilever rod, it is not only easier to obtain the scale on the azimuth line pointed to by the measuring pointer, but also to determine whether the resin pad body has horizontal displacement by measuring the initial projection position of the measuring pointer on the concentric marking ring group and the real-time projection position after the transformer has been running for a period of time. The degree of displacement of the resin pad body can be determined by measuring the centrifugal distance of the real-time projection position of the measuring pointer, so as to reset and tighten the resin pad body in a timely manner.

[0015] Furthermore, the concentric marking ring group includes multiple concentric rubber rings of different diameters, which are nested and connected sequentially from the outside to the inside; the surfaces of the multiple concentric rubber rings are coated with coatings of different colors.

[0016] Different concentric rubber rings are coated with different colors to distinguish them, so as to quickly determine the real-time projection position of the measuring pointer and compare it with the color of the concentric rubber ring corresponding to the real-time projection position of the previous measurement to determine the degree of offset of the resin pad body.

[0017] Furthermore, the bottom of the resin pad body is provided with a positioning groove, and pre-embedded nuts are provided on at least two sides of the positioning groove; the metal clamp is provided with a pad connecting bolt, and a pad connecting assembly is provided between the metal clamp and the resin pad body. The top of the pad connecting assembly is filled in the positioning groove, and the pad connecting bolt passes through the pad connecting assembly and connects with the pre-embedded nuts.

[0018] By cooperating with the positioning groove and the pad connecting assembly, the resin pad body can be quickly positioned and installed on the metal clamp. The pad connecting assembly also restricts the horizontal displacement of the resin pad body, ensuring the effective fixation of the resin pad body.

[0019] Furthermore, the pad connecting assembly includes a positioning connecting plate and an annular rubber pad; the top of the positioning connecting plate is provided with a positioning boss; the side wall of the positioning boss is provided with a first inclined surface; the annular rubber pad has an annular structure, its outer wall is tightly fitted with the inner wall of the positioning groove, and the inner wall is provided with a second inclined surface that is tightly fitted with the first inclined surface; the top of the positioning boss is tightly fitted with the bottom of the positioning groove.

[0020] The annular rubber pad facilitates flexible contact between the positioning connecting plate and the resin pad body, providing vibration elasticity margin for the resin pad body. Furthermore, the pressing fit between the first and second inclined surfaces increases the contact area between the positioning connecting plate and the annular rubber pad. The annular rubber pad surrounds the positioning boss, limiting its horizontal displacement and providing a certain degree of cushioning to the resin pad body without causing displacement.

[0021] Furthermore, a temperature sensor and a pressure sensor are also embedded in the sidewall of the resin pad body.

[0022] The temperature sensor can obtain the working environment temperature of the resin pad body in real time, and the pressure sensor can obtain the pressure value of the resin pad body in real time, so as to judge the working status of the transformer based on the working environment temperature and pressure value and detect problems in time.

[0023] The vacuum casting pad of this invention features a protrusion at the front end of the resin pad body and a second slot at the top of the protrusion for installing a low-voltage insulating cylinder located between the iron core and the low-voltage coil. This effectively prevents insulation failure caused by discharge breakdown of the low-voltage coil to the iron core in a 110kV dry-type transformer, meeting market demands. The first slot is used to install a high-voltage insulating cylinder located between the low-voltage coil and the high-voltage coil. The first and second slots effectively limit the displacement of the resin pad body, coil, and iron core, improving transformer product quality. An offset monitoring component is installed at the connection between the resin pad body and the metal clamp. The horizontal offset direction and amount of the resin pad body are determined by the relative position change of the calibration disk and the concentric marking ring group of the offset monitoring component. The vertical offset direction and amount of the resin pad body are determined by the position of the height scale line on the calibration column of the concentric marking ring group. This allows for timely correction and tightening of the resin pad body, preventing increased transformer noise caused by loosening of the resin pad body.

[0024] Secondly, the present invention also proposes a 110kV dry-type transformer pad casting mold for manufacturing the aforementioned vacuum casting pad. The mold includes a top plate, a bottom plate, a front plate, and two side plates. The front plate and the two side plates are connected to form a vertically penetrating mold cavity. The inner walls of the side plates are provided with horizontal recesses. The bottom plate is closed at the bottom of the mold cavity and is connected to the front plate and the two side plates respectively. The top plate is closed at the top of the mold cavity and is connected to the two side plates. The top plate is provided with an injection port, an air hole, and an observation port communicating with the mold cavity. The bottom of the top plate is provided with a first bottom surface, a second bottom surface, and a partition plate in sequence. The partition plate is located between the first bottom surface and the second bottom surface. The bottom of the top plate is provided with a hanging extension between the first bottom surface and the front plate. The bottom of the hanging extension is provided with a third bottom surface, and the third bottom surface is provided with a vertical recess. The height of the third bottom surface is lower than the bottom height of the partition plate.

[0025] Furthermore, a fourth bottom surface is provided at the bottom of the top plate, located between the first bottom surface and the second bottom surface; the top of the partition is located at the fourth bottom surface; the height of the first bottom surface and / or the second bottom surface is located between the fourth bottom surface and the bottom of the partition.

[0026] The 110kV dry-type transformer pad casting mold of the present invention forms a closed mold cavity by means of a top plate, a bottom plate, a front plate, and two side plates. The bottom of the top plate has overhanging extensions, vertical recesses, and partitions of different heights. Castable material is injected into the mold cavity through the injection port on the top plate, filling the entire cavity and resulting in high-quality molding of the pad's outer contour surface. Furthermore, the overhanging extensions, partitions, and top plate are an integral structure, eliminating the need for separate assembly and disassembly. This ensures high-quality molding of the grooves on the pad for installing the insulating cylinder. In particular, the pad can be integrally formed into multiple planes of different heights for installing high and low voltage coils and insulating cylinders, making it suitable for producing 110kV dry-type transformer pads. Additionally, excess castable material can overflow from the injection port, filling the space below the bottom plate within the mold cavity. This results in a flat platform for the produced pad, preventing material shortages and further improving the molding quality of the pad.

[0027] Thirdly, the present invention also proposes a method for manufacturing a vacuum casting pad for a 110kV dry-type transformer, using the aforementioned 110kV dry-type transformer pad casting mold; the manufacturing method includes the following steps:

[0028] Assemble the casting mold for the 110kV dry-type transformer pad block;

[0029] The assembled 110kV dry-type transformer pad block casting mold is placed into a vacuum container;

[0030] Using a vacuum pumping device connected to the vacuum container, a vacuum process is performed on the vacuum container and the 110kV dry-type transformer pad casting mold inside the vacuum container, so that the 110kV dry-type transformer pad casting mold is in a vacuum or negative pressure environment.

[0031] Using a casting pipe, the casting material is injected into the mold cavity through the injection port of the 110kV dry-type transformer pad casting mold until the casting material fills the mold cavity, forming the resin pad body;

[0032] After the resin pad body reaches the design strength, the 110kV dry-type transformer pad casting mold is removed.

[0033] The method of the present invention involves placing the assembled mold into a vacuum container, so that the mold is in a vacuum or negative pressure environment for casting. The casting material can quickly fill the mold cavity, there will be no casting dead corners, the casting quality is high, and the molding quality of the resin pad block body is good. Attached Figure Description

[0034] Figure 1 This is a three-dimensional structural diagram of the vacuum casting pad for the 110kV dry-type transformer of the present invention.

[0035] Figure 2 for Figure 1 A schematic diagram of the three-dimensional structure from another perspective.

[0036] Figure 3 This is a front view of the vacuum casting pad for the 110kV dry-type transformer of the present invention.

[0037] Figure 4 for Figure 3 A side view diagram.

[0038] Figure 5 for Figure 4 A top-down view.

[0039] Figure 6 This is a schematic diagram of the structure of the vacuum casting pad for the 110kV dry-type transformer of the present invention, which is installed on a metal clamp.

[0040] Figure 7 for Figure 6 A partial cross-sectional structural diagram.

[0041] Figure 8 for Figure 7 3D exploded view of the middle pad block connecting assembly.

[0042] Figure 9 for Figure 7 A three-dimensional structural diagram of the offset monitoring component.

[0043] Figure 10 for Figure 9 An enlarged structural diagram.

[0044] Figure 11 This is a three-dimensional structural diagram of the front and top plates of the 110kV dry-type transformer pad casting mold of the present invention after disassembly.

[0045] Figure 12 for Figure 11 A three-dimensional structural diagram of the top plate, a side plate, and a cast-in-place pad.

[0046] Figure 13 for Figure 12 A schematic diagram of the structure after the middle pad block is hidden.

[0047] Figure 14 for Figure 11 A schematic diagram of the structure after the two side plates are enclosed.

[0048] Figure 15 for Figure 13 Enlarged structural diagram of the central top plate.

[0049] Figure 16 for Figure 15 A schematic diagram of the main structure of the top plate.

[0050] Figure 17 for Figure 16 A top-view structural diagram.

[0051] Figure 18 for Figure 16 A schematic diagram of the structure viewed from below.

[0052] In the figure, 10-resin pad body; 11-first platform; 12-second platform; 13-first slot; 14-protrusion; 15-second slot; 16-positioning hole; 17-umbrella skirt; 18-positioning groove;

[0053] 19-Metal clamp; 20-Pack connecting assembly; 21-Pack connecting bolt; 22-Embedded nut; 23-Positioning connecting plate; 24-Annular rubber pad; 25-Positioning boss; 26-First inclined surface; 27-Second inclined surface;

[0054] 30-Offset monitoring component; 31-Padded block cantilever plate; 32-Clamping cantilever plate; 33-Calibration column; 34-Calibration disc; 35-Concentric marking ring group; 36-Height scale line; 37-Azimuth disc; 38-Azimuth scale line; 39-Reference pointer; 310-Measuring pointer; 311-L-shaped cantilever rod;

[0055] 410-Top plate; 411-Injection port; 412-Observation port; 413-Air hole; 414-Threaded lifting hole; 415-Suspended extension; 416-Vertical recess; 417-First bottom surface; 418-Second bottom surface; 419-Third bottom surface; 4110-Fourth bottom surface; 4111-Partition plate; 420-Bottom plate; 421-Positioning protrusion; 422-Second sealing groove; 430-Front plate; 440-Side plate; 441-Horizontal recess; 442-First sealing groove; 450-Mounting hole. Detailed Implementation

[0056] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0057] like Figure 1 , Figure 2 , Figure 3 The vacuum casting pad for a 110kV dry-type transformer shown includes a resin pad body 10; the top of the resin pad body 10 is provided with a first top surface; the first top surface is provided with a first platform 11, a second platform 12 and a first slot 13; the first slot 13 is located between the first platform 11 and the second platform 12; the front end of the resin pad body 10 is provided with a protrusion 14; the top of the protrusion 14 is provided with a second top surface; the second top surface is lower than the first top surface; the second top surface is provided with a second slot 15; the rear end and two sides of the resin pad body 10 are provided with umbrella skirts 17.

[0058] In this embodiment, the resin pad body 10, the protrusion 14, and the umbrella skirt 17 are all integrally molded by vacuum casting.

[0059] A 110kV dry-type transformer includes an iron core, a low-voltage coil, and a high-voltage coil arranged sequentially from the inside out; a low-voltage insulating cylinder is installed between the iron core and the low-voltage coil, and a high-voltage insulating cylinder is installed between the low-voltage coil and the high-voltage coil.

[0060] The first slot 13 is used to install the high-voltage insulating cylinder located between the low-voltage coil and the high-voltage coil. The second slot 15 is used to install the low-voltage insulating cylinder located between the iron core and the low-voltage coil.

[0061] By providing a protrusion 14 at the front end of the resin pad body 10 and a second slot 15 at the top of the protrusion 14 for installing a low-voltage insulating cylinder located between the iron core and the low-voltage coil, the insulation failure caused by the discharge breakdown of the low-voltage coil to the iron core of the 110kV dry-type transformer can be effectively avoided, thus meeting market demand.

[0062] The first slot 13 and the second slot 15 effectively restrict the displacement of the resin pad body 10, the coil and the iron core, thereby improving the quality of the transformer product.

[0063] like Figure 4 As shown, there are multiple first slots 13, which are spaced apart. In this embodiment, there are four first slots 13, and correspondingly, the high-voltage insulating cylinder can adopt a four-layer structure, with the end of the high-voltage insulating cylinder inserted into the first slot 13. If the high-voltage insulating cylinder adopts a three-layer structure, then the corresponding first slots 13 can be set to three.

[0064] Positioning holes 16 are respectively provided on the first platform 11 and the second platform 12. The positioning holes 16 are used for positioning the buffer pads installed on the first platform 11 and the second platform 12. Specifically, before the end face of the low-voltage coil contacts the first platform 11, a buffer pad is installed on the first platform 11, and the buffer pad is positioned and fixed using the positioning holes 16 on the first platform 11. After the buffer pad is installed on the first platform 11, the end face of the low-voltage coil contacts the buffer pad. Similarly, before the end face of the high-voltage coil contacts the second platform 12, a buffer pad is also installed on the second platform 12, and the buffer pad is positioned and fixed using the positioning holes 16 on the second platform 12. After the buffer pad is installed on the second platform 12, the end face of the high-voltage coil contacts the buffer pad. In practice, the low-voltage coil and the high-voltage coil should only make contact after the buffer pads on both the first platform 11 and the second platform 12 have been installed.

[0065] like Figure 5 As shown, the second slot 15 is an arc-shaped slot. There are multiple second slots 15, spaced apart. In this embodiment, there are two second slots 15, spaced apart along the radial direction of their arc-shaped slots. Figure 1 , Figure 5 As shown, the end face of the resin pad body 10 without the protrusion 14 is an arc surface, which is used to contact the outer wall of the low-voltage insulating cylinder.

[0066] The walls of the first slot 13 and the second slot 15 are inclined surfaces. Since the resin pad body 10, the protrusion 14 and the umbrella skirt 17 in this embodiment are integrally molded by vacuum casting, the inner walls of the first slot 13 and the second slot 15 are provided with inclined surfaces to facilitate demolding, and the vertical cross section of the umbrella skirt 17 is also triangular.

[0067] like Figure 1 , Figure 4 As shown, one end of the umbrella skirt 17 on the side of the resin pad body 10 extends to the protrusion 14. Figure 4 As shown, at least one umbrella skirt 17 is provided between the horizontal plane of the bottom of the first slot 13 and the horizontal plane of the second top surface of the resin pad body 10. Figure 2 As shown, the bottom of the resin pad body 10 is provided with a positioning groove 18. The positioning groove 18 is used for the installation and positioning of the vacuum casting pad in the transformer, and can also limit the lateral displacement of the vacuum casting pad.

[0068] The bottom of the resin pad body 10 is provided with a positioning groove 18, and pre-embedded nuts 22 are provided on at least two sides of the positioning groove 18. Figure 6 , Figure 7 As shown, a pad connecting bolt 21 is provided on the metal clamp 19, and a pad connecting assembly 20 is provided between the metal clamp 19 and the resin pad body 10. The top of the pad connecting assembly 20 is filled in the positioning groove, and the pad connecting bolt 21 passes through the pad connecting assembly 20 and is connected to the pre-embedded nut 22. Figure 8 As shown, the pad connecting assembly 20 includes a positioning connecting plate 23 and an annular rubber pad 24; the top of the positioning connecting plate 23 is provided with a positioning boss 25; the side wall of the positioning boss 25 is provided with a first inclined surface 26; the annular rubber pad 24 has an annular structure, its outer wall is tightly fitted with the inner wall of the positioning groove, and its inner wall is provided with a second inclined surface 27 that is tightly fitted with the first inclined surface 26; the top of the positioning boss 25 is tightly fitted with the bottom of the positioning groove. The pad connecting bolt 21 passes through the positioning connecting plate 23 and is connected to the pre-embedded nut 22.

[0069] like Figure 6 , Figure 9 , Figure 10 As shown, the vacuum casting pad for 110kV dry-type transformers also includes an offset monitoring component 30, which includes: a pad cantilever plate 31, a clamping cantilever plate 32, a calibration column 33, a calibration disk 34, and a concentric marking ring group 35.

[0070] One end of the pad cantilever plate 31 is connected to the resin pad body 10, and the other end is the cantilever end. A reference through hole is provided on the pad cantilever plate 31. A circular concentric marking ring group 35 is nested in the reference through hole.

[0071] One end of the clamp cantilever plate 32 is connected to the metal clamp 19, and the other end is a cantilever end; a vertical calibration post 33 is provided on the clamp cantilever plate 32; the calibration post 33 passes through the center of the concentric marking ring group 35; a circular calibration disk 34 is provided on the calibration post 33, the calibration disk 34 is located inside the concentric marking ring group 35, and the outer edge of the calibration disk 34 and the inner edge of the concentric marking ring maintain a radial distance; the calibration disk 34 coincides with the center of the concentric marking ring group 35; a height scale line 36 is provided on the calibration post 33 along its height direction.

[0072] The pad cantilever plate 31 and the clamping cantilever plate 32 are clamped at the upper and lower ends of the metal clamp 19. The pad cantilever plate 31 is bolted to the resin pad body 10, and any displacement of the resin pad body 10 can be transmitted to the pad cantilever plate 31. The clamping cantilever plate 32 is fixed to the metal clamp 19 by bolts. The metal clamp 19 is fixed relative to the resin pad body 10. During transformer operation or transportation, the metal clamp 19 will not move, but the resin pad body 10 may shift. Therefore, the pad cantilever plate 31 may shift relative to the clamping cantilever plate 32.

[0073] The surface of the pad cantilever plate 31 is also concentrically provided with an annular azimuth disk 37 on the outside of the concentric marking ring group 35; the azimuth disk 37 is provided with a plurality of azimuth scale lines 38 pointing to the center of the circle along the circumferential direction; the surface of the pad cantilever plate 31 is provided with a reference pointer 39 pointing to the azimuth scale line 38 on the outside of the azimuth disk 37; the calibration disk 34 is provided with a measuring pointer 310 pointing to the azimuth scale line 38 in the radial direction.

[0074] The calibration plate 34 is provided with an L-shaped cantilever rod 311, which includes a vertical rod and a horizontal rod. The vertical rod is connected to the calibration plate 34, and one end of the vertical rod is connected to the horizontal rod. The other end of the horizontal rod is cantilevered above the concentric marking ring group 35 and is connected to a measuring pointer 310.

[0075] The concentric marking ring group 35 includes multiple concentric rubber rings of different diameters, nested sequentially from the outside to the inside; the surfaces of the multiple concentric rubber rings are coated with coatings of different colors. For example, in this embodiment, there are three concentric rubber rings, with coating colors of red, yellow, and green from the outside to the inside. When the orthogonal projection of the measuring pointer 310 onto the concentric marking ring group 35 is on the red concentric rubber ring, the offset of the resin pad body 10 is very large, requiring immediate adjustment and re-fixing. When the orthogonal projection of the measuring pointer 310 onto the concentric marking ring group 35 is on the green concentric rubber ring, the offset of the resin pad body 10 is small, requiring continuous observation of the offset of the resin pad body 10. When the orthogonal projection of the measuring pointer 310 onto the concentric marking ring group 35 is on the yellow concentric rubber ring, it indicates a large offset of the resin pad body 10, requiring adjustment of the position of the resin pad body 10 and increased observation frequency.

[0076] Since the measuring pointer 310 is positioned above the concentric marking ring group 35 via the L-shaped cantilever rod 311, there is a height difference between the measuring pointer 310 and the pad cantilever plate 31 or the concentric marking ring group 35. When the pad cantilever plate 31 moves vertically or jumps relative to the clamping cantilever plate 32, the concentric marking ring group 35 usually does not collide with the measuring pointer 310. If the measuring pointer 310 is impacted or squeezed by the concentric marking ring group 35, it indicates that the vertical offset of the resin pad body 10 is very large, and the position needs to be adjusted and re-fixed immediately. Similarly, the vertical offset of the pad cantilever plate 31 can be determined by the position of the height scale line 36 corresponding to the horizontal projection of the pad cantilever plate 31 on the calibration column 33.

[0077] Regarding the horizontal offset, the horizontal offset and direction of the resin pad body 10 can be roughly determined by visually measuring the distance between the inner sides of the calibration disk 34 and the concentric mark ring group 35. For example, when the distance between the right side of the calibration disk 34 and the concentric mark ring group 35 is less than the distance between the left side of the calibration disk 34 and the concentric mark ring group 35, the resin pad body 10 is offset to the left. Similarly, when the distance between the right side of the calibration disk 34 and the concentric mark ring group 35 is greater than the distance between the left side of the calibration disk 34 and the concentric mark ring group 35, the resin pad body 10 is offset to the right.

[0078] Since multiple resin pad bodies 10 are arranged circumferentially along the high and low voltage coils or windings of the transformer, the resin pad bodies 10 may rotate around the centerline of the high and low voltage coils at a certain angle, while the metal clamps remain fixed. Therefore, the pad cantilever plate 31 and the clamp cantilever plate 32 deflect at an angle, and the corresponding position of the measuring pointer 310 on the azimuth scale line 38 changes. After the transformer is installed and commissioned, when the resin pad body 10 is in its initial position, the measuring pointer 310 and the reference pointer 39 are pointing in opposite directions. However, when the resin pad body 10 deflects, the measuring pointer 310 is no longer aligned with the reference pointer 39. The angle between the azimuth scale line 38 pointed to by the measuring pointer 310 and the azimuth scale line 38 pointed to by the reference pointer 39 is the deflection angle of the resin pad body 10.

[0079] To better monitor the transformer, temperature and pressure sensors are also embedded in the sidewalls of the resin pad body 10. The temperature sensor can obtain the operating ambient temperature of the resin pad body 10 in real time, and the pressure sensor can obtain the pressure value of the resin pad body 10 in real time, so as to determine the operating status of the transformer based on the operating ambient temperature and pressure values ​​and detect problems in a timely manner.

[0080] Based on the same inventive concept, this invention also proposes a 110kV dry-type transformer pad casting mold for manufacturing the aforementioned resin pad body 10. For example... Figures 11-18As shown, the mold of the present invention includes a top plate 410, a bottom plate 420, a front plate 430, and two side plates 440.

[0081] The front plate 430 and two side plates 440 are connected to form a vertically penetrating mold cavity; the inner wall of the side plate 440 is provided with a horizontal recess 441; the inner wall of each side plate 440 is provided with multiple horizontal recesses 441 along the height direction, and the horizontal recesses 441 are used for forming the umbrella skirt of the pad block. The horizontal cross-section of the side plate 440 is an L-shaped plate. The short sides of two side plates 440 are spliced ​​together, and the long sides are arranged opposite each other to form a U-shaped structure with a horizontal cross-section. After the two side plates 440 are spliced ​​together, the horizontal recesses 441 at the same horizontal height are connected one by one.

[0082] The front panel 430 is an arched structure that is set vertically.

[0083] The base plate 420 is enclosed at the bottom of the mold cavity and is connected to the front plate 430 and the two side plates 440 respectively. The top of the base plate 420 is provided with a positioning protrusion 421, which is used for forming the positioning groove at the bottom of the pad block.

[0084] The top plate 410 is enclosed at the top of the mold cavity and connected to the two side plates 440; the front plate 430 and the two side plates 440 surround and clamp the top plate 410, and similarly, the front plate 430 and the two side plates 440 surround and clamp the bottom plate 420. In this embodiment, the top of the top plate 410 is on the same horizontal plane as the top of the front plate 430 and the side plates 440, and the bottom of the bottom plate 420 is on the same horizontal plane as the bottom of the front plate 430 and the side plates 440.

[0085] like Figure 11 As shown, the front plate 430, side plate 440, top plate 410, and bottom plate 420 are all provided with horizontal mounting holes 450. These mounting holes 450 can be threaded holes. The side plate 440 has both transverse and longitudinal mounting holes 450 in the horizontal direction, where transverse refers to the width direction of the side plate 440, and longitudinal refers to the length direction of the side plate 440. The mounting holes 450 on the front plate 430 are aligned with the longitudinal mounting holes 450 on the side plate 440 and are connected by bolts. The mounting holes 450 on the top plate 410 are aligned with the transverse mounting holes 450 in the upper area of ​​the side plate 440 and are connected by bolts. The mounting holes 450 on the bottom plate 420 are aligned with the transverse mounting holes 450 in the lower area of ​​the side plate 440 and are connected by bolts. Through the mounting holes 450 and the bolt connections, the front plate 430, side plate 440, top plate 410, and bottom plate 420 are tightly connected as a single unit.

[0086] To ensure a tight seal, such as Figure 13 , Figure 14As shown, the mating end faces of the two side plates 440 and the mating end faces of the side plates 440 and the front plate 430 are provided with first sealing grooves 442; the front plate 430 and the two side plates 440 surround and clamp the bottom plate 420; the bottom plate 420 is provided with a second sealing groove 422 around its perimeter, and the second sealing groove 422 communicates with the first sealing groove 442; sealing strips are provided in the first sealing groove 442 and the second sealing groove 422. Under the action of the sealing strips, it is difficult for the castable refractory to seep out.

[0087] like Figures 15-18 As shown, the top plate 410 is provided with a sprue port 411 and an observation port 412 communicating with the mold cavity; the bottom of the top plate 410 is provided with a first bottom surface 417, a second bottom surface 418 and a partition plate 4111 in sequence; the partition plate 4111 is located between the first bottom surface 417 and the second bottom surface 418; the sprue port 411 penetrates through the first bottom surface 417; the observation port 412 penetrates through the second bottom surface 418. The observation port 412 and the sprue port 411 are respectively located at both ends of the top plate 410, which facilitates the observation of the pouring situation in the mold cavity through the observation port 412. When both the observation port 412 and the sprue port 411 overflow, the mold cavity is filled with pouring material.

[0088] A cantilever extension 415 is provided at the bottom of the top plate 410 between the first bottom surface 417 and the front plate 430. The cantilever extension 415 and the top plate 410 are integrally formed. A third bottom surface 419 is provided at the bottom of the cantilever extension 415, and a vertical recess 416 is provided on the third bottom surface 419. The height of the third bottom surface 419 is lower than the bottom height of the partition plate 4111. The inner wall of the vertical recess 416 is an arc surface.

[0089] like Figure 16 As shown, a fourth bottom surface 4110 is also provided between the bottom of the top plate 410 and the second bottom surface 417; the top of the partition plate 4111 is located on the fourth bottom surface 4110; the height of the first bottom surface 417 and / or the second bottom surface 418 is between the fourth bottom surface 4110 and the bottom of the partition plate 4111. There are multiple partition plates 4111, which are spaced apart. Figure 16 As shown, four partitions 4111 are provided.

[0090] In this embodiment, as Figure 16 The first bottom surface 417, the second bottom surface 418, the third bottom surface 419, and the fourth bottom surface 4110 shown are all horizontal planes. The distances between the third bottom surface 419, the bottom of the partition 4111, the fourth bottom surface 4110, and the top of the top plate 410 decrease sequentially. Among them, the first bottom surface 417 and the second bottom surface 418 are on the same horizontal plane, and the height of the first bottom surface 417 and the second bottom surface 418 is between the bottom of the partition 4111 and the fourth bottom surface 4110.

[0091] The top plate 410 is provided with vents 413 that communicate with the mold cavity; the vents 413 are distributed between the partitions 4111. Due to the function of the partitions 4111, it is difficult to vent air in the space between the partitions 4111. In order to ensure the casting quality of the space between the partitions 4111, vents 413 are provided in the corresponding area between the partitions 4111 of the top plate 410 so that the air in the space between the partitions 4111 can be discharged through the vents 413 during casting.

[0092] It should be noted that, in this embodiment, when the mold is being cast, the entire mold is placed in a negative pressure or vacuum environment, and then vacuum casting is performed through the injection port 411. Because it is in a negative pressure or vacuum environment, the casting material can fill the mold cavity completely, and there will be no voids, resulting in better molding quality.

[0093] The top plate 410 is provided with threaded lifting holes 414. The threaded lifting holes 414 are distributed in four directions of the top plate 410 and are evenly and symmetrically arranged. During lifting, the lifting ring is tightened into the threaded lifting hole 414 through the stud, and then the lifting ring is connected by a wire rope. The other end of the wire rope is connected to the crane, and the crane is used to lift the mold to the designated area.

[0094] After pouring is completed, when demolding, remove the bolts in the mounting hole 450, first remove the front plate 430, then separate the side plate 440, then pull the top plate 410 upwards, and then separate the formed pad from the bottom plate 420.

[0095] In some embodiments, a vacuum container is also included. The 110kV dry-type transformer spacer casting mold is located inside the vacuum container, and the 110kV dry-type transformer spacer casting mold is in a vacuum environment during spacer casting. The vacuum container includes an openable door or plate. Opening the door or plate allows the 110kV dry-type transformer spacer casting mold to be placed inside the vacuum container. The vacuum container is connected to a vacuum pumping device. After the door or plate is closed, the vacuum pumping device is used to evacuate the vacuum container, thereby placing the 110kV dry-type transformer spacer casting mold in a vacuum environment. The vacuum container is also connected to a casting pipe. One end of the casting pipe extends outside the vacuum container, and the other end connects to the injection port 411. The casting material is introduced through the casting pipe into the injection port 411 and then fills the mold cavity.

[0096] In addition, the inner wall of the mold cavity in this embodiment is designed with a taper or slope to facilitate mold demolding.

[0097] Based on the same inventive concept, this invention also proposes a method for manufacturing a vacuum casting pad for a 110kV dry-type transformer, using the aforementioned 110kV dry-type transformer pad casting mold; the manufacturing method includes the following steps:

[0098] Assemble the casting mold for 110kV dry-type transformer pad blocks;

[0099] The assembled 110kV dry-type transformer pad block casting mold is placed into a vacuum container;

[0100] Using a vacuum pumping device connected to a vacuum container, a vacuum process is performed on the vacuum container and the 110kV dry-type transformer pad casting mold inside the vacuum container, so that the 110kV dry-type transformer pad casting mold is in a vacuum or negative pressure environment.

[0101] Using a casting pipe, the casting material is injected into the mold cavity through the injection port of the 110kV dry-type transformer pad casting mold until the casting material fills the mold cavity and forms the resin pad body.

[0102] After the resin pad body reaches the design strength, the 110kV dry-type transformer pad casting mold is removed.

[0103] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A vacuum-cast spacer for a 110kV dry-type transformer, wherein the 110kV dry-type transformer comprises an iron core, a low-voltage coil, a high-voltage coil, and metal clamps; characterized in that, The vacuum casting pad includes a resin pad body and an offset monitoring component; The resin pad body has a first top surface on its top; the first top surface has a first platform, a second platform, and a first slot; the first slot is located between the first platform and the second platform; the first slot is used to install a high-voltage insulating cylinder located between the low-voltage coil and the high-voltage coil; the front end of the resin pad body has a protrusion; the top of the protrusion has a second top surface; the second top surface is lower than the first top surface; the second top surface has a second slot; the second slot is used to install a low-voltage insulating cylinder located between the iron core and the low-voltage coil; The rear end and two sides of the resin pad body are provided with umbrella skirts; the bottom of the resin pad body is connected to the metal clamp. The offset monitoring component includes: a pad cantilever plate, a clamp cantilever plate, a calibration post, a calibration disk, and a concentric marking ring group; One end of the pad cantilever plate is connected to the resin pad body, and the other end is a cantilever end. A reference through hole is provided on the pad cantilever plate. A set of concentric marking rings is nested in the reference through hole. One end of the clamp cantilever plate is connected to the metal clamp, and the other end is a cantilever end. A vertical calibration post is provided on the clamp cantilever plate. The calibration post passes through the center of the concentric marking ring set. A circular calibration disk is provided on the calibration post. The calibration disk is located inside the concentric marking ring set. The outer edge of the calibration disk and the inner edge of the concentric marking rings are radially spaced. The center of the calibration disk coincides with the center of the concentric marking ring set. A height scale line is provided on the calibration post along its height direction.

2. The vacuum-cast spacer for a 110kV dry-type transformer according to claim 1, characterized in that, The surface of the pad cantilever plate is also concentrically provided with an annular azimuth disk outside the concentric marking ring group; the azimuth disk is provided with a plurality of azimuth scale lines pointing to the center of the circle along the circumference; the surface of the pad cantilever plate is provided with a reference pointer pointing to the azimuth scale line outside the azimuth disk; the calibration disk is provided with a measuring pointer pointing radially to the azimuth scale line.

3. The vacuum casting pad for a 110kV dry-type transformer according to claim 2, characterized in that, The calibration plate is equipped with an L-shaped cantilever rod, which includes a vertical rod and a horizontal rod. The vertical rod is connected to the calibration plate, and one end of the vertical rod is connected to the horizontal rod. The other end of the horizontal rod is cantilevered above the concentric marking ring group and is connected to the measuring pointer.

4. The vacuum casting pad for a 110kV dry-type transformer according to claim 3, characterized in that, The concentric marking ring group includes multiple concentric rubber rings of different diameters, which are nested and connected sequentially from the outside to the inside; the surfaces of the multiple concentric rubber rings are coated with coatings of different colors.

5. The vacuum-cast spacer for a 110kV dry-type transformer according to claim 1, characterized in that, The bottom of the resin pad body is provided with a positioning groove, and pre-embedded nuts are provided on at least two sides of the positioning groove; the metal clamp is provided with a pad connecting bolt, and a pad connecting assembly is provided between the metal clamp and the resin pad body. The top of the pad connecting assembly is filled in the positioning groove, and the pad connecting bolt passes through the pad connecting assembly and is connected to the pre-embedded nuts.

6. The vacuum-cast spacer for a 110kV dry-type transformer according to claim 5, characterized in that, The pad connecting assembly includes a positioning connecting plate and an annular rubber pad; the top of the positioning connecting plate is provided with a positioning boss; the side wall of the positioning boss is provided with a first inclined surface; the annular rubber pad has an annular structure, its outer wall is tightly fitted with the inner wall of the positioning groove, and the inner wall is provided with a second inclined surface that is tightly fitted with the first inclined surface; the top of the positioning boss is tightly fitted with the bottom of the positioning groove.

7. The vacuum-cast spacer for a 110kV dry-type transformer according to claim 1, characterized in that, Temperature sensors and pressure sensors are also embedded in the sidewalls of the resin pad body.

8. A casting mold for a 110kV dry-type transformer pad, used to manufacture the vacuum casting pad as described in claim 1, characterized in that, The mold includes a top plate, a bottom plate, a front plate, and two side plates; the front plate and the two side plates are connected to form a vertically penetrating mold cavity; the inner walls of the side plates are provided with horizontal recesses; the bottom plate is closed at the bottom of the mold cavity and is connected to the front plate and the two side plates respectively; the top plate is closed at the top of the mold cavity and is connected to the two side plates; the top plate is provided with an injection port, an air hole, and an observation port communicating with the mold cavity; the bottom of the top plate is provided with a first bottom surface, a second bottom surface, and a partition plate in sequence; the partition plate is located between the first bottom surface and the second bottom surface; the bottom of the top plate is provided with a hanging extension between the first bottom surface and the front plate; the bottom of the hanging extension is provided with a third bottom surface, and the third bottom surface is provided with a vertical recess; the height of the third bottom surface is lower than the bottom height of the partition plate.

9. The 110kV dry-type transformer pad casting mold according to claim 8, characterized in that, The bottom of the top plate is located between the first bottom surface and the second bottom surface, and a fourth bottom surface is also provided; the top of the partition is located on the fourth bottom surface; the height of the first bottom surface and / or the second bottom surface is located between the fourth bottom surface and the bottom of the partition.

10. A method for manufacturing a vacuum-cast spacer block for a 110kV dry-type transformer, characterized in that, The manufacturing method employs the 110kV dry-type transformer pad casting mold as described in claim 8; the manufacturing method includes the following steps: Assemble the casting mold for the 110kV dry-type transformer pad block; The assembled 110kV dry-type transformer pad block casting mold is placed into a vacuum container; Using a vacuum pumping device connected to the vacuum container, a vacuum process is performed on the vacuum container and the 110kV dry-type transformer pad casting mold inside the vacuum container, so that the 110kV dry-type transformer pad casting mold is in a vacuum or negative pressure environment. Using a casting pipe, the casting material is injected into the mold cavity through the injection port of the 110kV dry-type transformer pad casting mold until the casting material fills the mold cavity, forming the resin pad body; After the resin pad body reaches the design strength, the 110kV dry-type transformer pad casting mold is removed.

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