Method for pressing body of low-noise shunt reactor

Abstract

The invention belongs to the field of shunt reactors, and relates to a low-noise shunt reactor body pressing method, which comprises the following steps: placing a pressing plate at the end part of a reactor body, and forming a round hole I in the center of the pressing plate; soft belt grooves with bending radians are formed in the portions, on the two sides of the first round hole, of the pressing plate, a second insulating plate is placed above the pressing plate, a second round hole is formed in the center of the second insulating plate, and a second cushion block and a third cushion block are bonded to the second insulating plate; two device body magnetic shields of a U-shaped structure are placed above the second insulating plate, a magnetic shielding gap filling piece is placed in a gap of the device body magnetic shields, the magnetic shielding gap filling piece comprises a pair of filling blocks and a pair of fan-shaped plates which are of an integrated structure, and first cushion blocks are bonded to the fan-shaped plates; an insulating plate I is arranged above the transformer body magnetic shield, and an upper iron yoke is arranged above the insulating plate I; the soft belt is placed in the soft belt groove, and pressure is applied into the soft belt to press the transformer body; and after pressing is completed, the soft belt is withdrawn. Under the condition that no redundant tool is used, the soft belt is used for pressing the transformer body, and it is guaranteed that the transformer body is evenly stressed.

Description

Technical Field

[0001] The invention belongs to the technical field of shunt reactors, and in particular relates to a method for compacting a body of a low-noise shunt reactor. Background Art

[0002] Shunt reactors are essential core components in ultra-high voltage (UHV) transmission networks, crucial for maintaining the safe and efficient operation of the entire transmission system. Despite their significant role in transmission networks, the noise and vibration generated during their operation pose numerous challenges to the robust implementation and long-term maintenance of transmission and transformation projects.

[0003] Low-noise shunt reactors are designed to fundamentally reduce vibration and noise levels, so compaction of the reactor body is crucial. Currently, shunt reactor bodies are compacted using hydraulic cylinders. However, this type of compaction allows the hydraulic cylinder to be positioned only above the reactor body, outside the yoke, and is unable to compact the reactor body below the yoke.

[0004] To ensure uniform force during compression, low-noise shunt reactors use a soft-belt press-fit method. However, because the magnetic shield of the device is made of silicon steel sheets bonded with resin, direct pressure on the shield can easily cause cracking. Due to the influence of the magnetic shielding at the ends of the device, the existing soft-belt press-fit method requires the production of a large number of pressing fixtures to meet the requirements. This not only makes the pressing process cumbersome, but also results in material waste due to the production of multiple pressing fixtures. Summary of the Invention

[0005] In response to the above technical problems, the present invention provides a novel low-noise shunt reactor body compression method. The design scheme for achieving the objectives of the present invention is as follows: A novel low-noise shunt reactor body compression method uses a soft belt to compress the body, including the following steps: A pressure plate is placed above the end of the body, and the lower part of the pressure plate is an end ring. The pressure plate is a square plate, and a circular hole is provided at the center of the pressure plate for the upper end of the core column to pass through; a plurality of soft belt grooves with curved arcs are symmetrically provided on the upper surface of the pressure plate on both sides of the circular hole, and the ends of the soft belt grooves extend to the two side edges of the pressure plate; A second insulating plate is placed above the pressing plate. The second insulating plate is a square plate. The size of the second insulating plate is larger than the pressing plate. A second circular hole is provided at the center of the second insulating plate for the upper end of the core column to pass through. A plurality of second spacers are bonded to the upper surface of the second insulating plate. A plurality of third spacers are bonded to the upper surface of the second insulating plate around the second circular hole. Two U-shaped magnetic shields of the device body are symmetrically placed above the insulating plate two on both sides of the circular hole two, and a magnetic shield gap filler is placed in the gap between the two magnetic shields of the device body. A circular hole three is provided at the center of the magnetic shield gap filler for the upper end of the core column to pass through. The magnetic shield gap filler includes a pair of filling blocks and a pair of fan-shaped plates of an integral structure. The thickness of the filling blocks is greater than the thickness of the fan-shaped plates. The pair of filling blocks are arranged opposite to each other, and the pair of fan-shaped plates are arranged opposite to each other. The filling blocks and the fan-shaped plates are located on the outer periphery of the circular hole three; the filling blocks have the same thickness as the magnetic shield of the device body, and a number of pads are bonded to the pair of fan-shaped plates. The edge positions of the two magnetic shields of the device body are pressed above the fan-shaped plates and the pads. An insulating plate 1 is placed above the magnetic shields of the two device bodies. The structure and size of the insulating plate 1 are the same as those of the insulating plate 2. An upper iron yoke is placed above the insulating plate 1. Place the soft belt in the soft belt groove and apply the required pressure to the soft belt to tighten the device body; After the device body is compacted, insert the fourth pad into the gap between the adjacent soft belts, release the pressure on the soft belt and remove it from the soft belt groove, insert the fifth pad into the soft belt groove, and tie the fourth and fifth pads to the insulating board two to form a whole.

[0006] Preferably, the pressing plate is made of laminated paperboard with a thickness of ≥50 mm.

[0007] Preferably, four protrusions are symmetrically fixedly provided on the inner circumference of the circular hole of the pressing plate.

[0008] Preferably, the second insulating plate is made of polyester material.

[0009] Preferably, the fan-shaped plate is a molded part made of kraft pulp.

[0010] Preferably, the filling block is made of polyester material.

[0011] Beneficial effects of the present invention: The method for compacting the body of a low-noise shunt reactor of the present invention improves the structural design of the end of the body and can compact the body with a soft belt without using redundant tooling, thereby ensuring uniform force on the body and improving the overall rigidity of the body, and having the value of wide promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 This is a structural diagram of an embodiment of the present invention in which the upper portion of the body is compressed by a soft belt; Figure 2 2. It is a schematic structural diagram of the magnetic shielding of the device body and the magnetic shielding gap filling member according to an embodiment of the present invention; Figure 3 2 is a schematic structural diagram of a magnetic shielding gap filler according to an embodiment of the present invention; Figure 4 is a structural schematic diagram of an insulating plate 2 according to an embodiment of the present invention; Figure 5 2 is a schematic structural diagram of a pressing plate according to an embodiment of the present invention; Figure 6 Schematic diagram of a curve showing a change equation of soft band pressure and height according to an embodiment of the present invention; Among them, 1. upper iron yoke, 2. insulating plate 1, 3. magnetic shield of the device body, 4. insulating plate 2, 5. pressing plate, 6. filling block, 7. soft belt, 8. soft belt groove, 9. fan-shaped plate, 10. pad 1, 11. pad 2, 12. pad 3. DETAILED DESCRIPTION

[0013] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, but not all of the embodiments.

[0014] In order to reduce the end magnetic leakage of the low-noise inductor, a body magnetic shield 3 is placed at the end of the inductor body. The body magnetic shield 3 is made of silicon steel sheets bonded with resin. The body magnetic shield 3 is divided into two symmetrical pieces, one on the outgoing line side and one on the cooling side. The body magnetic shield 3 is "U"-shaped, and there is a long gap between the two body magnetic shields 3.

[0015] like Figure 1-5 As shown, a novel low-noise shunt reactor body pressing method includes the following steps: A pressure plate 5 is placed above the end of the device body, and the lower part of the pressure plate 5 is an end ring. The pressure plate 5 is a square plate with a certain thickness. The pressure plate 5 is made of laminated cardboard with a thickness of ≥50mm. A circular hole is opened at the center of the pressure plate 5 for the upper end of the core column to pass through. Four protrusions are symmetrically fixed on the inner circumference of the circular hole. The protrusions are used to position the pressure plate 5 during installation. Three arc-shaped soft belt grooves 8 are symmetrically opened on the upper surface of the pressure plate 5 on the left and right sides of the circular hole. The two ends of the soft belt grooves 8 extend to the two side edges of the pressure plate 5. The soft belt 7 used to press the device body is placed in the soft belt grooves 8. Since the coil is circular, in order to ensure that each soft belt 7 can be pressed on the radial position of the coil with the maximum area, the soft belt grooves 8 of the pressure plate 5 have a curved arc.

[0016] An insulating plate 2 (4) is placed above the pressure plate 5. A circular hole (2) is provided in the center of the insulating plate 2 (4) for the upper end of the core column to pass through. The insulating plate 2 (4) is made of a hot-pressed polyester material with good compressive strength. Several pads (2) are bonded and fixed to the upper surface of the insulating plate 2 (4). Several pads (3) are bonded and fixed to the upper surface of the insulating plate 2 (4) around the circular hole (2). The insulating plate 2 (4) is a square plate larger than the outer edge of the pressure plate 5. The insulating plate 2 (4) is made of a polyester material with better hardness and heat resistance than cardboard. The insulating plate 2 (4) is placed between the soft belt 7 and the device body magnetic shield 3 to prevent direct force on the device body magnetic shield 3 during compression. Pads (2) (11) and (3) (12) act as oil channels, facilitating oil flow and heat dissipation.

[0017] Two magnetic shields 3 are placed above insulating plate 2 4 . A magnetic shield gap filler is placed in the long gap between the two magnetic shields 3 . A circular hole 3 is defined in the center of the magnetic shield gap filler for the upper end of the core leg to pass through. The magnetic shield gap filler comprises a pair of integral filler blocks 6 and a pair of sector plates 9 . The filler blocks 6 are thicker than the sector plates 9 . The pair of filler blocks 6 are positioned opposite each other, and the pair of sector plates 9 are positioned opposite each other. The filler blocks 6 and sector plates 9 are positioned around the periphery of the circular hole 3 . The pair of filler blocks 6 are positioned between the two magnetic shields 3 . The filler blocks 6 have the same thickness as the magnetic shields 3 . The filler blocks 6 are typically made of a polyester material with good hardness and heat resistance. The filler blocks 6 are used for leveling. Several spacers 10 are bonded and fixed to the pair of sector plates 9 . Both the sector plates 9 and the sector plates 10 are thin plates. The sector plates 9 are formed from kraft pulp and are used to increase creepage distance. The spacers 10 are made of polyester and are used for oil flow and heat dissipation. The edges of the two magnetic shields 3 are pressed on the fan-shaped plate 9 and the pad 10.

[0018] An insulating plate 1 2 is placed above the two magnetic shields 3 of the device body. The insulating plate 2 4 has the same structure as the insulating plate 1 2 , and the upper iron yoke 1 is placed above the insulating plate 1 2 .

[0019] When compacting the device body, the upper and lower iron yokes 1 and 2 are fixedly connected. The flexible strips 7 are placed in the flexible strip grooves 8 of the pressure plate 5, and the pressure required by the design drawings is applied to the flexible strips 7 to compact the device body. After compacting the device body, prefabricated spacers 4 are inserted into the gaps between adjacent flexible strips 7. The pressure on the flexible strips 7 is released until they are flat. The flexible strips 7 are then removed from the flexible strip grooves 8, and prefabricated spacers 5 are inserted into the grooves. All inserted spacers 4 and 5 are then tied together with the insulating plate 2 4.

[0020] The following are the specific implementation steps of a device body compression method: Insert the soft belt 7 into the soft belt groove 8, install a locking handle at one end of the soft belt 7, connect the other end of the soft belt 7 to the "soft belt pressing equipment", start the vacuum system of the "soft belt pressing equipment" (the soft belt pressing equipment is an existing product) to vacuum the soft belt 7 until the soft belt 7 is flat and there is no gas; seal the other end of the soft belt 7 with the oil injection and pressurization system of the "soft belt pressing equipment" through a pipe joint and a switch valve, start the oil injection and pressurization system of the "soft belt pressing equipment", pressurize it to the design pressure, and check that there is no abnormality in the soft belt 7 and there is no obvious deformation of the pressure plate 5.

[0021] Pressurize to the rated pressure, maintain the pressure for 5 minutes, and measure the height of the coil and the soft belt 7. According to the height of the soft belt 7, the pressure value for the next pressurization is obtained by querying the equation curve of the soft belt pressure and height change. Figure 6 As shown, Figure 6 The vertical axis is k = actual pressure / design pressure, and the horizontal axis is the height of the soft band 7. Repeat the above steps until the designed rated pressure and coil height requirements are met.

[0022] Start the oil return system of the "soft belt pressing equipment" to recover the transformer oil in the soft belt 7; remove the locking handle at the end of the soft belt 7 and take the soft belt 7 out of the soft belt groove 8.

[0023] The following are specific implementation steps of a method for making the soft belt 7: The flexible belt 7 can be made of a fire hose. The steps for making the flexible belt 7 are as follows: Select a section of fire hose and trim the head (one end) of the fire hose with scissors to ensure that the cut end of the fire hose is straight; Select a sleeve and a tapered pin that match the fire hose. The center position of the tapered pin in the longitudinal direction is a through tubular structure. One end of the sleeve is closed and has a through hole for the small end of the tapered pin to pass through. The diameter of the through hole is smaller than the diameter of the large end of the tapered pin. The small end of the tapered pin is provided with an external thread. By tightening the fastening nut on the external thread, the tapered pin and the sleeve can be fixedly connected into one. The inner diameter of the sleeve matches the outer diameter of the large end of the tapered pin. The inner diameter of the sleeve is slightly larger than the outer diameter of the large end of the tapered pin. The gap between the sleeve and the large end of the tapered pin needs to be able to accommodate the fire hose through interference fit. The inner diameter of the fire hose matches the outer diameter of the large end of the tapered pin. The outer diameter of the large end of the tapered pin is slightly smaller than the inner diameter of the fire hose. The head end of the fire hose can be interference fit on the large end of the tapered pin. Use a marker to mark the outer surface of the fire hose at the same depth as the cutout at the head of the fire hose. Hold the conical pin and secure the sleeve in a bench vise. Loosen the fastening nut at the small end of the conical pin and pull the conical pin out of the sleeve. Insert the large end of the conical pin into the head of the fire hose, then insert the small end of the conical pin into the sleeve. According to the markings on the outer surface of the fire hose, check whether the cut at the head of the fire hose has reached the bottom of the sleeve. When the cut at the head of the fire hose reaches the bottom of the sleeve, tighten the fastening nut at the small end of the tapered pin. Install the sleeve in a bench vise first to ensure the tightening force of the fastening nut. During the tightening process of the fastening nut, check the fire hose between the tapered pin and the sleeve to ensure that there are no wrinkles on the fire hose. After tightening the fastening nut, seal the small end of the tapered pin to one end of the switch valve through a pipe joint, and seal the other end of the switch valve to the oil injection and pressurization system of the "soft belt pressure equipment" through a pipe joint. Through the matching sleeve and tapered pin, the head of the fire hose can be reliably sealed and connected to the switch valve as a whole, ensuring that there will be no oil leakage at the head of the fire hose.

[0024] In the embodiments of the present invention, technical features not described in detail are all existing technologies or conventional technical means and will not be described in detail here.

[0025] Finally, it should be noted that the above embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them, and the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any person skilled in the art can modify or easily think of changes to the technical solutions described in the above embodiments within the technical scope disclosed by the present invention, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for compacting the body of a low-noise shunt reactor, using a soft belt (7) to compact the body of the reactor, characterized in that: The following steps are involved: A pressing plate (5) is placed above the end of the body, the lower part of the pressing plate (5) is an end ring, the pressing plate (5) is a square plate, a circular hole is provided at the center of the pressing plate (5) for the upper end of the core column to pass through; a plurality of soft belt grooves (8) with curved arcs are symmetrically provided on the upper surface of the pressing plate (5) on both sides of the circular hole, and both ends of the soft belt grooves (8) extend to the edges of both sides of the pressing plate (5); An insulating plate 2 (4) is placed above the pressing plate (5), wherein the insulating plate 2 (4) is a square plate, and the size of the insulating plate 2 (4) is larger than the pressing plate (5). A circular hole 2 is provided at the center of the insulating plate 2 (4) for the upper end of the core column to pass through. A plurality of spacers 2 (11) are bonded to the upper surface of the insulating plate 2 (4), and a plurality of spacers 3 (12) are bonded to the upper surface of the insulating plate 2 (4) around the circular hole 2. Two U-shaped magnetic shields (3) of the device body are symmetrically placed above the insulating plate (4) on both sides of the circular hole (2), and a magnetic shield gap filler is placed in the gap between the two magnetic shields (3) of the device body. A circular hole (3) is provided at the center of the magnetic shield gap filler for the upper end of the core column to pass through. The magnetic shield gap filler includes a pair of filling blocks (6) and a pair of fan-shaped plates (9) of an integral structure. The thickness of the filling blocks (6) is greater than that of the fan-shaped plates (9). The pair of filling blocks (6) are arranged oppositely, and the pair of fan-shaped plates (9) are arranged oppositely. The filling blocks (6) and the fan-shaped plates (9) are located on the periphery of the circular hole (3); the filling blocks (6) have the same thickness as the magnetic shield (3) of the device body, and a plurality of pads (10) are bonded to the pair of fan-shaped plates (9). The edges of the two magnetic shields (3) of the device body are pressed above the fan-shaped plates (9) and the pads (10). An insulating plate 1 (2) is placed above the two magnetic shields (3) of the device body. The structure and size of the insulating plate 1 (2) are the same as those of the insulating plate 2 (4). An upper iron yoke (1) is placed above the insulating plate 1 (2). The soft belt (7) is placed in the soft belt groove (8), and the required pressure is applied to the soft belt (7) to compress the body of the device; After the body is compressed, insert the pad four into the gap between the adjacent soft belts (7), release the pressure of the soft belt (7) and withdraw it from the soft belt groove (8), insert the pad five into the soft belt groove (8), and tie the pad four and pad five to the insulating plate two (4) to form a whole.

2. The method for compacting a low-noise shunt reactor according to claim 1, characterized in that: The pressing plate (5) is made of laminated paperboard with a thickness of ≥50 mm.

3. The method for compacting a low-noise shunt reactor according to claim 2, characterized in that: Four protrusions are symmetrically fixedly arranged on the inner circumference of the circular hole of the pressing plate (5).

4. The method for compacting a low-noise shunt reactor according to claim 1, characterized in that: The second insulating board (4) is made of polyester material.

5. The method for compacting a low-noise shunt reactor according to claim 1, characterized in that: The fan-shaped plate (9) is a molded part made of sulfate pulp.

6. The method for compacting a low-noise shunt reactor according to claim 5, characterized in that: The filling block (6) is made of polyester material.

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