Body structure of high-capacity and ultrahigh-impedance three-phase double-coil oil-immersed power transformer

Abstract

The utility model discloses a body structure of a high-capacity and ultrahigh-impedance three-phase double-ring oil-immersed power transformer, which comprises an iron core assembly, a clamp assembly and a winding assembly, the clamp assembly is arranged on the periphery of an iron yoke of the iron core assembly, and the winding assembly is sleeved on a main column of the iron core assembly; iron yokes are respectively arranged at the upper and lower ends of the main column; the clamping piece assembly comprises upper webs and lower webs, and the two upper webs are symmetrically arranged on the two sides of the upper iron yoke; the two lower webs are symmetrically arranged on the two sides of the lower iron yoke. The upper web plate and the lower web plate are each of a box-shaped structure, the lower surface of the upper web plate is arranged on the center line plane of the upper iron yoke, the upper surface of the lower web plate is arranged on the center line plane of the lower iron yoke, and the lower surface of the upper web plate and the upper surface of the lower web plate are each provided with a three-phase counteracting type magnetic shield; according to the utility model, the stray loss of the metal piece on the high-capacity and high-impedance transformer body and the temperature rise of the metal piece are obviously reduced by adopting the box-shaped clamping piece, the three-phase counteracting type magnetic shielding structure and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of oil-immersed transformers, in particular to a body structure of a large-capacity, ultra-high-impedance three-phase double-turn oil-immersed power transformer. Background Art

[0002] With the rapid development of my country's economy, the continuous increase in electricity demand, and the continuous advancement of power grid construction, the technology of power transformers, as the main equipment in the power transmission and transformation system, is also constantly updated and improved. High voltage and large capacity have become a trend in the development of power transformers. Increasing the capacity of transformers can greatly reduce the cost of unit electricity and improve the economy of the entire power system. In addition, in the event of a power system failure, the larger the transformer capacity, the faster the failure can be repaired and the reliability of the system can be improved. Therefore, increasing the capacity of transformers is conducive to improving the reliability and economy of the power grid.

[0003] The increase in transformer capacity not only improves the power transmission capacity, but also increases the short-circuit capacity of the system, thus placing higher requirements on the short-circuit resistance of the transmission equipment. In order to reduce the short-circuit current caused by short-circuit faults during the transmission process, reactors are often set or high-impedance transformers are used. Compared with the method of setting reactors, the method of increasing transformer impedance can reduce the number of reactors used, thereby reducing the number of transmission equipment and improving the reliability of the power grid. On the other hand, the increase in transformer impedance will bring about problems such as transformer loss and increased temperature rise. Loss and temperature rise problems have also become a design difficulty for large-capacity and ultra-high impedance transformers. At present, the methods for reducing loss and temperature rise on the transformer body include installing magnetic shielding on the clamping plate and optimizing the coil design. These methods are not effective for large-capacity and ultra-high impedance transformers.

[0004] In view of the above-mentioned defects, the inventor of the present invention finally obtained the present invention after a long period of research and practice. Utility Model Content

[0005] In order to solve the above technical defects, the technical solution adopted by the utility model is to provide a body structure of a large-capacity, ultra-high impedance three-phase double-turn oil-immersed power transformer, including an iron core assembly, a pull plate assembly, a clamp assembly, a winding assembly, a pressure ring assembly and a pressure block assembly, the iron core assembly includes a main column, a side column and an iron yoke, the main column is arranged between the two side columns, the clamp assembly is arranged on the periphery of the iron yoke, and is used to fix the pull plate assembly and clamp the iron core assembly, the winding assembly is sleeved on the main column, and the winding assembly is pressed and fixed by the pressure ring assembly and the pressure block assembly;

[0006] The iron yoke is provided with an upper iron yoke and a lower iron yoke, the upper iron yoke is provided at the top end of the main column, and the lower iron yoke is provided at the bottom end of the main column; the clamp assembly includes an upper clamp and a lower clamp, the upper clamp includes an upper web, and the two upper webs are symmetrically arranged on both sides of the upper iron yoke; the lower clamp includes a lower web, and the two lower webs are symmetrically arranged on both sides of the lower iron yoke;

[0007] The upper web and the lower web are both configured as box-shaped structures, the lower surface of the upper web is configured on the centerline plane of the upper iron yoke, and the upper surface of the lower web is configured on the centerline plane of the lower iron yoke.

[0008] An upper three-phase offset magnetic shield is arranged on the lower surface of the upper web, and a lower three-phase offset magnetic shield is arranged on the upper surface of the lower web; the upper three-phase offset magnetic shield and the lower three-phase offset magnetic shield are fixed to the corresponding upper web or the lower web by insulating screws.

[0009] Preferably, the upper clamp also includes an upper support beam, an upper positioning beam and an upper side beam, the upper support beam and the upper positioning beam are both arranged above the upper iron yoke, the upper side beam is arranged at the end of the upper web, and the two ends of the upper support beam, the upper positioning beam and the upper side beam are fixedly connected to the two upper webs at the same time.

[0010] Preferably, the lower clamp also includes a lower support beam, a lower positioning beam and a lower side beam, the lower support beam and the lower positioning beam are both arranged below the lower iron yoke, the lower side beam is arranged at the end of the lower web, and the two ends of the lower support beam, the lower positioning beam and the lower side beam are fixedly connected to the two lower webs at the same time.

[0011] Preferably, the pull plate assembly is provided with a main column pull plate corresponding to the main column, and the pull plate assembly is provided with a side column pull plate corresponding to the side column. The main column pull plate is made of stainless steel and is provided with a plurality of magnetic isolation grooves. The main column pull plate cooperates with the clamp assembly for limiting and fixing.

[0012] Preferably, the upper three-phase offset magnetic shield and the lower three-phase offset magnetic shield are made of high magnetic permeability oriented silicon steel sheets, and the upper three-phase offset magnetic shield and the lower three-phase offset magnetic shield are both configured as long strips and are disposed between the two side columns.

[0013] Preferably, the upper positioning beam is provided with a positioning pin, and the upper positioning beam is aligned and fixed to the top of the oil tank through the positioning pin; the lower positioning beam is provided with a positioning hole, and the lower positioning beam is aligned and fixed to the mounting pin at the bottom of the oil tank through the positioning hole.

[0014] Preferably, the pressure ring assembly includes an upper pressure ring and a lower pressure ring, the upper pressure ring and the lower pressure ring are respectively arranged at the upper and lower ends of the winding assembly, the winding assembly is supported on the lower pressure ring and is clamped and fixed by the upper pressure ring.

[0015] Preferably, the pressure block assembly is provided with an upper pressure block between the upper three-phase offset magnetic shield and the upper pressure ring, and four symmetrical groups of the upper pressure blocks are provided on the upper part of each phase for pressing the winding assembly; the pressure block assembly is provided with a lower pressure block between the lower three-phase offset magnetic shield and the lower pressure ring, and four symmetrical groups of the lower pressure blocks are provided on the lower part of each phase for supporting the winding assembly.

[0016] Preferably, the winding assembly includes a low-voltage winding, a high-voltage winding, a coarse-adjustment winding and a fine-adjustment winding, and the low-voltage winding, the high-voltage winding, the coarse-adjustment winding and the fine-adjustment winding are arranged in sequence from the inside to the outside on the core side; the low-voltage winding is a U-shaped spiral structure, the inner and outer layers of the low-voltage winding are both at the top, and the inner and outer layers are connected by a bottom transition transposition; the high-voltage winding is an inner-screen continuous structure connected in parallel up and down, and the high-voltage line end is led out from the middle of the high-voltage winding; the coarse-adjustment winding and the fine-adjustment winding are both structures connected in parallel up and down; the coarse-adjustment winding is a continuous structure, and the fine-adjustment winding is a tangled structure.

[0017] Preferably, all the coil wires on the winding assembly are self-adhesive transposed copper wires, and the wires of the low-voltage coils on the low-voltage winding are in the form of mesh-wrapped wires.

[0018] Compared with the prior art, the utility model has the beneficial effect that: the utility model significantly reduces the stray loss of metal parts on the body of a large-capacity, high-impedance transformer and reduces the temperature rise of the metal parts by adopting structures such as box-shaped clamps and three-phase offset magnetic shielding. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural front view of the body structure of the large-capacity, ultra-high impedance three-phase double-turn oil-immersed power transformer;

[0020] Figure 2 It is a structural side view of the body structure of the large-capacity, ultra-high-impedance three-phase double-turn oil-immersed power transformer;

[0021] Figure 3 A structural top view of the body structure of the large-capacity, ultra-high impedance three-phase double-turn oil-immersed power transformer;

[0022] Figure 4 The figure is a schematic block diagram of the arrangement and connection of the winding components.

[0023] The numbers in the figure represent:

[0024] 1- iron core assembly; 2- pull plate assembly; 3- clamp assembly; 4- winding assembly; 5- pressure ring assembly; 6- pressure block assembly; 11- main column; 12- side column; 13- upper iron yoke; 14- lower iron yoke; 21- main column pull plate; 22- side column pull plate; 31- upper clamp; 32- lower clamp; 41- low voltage winding; 42- high voltage winding; 43- coarse adjustment winding; 44- fine adjustment Winding; 51-upper pressure ring; 52-lower pressure ring; 61-upper pressure block; 62-lower pressure block; 311-upper web; 312-upper support beam; 313-upper positioning beam; 314-upper side beam; 315-upper three-phase offset magnetic shield; 321-lower web; 322-lower support beam; 323-lower positioning beam; 324-lower side beam; 325-lower three-phase offset magnetic shield. DETAILED DESCRIPTION

[0025] The above and other technical features and advantages of the present invention are described in more detail below in conjunction with the accompanying drawings.

[0026] Embodiment 1

[0027] like Figure 1 , Figure 2 , Figure 3 As shown, Figure 1 It is a structural front view of the body structure of the large-capacity, ultra-high impedance three-phase double-turn oil-immersed power transformer; Figure 2 It is a structural side view of the body structure of the large-capacity, ultra-high-impedance three-phase double-turn oil-immersed power transformer; Figure 3 It is a top view of the structure of the body of the large-capacity, ultra-high impedance three-phase double-turn oil-immersed power transformer.

[0028] The body structure of the large-capacity, ultra-high impedance three-phase double-turn oil-immersed power transformer described in the utility model includes an iron core component 1, a pull plate component 2, a clamp component 3, a winding component 4, a pressure ring component 5 and a pressure block component 6. The iron core component 1 includes a main column 11, a side column 12 and an iron yoke. The main column 11 is arranged between the two side columns 12, and the iron yoke is arranged at the upper and lower ends of the main column 11. The pull plate component 2 is provided with a main column pull plate 21 corresponding to the main column 11, and the pull plate component 2 is provided with a side column pull plate 22 corresponding to the side column 12. The clamp component 3 is arranged on the outer periphery of the iron yoke to fix the pull plate component 2 and clamp the iron core component 1. The winding component 4 is sleeved on the main column 11, and the winding component 4 is pressed and fixed by the pressure ring component 5 and the pressure block component 6. The main column pull plate 21 is set to a stainless steel material and is provided with a plurality of magnetic isolation grooves. The main column pull plate 21 cooperates with the clamp component 3 to perform limit fixing.

[0029] The utility model adopts the main column pull plate 21 made of stainless steel and provides a plurality of magnetic isolation grooves on the main column pull plate 21 to reduce the stray loss of the pull plate assembly 2 and thus reduce the temperature rise of the pull plate assembly 2.

[0030] Embodiment 2

[0031] In this embodiment, the iron yoke is provided with an upper iron yoke 13 and a lower iron yoke 14 . The upper iron yoke 13 is provided at the top end of the main column 11 , and the lower iron yoke 14 is provided at the bottom end of the main column 11 .

[0032] The main column pull plate 21 and the side column pull plate 22 are respectively installed on the surface of the corresponding main column 11 and the side column 12.

[0033] The clamp assembly 3 includes an upper clamp 31 and a lower clamp 32, and the upper clamp 31 includes an upper web 311, an upper support beam 312, an upper positioning beam 313, an upper side beam 314 and an upper three-phase offset magnetic shield 315. The two upper webs 311 are symmetrically arranged on both sides of the upper iron yoke 13, and the upper support beam 312 and the upper positioning beam 313 are both arranged above the upper iron yoke 13. The upper side beam 314 is arranged at the end of the upper web 311, and the two ends of the upper support beam 312, the upper positioning beam 313 and the upper side beam 314 are fixedly connected to the two upper webs 311 at the same time, thereby ensuring the stability of the clamping structure of the upper clamp 31.

[0034] Correspondingly, the lower clamp 32 includes a lower web 321, a lower support beam 322, a lower positioning beam 323, a lower side beam 324 and a lower three-phase offset magnetic shield 325. The two lower webs 321 are symmetrically arranged on both sides of the lower iron yoke 14, the lower support beam 322 and the lower positioning beam 323 are both arranged below the lower iron yoke 14, the lower side beam 324 is arranged at the end of the lower web 321, and the two ends of the lower support beam 322, the lower positioning beam 323 and the lower side beam 324 are fixedly connected to the two lower webs 321 at the same time, thereby ensuring the stability of the clamping structure of the lower clamp 32.

[0035] Preferably, the upper web 311 and the lower web 321 are both configured as box-shaped structures, the lower surface of the upper web 311 is disposed on the centerline plane of the upper iron yoke 13 , and the upper surface of the lower web 321 is disposed on the centerline plane of the lower iron yoke 14 .

[0036] The upper web 311 and the lower web 321 of the present invention are both box-shaped structures with high mechanical strength, and are therefore installed on the center line plane of the iron yoke away from the coil end, thereby reducing the stray loss of the clamp assembly 3.

[0037] The upper three-phase offset magnetic shield 315 is arranged on the lower surface of the upper web 311, and the lower three-phase offset magnetic shield 325 is arranged on the upper surface of the lower web 321; the upper three-phase offset magnetic shield 315 and the lower three-phase offset magnetic shield 325 are fixed to the corresponding upper web 311 or the lower web 321 by insulating screws.

[0038] Preferably, the upper three-phase offset magnetic shield 315 and the lower three-phase offset magnetic shield 325 are made of high magnetic permeability oriented silicon steel sheets, and the upper three-phase offset magnetic shield 315 and the lower three-phase offset magnetic shield 325 are both arranged in a long strip shape and arranged between the two side columns 12. By installing the three-phase offset magnetic shield on the corresponding upper web 311 or the lower web 321, it is used to offset the leakage magnetic flux with phase difference at the three-phase ends of the body, thereby reducing the stray loss of the clamp assembly 3 and reducing its temperature rise.

[0039] Generally, the upper positioning beam 313 is provided with a positioning pin, and the upper positioning beam 313 is fixed to the top of the oil tank through the positioning pin; the lower positioning beam 323 is provided with a positioning hole, and the lower positioning beam 323 is fixed to the mounting pin at the bottom of the oil tank through the positioning hole. The upper clamp 31 and the lower clamp 32 are both provided with positioning beams, so that the body is fully fixed to the top and bottom of the oil tank, so that it has high impact resistance during transportation and operation.

[0040] The pressure ring assembly 5 includes an upper pressure ring 51 and a lower pressure ring 52 , and the upper pressure ring 51 and the lower pressure ring 52 are respectively arranged at the upper and lower ends of the winding assembly 4 . The winding assembly 4 is supported on the lower pressure ring 52 and is clamped and fixed by the upper pressure ring 51 .

[0041] The pressing block assembly 6 is provided with an upper pressing block 61 between the upper three-phase offset magnetic shield 315 and the upper pressing ring 51, and four symmetrical groups of the upper pressing blocks 61 are arranged on the upper part of each phase for pressing the winding assembly 4; the pressing block assembly 6 is provided with a lower pressing block 62 between the lower three-phase offset magnetic shield 325 and the lower pressing ring, and four symmetrical groups of the lower pressing blocks 62 are arranged on the lower part of each phase for supporting the winding assembly 4.

[0042] like Figure 4 As shown, Figure 4The figure is a schematic diagram of the arrangement and connection of the winding assembly; the winding assembly 4 comprises a low voltage winding 41, a high voltage winding 42, a coarse adjustment winding 43 and a fine adjustment winding 44, wherein the low voltage winding 41, the high voltage winding 42, the coarse adjustment winding 43 and the fine adjustment winding 44 are arranged in sequence from the inside to the outside on the core side; the low voltage winding 41 is a U-shaped spiral structure, the inner and outer layers of the low voltage winding 41 are both at the top, and the inner and outer layers are connected by a bottom transition transposition; the high voltage winding 42 is an inner screen continuous structure connected in parallel up and down, and the high voltage line end leads out from the middle of the high voltage winding 42; the coarse adjustment winding 43 and the fine adjustment winding 44 are both in parallel up and down structures; the coarse adjustment winding 43 is a continuous structure, and the fine adjustment winding 44 is a tangled structure.

[0043] All coil wires on the winding assembly 4 are self-adhesive transposed copper wires, the size of a single sub-wire in the wire is small, and the wire of the low-voltage coil on the low-voltage winding 41 is in the form of a mesh-wrapped wire. By selecting a self-adhesive transposed wire with a small sub-wire size and using a mesh-wrapped wire for the low-voltage coil wire, the coil loss and temperature rise are further reduced.

[0044] The transformer adopting the body structure of the large-capacity, ultra-high impedance three-phase double-coil oil-immersed power transformer of the utility model adopts on-load voltage regulation, the voltage regulating switch is connected to the high-voltage neutral point, and the voltage regulation mode is coarse and fine voltage regulation. By adopting the coarse and fine voltage regulation mode, the load loss under the minimum tapping operation condition is reduced, thereby reducing the oil temperature rise and the coil temperature rise.

[0045] The above is only a preferred embodiment of the utility model, which is only illustrative and not restrictive. Those skilled in the art understand that many changes, modifications, and even equivalences can be made within the spirit and scope defined by the claims of the utility model, but they will all fall within the scope of protection of the utility model.

Claims

1. A body structure of a large-capacity, ultra-high impedance three-phase double-turn oil-immersed power transformer, characterized in that: It comprises an iron core assembly, a pull plate assembly, a clamp assembly, a winding assembly, a pressure ring assembly and a pressing block assembly, wherein the iron core assembly comprises a main column, a side column and an iron yoke, wherein the main column is arranged between the two side columns, the clamp assembly is arranged at the periphery of the iron yoke to fix the pull plate assembly and clamp the iron core assembly, the winding assembly is sleeved on the main column, and the winding assembly is pressed and fixed by the pressure ring assembly and the pressing block assembly; The iron yoke is provided with an upper iron yoke and a lower iron yoke, the upper iron yoke is provided at the top end of the main column, and the lower iron yoke is provided at the bottom end of the main column; the clamp assembly includes an upper clamp and a lower clamp, the upper clamp includes an upper web, and the two upper webs are symmetrically arranged on both sides of the upper iron yoke; the lower clamp includes a lower web, and the two lower webs are symmetrically arranged on both sides of the lower iron yoke; The upper web and the lower web are both configured as box-shaped structures, the lower surface of the upper web is configured on the centerline plane of the upper iron yoke, and the upper surface of the lower web is configured on the centerline plane of the lower iron yoke; An upper three-phase offset magnetic shield is arranged on the lower surface of the upper web, and a lower three-phase offset magnetic shield is arranged on the upper surface of the lower web; the upper three-phase offset magnetic shield and the lower three-phase offset magnetic shield are fixed to the corresponding upper web or the lower web by insulating screws.

2. The body structure of the large-capacity, ultra-high impedance three-phase double-coil oil-immersed power transformer according to claim 1 is characterized in that: The upper clamp also includes an upper support beam, an upper positioning beam and an upper side beam, the upper support beam and the upper positioning beam are both arranged above the upper iron yoke, the upper side beam is arranged at the end of the upper web, and the two ends of the upper support beam, the upper positioning beam and the upper side beam are fixedly connected to the two upper webs at the same time.

3. The body structure of the large-capacity, ultra-high impedance three-phase double-coil oil-immersed power transformer according to claim 2 is characterized in that: The lower clamp also includes a lower support beam, a lower positioning beam and a lower side beam, the lower support beam and the lower positioning beam are both arranged below the lower iron yoke, the lower side beam is arranged at the end of the lower web, and the two ends of the lower support beam, the lower positioning beam and the lower side beam are fixedly connected to the two lower webs at the same time.

4. The body structure of the large-capacity, ultra-high impedance three-phase double-coil oil-immersed power transformer according to claim 1 is characterized in that: The pull plate assembly is provided with a main column pull plate corresponding to the main column, and the pull plate assembly is provided with a side column pull plate corresponding to the side column. The main column pull plate is made of stainless steel and is provided with multiple magnetic isolation grooves. The main column pull plate cooperates with the clamp assembly to perform limiting and fixing.

5. The body structure of the large-capacity, ultra-high impedance three-phase double-coil oil-immersed power transformer according to claim 3 is characterized in that: The upper three-phase offset magnetic shield and the lower three-phase offset magnetic shield are made of high magnetic permeability oriented silicon steel sheets. The upper three-phase offset magnetic shield and the lower three-phase offset magnetic shield are both configured in a long strip shape and are disposed between the two side columns.

6. The body structure of the large-capacity, ultra-high impedance three-phase double-coil oil-immersed power transformer according to claim 3 is characterized in that: The upper positioning beam is provided with a positioning pin, and the upper positioning beam is aligned and fixed to the top of the oil tank through the positioning pin; the lower positioning beam is provided with a positioning hole, and the lower positioning beam is aligned and fixed to the installation pin at the bottom of the oil tank through the positioning hole.

7. The body structure of the large-capacity, ultra-high impedance three-phase double-coil oil-immersed power transformer according to claim 3 is characterized in that: The pressure ring assembly comprises an upper pressure ring and a lower pressure ring, wherein the upper pressure ring and the lower pressure ring are respectively arranged at the upper and lower ends of the winding assembly, and the winding assembly is supported on the lower pressure ring and is compressed and fixed by the upper pressure ring.

8. The body structure of the large-capacity, ultra-high impedance three-phase double-coil oil-immersed power transformer according to claim 7 is characterized in that: The pressing block assembly is provided with an upper pressing block between the upper three-phase offset magnetic shield and the upper pressing ring, and four symmetrical groups of the upper pressing blocks are provided on the upper part of each phase for pressing the winding assembly; the pressing block assembly is provided with a lower pressing block between the lower three-phase offset magnetic shield and the lower pressing ring, and four symmetrical groups of the lower pressing blocks are provided on the lower part of each phase for supporting the winding assembly.

9. The body structure of the large-capacity, ultra-high impedance three-phase double-coil oil-immersed power transformer according to claim 8, characterized in that: The winding assembly includes a low-voltage winding, a high-voltage winding, a coarse-adjustment winding and a fine-adjustment winding, wherein the low-voltage winding, the high-voltage winding, the coarse-adjustment winding and the fine-adjustment winding are arranged in sequence from the inside to the outside on the core side; the low-voltage winding is a U-shaped spiral structure, the inner and outer layers of the low-voltage winding are both at the top, and the inner and outer layers are connected by a bottom transition transposition; the high-voltage winding is an inner-screen continuous structure connected in parallel up and down, and the high-voltage line end is led out from the middle of the high-voltage winding; the coarse-adjustment winding and the fine-adjustment winding are both structures connected in parallel up and down; the coarse-adjustment winding is a continuous structure, and the fine-adjustment winding is a tangled structure.

10. The body structure of the large-capacity, ultra-high impedance three-phase double-coil oil-immersed power transformer according to claim 9, characterized in that: All the coil wires on the winding assembly are self-adhesive transposed copper wires, and the wires of the low-voltage coils on the low-voltage winding are in the form of mesh-wrapped wires.

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