CN109545522B - Oil-immersed variable-frequency transformer for 110kV high-power high-voltage variable-frequency device - Google Patents
Oil-immersed variable-frequency transformer for 110kV high-power high-voltage variable-frequency device Download PDFInfo
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- CN109545522B CN109545522B CN201910090799.0A CN201910090799A CN109545522B CN 109545522 B CN109545522 B CN 109545522B CN 201910090799 A CN201910090799 A CN 201910090799A CN 109545522 B CN109545522 B CN 109545522B
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- 230000001105 regulatory effect Effects 0.000 claims abstract description 14
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 11
- 238000004804 winding Methods 0.000 claims description 14
- 230000003247 decreasing effect Effects 0.000 claims description 2
- 238000011161 development Methods 0.000 abstract description 9
- 238000010276 construction Methods 0.000 abstract description 7
- 238000012423 maintenance Methods 0.000 abstract description 6
- 230000006835 compression Effects 0.000 description 11
- 238000007906 compression Methods 0.000 description 11
- 238000006243 chemical reaction Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 239000003345 natural gas Substances 0.000 description 2
- 230000010363 phase shift Effects 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/28—Coils; Windings; Conductive connections
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/06—Mounting, supporting or suspending transformers, reactors or choke coils not being of the signal type
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
- H01F27/36—Electric or magnetic shields or screens
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
- Ac-Ac Conversion (AREA)
Abstract
The invention provides an oil immersed variable frequency transformer for a 110kV high-power high-voltage variable frequency device, which comprises an iron core and a coil wound on the iron core; the primary side voltage is 110kV, and the secondary side voltage is 1.55kV; the coil comprises a 110kV high-voltage regulating coil, a 110kV high-voltage coil and a low-voltage coil which are sequentially wound from inside to outside; the end part of the 110kV high-voltage coil is provided with a high-voltage electrostatic plate, and an electrostatic screen is arranged between the 110kV high-voltage regulating coil and the iron core. The pressing device comprises two round table-shaped cushion blocks, the two round table-shaped cushion blocks are respectively fixed at the two ends of the pressing plate of the transformer body, grooves are formed in the upper end parts of the cushion blocks, the two ends of the web plates of the clamping piece of the transformer are respectively inserted into the grooves of the two cushion blocks, and the web plates of the clamping piece are pressed on the pressing plate of the transformer body through the cushion blocks. The transformer can be directly powered (110 kV) from the side of a power grid, so that the construction cost of the whole system is greatly reduced, the work maintenance amount of the site is reduced, and the development direction of the transformer is also.
Description
Technical Field
The invention relates to the technical field of oil-immersed variable frequency transformers, in particular to an oil-immersed variable frequency transformer for a 110kV high-power high-voltage variable frequency device.
Background
An important technology in high-voltage frequency-conversion speed-regulating technology is multiplexing rectification technology, and adopts an isolating transformer to superimpose (connect in series) several low-voltage modules to form high-voltage output, and is mainly formed from several power units and control unit, every power unit is powered by one three-phase winding of multi-winding isolating transformer, and the secondary windings of said multi-winding isolating transformer mutually have a phase difference so as to implement input multiplexing, and can eliminate the pollution of harmonic wave produced by every unit to power network.
The Western gas east transport project in China is an important content of the great strategy of Western development, is the transport of the natural gas in the Western region of China to the eastern region, connects the Western resources with the eastern market, plays a great role in promoting the economic development of China, particularly in the middle and western development, and has profound significance in improving the fuel structure of China, protecting the environment and realizing sustainable development. The high-power alternating current variable frequency speed regulation system for the natural gas pipeline conveying compressor unit has extremely urgent requirements, hundreds of sets of high-power alternating current variable frequency speed regulation systems for the compressor unit are expected to be required, and the high-power alternating current variable frequency speed regulation system is used as an oil immersed variable frequency transformer for a high-power high-voltage variable frequency device, so that the requirements are the same.
As shown in fig. 1, the primary voltage of the oil immersed rectifier transformer used in the high-power ac variable-frequency speed regulation system running in China at present is 10kV, and although the voltage level is common, a user needs to configure a step-down transformer and required matching equipment on the use site to reduce the power grid voltage to 10kV for use, which increases the construction cost and the maintenance workload of the user on the equipment, as shown in fig. 2, if the transformer can directly receive power (110 kV) from the power grid side, the construction cost of the whole system is greatly reduced, and the on-site work maintenance workload is also reduced, which is the development direction of the transformer.
The transformer adopts low-voltage side phase shifting, the pulse wave number of the transformer is more and usually is 36 pulse waves or more, so the number of windings on the low-voltage side of the transformer is more and usually is 6 windings or more, the high-voltage side of the transformer is 10kV in the past, but the line voltage on the user network side is 110kV, so a user needs to increase a step-down transformer with 110kV voltage level, and if the 110kV voltage is directly reduced to the working voltage required by the user frequency converter, the construction cost and maintenance workload of the user are greatly reduced.
Disclosure of Invention
In order to solve the problems in the background art, the invention provides the oil-immersed variable frequency transformer for the 110kV high-power high-voltage variable frequency device, which can directly receive power (110 kV) from the power grid side, so that the construction cost of the whole system is greatly reduced, the field work maintenance amount is reduced, and the development direction of the transformer is also the development direction.
In order to achieve the above purpose, the invention is realized by adopting the following technical scheme:
an oil immersed type variable frequency transformer for a 110kV high-power high-voltage variable frequency device comprises an iron core and a coil wound on the iron core; the variable frequency transformer also comprises a pressing device of the transformer body, and a clamping piece web plate of the transformer is pressed on the pressing plate of the transformer body through the pressing device.
The primary side voltage of the variable frequency transformer is 110kV, and the secondary side voltage is 1.55kV; the coil comprises a 110kV high-voltage regulating coil, a 110kV high-voltage coil and a low-voltage coil which are sequentially wound from inside to outside; the end part of the 110kV high-voltage coil is provided with a high-voltage electrostatic plate, and an electrostatic screen is arranged between the 110kV high-voltage regulating coil and the iron core.
The pressing device comprises two truncated cone-shaped cushion blocks, the cushion blocks are respectively fixed at two ends of the body pressing plate, grooves are formed in the upper end parts of the cushion blocks, two ends of a clamping piece web plate of the transformer are respectively inserted into the grooves of the two cushion blocks, and the clamping piece web plate is pressed on the body pressing plate through the cushion blocks.
The low-voltage coil comprises a plurality of low-voltage coils with different phase-shifting angles, and the phase-shifting angles comprise-20 degrees, +10 degrees, -10 degrees, +20 degrees, 0 degrees and 30 degrees.
The cushion block of the pressing device is also provided with a fixing plate and fixing nails, the fixing plate is fixed on the cushion block through the fixing nails, and the clamping piece web plate is fixed on the outer side of the clamping piece web plate.
The 110kV high-voltage coil adopts a intertwined continuous axial outgoing mode.
The 110kV high-voltage regulating coil adopts an eight-spiral axial wire outlet mode.
Compared with the prior art, the invention has the beneficial effects that:
1. the transformer can directly receive power (110 kV) from the power grid side, so that the construction cost of the whole system is greatly reduced, the work maintenance load on site is reduced, and the development direction of the transformer is also;
2. the oil-immersed rectifying transformer for 110kV high-voltage frequency conversion is first applied at home and abroad; the oil immersed rectifying transformer for 110kV high-voltage frequency conversion reduces the construction cost of the system and the occupied area of equipment; the oil immersed rectifying transformer for 110kV high-voltage frequency conversion can reduce the no-load loss of the transformer in the transformer substation by 19.6% and the load loss by 28%;
3. the low-voltage coil is connected with the transformer in a mode of 110kV voltage-regulating coils, 110kV high-voltage coils and low-voltage coils from inside to outside, because the low-voltage coil has a large number of coils and complex wiring;
4. the 110kV electric field intensity is high, so that the high-voltage coil adopts a intertwined continuous axial outgoing line (the intertwined continuous axial outgoing line is known in the art), and the end part is provided with an electrostatic plate;
5. an electrostatic screen is arranged between the high-voltage regulating coil and the iron core, the high-voltage regulating coil adopts an eight-spiral mode axial outgoing line (the eight-spiral mode axial outgoing line is known in the art), and the operation reliability of the transformer is enhanced;
6. the design of the device body compression structure eliminates a nail pressing bolt, a nail pressing nut and a nail pressing washer, changes the original nail pressing bolt and the nail pressing washer with smaller areas into larger cushion blocks, is compressed by a clamping piece web plate and is positioned by a fixing nail; after the area of the cushion block is increased, acting force is borne by a clamping piece web plate, the original bending condition is converted into a compression condition, the structural strength is high enough, and the structure is superior to the traditional structure.
Drawings
FIG. 1 is a diagram of a transformer system of a 110kV high-power high-voltage frequency conversion device in the background art;
FIG. 2 is a diagram of the transformer system of the 110kV high-power high-voltage frequency conversion device of the invention;
FIG. 3 is a layout of an oil immersed type variable frequency transformer body for the 110kV high-power high-voltage variable frequency device;
FIG. 4 is a wiring diagram of a high-voltage coil and a low-voltage coil of an oil-immersed variable-frequency transformer for a 110kV high-power high-voltage variable-frequency device;
FIG. 5 is a front view of a prior art body compression structure;
FIG. 6 is a side view of a prior art body compression structure;
FIG. 7 is a front view of the body compression structure of the present invention;
fig. 8 is a side view of the body compression structure of the present invention.
Wherein: 1-iron core 2-110kV high-voltage regulating coil 3-110kV high-voltage coil 4-low-voltage coil 5-electrostatic screen 6-high-voltage electrostatic plate 7-shielding 8-body pressing plate 9-clamping piece web 10-press nail gasket 11-press nail 12-press nail nut 13-press nail support plate 14-press cushion block 15-fixing nail 16-fixing plate.
Detailed Description
The following provides a detailed description of embodiments of the present invention.
As shown in fig. 2, an oil immersed type variable frequency transformer for a 110kV high-power high-voltage variable frequency device has a primary side voltage of 110kV and a secondary side voltage of 1.55kV.
As shown in fig. 3, the variable frequency transformer includes a core 1 and a coil wound on the core 1. The coil comprises a 110kV high-voltage regulating coil 2, a 110kV high-voltage coil 3 and a low-voltage coil 4 which are sequentially wound from inside to outside; the end part of the 110kV high-voltage coil 3 is provided with a high-voltage electrostatic plate 6, and an electrostatic screen 5 is arranged between the 110kV high-voltage regulating coil 2 and the iron core 1.
As shown in fig. 4, a wiring diagram of a 110kV high-voltage coil 3 and a low-voltage coil 4 is shown, the low-voltage coil 4 includes a plurality of low-voltage coils with different phase shift angles, and the phase shift angles include-20 °, +10°, -10 °, +20°, 0 °, 30 °. The low-voltage coil 4 sets the connection mode of the basic winding and the phase-shifting winding according to the phase-shifting angle. The 110kV high-voltage coil 3 adopts a intertwined continuous axial outgoing mode. The 110kV high-voltage regulating coil 2 adopts an eight-spiral axial wire outlet mode. The intertwined continuous axial wire-outlet mode and the eight-spiral axial wire-outlet mode are common knowledge in the technical field of transformers, and are not shown in the drawings.
In addition, in the plurality of low-voltage coils arranged up and down in fig. 3, in order to make the impedance of each winding of the plurality of low-voltage coils approximately equal, the output load of the transformer is balanced, and the operation reliability of the transformer is increased; the wire gauges of the upper layer winding and the lower layer winding can be adjusted differently, and the wire gauges of a plurality of low-voltage coils 4 arranged from top to bottom are sequentially decreased by 2-3 percent from top to bottom.
As shown in fig. 5-8, the variable frequency transformer further comprises a compression device of the transformer body. The clamping web 9 of the transformer is pressed against the body press plate 8 by means of a pressing device.
As shown in fig. 5-6, for the body compression structure of the prior art, a nail pressing support plate 13 is welded on a clamping piece web 9, the size of the body compression force is adjusted by screwing a bolt of a nail pressing 11 during assembly, and the body compression structure is locked by a nail pressing nut 12 after compression. The disadvantage of this structure is that the weld is more, if the control is not good during the welding, it may cause the cold joint. Because the weld is subjected to shearing forces, the structure is poor in strength and is likely to deform greatly or even tear. The maximum size of the contact part between the lower end of the pressing nail 11 and the pressing nail gasket 10 is the cross section of the pressing nail 11, the stress area is small, the stability is unstable, and the bearing capacity is insufficient.
As shown in fig. 7-8, the compressing device of the invention comprises two truncated cone-shaped cushion blocks 14 which are respectively fixed at two ends of the body pressing plate 8, grooves are formed at the upper end parts of the cushion blocks 11, two ends of the clamping piece web plates 6 of the transformer are respectively inserted into the grooves of the two cushion blocks 11, and the clamping piece web plates 9 are pressed on the body pressing plate 8 through the cushion blocks 14. The cushion block 14 of the pressing device is also provided with a fixing plate 16 and a fixing nail 15, the fixing plate 16 is fixed on the cushion block 14 through the fixing nail 15, and the clamping piece web 9 is fixed on the outer side of the clamping piece web 9.
The above examples are implemented on the premise of the technical scheme of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the above examples. The methods used in the above examples are conventional methods unless otherwise specified.
Claims (4)
1. An oil immersed type variable frequency transformer for a 110kV high-power high-voltage variable frequency device comprises an iron core and a coil wound on the iron core; the variable frequency transformer also comprises a pressing device of the transformer body, and a clamping piece web plate of the transformer is pressed on a pressing plate of the transformer body through the pressing device;
the variable-frequency transformer is characterized in that the primary side voltage of the variable-frequency transformer is 110kV, and the secondary side voltage is 1.55kV; the coil comprises a 110kV high-voltage regulating coil, a 110kV high-voltage coil and a low-voltage coil which are sequentially wound from inside to outside; a high-voltage electrostatic plate is arranged at the end part of the 110kV high-voltage coil, and an electrostatic screen is arranged between the 110kV high-voltage regulating coil and the iron core;
the pressing device comprises two truncated cone-shaped cushion blocks which are respectively fixed at two ends of the body pressing plate, grooves are formed in the upper end parts of the cushion blocks, two ends of a clamping piece web plate of the transformer are respectively inserted into the grooves of the two cushion blocks, and the clamping piece web plate is pressed on the body pressing plate through the cushion blocks;
the low-voltage coil comprises a plurality of low-voltage coils with different phase-shifting angles, wherein the phase-shifting angles comprise-20 degrees, +10 degrees, -10 degrees, +20 degrees, 0 degrees and 30 degrees; in a plurality of low-voltage coils arranged up and down, in order to make the impedance of each winding of the plurality of low-voltage coils approximately equal, the output load of the transformer is balanced, and the operation reliability of the transformer is increased; the wire gauges of the upper layer winding and the lower layer winding are adjusted differently, and the wire gauges of a plurality of low-voltage coils arranged from top to bottom are sequentially decreased by 2-3% from top to bottom.
2. The oil immersed variable frequency transformer for the 110kV high-power high-voltage variable frequency device according to claim 1, wherein the cushion block of the pressing device is further provided with a fixing plate and a fixing nail, the fixing plate is fixed on the cushion block through the fixing nail, and the clamping piece web is fixed on the outer side of the clamping piece web.
3. The oil immersed type variable frequency transformer for the 110kV high-power high-voltage variable frequency device according to claim 1, wherein the 110kV high-voltage coil adopts a intertwined continuous axial outgoing mode.
4. The oil immersed type variable frequency transformer for the 110kV high-power high-voltage variable frequency device according to claim 1, wherein the 110kV high-voltage regulating coil adopts an eight-spiral axial outgoing mode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910090799.0A CN109545522B (en) | 2019-01-30 | 2019-01-30 | Oil-immersed variable-frequency transformer for 110kV high-power high-voltage variable-frequency device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910090799.0A CN109545522B (en) | 2019-01-30 | 2019-01-30 | Oil-immersed variable-frequency transformer for 110kV high-power high-voltage variable-frequency device |
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| Publication Number | Publication Date |
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| CN109545522A CN109545522A (en) | 2019-03-29 |
| CN109545522B true CN109545522B (en) | 2024-03-29 |
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| CN201910090799.0A Active CN109545522B (en) | 2019-01-30 | 2019-01-30 | Oil-immersed variable-frequency transformer for 110kV high-power high-voltage variable-frequency device |
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| CN117790140B (en) * | 2023-11-29 | 2025-01-17 | 保定天威集团特变电气有限公司 | A 110kV direct-step-down multi-pulse phase-shifting rectifier transformer |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101968994A (en) * | 2010-07-16 | 2011-02-09 | 江苏上能变压器有限公司 | Double-ring on-load tap changer with ultrahigh impedance of 110 kV |
| CN101968993A (en) * | 2010-07-16 | 2011-02-09 | 江苏上能变压器有限公司 | 220 kilovolt grade low-voltage winding split on-load voltage-regulating wind power transformer |
| CN102543400A (en) * | 2011-12-23 | 2012-07-04 | 中国西电电气股份有限公司 | Low-voltage regulation coil device of traction transformer |
| CN102664541A (en) * | 2012-05-09 | 2012-09-12 | 广西柳州特种变压器有限责任公司 | Energy-saving-type rectification system |
| CN202736664U (en) * | 2012-07-27 | 2013-02-13 | 中国西电电气股份有限公司 | High-current low-voltage coil for controlling temperature rise of hot point and transformer with same |
| CN202816595U (en) * | 2012-07-24 | 2013-03-20 | 江苏天翔变压器有限公司 | High-insulation transformer |
| CN103413665A (en) * | 2013-08-16 | 2013-11-27 | 辽宁华冶集团发展有限公司 | High-power high-voltage frequency conversion oil-immersed rectifier transformer |
| CN203799818U (en) * | 2014-04-30 | 2014-08-27 | 山东达驰电气有限公司 | Pressing block structure for body of large transformer |
| CN104779043A (en) * | 2015-04-14 | 2015-07-15 | 保定天威集团特变电气有限公司 | 220 kV de-icing rectifier transformer |
| CN209199746U (en) * | 2019-01-30 | 2019-08-02 | 中石化石油工程设计有限公司青岛分公司 | 110kV high-power high voltage converter plant oil immersed type variable-frequency transformer |
-
2019
- 2019-01-30 CN CN201910090799.0A patent/CN109545522B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101968994A (en) * | 2010-07-16 | 2011-02-09 | 江苏上能变压器有限公司 | Double-ring on-load tap changer with ultrahigh impedance of 110 kV |
| CN101968993A (en) * | 2010-07-16 | 2011-02-09 | 江苏上能变压器有限公司 | 220 kilovolt grade low-voltage winding split on-load voltage-regulating wind power transformer |
| CN102543400A (en) * | 2011-12-23 | 2012-07-04 | 中国西电电气股份有限公司 | Low-voltage regulation coil device of traction transformer |
| CN102664541A (en) * | 2012-05-09 | 2012-09-12 | 广西柳州特种变压器有限责任公司 | Energy-saving-type rectification system |
| CN202816595U (en) * | 2012-07-24 | 2013-03-20 | 江苏天翔变压器有限公司 | High-insulation transformer |
| CN202736664U (en) * | 2012-07-27 | 2013-02-13 | 中国西电电气股份有限公司 | High-current low-voltage coil for controlling temperature rise of hot point and transformer with same |
| CN103413665A (en) * | 2013-08-16 | 2013-11-27 | 辽宁华冶集团发展有限公司 | High-power high-voltage frequency conversion oil-immersed rectifier transformer |
| CN203799818U (en) * | 2014-04-30 | 2014-08-27 | 山东达驰电气有限公司 | Pressing block structure for body of large transformer |
| CN104779043A (en) * | 2015-04-14 | 2015-07-15 | 保定天威集团特变电气有限公司 | 220 kV de-icing rectifier transformer |
| CN209199746U (en) * | 2019-01-30 | 2019-08-02 | 中石化石油工程设计有限公司青岛分公司 | 110kV high-power high voltage converter plant oil immersed type variable-frequency transformer |
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