CN105006353A - Oil-immersed 54 pulse wave frequency conversion transformer for large-power high-voltage frequency conversion apparatus - Google Patents
Oil-immersed 54 pulse wave frequency conversion transformer for large-power high-voltage frequency conversion apparatus Download PDFInfo
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- CN105006353A CN105006353A CN201510426954.3A CN201510426954A CN105006353A CN 105006353 A CN105006353 A CN 105006353A CN 201510426954 A CN201510426954 A CN 201510426954A CN 105006353 A CN105006353 A CN 105006353A
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Abstract
The invention relates to an oil-immersed 54 pulse wave frequency conversion transformer for a large-power high-voltage frequency conversion apparatus. High voltage employs three-phase input windings connected by use of a Y-shaped connection method, low voltage employs polyphase output windings connected by use of an extended triangular connection method, the low-voltage windings are divided into three large groups, and each large group comprises nine phase shift windings with phase shift angles respectively being +26.67 degrees, +20 degrees, +13.33 degrees, +6.67 degrees, 0 degree, -6.67 degrees, -13.33 degrees, -20 degrees and -26.67 degrees, the angle difference of each phase shift winding being 6.67 degrees; each phase is formed by connecting a plurality of power units in series; the high-voltage windings are also divided into three large groups, and the high-voltage windings and the low-voltage windings both employ crossover coil structures; and there are all together 81 windings at three phases of a secondary side, wires of low-voltage sleeves go out from the side wall of a fuel tank. According to the invention, a multiple-rectification technical design is employed, 54 pulse wave rectification of a single transformer is realized, input current harmonic waves of a system are substantially reduced, the radix of input currents is increased, and accordingly, the purpose of improving the input power factor of the system is improved; and the structure is reasonable, the manufacturing process is simple, the anti-short-circuit capability is high, the economic index is good, and the insulation reliability is good.
Description
Technical field
The present invention relates to transformer technology field, particularly relate to a kind of high-power high voltage converter plant oil immersed type 54 pulse wave variable-frequency transformer.
Background technology
An important technology in Medium Voltage Variable Frequency Speed Regulation Technology is multiple rectifying technology, it adopts isolating transformer multiple low-voltage module is superposed (series connection) and forms High voltage output, mainly be made up of multiple power cell and control unit, each power cell is powered by a three-phase windings of multi-winding isolation transformer, there is mutually a phase difference in its secondary coil of the isolating transformer of this Multiple coil, achieve input multiplex, the harmonic wave of each unit generation can be eliminated thus to the pollution of electrical network, this isolating transformer is indispensable critical elements in high voltage converter, its manufacturing technology is also one of technological maheup of this perfect harmony high voltage converter speed regulating device.
Number of patent application is that the Chinese patent of 201110176569.X (applying date is on June 28th, 2011) discloses one " Three-phase 48-pulse rectifier transformer ", " the 24 pulse wave rectifier transformers being exported winding phase shift by two deck valve sides form ", stricti jurise is said, it is a kind of transformer group, could not realize the multi-pulse rectification of unit.Number of patent application is that the Chinese patent of 200910040675.8 (applying date is on June 30th, 2009) discloses " a kind of 36 pulse high-power frequency conversion rectifier transformers ", achieve unit 36 pulse wave rectifier, this be also domestic at present disclosed in the transformer of maximum pulse wave rectifier that realized.In theory, pulse number is more, and commutating voltage ripple is less, and harmonic wave is also less, but transformer phase-shifting unit is more, and winding needs segmentation more, and institute takes up space larger, more complicated, and the difficulty therefore manufactured and designed is also higher.
The Homemade Transformers in the past used in domestic high power AC frequency conversion speed-adjusting system is substantially all dry-type rectifier transformer, aforesaid 36 pulse wave rectifier transformers also belong to dry-type rectifier transformer, because environment for use is severe, the easy moisture absorption of dry-type rectifier transformer is damaged, and oil immersed type rectifier transformer can meet the stable operation of various environment.The oil immersed type variable-frequency transformer major part used in the import high power AC frequency conversion speed-adjusting system of current domestic operation is imported product, the present invention is by research and development high-power high voltage converter plant oil immersed type variable-frequency transformer, achieve the production domesticization of oil immersed type 54 pulse wave variable-frequency transformer, commercialization and seriation first, this type of imported product can be substituted completely.
Summary of the invention
The invention provides a kind of high-power high voltage converter plant oil immersed type 54 pulse wave variable-frequency transformer, adopt multiple rectifying Technology design, achieve 54 pulse wave rectifiers of unit transformer, the Harmonics of Input of system is significantly reduced, and the radix of input current increases, and then reach the object improving system input power factor; It is rational in infrastructure, and manufacturing process is simple, and anti-short circuit capability is strong, and economic index is good, and insulating reliability is high; Through test prove transformer of the present invention partly pass through impedance and low-pressure side winding current unbalance factor < 2%, ensure that the safe and reliable operation of transformer.
In order to achieve the above object, the present invention realizes by the following technical solutions:
A kind of high-power high voltage converter plant oil immersed type 54 pulse wave variable-frequency transformer, high pressure adopts the three-phase input winding of Y connection, low pressure adopts the heterogeneous output winding of extend-triangle connection, low pressure winding is divided into three large group, wherein each large group comprises 9 Phase shift winding, its phase shifting angle is respectively+26.67 ° ,+20 ° ,+13.33 ° ,+6.67 °, 0 ° ,-6.67 ° ,-13.33 ° ,-20 ° ,-26.67 °, each Phase shift winding differential seat angle 6.67 °; Often to be formed by several power unit cascades, three-phase low-voltage export adjacent between mutual deviation 6.67 °, these 9 Phase shift winding control to trigger controllable silicon IGBT by the different time sequential pulse of three-phase and obtain positive and negative each 27 pulse waves; High pressure winding is also divided into three large group, and high pressure winding and low pressure winding all adopt disc coil structure; Secondary side often exports 27 windings mutually, and three-phase totally 81 windings, low-tension bushing in the outlet of fuel tank sidewall, totally 81 sleeve pipes.
Described every phase power cell is 9, and three-phase is totally 27 power cells.
Described secondary winding is divided into basic winding and Phase shift winding, and extend-triangle connected mode is positive sequence connection or backward connection.
Compared with prior art, the invention has the beneficial effects as follows:
1) adopt multiple rectifying Technology design, realize 54 pulse wave rectifiers, the Harmonics of Input of system is significantly reduced, and the radix of input current increases, and then reach the object improving system input power factor;
2) rational in infrastructure, high pressure winding adopts Y connection, and the corresponding low pressure of high pressure is divided into three large group, is coiled into disc coil structure; Low pressure winding adopts cake formula structure equally, has perfect heat-dissipating, the advantages such as anti-short circuit capability is strong;
3) high-pressure decomposing in frequency converter is become to organize voltage superposition more, make power device can select the device of low-voltage, high-current, reduce frequency conversion device cost, simplified manufacturing technique, improve frequency converter reliability;
4) through test prove transformer of the present invention partly pass through impedance and low-pressure side winding current unbalance factor < 2%, ensure that the safe and reliable operation of transformer.
Accompanying drawing explanation
Fig. 1 is that 54 pulse wave rectifiers of the present invention become theory diagram.
Fig. 2 is operation principle block diagram of the present invention.
Fig. 3 is the series connection figure of phase-splitting power cell in Fig. 2.
Fig. 4 is structural representation of the present invention.
Fig. 5 is 54 pulse wave polar plots in the present invention.
Fig. 6 is low-voltage lead elementary diagram of the present invention.
Fig. 7 is high-voltage connection schematic diagram of the present invention.
Fig. 8 a-Fig. 8 i is the present invention ± 26.67 °, ± 20 °, ± 13.33 °, the phase shift phase angle schematic diagram of ± 6.67 °, 0 ° Vector modulation.
Fig. 9 is that the present invention exports sleeve pipe layout schematic diagram.
In figure: basic winding 106. high pressure winding 107. sleeve pipe 108. of 101. transformer 102. power cell 103. secondary winding 104. Phase shift winding 105. is unshakable in one's determination
Embodiment
Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described further:
See Fig. 4, it is structural representation of the present invention, a kind of high-power high voltage converter plant of the present invention oil immersed type 54 pulse wave variable-frequency transformer 101, high pressure adopts the three-phase input winding of Y connection, low pressure adopts the heterogeneous output winding of extend-triangle connection, low pressure winding is divided into three large group, wherein each large group comprises 9 Phase shift winding, its phase shifting angle is respectively+26.67 ° ,+20 ° ,+13.33 ° ,+6.67 °, 0 ° ,-6.67 ° ,-13.33 ° ,-20 ° ,-26.67 °, each Phase shift winding differential seat angle 6.67 °; Often to be in series by several power cells 102, three-phase low-voltage export adjacent between mutual deviation 6.67 °, these 9 Phase shift winding 104 control to trigger controllable silicon IGBT by the different time sequential pulse of three-phase and obtain positive and negative each 27 pulse waves; High pressure winding 106 is also divided into three large group, and high pressure winding 106 and low pressure winding all adopt disc coil structure; Secondary side often exports 27 windings mutually, and three-phase totally 81 windings, low-tension bushing in the outlet of fuel tank sidewall, totally 81 sleeve pipes 107.
Described every phase power cell 102 is 9, and three-phase is totally 27 power cells 102.
Described secondary winding 103 is divided into basic winding 105 and Phase shift winding 104, and extend-triangle connected mode is positive sequence connection or backward connection.
A kind of high-power high voltage converter plant of the present invention oil immersed type 54 pulse wave variable-frequency transformer 101 can realize three functions: one is that input high voltage variable is become low pressure, thus need not be able to connect with the direct inversion of the power electronic device of low pressure; Two is realize between high pressure and low pressure and mutually insulated between each winding of low pressure, and the output of each like this low voltage unit directly can be connected and need not worry the problem of short circuit and circulation; Three is by by each for low pressure winding phase shift, reaches the object of phase shift multiple rectifying, Harmonics of Input is sharply reduced, significantly reduce the interference of frequency converter to electrical network.
Seeing Fig. 1, is that 54 pulse wave rectifiers of the present invention become theory diagram; The present invention 54 pulse wave rectifier transformer 101 is specially for modularization, multiplex, high voltage converter hand over the supporting research and development of straight governing system, in order to obtain required operating high voltage, the multiple power cell 102 of transformer is composed in series, by every 9 power cells 102 mutually in the present invention, three-phase totally 27 power cells 102 forms, and these 27 power cells 102 are total three-phase input winding on transformer 101.
Seeing Fig. 2, is operation principle block diagram of the present invention; In the present invention, transformer 101 high-pressure side adopts Y connection, is three-phase input winding; Low pressure adopts multiplex extend-triangle connection, object is to reduce frequency converter operating voltage, reduce the harmonic of input current, the secondary winding 103 of transformer 101 is divided into three large group, called after A group, B group, C group respectively, often comprise 9 Phase shift winding 4 in group, its phase shift angle is respectively+26.67 °+20 °+13.33 °+6.67 ° 0 °-6.67 °-13.33 °-20 °-26.67 °, each Phase shift winding differs 6.67 °, is often made up of 9 power unit cascades.
Transformer valve side of the present invention is lifted one's head many, and be all positioned over outer terminal for convenience of wiring, one time winding is placed in interior terminal.A tapping is without tap.Three phase converter transformer has three groups of windings, and between three groups of windings, operating voltage is the voltage between phases of frequency converter, and each unit access frequency converter is series connection, and phase shifting angle should progressively change and consistent with frequency converter in order, to reduce cell voltage gradient.Winding by Same Name of Ends rise around, if interior triangular wire is solid wire, Yan Bian can adopt double joint wire.Singlely weld tap with double joint conversion place.
Seeing Fig. 3, is the series connection figure of phase-splitting power cell in Fig. 2; Transformer 101 low-pressure side often needs 9 groups of secondary winding 103 mutually, three-phase output has 27 secondary winding 103 and forms 54 pulse waves, mutual deviation 6.67 ° between adjacent phase, these 9 secondary winding 103 are controlled to trigger controllable silicon by the different time sequential pulse of three-phase, obtain positive and negative each 27 pulse waves, thus obtain 54 pulse waves.
Seeing Fig. 4, is structural representation of the present invention; In the present invention, transformer 101 high-pressure side adopts Y connection, because transformer valve side is lifted one's head many, for convenience of wiring, high pressure winding 106 is placed on interior terminal, near 108 sides unshakable in one's determination, secondary winding 103 is positioned over outer terminal, be sleeved on outside high pressure winding 106, high pressure winding 106 is divided into three parts, is upper, middle and lower arrangement mode, separate with insulation board between every part, high-voltage connection and a point wiring are therefrom drawn; Valve side secondary winding 103 is also divided into three parts, every part is totally nine windings, phase shift angle sequence is from top to bottom respectively+26.67 °+20 °+13.33 °+6.67 ° 0 °-6.67 °-13.33 °-20 °-26.67 °, each Phase shift winding 104 order difference 6.67 °, three part coils arrangement modes are identical.
Fig. 5 is 54 pulse wave polar plots in the present invention; Seeing Fig. 6, is low-voltage lead elementary diagram of the present invention; Seeing Fig. 7, is high-voltage connection schematic diagram of the present invention; Secondary winding 103 of the present invention is divided into three large groups, be often 9 windings in group, wherein each secondary winding 103 is divided into again Phase shift winding 104 and basic winding 105, by the voltage exporting different angles according to calculation adjustment of umber of turn, corresponding high pressure winding 106 is also divided into 3 large groups, is conducive to the balance of transformer 101 output loading and the balance of impedance voltage like this.Basic winding 105 adopts triangle, and Phase shift winding 104 extends out in each vertex of a triangle, and extend-triangle connected mode is positive sequence connection or backward connection, can realize secondary voltage certain angle more advanced than primary voltage.The secondary voltage value of angle value advanced as required, an input voltage and needs can calculate the turn ratio of the basic winding of secondary, Phase shift winding and a winding.
Seeing Fig. 8 a-Fig. 8 i, is the present invention ± 26.67 °, ± 20 °, ± 13.33 °, the phase shift phase angle schematic diagram of ± 6.67 °, 0 ° Vector modulation; On the basis of electrical network three-phase voltage, being uniformly distributed many pulse waves voltage on valve side for obtaining, namely needing every phase voltage on valve side to be uniformly distributed expansion in 120 °.Utilize Y, d11 and Yd1 two kinds of wiring groups, reach mutual phasing 60 ° for this reason.Recycling is paid limit delta connection and is prolonged the phase angle that limit phase shift obtains needs to both sides.According to wiring group definition, clockwise phase shift is+, counterclockwise phase shift is-.In the present invention, the phase shifting angle of 54 pulse waves is spaced apart: 360 ° of ÷ 18=6.67 °.Concrete phase shift angle is respectively+26.67 ° ,+20 ° ,+13.33 ° ,+6.67 °, 0 ° ,-6.67 ° ,-13.33 ° ,-20 ° ,-26.67 °.
Seeing Fig. 9, is that the present invention exports sleeve pipe 107 and arranges schematic diagram.Circuit Fault on Secondary Transformer often exports totally 54 windings mutually, and three-phase totally 81 windings, low-tension bushing in the outlet of fuel tank sidewall, totally 81 sleeve pipes 107.
A kind of high-power high voltage converter plant of the present invention oil immersed type 54 pulse wave variable-frequency transformer 101, the voltage that each power cell 102 requires transformer to export as far as possible unanimously, partly the passing through impedance unbalance rate and must control within 2% of transformer.
The present invention, by calculating the Electric Field Numerical Calculation of insulation system, wave process, determines rationally, optimizes, economical Main Insulation Structure of Electric, longitudinal insulating structure; As everyone knows, transformer is in operation, and except bearing long-term work voltage, also will bear overvoltage in short-term, i.e. built-in function overvoltage and external lightning impulse overvoltage.Wherein, the main insulation impact of built-in function overvoltage on transformer is large, and the longitudinal insulation of external lightning impulse overvoltage major effect transformer.The size of the main longitudinal insulation of transformer, determines the economy of power transformer product.So want to design the product that economic index is good, manufacturing process is simple, insulating reliability is high, the Electric Field Distribution of transformer insulation structure under overvoltage effect and electric potential gradient just must be understood fully.The present invention is in design-calculated process, and appliance computer software carries out the electric Field Calculation of insulation system, and the emphasis of research is electric field in high pressure winding main empty path and Analysis of End Electric Field.The puncture voltage of paper oil insulation structure, not only relevant with the geometrical form in insulating oil gap, size, but also with the shape of electrode and grounded part and position each other thereof and distance dependent.Therefore, in order to correctly select insulation system, understand the position of wherein maximum field strength, and the electric field intensity value calculating these positions is very important.The electric field of high pressure winding main empty path, can calculate by concentric column electrode, be uniform electric field.But the impact of electrode surface on electric field can not be ignored, especially high pressure winding surface, because voltage is high, intersegmental exist oil clearance, and the corner angle of strip conductor and the factor such as stay or cushion block, can make uniform electric field distort in addition, add local field strength, so revise with a coefficient being greater than 1.
Claims (3)
1. a high-power high voltage converter plant oil immersed type 54 pulse wave variable-frequency transformer, high pressure adopts the three-phase input winding of Y connection, low pressure adopts the heterogeneous output winding of extend-triangle connection, it is characterized in that, low pressure winding is divided into three large group, wherein each large group comprises 9 Phase shift winding, and its phase shifting angle is respectively+26.67 ° ,+20 ° ,+13.33 ° ,+6.67 °, 0 ° ,-6.67 ° ,-13.33 ° ,-20 ° ,-26.67 °, each Phase shift winding differential seat angle 6.67 °; Often to be formed by several power unit cascades, three-phase low-voltage export adjacent between mutual deviation 6.67 °, these 9 Phase shift winding control to trigger controllable silicon IGBT by the different time sequential pulse of three-phase and obtain positive and negative each 27 pulse waves; High pressure winding is also divided into three large group, and high pressure winding and low pressure winding all adopt disc coil structure; Secondary side often exports 27 windings mutually, and three-phase totally 81 windings, low-tension bushing in the outlet of fuel tank sidewall, totally 81 sleeve pipes.
2. a kind of high-power high voltage converter plant oil immersed type 54 pulse wave variable-frequency transformer according to claim 1, it is characterized in that, described every phase power cell is 9, and three-phase is totally 27 power cells.
3. a kind of high-power high voltage converter plant oil immersed type 54 pulse wave variable-frequency transformer according to claim 1, it is characterized in that, described secondary side winding is divided into basic winding and Phase shift winding, and extend-triangle connected mode is positive sequence connection or backward connection.
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| CN201510426954.3A CN105006353A (en) | 2015-07-20 | 2015-07-20 | Oil-immersed 54 pulse wave frequency conversion transformer for large-power high-voltage frequency conversion apparatus |
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| CN201510426954.3A CN105006353A (en) | 2015-07-20 | 2015-07-20 | Oil-immersed 54 pulse wave frequency conversion transformer for large-power high-voltage frequency conversion apparatus |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106449068A (en) * | 2016-12-19 | 2017-02-22 | 保定天威集团特变电气有限公司 | 3*36 pulse wave phase-shifting rectifier transformer |
| CN106710850A (en) * | 2016-11-29 | 2017-05-24 | 保定天威集团特变电气有限公司 | Direct step-down 54-pulse rectifier transformer for direct current furnace |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020190697A1 (en) * | 2001-04-27 | 2002-12-19 | Jerzy Ferens | 18-pulse rectification system using a wye-connected autotransformer |
| CN201048075Y (en) * | 2007-06-13 | 2008-04-16 | 常州特种变压器有限公司 | 18 pulse wave commutator transformer |
| CN101635198A (en) * | 2009-06-30 | 2010-01-27 | 东莞市光华实业有限公司 | 36-pulse high-power frequency conversion rectifier transformer |
| CN103594237A (en) * | 2013-11-28 | 2014-02-19 | 佛山市欧立电子有限公司 | 18-pulse phase shift rectifier transformer |
| CN204857403U (en) * | 2015-07-20 | 2015-12-09 | 辽宁华冶集团发展有限公司 | High -power high -voltage frequency converters device is with oily 54 pulse wave frequency conversion transformers of formula |
-
2015
- 2015-07-20 CN CN201510426954.3A patent/CN105006353A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020190697A1 (en) * | 2001-04-27 | 2002-12-19 | Jerzy Ferens | 18-pulse rectification system using a wye-connected autotransformer |
| CN201048075Y (en) * | 2007-06-13 | 2008-04-16 | 常州特种变压器有限公司 | 18 pulse wave commutator transformer |
| CN101635198A (en) * | 2009-06-30 | 2010-01-27 | 东莞市光华实业有限公司 | 36-pulse high-power frequency conversion rectifier transformer |
| CN103594237A (en) * | 2013-11-28 | 2014-02-19 | 佛山市欧立电子有限公司 | 18-pulse phase shift rectifier transformer |
| CN204857403U (en) * | 2015-07-20 | 2015-12-09 | 辽宁华冶集团发展有限公司 | High -power high -voltage frequency converters device is with oily 54 pulse wave frequency conversion transformers of formula |
Non-Patent Citations (2)
| Title |
|---|
| 张秀梅等: "变频器用多脉冲整流变压器的移相", 《包钢科技》 * |
| 王鹏等: "高压变频器36脉波移相变压器的设计", 《电气开关》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106710850A (en) * | 2016-11-29 | 2017-05-24 | 保定天威集团特变电气有限公司 | Direct step-down 54-pulse rectifier transformer for direct current furnace |
| CN106449068A (en) * | 2016-12-19 | 2017-02-22 | 保定天威集团特变电气有限公司 | 3*36 pulse wave phase-shifting rectifier transformer |
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Application publication date: 20151028 |