WO2021073121A1 - 一种平面变压器及有源电路 - Google Patents

一种平面变压器及有源电路 Download PDF

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Publication number
WO2021073121A1
WO2021073121A1 PCT/CN2020/093655 CN2020093655W WO2021073121A1 WO 2021073121 A1 WO2021073121 A1 WO 2021073121A1 CN 2020093655 W CN2020093655 W CN 2020093655W WO 2021073121 A1 WO2021073121 A1 WO 2021073121A1
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Prior art keywords
winding
magnetic
transformer
parallel
magnetic columns
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PCT/CN2020/093655
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English (en)
French (fr)
Inventor
王宁
程杰斌
谭威
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华为技术有限公司
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Priority to EP20876009.0A priority Critical patent/EP4036941B1/en
Publication of WO2021073121A1 publication Critical patent/WO2021073121A1/zh
Priority to US17/721,034 priority patent/US20220238268A1/en

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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
    • H01F27/24—Magnetic cores
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F3/00—Cores, Yokes, or armatures
    • H01F3/10—Composite arrangements of magnetic circuits
    • 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
    • H01F27/2804—Printed windings
    • 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
    • H01F27/2823—Wires
    • 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
    • H01F27/30—Fastening or clamping coils, windings, or parts thereof together; Fastening or mounting coils or windings on core, casing, or other support
    • H01F27/306—Fastening or mounting coils or windings on core, casing or other support
    • 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
    • H01F27/38—Auxiliary core members; Auxiliary coils or windings
    • 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
    • H01F27/2804—Printed windings
    • H01F2027/2809—Printed windings on stacked layers
    • 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
    • H01F27/2804—Printed windings
    • H01F2027/2814—Printed windings with only part of the coil or of the winding in the printed circuit board, e.g. the remaining coil or winding sections can be made of wires or sheets
    • 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
    • H01F27/2804—Printed windings
    • H01F2027/2819—Planar transformers with printed windings, e.g. surrounded by two cores and to be mounted on printed circuit
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Definitions

  • This application relates to the field of circuits, in particular to a planar transformer and an active circuit.
  • Planar transformers use copper foil traces inside multilayer PCBs as windings, which have the advantages of flexible winding design, simple assembly, and high power density; most of the DC conversion power supplies used in telecommunications equipment are designed in the form of board-mounted module power supplies.
  • the transformer is mainly designed in the form of a planar transformer.
  • the following solutions generally exist to reduce the loss of the transformer while maintaining the number of layers of the multilayer PCB and the copper thickness of each layer of copper foil unchanged. 1. Optimize the winding stack of the planar transformer and reduce the eddy current loss of the winding stack; 2. Optimize the winding end routing of the planar transformer to reduce the end loss; 3. Reduce the number of turns of the primary and secondary sides of the transformer and reduce the winding loss Conduction loss.
  • the first two solutions are universal, and will be used when designing planar transformers, but they can only reduce losses to a certain extent.
  • the third solution is simple to use, but there are limitations.
  • the transformation ratio K the number of turns of the primary winding Np/the number of turns of the secondary winding Ns, and K>0.
  • the conventional transformer winding design usually chooses smaller Np and Ns.
  • the disadvantage of traditional transformer design is that once the primary winding turns Np and the secondary winding turns Ns are simplified to the uncommon divisor, there is no way to make Np and Ns smaller; this restricts the further reduction of transformer losses.
  • the high loss of the transformer will lead to an increase in the heat consumption density of the power supply when the power of the power supply increases, which requires a high-power power supply to meet the heat dissipation requirements, thereby restricting the increase in the power density of the power supply.
  • the embodiment of the present application provides a planar transformer, which can effectively reduce the number of winding turns of the transformer, reduce the winding loss of the transformer, and improve the efficiency of the transformer.
  • the present application provides a planar transformer including a winding structure and a magnetic core structure.
  • the winding structure includes a primary winding and a secondary winding.
  • the magnetic core structure includes a first magnet part, a second magnet part and a plurality of magnetic columns, A plurality of magnetic columns are located between the first magnet part and the second magnet part, wherein the primary winding is wound around M magnetic columns of the plurality of magnetic columns, M is a positive integer, and M ⁇ 3, where M Among the magnetic columns, the cross-sectional area of at least one magnetic column is different from the cross-sectional area of other magnetic columns.
  • the planar transformer of this structure by changing the size of the magnetic column, the cross-sectional area of at least one magnetic column is different from the cross-sectional area of other magnetic columns, thereby forming partial magnetic flux cancellation when the winding is wound around the magnetic column , It can further obtain the fractional transformation ratio; compared with the traditional transformer with the same fractional transformation ratio, it can effectively reduce the number of turns of the secondary winding, which is beneficial to reduce the DC resistance and AC resistance of the transformer winding (DCR/ACR) , Can effectively improve the conversion efficiency of the planar transformer.
  • the planar transformer When the planar transformer is applied to the power supply, it can effectively increase the high power density of the power supply and improve the thermal performance of the power supply.
  • the primary winding is wound in series or series-parallel around the M magnetic columns; wherein, the series-parallel winding refers to the primary winding Connect X magnetic columns in series and MX magnetic columns in parallel, where X is a positive integer smaller than the value of M.
  • the fractional transformation ratio of the transformer can be realized in a simple winding manner, which has the advantage of simple manufacturing process.
  • By connecting the primary winding around M magnetic columns in series and parallel it is possible to wind around fewer transformer magnetic columns to achieve the transformer's fractional transformation ratio, thereby reducing the size of the transformer; when the planar transformer is applied to the power supply, It can effectively improve the high power density of the power supply.
  • regardless of whether the primary winding is wound in series or series-parallel around M magnetic columns it achieves the same fractional transformation ratio compared with the traditional planar transformer, and has fewer winding turns, which can effectively reduce the loss of the transformer.
  • the transformer further includes at least one primary side parallel winding, and each primary side parallel winding surrounds At least a part of the magnetic columns in the plurality of magnetic columns are wound in series or in series and parallel.
  • each primary side parallel winding is wound in series or in series and parallel around the other M magnetic columns of the plurality of magnetic columns, wherein , The primary winding and the at least one primary parallel winding are connected in parallel.
  • the sum of the cross-sectional area of the magnetic column wound by each primary side parallel winding is the same as that of the primary side winding
  • the ratio of the total cross-sectional area of the M magnetic columns wound is 80%-120%.
  • the secondary winding is wound around one of the plurality of magnetic pillars.
  • the transformer further includes at least one secondary side parallel winding, and each secondary side parallel winding surrounds a plurality of magnetic columns One of the magnetic columns is wound; the secondary winding and at least one secondary parallel winding are connected in parallel.
  • the total number of secondary windings and at least one secondary parallel winding is P, and P is a positive integer, P ⁇ 2.
  • the ratio of the cross-sectional area of the P magnetic columns corresponding to the P secondary windings and the parallel windings is A1: A2:...: AP, the turns of the P secondary windings and the secondary parallel windings on the P magnetic columns
  • the numbers are Ns1, Ns2,..., NsP, where the values of A1*Ns1 and A2*Ns2,..., AP*NsP satisfy at least one of the following conditions: equal; or, the ratio between any two values is 80 %-120%.
  • At least a part of the plurality of magnetic pillars and the first magnet part have an integrated structure, And/or, at least a part of the magnetic column and the second magnet are an integral structure; or, each of the plurality of magnetic columns is composed of an upper magnetic column and a lower magnetic column, wherein at least a part of the upper magnetic column
  • the column and the first magnet part are an integral structure, and/or, at least a part of the lower magnetic column and the second magnet part are an integral structure.
  • the cross section of the magnetic column is a circle, an ellipse, a rectangle, a square, or an irregular shape.
  • an active circuit in a second aspect, includes the planar transformer according to the first aspect or any one of the implementation manners of the first aspect.
  • the planar transformer provided by this application is designed to be flexible.
  • the design of transformers with different fractional turns ratios can be realized by changing the number and area of the transformer core pillars and matching the corresponding winding design. It can be flexibly applied to power supplies with different input and output voltages and has winding The number of turns is small and the winding loss is reduced.
  • Figure 1-1 is a schematic diagram of the secondary winding design of a transformer provided by prior art one;
  • Figure 1-2 is a schematic diagram of a winding method of a secondary winding of a transformer provided by prior art 1;
  • Figures 1-3 are schematic diagrams of the winding method of the primary winding of the transformer provided by prior art one;
  • Figure 2-1 is a schematic diagram of the current flow in the secondary winding of the transformer provided by the second prior art
  • Figure 2-2 is a schematic diagram of the structure of a transformer with two full-bridge units provided by the second prior art
  • Figure 2-3 is a schematic diagram of the structure of a transformer with four full-bridge units provided by the second prior art
  • Figure 3-1 is a schematic diagram of the structure of a transformer with grooves on the side posts provided by prior art 3;
  • Figure 3-2 is a schematic diagram of the structure of a transformer with through-holes on the side posts provided by prior art three;
  • Figures 4-1 and 4-2 are schematic diagrams of the magnetic core structure of the planar transformer provided by the embodiments of the application;
  • FIG. 5 is a schematic diagram of a winding structure (a primary winding is wound in series) of a planar transformer provided by an embodiment of the application;
  • FIG. 6 is a schematic diagram of another winding structure (a primary winding is wound in series and parallel) of a planar transformer provided by an embodiment of the application;
  • FIG. 7 is a schematic diagram of another winding structure (a plurality of primary windings are respectively wound in series) of a planar transformer provided by an embodiment of the application;
  • 8-1, 8-2, 8-3, and 8-4 are schematic diagrams of yet another winding structure (including one primary winding and multiple secondary windings) of the planar transformer provided by the embodiments of this application;
  • FIG. 9 is a schematic diagram of winding the planar transformer provided by this application when it is wound on a multilayer circuit board.
  • this scheme divides the secondary winding into two windings in parallel.
  • w2 and w3 form one turn of the secondary winding
  • w1 and w4 form another One-turn secondary winding; when the transformer is working, it is assumed that the primary current flows counterclockwise.
  • Faraday’s law of electromagnetic induction the direction of the secondary winding induced current is clockwise, and its flow paths are G-SR2-w2-P and G- SR3-w3-P.
  • the G terminal of the two parallel windings on the secondary side of the transformer are connected together, and the P terminal is also connected together.
  • w2 and w3 are connected in parallel.
  • the turns of the winding together form a one-turn winding.
  • the magnetic flux generated by w2 and w3 working at the same time is equivalent to the magnetic flux generated by one turn of the ordinary winding; the primary winding is wound according to the conventional winding method, as shown in Figure 1. -3 shown.
  • the working principle is similar. This scheme can effectively reduce the winding loss of the transformer by reducing the number of turns of the transformer winding by half.
  • the disadvantage of the prior art 1 is that only 0.5-turn winding design on the secondary side of the transformer can be realized, and the number of turns of the primary winding is limited, and the number of turns of the primary winding is required to be an even number. For example, when designing a transformer with the primary and secondary winding turns of 7:1, the secondary winding cannot be designed with 0.5 turns if the same function is satisfied.
  • the second prior art specifically referring to patent WO2018160962A1, proposes a variable inverter-rectifier transformer (Variable inverter-rectifier transformer, VIRT) design technology, which can also realize the design of a fractional turns ratio transformer.
  • VIRT variable inverter-rectifier transformer
  • Figure 2-1 a VIRT with two basic full-bridge units is provided, where A1 and A2 form a full-bridge unit, and B1 and B2 form another full-bridge unit.
  • Its working principle is the same as the above-mentioned current situation.
  • the first technique is similar, the difference is that the secondary side in the prior art 1 is a full-wave rectifier circuit, and the secondary side in the prior art 2 is a full-bridge rectifier circuit.
  • the transformer shown in Figure 2-2 can realize the design with the number of winding turns N:0.5; the transformer shown in Figure 2-3 can realize the design with the number of winding turns N:0.25.
  • the secondary winding of the transformer can achieve a 0.5-turn fractional turns ratio design
  • the secondary rectifier circuit requires two full-bridge circuits, and more power devices are used. If a smaller fractional turns ratio design is implemented, more power devices are required, and the required drivers are correspondingly increased.
  • the engineering implementation is complicated and the cost is higher.
  • Patent CN1257518C provides a transformer core that can realize fractional turns, as shown in Figure 3-1 and Figure 3-2.
  • the transformer proposed in this patent includes a magnetic core composed of a central column and two side columns, and at least one side column is provided with a groove ( Figure 3-1) or at least one through hole ( Figure 3-2).
  • the design of the fractional-turn transformer is realized by winding the windings on the grooves or through holes on the center and side posts of the magnetic core.
  • the fractional turns ratio design proposed by the patent CN1257518C is only aimed at the core structure with one center pillar and two side pillars.
  • the basic principle is to achieve magnetic flux cancellation by winding one or more turns on the secondary side of the transformer.
  • This design solution will increase the loss due to the increase in the number of winding turns, and in the design of high-current transformers, the width of the groove or the through hole will additionally reduce the effective magnetic flux area of the side leg of the magnetic core, resulting in the magnetic core becoming larger. The utilization rate of the magnetic core becomes low.
  • planar transformer design provided by the above three schemes cannot achieve the number of primary-side fractional turns, and therefore cannot effectively reduce the number of turns of the transformer winding, resulting in large transformer losses and restricting the increase in power density of the power supply.
  • the embodiment of the present application provides a planar transformer including a winding structure and a magnetic core structure, wherein the winding structure includes a primary winding and a secondary winding.
  • the magnetic core structure includes a plurality of magnetic pillars, and the number of the plurality of magnetic pillars is greater than or equal to three. Among them, the number of primary windings is greater than or equal to 1, and the number of secondary windings is greater than or equal to 1.
  • One of the primary windings is wound around M magnetic columns among multiple magnetic columns, where M is a positive integer and M ⁇ 3.
  • M is a positive integer and M ⁇ 3.
  • at least one of the magnetic columns has the same cross-sectional area as the other The cross-sectional area of the magnetic column is not the same.
  • the specific winding method includes: the primary winding is wound in series or in series and parallel around the M magnetic columns.
  • series connection means that the winding is wound on multiple magnetic columns through one winding end, and the winding end is independently wound during the winding process without branching Diversion.
  • the winding passes through a winding end (current inflow end).
  • a winding end current inflow end
  • branch is separated.
  • Each branch is wound around several magnetic columns, and each branch is at the end of the winding. Synthesize back to a winding end (as the outflow end of the current).
  • Series-parallel winding refers to the primary winding around X magnetic columns in series and M-X magnetic columns in parallel, where X is a positive integer less than the value of M.
  • Figure 4-1 shows a magnetic core structure of a planar transformer provided by an embodiment of the present application.
  • the magnetic core structure 5 includes a first magnet part 1, a second magnet part 2 and six magnetic pillars 3 (that is, the number of magnetic pillars included in the magnetic core structure is 6), and the magnetic pillars 3 are located in the first magnet part 1 and the second magnet part.
  • the first magnet part 1 and the second magnet part 2 are both rectangular plate-shaped structures, and the magnetic column 3 is a cylindrical structure.
  • the cross-sectional area of at least one magnetic column 3 is different from the cross-sectional area of other magnetic columns 3.
  • Each magnetic column 3 is a separate structure, which is composed of an upper magnetic column 31 and a lower magnetic column 32, wherein the upper magnetic column 31 and the lower magnetic column 32 have the same cross section, and the upper magnetic column 31 and the lower magnetic column 32 have the same cross section. There is an air gap 4 between.
  • the upper magnetic column 31 and the lower magnetic column 32 can be formed as an integral structure, that is, each magnetic column 3 is made into an integral structure, that is, the magnetic column 3 is made into a cylindrical body, and each magnetic column 3 is a cylindrical body. .
  • Figure 4-2 shows another magnetic core structure of a planar transformer provided by an embodiment of the present application.
  • the first magnet part 1 and the second magnet part 2 are both circular plate-shaped structures, and the magnetic column 3 is a rectangular parallelepiped structure. (That is, the number of multiple magnetic columns included in the magnetic core structure is 4).
  • the other structure is similar to that shown in Figure 4-1, and will not be repeated.
  • the number of magnetic columns 3 can be selected arbitrarily, and the selection is made according to the specific transformation ratio, power and other operating parameters when designing the transformer.
  • At least a part of the upper magnetic column 31 and the first magnet portion 1 may be formed as an integral structure, and at least a part of the lower magnetic column 32 may also be formed as an integral structure with the second magnet portion 32 to facilitate the installation of the transformer and the winding.
  • the winding system may be formed as an integral structure, and at least a part of the lower magnetic column 32 may also be formed as an integral structure with the second magnet portion 32 to facilitate the installation of the transformer and the winding.
  • part of the magnetic column 3 may also be formed as an integral structure with the first magnet part 1, and another part of the magnetic column may be formed as an integral structure with the second magnet part 32.
  • first magnet part 1 and/or the second magnet part 2 may also be other irregular plate-shaped bodies, and the cross section of the magnetic column 3 may also be elliptical or rectangular or square or irregular, so that Transformers can be designed to match various types of installation spaces.
  • the height ratio of the upper magnetic column 31 and the lower magnetic column 32 of each magnetic column 3 may be equal or unequal; thereby, more manufacturing errors can be allowed and manufacturing costs can be reduced.
  • the height of the upper magnetic column 31 and the lower magnetic column 32 of any one of the magnetic columns 3 may be equal or unequal; thus, more manufacturing errors can be allowed and manufacturing costs can be reduced.
  • the magnetic core structure provided in the above-mentioned embodiment of the present application is taken as an example to describe the planar transformer winding structure provided in the embodiment of the present application.
  • the primary windings are wound in series on the first four magnetic columns, respectively winding the first four magnetic columns one turn.
  • the secondary winding is wound on the first magnetic column, the number of turns is 1 turn.
  • Np1, Np2, Np3, and Np4 are the number of winding turns generated by the primary winding on the magnetic column A1, A2, A3, and A4 respectively.
  • Ip is the current in the primary winding
  • R1, R2, R3, and R4 are the magnetic resistances on the magnetic columns A1, A2, A3, and A4, respectively.
  • l is the length of the magnetic circuit
  • ⁇ is the permeability of the magnetic circuit material
  • Ae is the cross-sectional area of the magnetic circuit.
  • the four magnetic columns are located between the first magnet part and the second magnet part, and the four magnetic columns have the same height, that is, the length of the magnetic circuit of each magnetic column is the same; and the material of the magnetic column is the same , That is, the magnetic permeability is also the same; but the cross-sectional area between the magnetic columns is different.
  • planar transformer provided in the embodiments of the present application, a fractional transformation ratio can be achieved. Compared with the traditional transformer design, its advantages are shown in Table 1 below: When the implementation transformation ratio is 3.5, the embodiment of the present application The provided planar transformer has 44% fewer turns than traditional transformers (4 turns are reduced).
  • the primary winding is only wound on four magnetic columns. It is understandable that the number of magnetic columns wound by the primary winding is optional, and the number of magnetic columns is designed according to different designs.
  • the demand can be selected as any value of more than three.
  • Figure 6 provides another type of transformer, where the primary winding is wound in series and parallel on multiple magnetic columns.
  • the transformer is provided with four magnetic columns, of which the primary windings are wound in series on the A3 and A4 magnetic columns, and are wound in parallel on the A1 and A2 magnetic columns, forming a series-parallel winding method.
  • the planar transformer provided in this embodiment will be described in detail.
  • Np1, Np2, Np3, and Np4 are the number of turns of the primary winding on the magnetic column A1, A2, A3, and A4 respectively.
  • Ip is the current in the main circuit of the primary winding
  • R1, R2, R3, and R4 are the magnetic resistances on the magnetic columns A1, A2, A3, and A4, respectively.
  • l is the length of the magnetic circuit
  • ⁇ is the permeability of the magnetic circuit material
  • Ae is the cross-sectional area of the magnetic circuit.
  • the primary winding is wound in series and parallel on a plurality of magnetic columns, at least one of which has a different cross-sectional area than the other magnetic columns, and a fractional turns ratio can be achieved.
  • Figure 7 provides another planar transformer, on which multiple primary windings are provided, and each primary winding is wound on multiple magnetic columns.
  • the transformer there are two primary windings, and each primary winding is wound on three of the magnetic columns. To facilitate the distinction, the two primary windings are divided into the first primary winding and the primary parallel winding.
  • planar transformer provided in FIG. 7 will be described in detail.
  • first primary winding and the primary parallel winding are connected in parallel.
  • first primary winding is connected in series with the primary parallel winding, it is of the type similar to the planar transformer provided in Figure 5: a primary winding is wound in series on six magnetic columns
  • the primary side parallel winding is wound in series on the magnetic columns A2, A4, and A6, and one turn is wound on the three magnetic columns respectively.
  • Ip is the current in the main circuit of the primary winding.
  • the first primary winding and the primary parallel winding are connected in parallel. Therefore, in the first primary winding and the primary parallel winding, the currents are respectively
  • R1, R2, R3, R4, R5, R6 are the magnetic resistance on the magnetic column A1, A2, A3, A4, A5, and A6 respectively.
  • l is the length of the magnetic circuit
  • ⁇ is the permeability of the magnetic circuit material
  • Ae is the cross-sectional area of the magnetic circuit.
  • the primary side parallel winding is optional, and only one of the two primary side windings may be retained.
  • the output with a transformation ratio of 2.5 can also be achieved.
  • the first primary winding is wound in series on the magnetic columns A1, A3, and A5, and the primary side parallel winding is wound in series on the magnetic columns A2, A4, and A6; among them, the magnetic columns A1, A3,
  • the sum of the cross-sectional area of A5 is equal to the sum of the cross-sectional areas of the magnetic columns A2, A4, and A6.
  • the inventor of the present application has selected a good output efficiency when the ratio of the two cross-sectional areas is between 80% and 120% through multiple experiments. That is, it is preferable to set the ratio of the total cross-sectional area of the magnetic column wound by each primary side parallel winding to the total cross-sectional area of the magnetic column wound by the first primary winding to be 80%-120% Within.
  • an embodiment of the present application also provides a planar transformer with multiple secondary windings and four transformers with different transformation ratios.
  • a planar transformer with multiple secondary windings and four transformers with different transformation ratios.
  • the planar transformer shown in Figure 8-1 is based on the planar transformer shown in Figure 6 with three secondary windings added.
  • the four magnetic columns A1, A2, A3, and A4 respectively constitute four basic transformers, and the four secondary windings are connected in parallel to form a final matrix transformer.
  • the secondary winding is wound with 1 turn on the corresponding magnetic column A1, A3, A4, and the secondary winding is wound with 2 turns on the magnetic column A2.
  • the four basic transformers composed of four magnetic columns A1, A2, A3, and A4, and the matrix transformer composed of four secondary windings connected in parallel, have a transformation ratio of 3.5.
  • the transformation ratios of the four basic transformers formed by the four magnetic columns A1, A2, A3, and A4 are all equal, which are all 3.5.
  • the inventor of the present application has debugged and verified the planar transformer provided by the present application through design tests, set the value of Ae1*Ns1 of a magnetic column and the corresponding secondary winding as a reference value M, and set the other magnetic columns of the planar transformer and Multiple secondary windings are designed to satisfy the value of Ae2*Ns2, Ae3*Ns3, Ae4*Ns4 falling within the range of (80%-120%)*M, which can better guarantee the above technical effects and make the secondary windings
  • the output voltage values are approximately equal, which is conducive to more accurate power control of the planar transformer.
  • the transformation ratio of the transformer is (Refer to the above formula for the specific calculation principle), the transformation ratio of the matrix transformer composed of four secondary windings connected in parallel
  • the common form is to pierce the magnetic column in the printed circuit board, and the winding is the wire laid on the printed circuit board.
  • the printed circuit board generally has a multilayer structure, which contains multiple copper clad layers and a dielectric layer, and the copper foil on the copper clad layer is used to form the traces of the transformer windings. It can be understood that, in the embodiments of the present application, the number of copper-clad layers on which windings are laid is not limited.
  • the winding can be formed on two or more copper-clad layers across layers to avoid the situation of "stacked wires" ("stacked wires” means that during the winding process around the magnetic column, the winding lines cross to form Short circuit), as shown in Figure 9, by forming the winding cross-layer on two or more copper-clad layers, when the winding line is wound on a copper-clad layer, there may be "overlapped wires".
  • the circuit extends along the through hole between the layers/or the hole on the circuit board for accommodating the magnetic column, and extends to other copper clad layers to complete the winding; that is, through the wires, the different copper clad layers
  • the copper foil used to form the transformer windings is connected.
  • the windings of the transformer can also be wires covered with an insulating layer. At this time, when the windings are wound around the magnetic column, the "stacking" situation can be allowed. At this time, the windings can only be formed in one Layer circuit board.
  • the present application also provides an active circuit, and the active circuit includes any of the planar transformers provided in the foregoing embodiments.
  • the active circuit can be any one or more of the following types: full-bridge topology circuit, half-bridge topology circuit, active clamp topology circuit, LLC topology circuit, BUCK+LLC two-stage topology circuit, BUCK-BOOST+LLC two -Level topology circuit, Boost+LLC two-level topology circuit, forward topology circuit, flyback topology circuit, isolated topology circuit, two-level topology circuit, and non-isolated topology circuit.

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Abstract

本申请提供一种平面变压器及一种有源电路，可应用于5G移动通信技术、云计算等领域的电信设备和通信电源。平面变压器，包括绕组结构和磁芯结构，绕组结构包括原边绕组和副边绕组，磁芯结构包括第一磁体部、第二磁体部和多个磁柱，多个磁柱位于第一磁体部和第二磁体部之间，原边绕组围绕多个磁柱的其中M个磁柱进行绕制，M为正整数、且M≥3，在M个磁柱中，至少有一个磁柱的横截面积与其它磁柱的横截面积不相同。该平面变压器，能够以较少的绕组匝数实现分数变压比，通过减少变压器绕组的匝数，有效降低变压器的损耗.

Description

一种平面变压器及有源电路
本申请要求于2019年10月14日提交的申请号为201910974525.8、发明名称为“一种平面变压器及有源电路”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及电路领域，尤其涉及一种平面变压器及有源电路。
背景技术
平面变压器，利用多层PCB内部的铜箔走线作为绕组，具有绕组设计灵活、组装简单、功率密度高等优点；电信设备中使用的直流变换电源，大部分以板装模块电源的形式设计，其变压器以平面变压器形式设计为主。
平面变压器的绕组设计中，维持多层PCB的层数和每层铜箔铜厚不变的情况下，降低变压器的损耗一般存在如下几种解决手段。一、优化平面变压器的绕组叠层，降低绕组叠层的涡流损耗；二、优化平面变压器的绕组端头走线，降低端头损耗；三、减少变压器的原副边的匝数，降低绕组的导通损耗。在上述三种降低损耗的方案中，前两种解决手段是通用手段，在设计平面变压器时都会采用，但是只能在一定程度上降低损耗。第三种解决手段使用起来简单，但是存在有局限性。
具体来说，变压器一般包括原边绕组和副边绕组，其中，变压比K＝原边绕组匝数Np/副边绕组匝数Ns，K>0。在设计变压器时，根据输入输出电压的要求，变压比K选择不同的值，即，在设计变压器时，K值是由设计需求确定的。基于K值，在选择绕组的匝数时，原边绕组的匝数Np和副边绕组的匝数Ns的选择是多样的。例如：设计一个Np/Ns＝2.5的变压器，在满足磁芯不饱和的前提下，Np和Ns有多种组合，例如Np＝20、Ns＝8，或者Np＝10、Ns＝4，或者Np＝5、Ns＝2。为了降低变压器的损耗，常规的变压器绕组的设计，通常会选择较小的Np、Ns，如上面K＝2.5的变压器设计，在满足磁芯不饱和的前提下，会选择Np＝5，Ns＝2的绕组方案。传统变压器设计的缺点是，一旦原边绕组匝数Np和副边绕组匝数Ns，简化到无公约数，则Np和Ns就没有办法进一步较小；这制约了变压器损耗的进一步减小。另外，变压器损耗高会导致在电源功率增加时、电源热耗密度增大，从而需要高功率电源满足散热要求，从而制约电源功率密度的提升。
发明内容
本申请实施例提供了一种平面变压器，能够有效减少变压器的绕组匝数、降低变压器的绕组损耗，提升变压器的效率。
第一方面，本申请提供一种平面变压器，包括绕组结构和磁芯结构，绕组结构包括原边绕组和副边绕组，磁芯结构包括第一磁体部、第二磁体部和多个磁柱，多个磁柱位于第一磁体部和第二磁体部之间，其中，原边绕组围绕多个磁柱中的M个磁柱进行绕制，M为正整数、且M≥3，在M个磁柱中，至少有一个磁柱的横截面积与其它磁柱的横截面积不相同。
该种结构的平面变压器，通过改变磁柱的大小，使得至少一个磁柱的横截面积与其它磁柱的横截面积不相同，从而在绕组围绕磁柱进行绕制时，形成部分磁通抵消，进一步的可以获得分数变压比；与获得相同分数变压比的传统变压器相比，能够有效减少副边绕组的匝数，从而有利于降低变压器绕组的直流电阻和交流电阻(DCR/ACR)，可以有效提高平面变压器的转换效率。将平面变压器应用于电源时，能够有效提高电源的高功率密度、改善电源的热性能。
根据第一方面，在所述变压器第一种可能的实现方式中，原边绕组围绕所述M个磁柱进行串联、或者串并联绕制；其中，串并联绕制，指的是原边绕组绕X个磁柱串联以及绕M-X个磁柱并联，其中X为小于M值的正整数。
通过将原边绕组围绕M个磁柱进行串联，能够以简单的绕线方式实现变压器的分数变压比，具有制造工艺简单的优点。通过将原边绕组围绕M个磁柱进行串并联，能够围绕较少的变压器磁柱进行绕线而实现变压器的分数变压比，从而能够降低变压器的尺寸空间；将平面变压器应用于电源时，能够有效提高电源的高功率密度。同时，不论将原边绕组围绕M个磁柱进行串联还是串并联绕制，相对于传统平面变压器实现相同的分数变压比，都具有更少的绕组匝数，能够有效降低变压器的损耗。
根据第一方面或第一方面的第一种可能的实现方式，在所述变压器第二种可能的实现方式中，所述变压器还包括至少一个原边并列绕组，每个原边并列绕组均围绕多个磁柱中的至少一部分磁柱进行串联、或者串并联绕制，优选的，每个原边并列绕组围绕多个磁柱中的另外M个磁柱进行串联、或者串并联绕制，其中，原边绕组与上述至少一个原边并列绕组之间均并联连接。
根据第一方面的第二种可能的实现方式，在所述变压器第三种可能的实现方式中，每个原边并列绕组所绕制的磁柱横截面积的总和，与所述原边绕组所绕制的所述M个磁柱横截面积的总和的比值，为80％-120％。
根据第一方面，或以上第一方面的任意一种实现方式，在所述变压器第四种可能的实 现方式中，副边绕组围绕多个磁柱中的一个磁柱进行绕制。
根据第一方面的第四种可能的实现方式，在所述变压器第五种可能的实现方式中，所述变压器还包括至少一个副边并列绕组，每个副边并列绕组均围绕多个磁柱中的其中一个磁柱进行绕制；副边绕组和至少一个副边并列绕组之间均并联连接。
根据第一方面的第五种可能的实现方式，在所述变压器第六种可能的实现方式中，副边绕组和至少一个副边并列绕组的总数量为P个，P为正整数、P≥2，P个副边绕组和并列绕组所对应的P个磁柱的横截面积的比例为A1：A2：…：AP，P个副边绕组和副边并列绕组在P个磁柱上的匝数分别为Ns1、Ns2、…、NsP，其中，A1*Ns1与A2*Ns2、…、AP*NsP的值满足如下条件中的至少一个：相等；或者，任意两个值之间的比值为80％-120％。
根据第一方面，或以上第一方面的任意一种实现方式，在所述变压器第七种可能的实现方式中，多个磁柱中，至少一部分磁柱与第一磁体部为一体式结构，和/或，至少一部分磁柱与所述第二磁体为一体式结构；或者，多个磁柱中的每个磁柱均由上磁柱和下磁柱组成，其中，至少一部分所述上磁柱与所述第一磁体部为一体式结构，和/或，至少一部分所述下磁柱与所述第二磁体部为一体式结构。
根据第一方面的第七种可能的实现方式，在所述变压器第八种可能的实现方式中，磁柱的横截面为圆形、椭圆形、矩形、正方形或者不规则形状。
第二方面，提供了一种有源电路，所述有源电路包括第一方面或第一方面任意一种实现方式所述的平面变压器。
本申请提供的平面变压器设计灵活，可以通过改变变压器磁芯柱子的数量和面积，配合相应的绕组设计，实现不同分数匝比的变压器设计，可以灵活应用于不同输入、输出电压的电源，具备绕组匝数少、降低绕组损耗的有益效果。
附图说明
图1-1为现有技术一提供的变压器的副边绕组设计原理图；
图1-2为现有技术一提供的变压器的副边绕组的绕制方式示意图；
图1-3为现有技术一提供的变压器的原边绕组的绕制方式示意图；
图2-1为现有技术二提供的变压器的副边绕组电流流向示意图；
图2-2为现有技术二提供的带有两个全桥单元的变压器结构示意图；
图2-3为现有技术二提供的带有四个全桥单元的变压器结构示意图；
图3-1为现有技术三提供的边柱带有凹槽的变压器结构示意图；
图3-2为现有技术三提供的边柱带有通孔的变压器结构示意图；
图4-1、4-2为本申请实施例提供的平面变压器的磁芯结构的示意图；
图5为本申请实施例提供的平面变压器的一种绕组结构(一个原边绕组串联绕制)的示意图；
图6为本申请实施例提供的平面变压器的另一种绕组结构(一个原边绕组串并联绕制)的示意图；
图7为本申请实施例提供的平面变压器的又一种绕组结构(多个原边绕组分别串联绕制)的示意图；
图8-1、8-2、8-3、8-4为本申请实施例提供的平面变压器的再一种绕组结构(包括一个原边绕组和多个副边绕组)的示意图；
图9为本申请提供的平面变压器在多层电路板上绕制时绕线的示意图。
具体实施方式
为了使本申请的目的、技术方案和优点更加清楚，下面将结合附图对本申请作进一步地详细描述。其中，在本申请的描述中，除非另有说明，“多个”的含义是两个或两个以上。
现有技术中，存在现有技术一，其能够实现副边0.5匝的变压器设计，可以将一个原副边绕组匝数比值n:1(n为大于0的偶数)的变压器，设计实际绕组匝数为n/2:0.5。
如图1-1、图1-2和图1-3所示，该方案将副边绕组分成两个绕组并联，变压器设计时，将w2和w3组成一匝副边绕组，w1和w4组成另外一匝副边绕组；变压器工作时，假设原边电流为逆时针流动，根据法拉第电磁感应定律，副边绕组感应电流的方向为顺时针，其流动路径为G-SR2-w2-P和G-SR3-w3-P。如图1-1所示：变压器的副边两个并列绕组中的G端是连在一起的，P端也是连在一起的，如图1-2所示，w2和w3两个并联的半匝绕组共同组成了一个一匝绕组，w2和w3同时工作所产生的磁通，与一匝普通绕组产生的磁通等效；原边绕组则是按照常规绕线方式进行绕制，如图1-3所示。当变压器原边绕组电流为顺时针流动时，其工作原理类似。该方案通过将变压器绕组匝数降低一半，可以有效降低变压器的绕组损耗。现有技术一的缺点在于，只能实现变压器副边0.5匝绕组设计，并且对原边绕组的匝数有限制、需要原边绕组的匝数为偶数。例如，当设计一个原副边绕组匝数为7:1的变压器，在满足相同功能的情况下，则副边绕组无法设计成0.5匝。
现有技术二，具体参见专利WO2018160962A1，提出了一种可变逆变整流变压器(Variable inverter-rectifier transformer，VIRT)设计技术，也可以实现分数匝比变压器设计。如图2-1所示，提供了一种具有两个基本全桥单元的VIRT，其中A1，A2组成了一个全桥单元，B1，B2组成了另外一个全桥单元，其工作原理与上述现有技术一类似，区 别在于，现有技术一中的副边为全波整流电路，现有技术二中的副边为全桥整流电路。图2-2所示的变压器，可以实现绕组匝数为N：0.5的设计；图2-3所示的变压器，可以实现实现绕组匝数为N：0.25的设计。
对于现有技术二所提供的方案，虽然变压器副边绕组可以实现0.5匝分数匝比设计，但是副边整流电路需要两个全桥电路，使用的功率器件较多。如果实现更小的分数匝比设计，则需要的功率器件更多，需要的驱动也相应增多，工程实现复杂，成本较高。
现有技术三，专利CN1257518C提供了一种可实现分数匝的变压器磁芯，如图3-1和图3-2所示。该专利提出的变压器包括由一个中柱和两个边柱构成的磁芯，在至少一个边柱上开设一个凹槽(图3-1)或者至少一个通孔(图3-2)。通过将绕组绕制在上述的磁芯的中柱和边柱上的凹槽或者通孔上，实现分数匝变压器的设计。
专利CN1257518C提出的分数匝比设计方案，只是针对于具有一个中柱和两个边柱的磁芯结构，其基本原理是通过在变压器副边多绕一匝或者多匝绕组，实现磁通抵消，从而实现分数匝。该设计方案由于绕组匝数的增加会导致增加损耗，并且在大电流变压器设计时，凹槽或者通孔的宽度，会额外减少磁芯的边柱的有效磁通面积，导致磁芯变大，磁芯的利用率变低。
上述三种方案提供的平面变压器设计由于不能实现原边分数匝数，因而不能有效减少变压器绕组的匝数，造成变压器损耗较大，同时也制约了电源功率密度的提升。
本申请实施例提供了一种平面变压器，包括绕组结构和磁芯结构，其中绕组结构包括原边绕组和副边绕组。
其中，磁芯结构包括多个磁柱，该多个磁柱的数量大于或等于3。其中，原边绕组的数量大于或等于1，副边绕组的数量大于或等于1。
其中一个原边绕组围绕多个磁柱中的M个磁柱进行绕制，M为正整数、且M≥3，在所述M个磁柱中，至少有一个磁柱的横截面积与其它磁柱的横截面积不相同。具体绕制方式包括：原边绕组围绕所述M个磁柱进行串联、或者串并联绕制。
本申请中对于绕制过程中绕制方式明确如下：串联，指的是绕组通过一个绕线端在多个磁柱上进行绕制，绕制过程中绕线端独立的绕制，不进行分支分流。并联，则是绕组通过一个绕线端(电流流入端)，在开始绕制时分出多个支路、每个支路分别绕若干个磁柱进行绕制，各支路在绕线的末端再合成回一条绕线端(作为电流的流出端)。串并联绕制，指的是原边绕组绕X个磁柱串联以及绕M-X个磁柱并联，其中X为小于M值的正整数。
图4-1给出了本申请实施例提供的平面变压器的一种磁芯结构。磁芯结构5包括第一磁体部1、第二磁体部2和六个磁柱3(即磁芯结构所包括多个磁柱的数量为6)，磁柱3位 于第一磁体部1和第二磁体部2之间，第一磁体部1和第二磁体部2均为矩形板状结构，磁柱3为圆柱结构。其中，至少有一个磁柱3的横截面面积与其它磁柱3的横截面面积不同。
每个磁柱3为分体结构、均由上磁柱31和下磁柱32构成，其中，上磁柱31和下磁柱32具有相同的横截面，在上磁柱31和下磁柱32之间存在气隙4。另外，上磁柱31和下磁柱32可以形成为一体结构，也就是每个磁柱3做成为一体结构，即，将磁柱3做成圆柱体、每一个磁柱3都是一个圆柱体。
图4-2给出了本申请实施例提供的平面变压器的另一种磁芯结构，其中的第一磁体部1和第二磁体部2均为圆形板状结构，磁柱3为长方体结构(即磁芯结构所包括的多个磁柱的数量为4)。其它结构与图4-1所示的类似，不再赘述。
针对本申请上述实施例所提供的磁芯结构，在设计制造时还可以作出如下变型。
可选的，磁柱3的数量可以任意选择，在设计变压器时根据具体的变压比、功率等工况参数作出选择。
可选的，至少一部分上磁柱31可以与第一磁体部1形为一体式结构，至少一部分下磁柱32也可以与第二磁体部32形成为一体式结构，以利于变压器的安装以及绕组的绕制。
可选的，将磁柱3设计为一体结构时，部分磁柱3还可以与第一磁体部1形为一体式结构，另一部分磁柱可以与第二磁体部32形成为一体式结构。
可选的，第一磁体部1和/或第二磁体部2还可以为其它不规则的板状体，磁柱3的横截面还可以为椭圆形或矩形或正方形或不规则形状，以使得变压器能够设计用于匹配各种不同类型的安装空间。
可选的，多个磁柱3中，每个磁柱3的上磁柱31和下磁柱32的高度比值，可以相等也可以不等；从而可以允许更多的制造误差，降低制造成本。
可选的，多个磁柱3中，任一个磁柱3的上磁柱31和下磁柱32的高度，可以相等也可以不等；从而可以允许更多的制造误差，降低制造成本。
下面以本申请上述实施例提供的磁芯结构为例，对本申请实施例提供的平面变压器绕组结构进行描述。
图5给出了一种原边绕组围绕M个磁柱串联绕制的示意图。其中，原边绕组在六个磁柱中的四个磁柱上进行绕制(即M＝4)，副边绕组在六个磁柱中的其中一个磁柱上绕制。以下对该实施例提供的平面变压器进行具体的原理说明。
六个磁柱的横截面面积(下面简称截面积)分别为Ae1，Ae2，Ae3，Ae4，Ae5，Ae6，设定Ae1＝2Ae2＝Ae3＝Ae4＝Ae5＝Ae6。原边绕组在前四个磁柱上串联绕制、分别绕前四个磁柱 1匝。副边绕组在第1个磁柱上绕制，圈数为1匝。
根据法拉第电磁感应定律：
Figure PCTCN2020093655-appb-000001
其中，
Figure PCTCN2020093655-appb-000002
分别是原边绕组在A1，A2，A3，A4磁柱上产生的磁通；
Np1、Np2、Np3、Np4分别是原边绕组在A1，A2，A3，A4磁柱上产生的绕组匝数，本例当中：Np1＝Np2＝Np3＝Np4＝1；
Ip是原边绕组中的电流；
R1、R2、R3、R4分别是A1，A2，A3，A4磁柱上的磁阻。
原边绕组的电压Up：
Figure PCTCN2020093655-appb-000003
Ns表示副边绕组在A1柱子上产生的绕组匝数,本例当中,Ns＝1；
副边绕组的电压Us：
Figure PCTCN2020093655-appb-000004
变压器的变压比K：
Figure PCTCN2020093655-appb-000005
根据磁阻R的定义：
Figure PCTCN2020093655-appb-000006
其中，
l是磁路的长度，
μ是磁路材料的磁导率，
Ae是磁路的截面积。
在本实施例当中,四个磁柱均处于第一磁体部和第二磁体部之间，四个磁柱具有相同的高度，即每个磁柱的磁路长度相同；并且磁柱的材料相同、即磁导率也相同；只是磁柱之间的截面积不同。四个磁柱的截面积分别表示为Ae1、Ae2、Ae3、Ae4，则截面积关系为：Ae1＝2Ae2＝Ae3＝Ae4。
因此，
Figure PCTCN2020093655-appb-000007
由此可知，根据本申请实施例所提供的平面变压器，可以实现分数变压比，与传统的变压器设计相比，其优势如下表1所示：实现变压比为3.5时，本申请实施例提供的平面变压器比传统变压器的绕组数量减少44％的匝数(减少了4匝)。
表1-传统变压器与本申请图5实施例提供的平面变压器匝数对比表
  匝比 原边绕组匝数 副边绕组匝数 备注
传统变压器 3.5 7 2 绕组共9匝
图5实施例的变压器 3.5 4 1 绕组共5匝
图5所示出的变压器中，原边绕组只是在四个磁柱上进行了绕线，可以理解的是，原边绕组所绕线的磁柱数量是可选的，磁柱数量根据不同设计需求可以选择为三个以上的任意值。
图6提供了另一种变压器类型，原边绕组在多个磁柱上串并联绕制。该变压器设有四个磁柱，其中原边绕组在A3、A4磁柱上串联绕制、在A1、A2磁柱上并联绕制，形成串并联绕制的方式。以下，对该实施例提供的平面变压器作出具体说明。
该变压器磁芯的四个磁柱截面积分别为Ae1，Ae2，Ae3，Ae4，其中，Ae1＝Ae2＝Ae3＝2Ae4；原边绕组分别围绕A3、A4磁柱1匝，然后并联绕制A1，A2磁柱1匝；副边绕组在磁柱A1上绕制2匝。
根据法拉第电磁感应定律：
Figure PCTCN2020093655-appb-000008
其中，
Figure PCTCN2020093655-appb-000009
分别是原边绕组在A1，A2，A3，A4磁柱上产生的磁通；
Np1、Np2、Np3、Np4分别是原边绕组在A1，A2，A3，A4磁柱上绕制的匝数，本例当中：Np1＝Np2＝Np3＝Np4＝1；
Ip是原边绕组的干路中的电流；
R1、R2、R3、R4分别是A1，A2，A3，A4磁柱上的磁阻。
原边绕组的电压Up：
Figure PCTCN2020093655-appb-000010
副边绕组的电压Us：
Figure PCTCN2020093655-appb-000011
Ns用于表示副边绕组在A1磁柱上绕制的匝数，本例当中Ns＝2。
因而，
Figure PCTCN2020093655-appb-000012
Figure PCTCN2020093655-appb-000013
变压器的变压比K：
Figure PCTCN2020093655-appb-000014
根据磁阻R的定义：
Figure PCTCN2020093655-appb-000015
其中，l是磁路的长度，μ是磁路材料的磁导率，Ae是磁路的截面积。本例当中,每个磁柱的长度相同、磁导率也相同，只是截面积不同，截面积Ae1＝Ae2＝Ae3＝2Ae4。
因此，
Figure PCTCN2020093655-appb-000016
本申请实施例中，原边绕组通过在多个磁柱上串并联绕制，其中至少有一个磁柱和其它磁柱的截面积不等，可以实现分数匝比。
由此可知，根据图6所提供的平面变压器，可以实现分数变压比，与传统的变压器设计相比，其优势如下表2所示：实现变压比为2.5时，本申请实施例提供的平面变压器比传统变压器的绕组数量减少43％的匝数(在7匝基础上减少了3匝)。
表2-传统变压器与图6实施例提供的平面变压器匝数对比表
  匝比 原边绕组匝数 副边绕组匝数 备注
传统变压器 2.5 5 2 绕组共7匝
图6实施例的变压器 2.5 3 1 绕组共4匝
图7提供了另一种平面变压器，在该变压器上，设有多个原边绕组，每个原边绕组均在多个磁柱上进行绕制。在该变压器上，设有两个原边绕组，每个原边绕组均在其中三个磁柱上进行绕线。为便于区分，将两个原边绕组分为第一原边绕组和原边并列绕组。
以下，对图7所提供的平面变压器作出具体说明。
其中，第一原边绕组与原边并列绕组并联连接。(可以理解的是，如果第一原边绕组与原边并列绕组串联连接，即为类似于图5所提供平面变压器的类型：一个原边绕组在六个磁柱上串联绕制)
六个磁柱的截面积分别为Ae1＝Ae2＝Ae3＝Ae4＝2Ae5＝2Ae6；第一原边绕组在磁柱A1、A3、A5上串联绕制、分别在该三个磁柱上绕线1匝，原边并列绕组则在磁柱A2、A4、A6串联绕制、分别在该三个磁柱上绕线1匝。
根据法拉第电磁感应定律：
Figure PCTCN2020093655-appb-000017
Figure PCTCN2020093655-appb-000018
其中，
Figure PCTCN2020093655-appb-000019
分别是第一原边绕组在A1，A3，A5磁柱上产生的磁通；
Np11、Np13、Np15分别是第一原边绕组在磁柱A1、A3、A5上绕制的匝数，Np22、Np24、Np26分别是原边并列绕组在磁柱A2、A4、A6上绕制的匝数，本例当中，Np11＝Np13＝Np15＝Np22＝Np24＝Np26＝1；
Ip是原边绕组的干路中的电流，第一原边绕组与原边并列绕组并联连接，因而，在第一原边绕组和原边并列绕组中，电流分别为
Figure PCTCN2020093655-appb-000020
R1、R2、R3、R4、R5、R6分别是A1，A2，A3，A4，A5，A6磁柱上的磁阻。
第一原边绕组的电压Up1：
Figure PCTCN2020093655-appb-000021
Figure PCTCN2020093655-appb-000022
副边绕组的电压Us：
Figure PCTCN2020093655-appb-000023
Ns是副边绕组在A1磁柱上绕制的匝数，本例当中Ns＝1。
因而，
Figure PCTCN2020093655-appb-000024
变压器的变压比K：
Figure PCTCN2020093655-appb-000025
根据磁阻R的定义：
Figure PCTCN2020093655-appb-000026
其中，l是磁路的长度，μ是磁路材料的磁导率，Ae是磁路的截面积。本例当中,每个磁柱的长度相同、磁导率也相同，只是截面积不同，截面积Ae1＝Ae2＝Ae3＝Ae4＝2Ae5＝2Ae6。
因此，
Figure PCTCN2020093655-appb-000027
由此可知，根据图7所提供的平面变压器，可以实现分数变压比，与传统的变压器设计相比，其优势如下表3所示：实现变压比为2.5时，本申请实施例提供的平面变压器比传统变压器的绕组数量减少43％的匝数(在7匝基础上减少了3匝)。
表3-传统变压器与图7实施例提供的平面变压器匝数对比表
  匝比 原边绕组匝数 副边绕组匝数 备注
传统变压器 2.5 5 2 绕组共7匝
图7实施例的变压器 2.5 3 1 绕组共4匝
可以理解的，在图7实施例提供的平面变压器中，原边并列绕组为可选的，两个原边绕组可以只保留一个。同样可以实现变压比为2.5的输出。
在图7实施例中，第一原边绕组在磁柱A1、A3、A5上串联绕制，原边并列绕组则在磁柱A2、A4、A6串联绕制；其中，磁柱A1、A3、A5的截面积之和与磁柱A2、A4、A6的截面积之和相等。通过该种绕制和设计，能够使得第一原边绕组所构成的基本变压器与原边并列绕组所构成的基本变压器二者形成并联变压器时，二者的输出电压值相同，从而，避免由于两个基本变压器的输出电压值不同而造成并联变压器内部出现环流。
在工程实现上，由于磁柱截面积的制造和安装误差，实际并不能达到第一原边绕组所绕制磁柱的截面积之和，与原边并列绕组所绕制磁柱的截面积之和，二者数值完全相等。本申请发明人在具体设计时，通过多次实验测试，选定二者截面积之比介于80％-120％时，具有良好的输出效率。即，优选将每个原边并列绕组所绕制的磁柱横截面积的总和，与第一原边绕组所绕制的磁柱横截面积的总和的比值，设定为80％-120％以内。
进一步的，参见图8-1、8-2、8-3、8-4，本申请实施例还提供了一种设置多个副边绕组的平面变压器，并通过四种不同变压比的变压器作出举例说明。假设有4个副边绕组，其中一个称为第一副边绕组，其它的称为并列副边绕组。
图8-1所示出的平面变压器是在图6所示平面变压器的基础上增加了三个副边绕组。其中，四个磁柱A1、A2、A3、A4分别构成四个基本变压器，四个副边绕组并联连接，从而组成一个最终的矩阵变压器。副边绕组分别在对应的磁柱A1、A3、A4上绕制1匝，副边绕组在磁柱A2上绕制2匝。
对于磁柱A1、A3、A4构成的基本变压器，其变压比K1＝K3＝K5＝3.5，具体原理参照上述公式。
对于磁柱A2所构成的基本变压器，副边绕组上的电压值：
Figure PCTCN2020093655-appb-000028
Figure PCTCN2020093655-appb-000029
对于磁柱A2构成的基本变压器，其变压比为K2：
Figure PCTCN2020093655-appb-000030
因此，四个磁柱A1、A2、A3、A4所构成的四个基本变压器，通过四个副边绕组并联连接所组成的矩阵变压器，其变压比都是为3.5。
在该方案提供的平面变压器中，四个磁柱A1、A2、A3、A4所分别构成的四个基本变压器的变压比均相等，都是3.5。其中，四个副边绕组所绕线的四个磁柱，截面积Ae1：Ae2：Ae3：Ae4＝2:1:2:2，四个副边绕组的匝数Ns1：Ns2：Ns3：Ns4＝1:2:1:1。也就是说，通过公式Ae1*Ns1＝Ae2*Ns2＝Ae3*Ns3＝Ae4*Ns4对匝数和磁柱进行设定，能够保证四个副边绕组的输出电压值相等，因而降低变压器内部的出现的钳制和环流现象，利于平面变压器的稳态输出。
可知的是，在实际加工过程中，对于磁柱等变压器结构件，由于制造精度、加工误差等因素，所安装的磁柱的结构参数很难做到设计要求的100％精度。本申请发明人通过设计试验，对本申请所提供的平面变压器进行调试和验证，将一个磁柱和对应副边绕组的Ae1*Ns1的值设为一参考值M，将平面变压器的其它磁柱和多个副边绕组设计为满足Ae2*Ns2、Ae3*Ns3、Ae4*Ns4的值均落入(80％-120％)*M范围内，则可以较好的保障上述技术效果，使副边绕组的输出电压值近似相等，有利于平面变压器的功率控制更准确。
图8-2所示出的平面变压器中，四个磁柱的截面积Ae1＝Ae2＝Ae3＝3*Ae4，即，Ae1：Ae2：Ae3：Ae4＝3:3:3:1，四个副边绕组在该四个磁柱上的匝数Ns1：Ns2：Ns3：Ns4＝1:1:1:3；该四个副边绕组的输出电压值相等，四个磁柱所对应的四个基本变压器的变压比均为
Figure PCTCN2020093655-appb-000031
(具体计算原理参见上述公式)，通过四个副边绕组并联连接所组成的矩阵变压器的变压比为
Figure PCTCN2020093655-appb-000032
图8-3所示出的平面变压器中，四个磁柱的截面积Ae1＝Ae2＝2*Ae3＝3*Ae4，即，Ae1：Ae2：Ae3：
Figure PCTCN2020093655-appb-000033
四个副边绕组在该四个磁柱上的匝数Ns1：Ns2：Ns3：Ns4＝1:1:2:3；该四个副边绕组的输出电压值相等，四个磁柱所对应的四个基本变压器的变压比均为
Figure PCTCN2020093655-appb-000034
通过四个副边绕组并联连接所组成的矩阵变压器的变压比为
Figure PCTCN2020093655-appb-000035
图8-4所示出的平面变压器中，四个磁柱的截面积Ae1＝Ae2＝3*Ae3＝4*Ae4，即，Ae1：Ae2：Ae3：
Figure PCTCN2020093655-appb-000036
四个副边绕组在该四个磁柱上的匝数Ns1：Ns2：Ns3：Ns4＝1:1:3:4；该四个副边绕组的输出电压值相等，四个磁柱所对应的四个基本变压器的变压比均为
Figure PCTCN2020093655-appb-000037
通过四个副边绕组并联连接所组成的矩阵变压器的变压比为
Figure PCTCN2020093655-appb-000038
对于以上实施例提供的平面变压器，其常见形式是将磁柱穿设在印刷电路板中，绕组是布设在印刷电路板上的导线。印刷电路板一般为多层结构、其中包含多层覆铜层和介质层，利用覆铜层上的铜箔形成变压器绕组的走线。可以理解的是，本申请各实施例中，对布设绕组的覆铜层的层数并不进行限制。例如，绕组可以跨层形成在两层或多层覆铜层上、以避免“叠线”的情况(“叠线”是指绕组在围绕磁柱绕线过程中，绕组的线路有交叉从而形成短路)，如图9所示，通过将绕组跨层形成在两层或多层覆铜层上，当绕组的线路在一层覆铜层上绕线可能出现“叠线”的情况时，绕组的线路沿着层与层之间的穿设孔/或者电路板上用于容置磁柱的孔，延伸到其它覆铜层继续完成绕线；即，通过导线，将不同覆铜层上的用于形成变压器绕组的铜箔进行连接。
另外可以理解的是，变压器的绕组也可以为包覆绝缘层的导线，此时绕组在围绕磁柱进行绕线时、则可以允许“叠线”的情况出现，此时绕组可以仅形成在一层电路板上。
本申请还提供了一种有源电路，有源电路中包括上述实施例提供的任一种的平面变压器。有源电路可以为以下类型的任意一种或多种：全桥拓扑电路、半桥拓扑电路、有源钳位拓扑电路、LLC拓扑电路、BUCK+LLC两级拓扑电路、BUCK-BOOST+LLC两级拓扑电路、Boost+LLC两级拓扑电路、正激式拓扑电路、反激式拓扑电路、隔离式拓扑电路、两级拓扑电路以及非隔离式拓扑电路。
尽管结合具体特征及其实施例对本申请进行了描述，显而易见的，在不脱离本申请的精神和范围的情况下，可对其进行各种修改和组合。相应地，本说明书和附图仅仅是所附权利要求所界定的本申请的示例性说明，且视为已覆盖本申请范围内的任意和所有修改、变化、组合或等同物。显然，本领域的技术人员可以对本申请进行各种改动和变型而不脱 离本申请的范围。这样，倘若本申请的这些修改和变型属于本申请权利要求及其等同技术的范围之内，则本申请也意图包括这些改动和变型在内。

Claims (10)

  1. 一种平面变压器，包括绕组结构和磁芯结构，所述绕组结构包括原边绕组和副边绕组，所述磁芯结构包括第一磁体部、第二磁体部和多个磁柱，所述多个磁柱位于第一磁体部和第二磁体部之间，
    其特征在于，
    所述原边绕组围绕所述多个磁柱中的M个磁柱进行绕制，M为正整数、且M≥3，在所述M个磁柱中，至少有一个磁柱的横截面积与其它磁柱的横截面积不相同。
  2. 根据权利要求1所述的平面变压器，其特征在于，
    所述原边绕组围绕所述M个磁柱进行串联、或者串并联绕制；其中所述的串并联绕制，指的是原边绕组绕X个磁柱串联以及绕M-X个磁柱并联，其中X为正整数。
  3. 根据利要求1或2所述的平面变压器，其特征在于，
    还包括至少一个原边并列绕组，每个原边并列绕组均围绕所述多个磁柱中的至少一部分磁柱进行串联、或者串并联绕制，其中，所述原边绕组与所述至少一个原边并列绕组之间均并联连接。
  4. 根据权利要求3所述的平面变压器，其特征在于，
    其中每个所述原边并列绕组所绕制的磁柱横截面积的总和，与所述原边绕组所绕制的所述M个磁柱横截面积的总和的比值为80％-120％。
  5. 根据权利要求1-4任一项所述的平面变压器，其特征在于，
    所述副边绕组围绕多个磁柱中的一个磁柱进行绕制。
  6. 根据权利要求5所述的平面变压器，其特征在于，
    还包括至少一个副边并列绕组，每个副边并列绕组均围绕所述多个磁柱中的其中一个磁柱进行绕制；
    所述副边绕组和所述至少一个副边并列绕组之间均并联连接。
  7. 根据权利要求6所述的平面变压器，其特征在于，
    所述副边绕组和所述至少一个副边并列绕组的总数量为P个，P为正整数、P≥2，
    所述P个副边绕组和副边并列绕组所对应的P个磁柱的横截面积的比例为A1：A2：…：AP，
    所述P个副边绕组和副边并列绕组在所述P个磁柱上的匝数分别为Ns1、Ns2、…、NsP，其中，A1*Ns1与A2*Ns2、…、AP*NsP的值满足如下条件中的至少一个：
    相等；或者，
    任意两个之间的比值为80％-120％。
  8. 根据权利要求1-7任一项所述的平面变压器，其特征在于，
    所述多个磁柱中，至少一部分所述磁柱与所述第一磁体部为一体式结构，和/或，至少一部分所述磁柱与所述第二磁体为一体式结构；
    或者，
    所述多个磁柱中的每个磁柱均由上磁柱和下磁柱组成，其中，至少一部分所述上磁柱与所述第一磁体部为一体式结构，和/或，至少一部分所述下磁柱与所述第二磁体部为一体 式结构。
  9. 根据权利要求8所述的平面变压器，其特征在于，
    所述多个磁柱中的任一个磁柱的横截面为圆形、椭圆形、矩形、正方形或者不规则形状。
  10. 一种有源电路，其特征在于，所述有源电路包括如权利要求1-9中任一项所述的平面变压器。
PCT/CN2020/093655 2019-10-14 2020-06-01 一种平面变压器及有源电路 WO2021073121A1 (zh)

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Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109686538B (zh) * 2018-12-11 2020-07-28 华为技术有限公司 一种变压器以及电源
CN110828126B (zh) * 2019-10-14 2023-04-07 华为数字能源技术有限公司 一种平面变压器及有源电路
CN114270458B (zh) * 2020-07-06 2024-07-05 华为数字能源技术有限公司 一种矩阵变压器、功率变换器和矩阵变压器绕组的排布方法
CN114005653B (zh) * 2020-07-28 2023-11-10 华为技术有限公司 一种变压器、开关电源及通信设备
CN112562983B (zh) * 2020-10-28 2022-03-25 南京航空航天大学 一种基于非整数匝绕组设计的pcb板平面型变压器
CN112837905A (zh) * 2021-01-07 2021-05-25 广州金升阳科技有限公司 一种磁芯及包含该磁芯的平面变压器
CN113809904B (zh) * 2021-09-28 2024-03-29 天津大学 一种基于llc谐振变换器拓扑磁集成的矩阵变压器
CN114823092B (zh) * 2022-04-25 2024-03-12 湖南工程学院 轻量化变压器、轻量化变压器设计方法及高压电源
CN114974802A (zh) * 2022-05-18 2022-08-30 英飞特电子（杭州）股份有限公司 一种磁性器件、谐振电路及led驱动电源
CN117373792A (zh) * 2022-06-30 2024-01-09 中兴通讯股份有限公司 变压器、多电平电源调制电路、控制方法及装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1409333A (zh) * 2001-09-14 2003-04-09 台达电子工业股份有限公司 一种可实现分数匝的通用变压器铁心及其绕组结构
JP2010278387A (ja) * 2009-06-01 2010-12-09 Mitsubishi Electric Corp 高耐圧平面トランス
CN107946045A (zh) * 2017-09-27 2018-04-20 昆明理工大学 一种半匝绕组的可调漏感平面变压器
WO2018160962A1 (en) 2017-03-02 2018-09-07 Massachusetts Institute Of Technology Variable inverter-rectifier-transformer
CN110828126A (zh) * 2019-10-14 2020-02-21 华为技术有限公司 一种平面变压器及有源电路

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6348848B1 (en) * 2000-05-04 2002-02-19 Edward Herbert Transformer having fractional turn windings
US20080048818A1 (en) * 2006-08-25 2008-02-28 Hong Mao Transformers with improved voltage-step-down ratios and DC-to-DC power converters employing same
CN204632497U (zh) * 2014-09-01 2015-09-09 杨玉岗 一种多相磁集成耦合电感器
CN109390131B (zh) * 2017-08-02 2023-12-29 Abb瑞士股份有限公司 集成磁性组件及组装其的方法
CN108648899B (zh) * 2018-03-27 2022-02-11 华为数字能源技术有限公司 一种磁集成器件、变换器、功率因数校正电路及方法
FR3089675B1 (fr) * 2018-12-07 2020-11-20 Commissariat Energie Atomique Dispositif d’induction electromagnetique

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1409333A (zh) * 2001-09-14 2003-04-09 台达电子工业股份有限公司 一种可实现分数匝的通用变压器铁心及其绕组结构
CN1257518C (zh) 2001-09-14 2006-05-24 台达电子工业股份有限公司 一种可实现分数匝的通用变压器铁心及其绕组结构
JP2010278387A (ja) * 2009-06-01 2010-12-09 Mitsubishi Electric Corp 高耐圧平面トランス
WO2018160962A1 (en) 2017-03-02 2018-09-07 Massachusetts Institute Of Technology Variable inverter-rectifier-transformer
CN107946045A (zh) * 2017-09-27 2018-04-20 昆明理工大学 一种半匝绕组的可调漏感平面变压器
CN110828126A (zh) * 2019-10-14 2020-02-21 华为技术有限公司 一种平面变压器及有源电路

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4036941A4

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