WO2020019571A1

WO2020019571A1 - Planar transformer having vertical windings

Info

Publication number: WO2020019571A1
Application number: PCT/CN2018/114574
Authority: WO
Inventors: 邵革良; 管春杨
Original assignee: 深圳市伊戈尔沐磁科技有限公司; 伊戈尔电气股份有限公司
Priority date: 2018-07-24
Filing date: 2018-11-08
Publication date: 2020-01-30
Also published as: CN108987066A

Abstract

A planar transformer having vertical windings. The transformer is formed by assembling a coil winding and a magnetic core. The coil winding comprises at least one primary winding (A) and at least one secondary winding (B). The primary winding and the secondary winding are mutually nested to form the coil winding. In the primary and secondary windings, the number of loops having adjacent loops that are the same type of winding is less than or equal to 1/3 of the total number of loops in the coil winding. The primary winding and/or the secondary winding are wound and fabricated vertically by using flat electromagnetic wires having a width to thickness ratio W/T ≥ 20, and an insulation coating is provided on surfaces of the flat electromagnetic wires. The present invention realizes ideal coupling between the primary and secondary windings, and significantly reduces high-frequency losses caused by windings in high-frequency transformers. The structure of the coil winding of the novel transformer enables a reduction in coil losses caused by a skin effect at a high frequencies, and is therefore appropriate for high-power high-frequency applications.

Description

Vertically wound flat transformer

Technical field

[0001] The present invention relates to the technical field of electronic components, and in particular, to a vertical-wound flat transformer.

Background technique

[0002] With the rapid development of new energy vehicles, high-power high-frequency switching power supply technology characterized by charging and discharging large-capacity energy storage batteries is becoming one of the important core technologies of new energy vehicle technology.

[0003] The charging and discharging of batteries as a source of power for new energy vehicles has the characteristics of high power and large capacity. At the same time, in order to achieve rapid charging of large capacity batteries, the vehicle-mounted power conversion device pursues high power density of power converters. , Is one of the most core power supply technologies for vehicle-mounted power supplies (such as OBC power supplies, DC / DC, DC / AC and other high-power power supplies).

[0004] Regarding the power conversion of the battery, in order to achieve electrical safety and prevent leakage, the power conversion of the battery's charge and discharge equipment must perform effective electrical connection between the power supply end (power input end) and the power receiving end (power load output end). Insulation and isolation. Therefore, in these power supply power conversion equipment, a power supply topology circuit having a high-frequency switching power supply power transformer must be used.

[0005] For a ground charging device (such as a DC charging makeup) for realizing the charging of a new energy vehicle, its energy source is taken from a power frequency single-phase or three-phase AC power, so the charging equipment must also use a high-frequency switching power supply. The power transformer performs electrical safety isolation between the power grid and the car battery to achieve its high-power power conversion and power transmission to control its charging of the car battery.

[0006] Generally speaking, the power supply of the on-board charger OBC of passenger cars is 3.3KW, 6.6KW, etc., and the power of OBC of commercial vehicles and large passenger cars is greater (such as 15KW or more). For common DC Charging makeup power module, the power of its single module is generally 7.5KW, 15KW, 20KW and so on. Vehicle DC / DC, DC / AC and other power sources, their power is also above 1.5KW, 3KW and other power. In the future, as the requirements for charging speed continue to increase, the stand-alone power will show a trend of ultra-high power.

[0007] The low-cost, high-power density requirements and technical trends of these power supply devices have become such high-frequency power transformers that connect to the primary and secondary circuits of the power supply, provide electrical isolation, and achieve main power transmission. The most critical technical bottleneck for power technology advancement. [0008] In order to fundamentally solve the above technical bottlenecks, the present invention proposes a brand new flat transformer technical solution to eliminate high-frequency copper losses that affect the high-density design of transformers.

Summary of invention

technical problem

Problem solution

Technical solutions

[0009] The present invention provides a flat-wire vertical-wound inductor and a vertical-wound inductor in response to the above-mentioned shortcomings in the prior art.

[0010] A vertical-wound flat transformer is assembled by a coil winding and a magnetic core, and the coil winding includes at least

1 primary winding and at least 1 secondary winding, the primary winding and the secondary winding are inlaid with each other to form the coil winding, and adjacent coils of any single-turn coil in the primary winding and the secondary winding The number of turns of the coils belonging to the same winding is less than or equal to 1/3 of the total number of turns of the coil windings. The surface of the flat electromagnetic wire is covered with an insulating film; such a design has a significant effect of preventing high-frequency proximity effects.

[0011] Further, the flat electromagnetic wire may use two or more bare copper flat wires of equal width, or enameled flat wires, or a combination of bare copper flat wires and enameled flat wires in parallel, and then perform Multi-core wires with larger cross-sectional area are formed by sintering or hot-melt wrapping of insulating film; using the multi-core wires to wind primary coils or duplicate coils wound in parallel, at this time, the same primary coils wound in parallel The coil, or the same secondary coil, can be equivalent to a primary or secondary coil because any one of the turns and the adjacent parallel coils are in an equipotential state during operation. It is considered to only increase the same primary side, Or the secondary side wire is used; through this design, the loss of the high-frequency skin effect of the coil can be better improved.

[0012] Furthermore, the width-to-thickness ratio of the single-core wire in the multi-core wire W / T ^ 10

[0013] Further, the insulating film of the flat electromagnetic wire is generally wrapped and sintered by using a polyimide film-type insulating film.

[0014] Further, the insulating film of the flat electromagnetic wire may also be a high-performance insulating material such as PEEK, and a dense and uniform insulating film may be formed on the surface of the flat electromagnetic wire as a reinforced insulation by hot-melt encapsulation.

[0015] Further, the coil winding may include one primary winding and multiple secondary windings or multiple secondary windings. Composed of series and parallel.

[0016] Further, the coil winding may be composed of one secondary winding and multiple primary windings or multiple primary windings in series and parallel.

[0017] Further, the coil winding may also be formed by combining multiple primary windings and multiple secondary windings in series and parallel.

[0018] Further, the coil winding may be placed on the core post of the magnetic core or on the side post of the magnetic core according to the structural design requirements of the transformer.

[0019] Further, only the primary winding or the secondary winding may be vertically wound with a flat electromagnetic wire having a width / thickness ratio of W / T 20, or the primary winding and the secondary winding may both adopt an aspect ratio. The flat electromagnetic wire with WA> 20 is wound vertically.

[0020] Further, the vertical winding shape of the coil winding is a circle, an ellipse or a square with an R angle greater than the width of the single-core vertical winding wire.

[0021] Further, the material of the magnetic core is generally a high-frequency low-loss magnetic core material such as a ferrite material suitable for high-frequency applications, a metal soft magnetic powder core material, or a silicon steel or an amorphous magnetic core material. .

[0022] Further, the shape of the magnetic core is not limited, and may be a common shape such as PQ, EE, or may be a combination of magnetic cores of other shapes such as a block magnetic core, and assembly and bonding.

[0023] Further, a non-magnetic air gap is provided between the plurality of magnetic core segments.

[0024] The vertical-wound flat transformer of the present invention is formed by the flat electromagnetic wire, and is wound through a vertical winding process to form a winding coil, and then the vertical-wound primary and secondary windings are completely coupled with each other according to a prescribed assembly method or The transformer winding coil is constructed near the completion of the coupling, and a transformer constituted by inserting a magnetic core into the winding coil. The beneficial effects of the invention

Beneficial effect

[0025] Compared with the prior art, the present invention has the following beneficial effects: Since the winding coils adjacent to the upper and lower sides of any one turns of the primary winding are secondary windings, the phase of any one winding of the secondary winding is also the same. The adjacent upper and lower windings are primary windings, so such a transformer coil structure actually constitutes an ideal coupling between the primary and secondary windings, and when the transformer operates at high frequency, the electric field formed by the primary windings and the adjacent secondary windings The electric field induced by the winding constitutes a complete electric field decoupling, so that the high-frequency proximity benefits inside the primary and secondary sides are eliminated, and the high-frequency loss of the high-frequency transformer winding is greatly reduced. The invention adopts a vertical winding structure with a large aspect ratio. The idea is that the width-to-thickness ratio WAT of the vertically wound wire with reinforced insulation used in the present invention is more than 20 times. For a higher width-to-thickness wire, the smaller the thickness of the same cross section, the larger the surface area of the wire. The skin effect caused by the high-frequency current flowing through the wire is not obvious. Therefore, the winding coil of the new type transformer with such a structure has smaller coil loss caused by the high-frequency skin effect, which is very suitable for high-power high-frequency applications.

Brief description of the drawings

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a schematic structural diagram of a flat electromagnetic wire according to the present invention;

[0027] FIG. 2 is a partially enlarged view at G in FIG. 1;

[0028] FIG. 3 is a schematic structural diagram of a helical flat coil winding wound by a flat electromagnetic wire according to the present invention;

4 is a schematic structural diagram of a coil winding of the present invention;

[0030] In the figure: 1. Flat electromagnetic wire; 2. Insulation film; A. Primary winding; B. Secondary winding.

Invention Examples

Embodiments of the invention

DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, but not all of the implementations. example. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0033] As shown in FIGS. 1 to 4, a vertical-wound flat transformer is assembled by a coil winding and a magnetic core, the coil winding includes a primary winding and a secondary winding, and the primary winding The secondary winding is inlaid with each other to form the coil winding, and the adjacent windings of any single-turn coil in the primary winding and the secondary winding belong to the same winding, and the number of coil turns is less than or equal to the total number of the coil windings. 1/3, the primary winding and / or the secondary winding are wound by using a flat electromagnetic wire having a width-to-thickness ratio WA> 20, and the width-to-thickness ratio W / T = 30 shown in FIG. 1 is provided on the surface of the flat electromagnetic wire. Covered with an insulating film.

[0034] Further, the flat electromagnetic wire may use two or more bare copper flat wires of equal width, or enameled flat wires, or a combination of bare copper flat wires and enameled flat wires in parallel, and then proceed. Multi-core wire with a larger cross-section of the wire by sintering or hot-melt-wrapping the insulating film; using the multi-core wire Primary windings or duplicate coils wound in parallel. At this time, the same primary windings or the same secondary windings wound in parallel at this time can be equivalent to any one of the turns and the adjacent parallel coils in an equipotential state during operation. A primary or secondary coil is considered to be used by only the same primary or secondary conductor that increases the cross-section of the wire; by this design, the high-frequency skin effect loss of the coil can be better improved.

[0035] Furthermore, the width-to-thickness ratio W / T ^ 10 of the single-core wire in the multi-core wire.

[0036] Further, the insulating film of the flat electromagnetic wire is generally wrapped and sintered by using a polyimide film-type insulating film.

[0037] Further, the insulating film of the flat electromagnetic wire may also be a high-performance insulating material such as PEEK, and a dense and uniform insulating film may be formed on the surface of the flat electromagnetic wire by hot-melt encapsulation as a reinforced insulation.

[0038] Further, the coil winding may be composed of one primary winding and a plurality of secondary windings or a plurality of secondary windings connected in series and in parallel.

[0039] Further, the coil winding may also be composed of one secondary winding and multiple primary windings or multiple primary windings in series and parallel.

[0040] Further, the coil winding may also be formed by combining multiple primary windings and multiple secondary windings in series and parallel.

[0041] Further, the coil winding may be placed on the core post of the magnetic core or on the side post of the magnetic core according to the structural design requirements of the transformer.

[0042] Further, only the primary winding or the secondary winding may be vertically wound with a flat electromagnetic wire having a width / thickness ratio of W / T 20, or the primary winding and the secondary winding may both adopt an aspect ratio. The flat electromagnetic wire with WA> 20 is wound vertically.

[0043] Further, the vertical winding shape of the coil winding is a circle, an ellipse, or a square having an R angle greater than the width of the single-core vertical winding wire.

[0044] Further, the material of the magnetic core is generally a high-frequency low-loss magnetic core material such as a ferrite material suitable for high-frequency applications, a metal soft magnetic powder core material, or a silicon steel or an amorphous magnetic core material. .

[0045] Further, the shape of the magnetic core is not limited, and may be a common shape such as PQ, EE, etc., or may be a combination of magnetic cores of other shapes, such as a block magnetic core, which are assembled and bonded.

[0046] Furthermore, a non-magnetic air gap is provided between the plurality of magnetic core segments. [0047] It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, the embodiments are to be regarded as exemplary and non-limiting in every respect. The scope of the present invention is defined by the appended claims rather than the above description, and therefore is intended to fall within the claims. All changes that come within the meaning and scope of equivalents are encompassed by the invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0048] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment includes only an independent technical solution, and this description of the specification is merely for the sake of clarity. As a whole, the technical solutions in the embodiments can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims

Claim

[Claim 1] A vertical-wound flat transformer composed of a coil winding and a magnetic core, characterized in that the coil winding includes at least one primary winding and at least one secondary winding, and the primary winding The winding and the secondary winding are inlaid with each other to form the coil winding, and the adjacent windings of any single-turn coil in the primary winding and the secondary winding belong to the same winding, and the number of coil turns is less than or equal to the total number of turns of the coil winding. The primary winding and / or the secondary winding are vertically wound by using a flat electromagnetic wire having a width / thickness ratio of W / 1 ^ 20, and the surface of the flat electromagnetic wire is covered with an insulating film.

[Claim 2] The vertical-wound flat transformer according to claim 1, wherein the flat electromagnetic wire is composed of two or more equal-width bare copper flat wires, or enameled flat wires, Or, a bare copper flat wire and an enameled flat wire are combined in parallel, and then the insulation film is wrapped and sintered or hot-melted to form a multi-core wire with a larger cross-sectional area of the wire.

[Claim 3] The vertical-wound flat transformer according to claim 2, wherein a width-to-thickness ratio W / T ^ IO of the single-core wire in the multi-core wire.

[Claim 4] The vertical-wound flat transformer according to claim 1, wherein the insulating film of the flat electromagnetic wire is wound by sintering with a polyimide film.

[Claim 5] The vertical-wound flat transformer according to claim 1, characterized in that the insulating film of the flat electromagnetic wire is formed densely and uniformly on the surface of the flat electromagnetic wire by using PEEK and hot-melt encapsulation. Insulation film.

[Claim 6] The vertical-wound flat transformer according to claim 1, wherein the coil winding comprises a primary winding and a plurality of secondary windings or a plurality of secondary windings connected in series and in parallel.

[Claim 7] The vertical-wound flat transformer according to claim 1, wherein the coil winding comprises a secondary winding and a plurality of primary windings or a plurality of primary windings connected in series and in parallel.

[Claim 8] The vertical-wound flat transformer according to claim 1, wherein the coil winding is formed by combining a plurality of primary windings and a plurality of secondary windings in series and parallel.

[Claim 9] The vertical-wound flat transformer according to claim 1, wherein the vertical winding shape of the coil winding group is a circle, an ellipse, or a square having an R angle greater than the width of a single-core vertical winding wire.

[Claim 10] The vertical-wound flat transformer according to claim 1, wherein the magnetic core is composed of A plurality of block-shaped cores and / or other-shaped cores are assembled, bonded, and a non-magnetic air gap is provided between the plurality of core sections.