A winding structure with low height and high space utilization and its application

Abstract

The present invention discloses a winding structure with low height and high space utilization, comprising: a winding, the winding is wound by a plurality of winding units; a window, the window is formed at the center of the winding; the envelope shape of the cross section of the winding unit has a long side of the envelope shape and a short side of the envelope shape, and the ratio of the long side of the envelope shape to the short side of the envelope shape is n; wherein n≥2; the winding unit comprises a vertical winding unit and a horizontal winding unit; the vertical winding unit is a winding unit of a turn adjacent to the window, and the long side of the envelope shape of the vertical winding unit is arranged along the axial direction of the window; the other winding units in the winding are all horizontal winding units, and the long side of the envelope shape of the horizontal winding unit is arranged along the radial direction of the window. The present invention can achieve a lower winding thickness and a higher core window filling rate while ensuring that the winding has a lower winding impedance, thereby providing strong support for further reducing the space, especially the height, of the power converter.

Description

Technical Field

[0001] The invention belongs to the technical field of winding coils, and in particular relates to a winding structure with low height and high space utilization and application thereof. Background Art

[0002] As portable devices have higher and higher requirements for space, especially height, the corresponding power supply modules are also facing the same urgent needs. With the development of modern power electronics technology, the current main power converter is a switching power supply, in which the space and height of the magnetic core components (inductors, transformers, etc.) usually account for a large proportion of the power converter.

[0003] A typical magnetic core component usually consists of two parts, the magnetic core and the winding set in the core window. In order to obtain lower winding impedance, it is usually necessary to use wires with larger cross-sectional areas (Litz wire or single-strand wire), and the increase in wire diameter will directly increase the thickness of the winding, and produce a larger space volume waste under the same winding structure.

[0004] Therefore, how to reduce the thickness of the winding and increase the filling rate of the winding in the core window is an urgent problem to be solved. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a winding structure with low height and high space utilization, which ensures that the winding can achieve a lower winding thickness and a higher core window filling rate while having a lower winding impedance, thereby providing strong support for further reducing the space, especially the height, of the power converter.

[0006] A first aspect of the present invention provides a winding structure with low height and high space utilization, characterized in that it comprises:

[0007] A winding, wherein the winding is wound by a plurality of winding units;

[0008] a window formed in the center of the winding;

[0009] The envelope shape of the cross section of the winding unit has a long side of the envelope shape and a short side of the envelope shape, and the ratio of the long side of the envelope shape to the short side of the envelope shape is n; wherein n≥2, and in practical applications, due to factors such as deformation of the winding cross section, n only needs to be close to an integer;

[0010] The winding unit comprises a vertical winding unit and a horizontal winding unit;

[0011] The vertical winding unit is a winding unit that is adjacent to the window, and the long side of the envelope of the vertical winding unit is arranged along the axial direction of the window;

[0012] The other turn winding units in the winding are all horizontal winding units, and the long side direction of the envelope shape of the horizontal winding unit is arranged along the radial direction of the window.

[0013] Preferably, it further comprises a transition zone, and the parallel winding units are formed into vertical winding units after passing through the transition zone.

[0014] Preferably, the winding units of two adjacent turns transition in a layer-changing transition zone, and when the kth turn of the winding unit transitions to the (k-1)th turn, it is twisted 90° along a first direction; when the kth turn of the winding unit transitions from another winding direction to the (k+1)th turn, it is twisted 90° along a second direction; the first direction is clockwise or counterclockwise, and the second direction is opposite to the first direction.

[0015] Preferably, n is an integer.

[0016] Preferably, the total number of turns P of the winding unit is (n×m+1); wherein m≥1, and m is an integer.

[0017] Preferably, the winding unit comprises at least two winding wires.

[0018] Preferably, in the winding, at least two strands of the windings are alternately arranged adjacent to each other.

[0019] Preferably, at least two of the windings are alternately arranged adjacent to each other in the axial direction of the window and in the radial direction of the window.

[0020] Preferably, the winding wire is Litz wire.

[0021] Preferably, the winding unit is a winding wire.

[0022] Preferably, the winding wire is a flat wire, and the aspect ratio of the cross section of the flat wire is an integer or a simple integer ratio. Similarly, the numerical value here only needs to be close.

[0023] Preferably, the winding unit includes at least two sub-windings.

[0024] Preferably, the winding has two lead-out terminals, and the angle formed by the two lead-out terminals and the center of the window is 0° to 360°.

[0025] The second aspect of the present invention also provides an application of a winding structure with low height and high space utilization. In a soft switching circuit, a winding unit with at least two winding strands is used, and a winding structure with low height and high space utilization using Litz wire as the winding is used.

[0026] A third aspect of the present invention provides an application of a winding structure with low height and high space utilization, in which at least two groups of different windings of the transformer are used as winding units in a transformer with a frequency of 500 kHz or more.

[0027] The present invention has the following beneficial effects:

[0028] (1) While ensuring low winding impedance, the thickness of the winding can be greatly reduced, the loss of the winding can be reduced, and the efficiency of power conversion can be improved;

[0029] (2) The present invention has a very high space utilization rate and can reduce the size of the magnetic core component, thereby reducing the size of the power converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A schematic diagram of a winding structure with low height and high space utilization disclosed in Embodiment 1 of the present invention;

[0032] Figure 2 It is a cross-sectional view along the BB direction of the winding structure with low height and high space utilization disclosed in the first embodiment of the present invention;

[0033] Figure 3A , Figure 3B A cross-sectional view of the winding structure with low height and high space utilization in the AA direction disclosed in the first embodiment of the present invention;

[0034] Figure 4 A cross-sectional view in the AA direction of a winding structure with low height and high space utilization disclosed in the second embodiment of the present invention;

[0035] Figure 5 It is a cross-sectional view in the AA direction of a winding structure with low height and high space utilization disclosed in the third embodiment of the present invention;

[0036] Figure 6 It is a cross-sectional view along the AA direction of the winding structure with low height and high space utilization disclosed in the fourth embodiment of the present invention.

[0037] Among them: 1 vertical winding unit; 2 horizontal winding unit; 3 window; 4 lead-out terminal; 5 layer change transition zone. DETAILED DESCRIPTION

[0038] The purpose of the present invention is to provide a winding structure with low height and high space utilization, which can ensure that the winding has a lower winding impedance while achieving a lower winding thickness and a higher core window filling rate, thereby providing strong support for further reducing the space, especially the height, of the power converter.

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Embodiment 1

[0041] like Figure 1 and Figure 2 As shown, the embodiment of the present invention discloses a winding structure with low height and high space utilization, including:

[0042] A winding, the winding is wound by a plurality of winding units;

[0043] a window 3, the window being formed at the center of the winding;

[0044] The envelope shape of the cross section of the winding unit has an envelope shape long side and an envelope shape short side, and the ratio of the envelope shape long side to the envelope shape short side is n; wherein n≥2; in practical applications, due to factors such as deformation of the winding cross section, n only needs to be close to an integer;

[0045] The winding unit includes a vertical winding unit 1 and a horizontal winding unit 2. The vertical winding unit 1 is a turn winding unit adjacent to the window 3, and the long side of the envelope shape of the vertical winding unit 1 is arranged along the axial direction of the window 3; the other turn winding units in the winding are all horizontal winding units 2, and the long side direction of the envelope shape of the horizontal winding unit is arranged along the radial direction of the window 3.

[0046] The winding has a layer-changing transition zone 5, and two adjacent winding units transition in the layer-changing transition zone 5. When the (k-1)th turn winding unit transitions to the kth turn, it is twisted 90° along a first direction, and when the kth turn winding unit transitions to the (k+1)th turn, it is twisted 90° along a second direction; the first direction is clockwise or counterclockwise, and the second direction is opposite to the first direction.

[0047] The winding unit includes at least two windings, and the total number of turns P of the winding unit is (n×m+1); wherein m≥1, and m is an integer.

[0048] like Figure 3A As shown, the winding unit of this embodiment has two windings per turn, with a total of three turns, of which the vertical winding unit 1 is the second turn.

[0049] The winding of the present embodiment is made as follows: firstly, two strands of winding wire are arranged in the vertical direction, and wound along the window 3 for one turn, forming a vertical winding unit 1 with a number k; then, the long side direction of the cross-sectional envelope rectangle of the two strands of winding wire is twisted 90° counterclockwise in the layer-changing transition zone 5 between the winding lead terminals 4, and then each is wound along the axis of the window 3 for one turn, forming horizontal winding units 2 with a number (k+1) and (k-1), respectively. At this time, the thickness of the winding is twice the winding diameter, while the thickness of the three-turn winding using a single strand is also twice the wire diameter, but its wire diameter is relatively large. Therefore, the winding structure of the present invention can achieve a lower winding thickness while ensuring a lower winding impedance.

[0050] In other embodiments, the layer-changing transition zone 5 can also twist the long sides of the cross-sectional envelope rectangle of the two strands of wire by 90° clockwise. If the twisting directions are different when forming the one-turn horizontal winding units 2 labeled (k+1) and (k-1), then Figure 3B shown.

[0051] like Figure 3A and Figure 3B As shown, in the winding, at least two windings are alternately arranged adjacent to each other. Figure 3A In the embodiment, at least two windings are alternately arranged adjacent to each other along the axial direction of the window 3 and the radial direction of the window 3, and the windings of the two parallel coils are alternately arranged on any cross section. Therefore, the two coils have the same turn length, the impedance is equal, and the current is evenly distributed in the two coils, so that lower losses can be obtained. And no circulating current will be formed between the two coils due to inconsistent impedance, thus avoiding additional losses. Therefore, the winding has the significant advantage of low loss. Furthermore, due to the alternating arrangement of the windings of the two parallel coils, leakage flux balance can be achieved, effectively avoiding the circulating current of the two coils, and achieving the effect of current-sharing parallel connection.

[0052] The winding has the shortest distance from the center in the direction around the window 3, so the turn length of each turn of the winding is relatively short, so that a lower winding impedance can be obtained, which is of great significance for reducing winding losses and improving the efficiency of power conversion. In addition, since the winding adopts a double-strand parallel winding structure, it can be considered as two coils connected in parallel. The layer-changing transition zone 5 between the winding legs has a slightly lower winding filling rate due to the inevitable winding structure of the missing number of winding turns, and the windings in other positions efficiently fill the space of the core window. Therefore, the winding structure has an extremely high space utilization rate. This has a positive effect on reducing the size of the core component and thus reducing the size of the power converter.

[0053] It should be noted that the wire used for the two-strand parallel winding can be adaptively selected according to different usage conditions such as frequency and current, such as single-strand insulated wire, single-strand enameled wire, enameled Litz wire, silk-covered Litz wire, self-adhesive Litz wire, three-layer insulated single-strand wire, three-layer insulated Litz wire, etc.

[0054] It should be noted that the angle formed by the lead-out terminal 4 of the winding and the center of the window 3 can be freely set between 0° and 360° according to application requirements.

[0055] Embodiment 2

[0056] On the basis of the first embodiment, the winding may be provided with more turns, and the total number of turns P of the winding unit is (n×m+1); wherein m≥1, and m is an integer.

[0057] In this embodiment, the winding unit is provided with 5 turns, wherein the 1st turn and the 2nd turn are located in the first layer, and the 4th turn and the 5th turn are located in the second layer. Figure 4 As shown, the remaining technical features are similar to those of Example 1 and will not be repeated here.

[0058] Embodiment 3

[0059] On the basis of the first embodiment, the winding unit can also be provided with more strands of winding wires to be wound in parallel. For example, 3 strands of winding wires to be wound in parallel are provided. Figure 5 As shown, the long side direction of the enveloping rectangle of the turn near the center column marked k is parallel to the axial direction of the window 3. One end of the kth turn is wound with one turn to form the (k-1)th turn, and the other end is wound with two turns to form the (k+1)th turn and the (k+2)th turn. The remaining technical features are similar to those of the first embodiment and will not be repeated.

[0060] In a preferred embodiment, the winding unit includes at least two sub-windings, and the multiple strands of different wires wound in parallel can be different windings of a transformer. For example, two windings of a transformer are wound in parallel, so that the two windings are tightly and evenly interlaced, which can achieve better coupling, and is particularly suitable for scenarios requiring low leakage inductance, such as scenarios with frequencies up to 500kHZ or above.

[0061] Embodiment 4

[0062] like Figure 6 As shown, for practical applications, all of the above embodiments can use flat wires instead of double-strand parallel windings. The outer contour of the flat wire is flat. In actual use, single-strand rectangular flat copper wire, flat Litz wire, laminated copper foil flat wire, etc. can also be selected as needed. It is only necessary that the ratio of the long side to the short side of the envelope shape of the cross-section of the winding unit be close to an integer.

[0063] In summary, the multi-strand parallel winding method proposed in the present invention can not only achieve a low height and make full use of the flat space, but also the leakage flux between the multi-strand parallel wires is very small. When multiple strands are wound in parallel, the current distribution between the strands is very good. When multiple strands are wound in parallel as a multi-winding transformer, extremely low leakage inductance between the windings can be achieved. The present invention is particularly suitable for the parallel winding of multiple strands of Litz wire (because if it is a single strand of solid copper wire, it can be directly wound with a flat copper wire, rather than multiple strands of parallel winding). Since it is Litz wire, it is particularly suitable for scenes with large AC components, usually soft-switching high-frequency converters. Because the soft-switching circuit requires a larger ripple current to achieve zero-voltage opening of the power device. Because the AC resistance of the Litz wire can be close to the DC resistance, and the AC resistance of the solid copper wire will be greater than 5 times or even more than 10 times the DC resistance. Therefore, the present invention can not only be realized in situations where the original Litz wire cannot be realized, but also greatly improve the efficiency, and achieve true high-frequency, small-volume, and high-efficiency contribution.

[0064] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0065] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A winding structure with low height and high space utilization, characterized in that: include: A winding, wherein the winding is wound by a plurality of winding units; a window formed in the center of the winding; A transition zone is formed, and the horizontal winding unit is formed into a vertical winding unit after passing through the transition zone; The envelope shape of the cross section of the winding unit has a long side of the envelope shape and a short side of the envelope shape, and the ratio of the long side of the envelope shape to the short side of the envelope shape is n; wherein n≥2, n is an integer; the total number of turns P of the winding unit is (n×m+1); wherein m≥1, m is an integer; The multi-turn winding unit includes a one-turn vertical winding unit and a multi-turn horizontal winding unit; The vertical winding unit is a winding unit that is adjacent to the window, and the long side of the envelope of the vertical winding unit is arranged along the axial direction of the window; The remaining winding units in the winding are all horizontal winding units, and the long side direction of the envelope shape of the horizontal winding unit is arranged along the radial direction of the window; The preceding winding unit of the vertical winding unit, the vertical winding unit and the following winding unit of the vertical winding unit are continuously wound by twisting the envelope shape by 90° at both ends of the corresponding turns of the vertical winding unit; The winding unit comprises at least two windings, and the at least two windings are alternately arranged adjacent to each other along the axial direction of the window and in the radial direction of the window.

2. The winding structure according to claim 1, characterized in that: The winding wire is Litz wire.

3. The winding structure according to claim 1, characterized in that: The winding unit includes at least two winding wires, and the at least two winding wires are alternately arranged adjacent to each other along the axial direction of the window and the radial direction of the window, so as to be replaced by: the winding unit is a single winding wire.

4. The winding structure according to claim 3, characterized in that: The winding wire is a flat wire.

5. The winding structure according to claim 1, characterized in that: The winding unit includes at least two sub-windings.

6. The winding structure according to claim 1, characterized in that: The winding has two lead-out terminals, and the angle formed by the two lead-out terminals and the center of the window is 0° to 360°.

7. Application of a winding structure with low height and high space utilization, characterized in that: In the soft switching circuit, the winding structure with low height and high space utilization as claimed in claim 2 is adopted.

8. Application of a winding structure with low height and high space utilization, characterized in that: In a transformer with a frequency of 500 kHz or more, a winding structure with low height and high space utilization as claimed in claim 5 is adopted, and at least two of the sub-windings are at least two different windings of the transformer.

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