Coupled inductance and dc converter

Abstract

The application discloses a coupling inductor and a direct current converter, the coupling inductor comprising a magnetic core assembly and a plurality of windings, the magnetic core assembly comprising two magnetic core cover plates and a plurality of magnetic columns, the plurality of magnetic columns being arranged between the two magnetic core cover plates; wherein one of the plurality of magnetic columns is a center column, and the rest of the plurality of magnetic columns are side columns, the side columns being arranged around the center column, the center distance between the center column and any side column being equal, the center distance between any two adjacent side columns being equal, and the plurality of windings being wound around the outer periphery of the plurality of magnetic columns respectively. After energization, the magnetic flux generated by the current in each winding weakens each other in the magnetic columns, so that the magnetic flux is not easy to saturate, the size of the magnetic columns can be reduced, and the size of the coupling inductor is reduced, thereby adapting to smaller installation space.

Description

Technical Field

[0001] This invention relates to the field of circuit technology, and more particularly to a coupled inductor and DC-DC converter. Background Technology

[0002] In order to achieve full and reasonable scheduling and management of electrical energy, bidirectional DC-DC converters are increasingly needed in various situations. Among bidirectional DC-DC converters, bidirectional multiphase interleaved Buck-Boost topology circuits are widely used.

[0003] In existing bidirectional multiphase interleaved Buck-Boost topologies, most output filter inductors are discrete, which occupy a significant amount of installation space. While some circuits use multiphase coupled inductors, the coupling between any two phases of these inductors is difficult to balance, thus affecting anti-coupling performance. Therefore, existing technologies cannot effectively achieve multiphase coupling of inductors.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] The main objective of this invention is to provide a coupling inductor for use in DC-DC converters, aiming to solve the problem of the large installation space occupied by existing output filter inductors.

[0006] To achieve the above objectives, the coupled inductor proposed in this invention includes a magnetic core assembly and multiple windings. The magnetic core assembly includes two magnetic core cover plates and multiple magnetic pillars, with the multiple magnetic pillars disposed between the two magnetic core cover plates. Among the multiple magnetic pillars, one magnetic pillar is a central pillar, and the remaining magnetic pillars are side pillars. The side pillars are arranged around the central pillar, and the center distance between the central pillar and any of the side pillars is equal, as is the center distance between any two adjacent side pillars. The multiple windings are respectively wound around the outer periphery of the multiple magnetic pillars.

[0007] Preferably, the two magnetic core cover plates are arranged correspondingly, the surface of any one magnetic core cover plate facing the other magnetic core cover plate is the working surface, the magnetic column is perpendicular to the working surface of the magnetic core cover plate, the central column is arranged at the geometric center of the working surface, and a plurality of side columns are spaced around the central column.

[0008] Preferably, the working surface is a regular polygon, the number of sides of the regular polygon is the same as the number of side pillars, and any two side pillars are symmetrically arranged; or, the working surface is circular.

[0009] Preferably, the number of magnetic pillars is N, where N≥4.

[0010] Preferably, the winding wound around the outer periphery of the side post is a side winding, and the winding wound around the outer periphery of the center post is a main winding.

[0011] When N≤7, ds≥4×Sin(360 / (N-1) / 2)-2,

[0012] When N≥8, ds≤2-4×Sin(360 / (N-1) / 2),

[0013] Where d is the distance between any two adjacent side windings, and s is the distance between the main winding and any one of the side windings.

[0014] Preferably, the winding wound around the outer periphery of the side post is a side winding, and the winding wound around the outer periphery of the center post is a main winding.

[0015] When N = 4, ds ≥ 1.46WC + 1.46R.

[0016] When N = 5, ds ≥ 0.83WC + 0.83R.

[0017] When N = 6, ds ≥ 0.35WC + 0.35R.

[0018] Wherein, d is the distance between any two adjacent side windings, s is the distance between the main winding and any one of the side windings, the cross-sectional dimension of the winding is WC, and the radius of the magnetic column is R.

[0019] Preferably, each of the magnetic pillars is connected to at least one of the two magnetic core cover plates.

[0020] Preferably, the magnetic column includes two sub-columns spaced apart along its length, with an air gap between the two sub-columns.

[0021] Preferably, one end of the magnetic column is connected to the magnetic core cover plate, and an air gap is provided between the other end of the magnetic column and another magnetic core cover plate.

[0022] Preferably, the magnetic column includes an inductance adjustment section, which is filled with a material whose permeability is lower than that of the magnetic core cover plate.

[0023] Preferably, the sensitivity adjustment part is disposed at one end of the magnetic column, the sensitivity adjustment part abuts against the magnetic core cover plate, and the other end of the magnetic column is connected to another magnetic core cover plate.

[0024] In addition, the present invention also proposes a DC converter, which includes the coupled inductor, capacitor and multiple switching devices as described above.

[0025] In this invention, the coupling inductor includes a magnetic core assembly and multiple windings. The magnetic core assembly includes two core cover plates and multiple magnetic pillars, with the magnetic pillars positioned between the two core cover plates. One of the magnetic pillars is a central pillar, and the remaining pillars are side pillars arranged around the central pillar. The center distance between the central pillar and any side pillar is equal, and the center distance between any two adjacent side pillars is also equal. This achieves balanced coupling between any two phases, maximizing anti-coupling performance and effectively improving the efficiency of the Buck-Boost power supply. Furthermore, each winding is wound around the outer periphery of its corresponding magnetic pillar. When current flows through the winding, the magnetic flux generated by the current in the winding weakens each other within the magnetic pillar, and the leakage flux generated by the current in the winding is distributed in the region between the windings and reinforces each other. After energization, the magnetic flux generated by the current in each winding weakens each other within the magnetic pillar, making magnetic flux less prone to saturation. This allows for a smaller magnetic pillar size, and consequently, a smaller coupling inductor size, thus adapting to a smaller installation space. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0027] Figure 1 This is an exploded view of the structure of the coupled inductor in one embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the assembly structure of the winding and the magnetic column in one embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of another angle assembly structure of the winding and the magnetic column in one embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the magnetic core assembly in one embodiment of the present invention;

[0031] Figure 5 This is an exploded view of the structure of the coupled inductor in another embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of the assembly structure of the winding and the magnetic column in another embodiment of the present invention;

[0033] Figure 7 This is a schematic diagram of another angle assembly structure of the winding and the magnetic column in another embodiment of the present invention;

[0034] Figure 8 This is an exploded view of the structure of the coupled inductor in another embodiment of the present invention;

[0035] Figure 9 This is a schematic diagram of the assembly structure of the winding and the magnetic column in another embodiment of the present invention;

[0036] Figure 10 This is a schematic diagram of another angle assembly structure of the winding and the magnetic column in another embodiment of the present invention;

[0037] Figure 11 This is a schematic diagram of a coupled inductor used in a multiphase interleaved Buck-Boost topology circuit according to an embodiment of the present invention.

[0038] Explanation of icon numbers:

[0039] label name label name 1 magnetic core assembly 203 Third winding 11 Magnetic core cover plate 204 Fourth winding 12 Magnetic column 205 Fifth winding 121 Central column 101 First magnetic column 122 Side Column 102 Second magnetic column 123 Sub-pillar 103 Third magnetic column 2 winding 104 Fourth magnetic column 201 First winding 105 Fifth Magnetic Pillar 202 Second winding

[0040] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0042] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0043] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0044] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0046] This invention proposes a coupled inductor and a DC-DC converter, aiming to solve the problem that existing output filter inductors, which use discrete inductors, occupy a large installation space.

[0047] Please refer to Figure 1 and Figure 2 As shown, the coupled inductor includes a magnetic core assembly 1 and multiple windings 2. The magnetic core assembly 1 includes two magnetic core cover plates 11 and multiple magnetic pillars 12. The multiple magnetic pillars 12 are disposed between the two magnetic core cover plates 11. One of the multiple magnetic pillars 12 is a central pillar 121, and the remaining magnetic pillars 12 are side pillars 122. The side pillars 122 are arranged around the central pillar 121. The center distance between the central pillar 121 and any side pillar 122 is equal, and the center distance between any two adjacent side pillars 122 is equal. The multiple windings 2 are respectively wound around the outer periphery of the multiple magnetic pillars 12.

[0048] The coupling inductor of the present invention includes a magnetic core assembly 1 and multiple windings 2. The magnetic core assembly 1 includes multiple magnetic pillars 12 and two spaced-apart magnetic core cover plates 11. The permeability of the magnetic core cover plates 11 can be the same as the permeability of the magnetic pillars 12. The multiple magnetic pillars 12 are all disposed between the two magnetic core cover plates 11, and one of the multiple magnetic pillars 12 is a central pillar 121, while the remaining magnetic pillars 12 are side pillars 122. The side pillars 122 are arranged around the central pillar 121, and the center distance between the central pillar 121 and any side pillar 122 is equal, as is the center distance between any two adjacent side pillars 122. The aforementioned center distance can be the straight-line distance between the geometric centers of two magnetic pillars 12, or it can be the straight-line distance between specific positions of two magnetic pillars 12. The specific distance can be determined according to the actual situation, and this specification does not limit this aspect in the embodiments.

[0049] In one implementation, it can be as shown in the appendix. Figure 3 , 7As shown in Figure 10, the center distance between any side pillars 122 can be d1, and the center distance between the central pillar 121 and any side pillar 122 can be d2.

[0050] In this embodiment, the number of windings 2 corresponds one-to-one with the number of magnetic pillars 12. Each winding 2 is wound around the outer periphery of its corresponding magnetic pillar 12. When current flows through a winding 2, the magnetic flux generated by the current in the winding 2 weakens each other in the magnetic pillar 12, and the leakage flux generated by the current in the winding 2 is distributed in the region between each winding 2 and reinforces each other. After the coupled inductor of the present invention is energized, the magnetic flux generated by the current in each winding 2 weakens each other in each magnetic pillar 12, making the magnetic flux less prone to saturation. This allows for a reduction in the size of the magnetic pillar 12, thereby reducing the size of the coupled inductor, thus adapting to a smaller installation space and contributing to cost reduction.

[0051] Furthermore, please combine Figure 11 As shown, in a multiphase interleaved Buck-Boost topology circuit, 10 discrete inductors are originally required, but if a more efficient method is used... Figure 1 The coupled inductor shown has 5 magnetic pillars 12, but only 2 are needed. Therefore, the coupled inductor of the present invention can reduce the number of magnetic components, save the space occupied by multiple magnetic components due to installation, and reduce costs.

[0052] In this regard, please combine Figure 4 As shown, in one embodiment, two magnetic core cover plates 11 are correspondingly arranged, and the surface of any one magnetic core cover plate 11 facing the other magnetic core cover plate 11 is the working surface, which is an axisymmetric plane. The magnetic pillar 12 is perpendicular to the working surface of the magnetic core cover plate 11. The central pillar 121 is arranged at the geometric center of the working surface, and a plurality of side pillars 122 are spaced around the central pillar 121. In this embodiment, when current flows into the winding 2, since the plurality of side pillars 122 are evenly distributed around the central pillar 121, and the central pillar 121 can be arranged corresponding to the geometric center of the working surface.

[0053] In this embodiment, the magnetic flux generated by the current in any one winding 2 in the magnetic column 12 on which the winding 2 is wound is opposite in direction to the total magnetic flux generated by the other windings 2 in the magnetic column 12, and can cancel each other out. In addition, the leakage magnetic flux generated by the current in the winding 2 is mainly distributed in the region between the winding 2 and its adjacent windings 2. The leakage magnetic flux generated by the current in each winding 2 is regular and uniform in these regions, making the leakage magnetic flux path less prone to saturation. This makes the magnetic flux density in the core cover plate 11 and the magnetic column 12 more uniform, which is beneficial to reducing the loss of the magnetic core.

[0054] In one specific embodiment, the five-phase coupled inductor can be as follows: Figure 2As shown, the five-phase coupled inductor may include a first winding 201, a second winding 202, a third winding 203, a fourth winding 204, a fifth winding 205, a first magnetic post 101, a second magnetic post 102, a third magnetic post 103, a fourth magnetic post 104, and a fifth magnetic post 105. The first winding 201, the second winding 202, and the fifth winding 205 form a first region; the second winding 202, the third winding 203, and the fifth winding 205 form a second region; the third winding 203, the fourth winding 204, and the fifth winding 205 form a third region; and the fourth winding 204, the first winding 201, and the fifth winding 205 form a fourth region.

[0055] When the currents in the five-phase coupled inductor are respectively as follows Figure 2 When the directions indicated in the diagram are set, the magnetic flux formed by the first winding 201 in the first magnetic post 101 is opposite in direction to the magnetic flux formed by the second winding 202 in the second magnetic post 102, the magnetic flux formed by the third winding 203 in the third magnetic post 103, the magnetic flux formed by the fourth winding 204 in the fourth magnetic post 104, and the magnetic flux formed by the fifth winding 205 in the fifth magnetic post 105, and they cancel each other out.

[0056] The magnetic flux formed by the second winding 202 in the second magnetic post 102 is opposite in direction to the magnetic flux formed by the first winding 201 in the first magnetic post 101, the magnetic flux formed by the third winding 203 in the third magnetic post 103, the magnetic flux formed by the fourth winding 204 in the fourth magnetic post 104, and the magnetic flux formed by the fifth winding 205 in the fifth magnetic post 105, and cancels each other out.

[0057] The magnetic flux formed by the third winding 203 in the third magnetic post 103 is opposite in direction to the magnetic flux formed by the first winding 201 in the second magnetic post 101, the magnetic flux formed by the second winding 202 in the second magnetic post 102, the magnetic flux formed by the fourth winding 204 in the fourth magnetic post 104, and the magnetic flux formed by the fifth winding 205 in the fifth magnetic post 105, and cancels each other out.

[0058] The magnetic flux formed by the fourth winding 204 in the fourth magnetic post 104 is opposite in direction to the magnetic flux formed by the first winding 201 in the first magnetic post 101, the magnetic flux formed by the second winding 202 in the second magnetic post 102, the magnetic flux formed by the third winding 203 in the third magnetic post 103, and the magnetic flux formed by the fifth winding 205 in the fifth magnetic post 105, and cancels each other out.

[0059] The magnetic flux formed by the fifth winding 205 in the first magnetic post 105 is opposite in direction to the magnetic flux formed by the first winding 201 in the first magnetic post 101, the magnetic flux formed by the second winding 202 in the second magnetic post 102, the magnetic flux formed by the third winding 203 in the third magnetic post 103, and the magnetic flux formed by the fourth winding 204 in the fourth magnetic post 104, and cancel each other out.

[0060] The current i1 in the first winding 201 generates a portion of the magnetic flux in the first magnetic post 101, which returns to the first magnetic post 101 through the first region, the second region, the third region, and the fourth region, forming the leakage magnetic flux of the first winding 201; the leakage magnetic flux of the first winding 201 is mainly distributed in the first region and the fourth region close to the first magnetic post 101.

[0061] The magnetic flux generated by the current i2 in the second winding 202 in the second magnetic post 102 returns to the second magnetic post 102 through the first region, the second region, the third region, and the fourth region, forming the leakage flux of the second winding 202; the leakage flux of the second winding 202 is mainly distributed in the first region and the second region close to the second magnetic post 102.

[0062] The magnetic flux generated by the current i3 in the third winding 203 in the third magnetic post 103 returns to the third magnetic post 103 through the first region, the second region, the third region, and the fourth region, forming the leakage flux of the third winding 203; the leakage flux of the third winding 203 is mainly distributed in the second and third regions close to the third magnetic post 103.

[0063] The magnetic flux generated by the current i4 in the fourth winding 204 in the fourth magnetic post 104 returns to the fourth magnetic post 104 through the first region, the second region, the third region, and the fourth region, forming the leakage flux of the fourth winding 204; the leakage flux of the fourth winding 204 is mainly distributed in the third and fourth regions close to the fourth magnetic post 104.

[0064] The current i5 in the fifth winding 205 generates a portion of the magnetic flux in the fifth magnetic post 105, which returns to the fifth magnetic post 105 through the first region, the second region, the third region, and the fourth region, forming the leakage magnetic flux of the fifth winding 205; the leakage magnetic flux of the fifth winding 205 is evenly distributed in the first region, the second region, the third region, and the fourth region close to the fifth magnetic post 105.

[0065] When the current in the winding follows Figure 2 When the orientation is set as shown, the main magnetic flux generated by the current in the winding cancels each other out in the magnetic column; the leakage magnetic flux generated by the current in the winding is regularly distributed in the first, second, third and fourth regions and reinforces each other; therefore, the five-phase coupled inductor operates in an anti-coupling state; anti-coupling means that when the magnetic flux generated by the current in two or more windings cancels each other out, the two or more windings form two-phase or more anti-coupling; the main magnetic flux in the magnetic column cancels each other out and is not easy to saturate, so the size of the magnetic column can be reduced, which can meet the saturation requirement and reduce the size of the multi-phase coupled inductor; which is beneficial to cost reduction.

[0066] Furthermore, in one embodiment, the working surface is a regular polygon, the number of sides of the regular polygon is the same as the number of side posts 122, and any two side posts 122 are symmetrically arranged. For ease of design and manufacturing, the working surface of the core cover plate 11 can be designed as a regular polygon, the number of sides of the working surface is the same as the number of side posts 122, the central post 121 is set at the geometric center of the working surface, and multiple side posts 122 are evenly spaced around the central post 121, and any two side posts 122 are symmetrically arranged, so that the spacing between each adjacent side post 122 is the same, and the spacing between the central post 121 and any one side post 122 is also the same, so that the area enclosed by the central post 121 and any two adjacent side posts 122 is the same, and the leakage flux generated by the current in each winding 2 is regular and uniform in these areas, making the leakage flux path less prone to saturation, and making the magnetic flux density in the core cover plate 11 and the magnetic post 12 more uniform, which is beneficial to reducing the loss of the magnetic core.

[0067] In another embodiment, please combine Figure 5 and Figure 8 As shown, the working surface is circular. Since the circular magnetic core cover plate 11 has multiple axes of symmetry, it can accommodate more magnetic pillars 12. The central pillar 121 is located at the center of the magnetic core cover plate 11, and multiple side pillars 122 are evenly spaced around the central pillar 121.

[0068] In another embodiment, the number of magnetic pillars 12 is N, where N can be a positive integer greater than or equal to 4, such as 4, 5, 8, 10, etc. The specific number can be determined according to the actual situation, and this specification does not limit this embodiment.

[0069] In one embodiment, the exploded diagram of the coupled inductance when N is 4 is as follows: Figure 5 As shown, one of the four magnetic pillars 12 is the center pillar 121, and the other three magnetic pillars 12 are the side pillars 122. The three side pillars 122 are arranged around the center pillar 121. The center distance between the center pillar 121 and any side pillar 122 is equal, and the center distance between any two adjacent side pillars 122 is equal. The four windings 2 are arranged one-to-one with the four magnetic pillars 12, and each winding 2 is wound around the outer periphery of the corresponding magnetic pillar 12.

[0070] In one embodiment, the exploded diagram of the coupled inductance when N is 6 is as follows: Figure 8 As shown, one of the six magnetic pillars 12 is the center pillar 121, and the other five magnetic pillars 12 are the side pillars 122. The five side pillars 122 are arranged around the center pillar 121. The center distance between the center pillar 121 and any side pillar 122 is equal, and the center distance between any two adjacent side pillars 122 is equal. The six windings 2 are arranged one-to-one with the six magnetic pillars 12, and each winding 2 is wound around the outer periphery of the corresponding magnetic pillar 12.

[0071] Of course, the coupling inductors in this application are not limited to the examples above. Those skilled in the art may make other changes based on the technical essence of the embodiments in this specification. However, as long as the functions and effects they achieve are the same as or similar to those in the embodiments in this specification, they should be covered within the protection scope of the embodiments in this specification.

[0072] In one embodiment, the winding 2 wound around the outer periphery of the side post 122 is the side winding, and the winding 2 wound around the outer periphery of the center post 121 is the main winding. When N≤7, please refer to... Figure 3 , Figure 7 as well as Figure 10 As shown, d is the distance between any two adjacent side windings, and s is the distance between the main winding and any side winding. ds ≥ 4 × Sin(360 / (N-1) / 2) - 2, while when N ≥ 8, ds ≤ 2 - 4 × Sin(360 / (N-1) / 2). The inductance and coupling coefficient of the coupled inductor can be adjusted by regulating parameters such as the distance d between any two adjacent side windings and the distance s between the main winding and any side winding.

[0073] Furthermore, please combine Figure 3 , Figure 7 as well as Figure 10 As shown, in order to achieve multiple functions, the winding 2 wound around the outer periphery of the side post 122 is the side winding, and the winding 2 wound around the outer periphery of the center post 121 is the main winding. When N=4, ds≥1.46WC+1.46R, when N=5, ds≥0.83WC+0.83R, and when N=6, ds≥0.35WC+0.35R. Here, d is the distance between any two adjacent side windings, and s is the distance between the main winding and any side winding. The cross-sectional dimension of the winding 2 is WC, and the radius of the magnetic post 12 is R. Where WC is the cross-sectional dimension of winding 2, that is, the width or diameter of the cross-section of winding 2. When the distance d between any two adjacent side windings remains unchanged, the larger the radius R of the magnetic post 12, the higher the coupling coefficient of the coupled inductor. When the radius R of the magnetic post 12 remains unchanged, the larger the distance d between any two adjacent side windings, the larger the leakage inductance. The smaller the distance d between any two adjacent side windings, the smaller the leakage inductance value.

[0074] Therefore, the inductance and coupling coefficient can be adjusted by modifying parameters such as the radius of the magnetic post 12 and the spacing d between any two adjacent side windings. When N=4, ds≥1.46WC+1.46R; when N=5, ds≥0.83WC+0.83R; and when N=6, ds≥0.35WC+0.35R. This allows the leakage inductance of the coupled inductor to be distributed more regularly and evenly in the region between adjacent magnetic posts 12, making the leakage flux path less prone to saturation. Consequently, the flux density distribution in the core and core cover 11 is more uniform, which is beneficial for reducing core losses.

[0075] In one embodiment, each magnetic post 12 can be connected to at least one of the two magnetic core cover plates 11. To make the fixation of each magnetic post 12 more reliable, each magnetic post 12 can be connected to at least one of the two magnetic core cover plates 11, such as... Figure 4 As shown, the two ends of each magnetic post 12 are connected to two magnetic core cover plates, respectively. Figure 8 As shown, each magnetic post 12 is connected to a magnetic core cover plate 11. This connection facilitates the assembly of the coupled inductor.

[0076] Please combine Figure 1 and Figure 4 As shown, in one embodiment, the magnetic column 12 may include two sub-columns 123 spaced apart along its length, and an air gap may be provided between the ends of the two sub-columns 123 that are close to each other. The air gap may refer to a portion of the magnetic path in the magnetic column 12 being composed of air, or it may refer to a portion of the magnetic path in the magnetic column 12 being composed of a filling material with low magnetic permeability. The specific configuration can be determined according to actual conditions, and this embodiment does not limit the specific configuration.

[0077] In this embodiment, the ends of the two sub-posts 123 that are far apart from each other can be connected to the two magnetic core cover plates 11 respectively. Specifically, the first end of the first sub-post 123 is connected to the magnetic core cover plate 11, and the second end of the second sub-post 123 is connected to the magnetic core cover plate 11, wherein the first end of the first sub-post and the second end of the second sub-post are far apart from each other.

[0078] In this embodiment, the air gap between the two sub-pillars 123 can be used to control the inductance, that is, the inductance of the coupled inductor can be adjusted by adjusting the size of the air gap.

[0079] Furthermore, please combine Figure 8As shown, in one embodiment, one end of the magnetic column 12 is connected to one of the magnetic core cover plates 11, and an air gap is provided between the other end and the other magnetic core cover plate 11. To facilitate the assembly and production of the coupled inductor, the magnetic column 12 can be made into a whole, with one end of the magnetic column 12 connected to one magnetic core cover plate 11 and an air gap provided between the other end and the other magnetic core cover plate 11, so that the inductance of the coupled inductor can be adjusted by adjusting the size of the air gap.

[0080] In one embodiment, the magnetic post 12 may include an inductance adjustment section, which may be filled with a material whose permeability is lower than that of the magnetic core cover plate 11, thereby adjusting the inductance of the magnetic post 12. The inductance adjustment section may be located in the middle of the magnetic post 12, or at the end of the magnetic post 12, etc., depending on the actual situation. This specification does not limit this embodiment.

[0081] In this embodiment, the material with a magnetic permeability lower than that of the magnetic core cover plate 11 can be epoxy resin or other materials. The specific material can be selected according to the actual situation, and this embodiment does not limit it.

[0082] In one embodiment, the inductance adjustment section can be disposed at one end of the magnetic post 12, abutting against the core cover plate 11, and the other end of the magnetic post 12 is connected to another core cover plate 11. A material with a permeability lower than that of the core cover plate 11 can be injected into the gap between each magnetic post 12 and the core cover plate 11, and after curing, form the inductance adjustment section, connecting the magnetic post 12 and the core cover plate 11. This makes the magnetic post 12 more securely fixed, thereby improving the structural performance of the coupled inductor. It should be noted that the inductance adjustment section can also be disposed at other locations within the magnetic post 12; specific locations are not limited.

[0083] Furthermore, this invention also proposes a DC-DC converter, which includes a capacitor, multiple switching devices, and a coupling inductor as described above. Please refer to... Figure 11As shown in the attached diagram, this is a 5-phase interleaved Buck-boost topology circuit. The function of this circuit is to adjust the input voltage Vin on the left to the output voltage Vo on the right. Vo is typically lower than Vin, and Vo is used to charge the battery. When the battery is fully charged, or when the battery is fully charged from the photovoltaic panel, the energy stored in the battery can be discharged from Vo to Vin through the topology circuit, and Vin is ultimately fed back to the grid. The currents in the inductors L1 to L5 connected to the five bridge arms are the same in magnitude but opposite in direction to the currents in the five bridge arms L6 to L10. The phase difference of the inductor currents in the five bridge arms L1 to L5 is 360° / n = 360° / 5 = 72°. This interleaved control is to reduce output current ripple and reduce the amount of output capacitor used. The inductors in this five-phase interleaved configuration can use the aforementioned coupled inductors, with the specific structure referring to the above embodiment. This improves efficiency while further reducing the size of the magnetic core, saving space and reducing costs. Since this DC-DC converter adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here.

[0084] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A coupled inductor, characterized in that, The coupled inductor includes: A magnetic core assembly includes two magnetic core cover plates and a plurality of magnetic pillars, wherein the plurality of magnetic pillars are disposed between the two magnetic core cover plates; wherein, one of the plurality of magnetic pillars is a central pillar, and the remaining several magnetic pillars are side pillars, the several side pillars are arranged around the central pillar, the center distance between the central pillar and any of the side pillars is equal, and the center distance between any two adjacent side pillars is equal; Multiple windings are respectively wound around the outer periphery of multiple magnetic pillars, such that when current passes through the windings, the main magnetic flux generated by the current in the windings weakens each other in the magnetic pillars. The number of the plurality of magnetic pillars is N, where N≥4.

2. The coupled inductor as described in claim 1, characterized in that, The two magnetic core cover plates are arranged correspondingly, and the surface of any one magnetic core cover plate facing the other magnetic core cover plate is the working surface. The magnetic column is perpendicular to the working surface of the magnetic core cover plate. The central column is located at the geometric center of the working surface, and a number of the side columns are spaced around the central column.

3. The coupled inductor as described in claim 2, characterized in that, The working surface is a regular polygon, the number of sides of the regular polygon is the same as the number of side pillars, and any two side pillars are symmetrically arranged. or, The working surface is circular.

4. The coupled inductor as described in claim 1, characterized in that, The winding wound around the outer periphery of the side column is the side winding, and the winding wound around the outer periphery of the center column is the main winding. When N≤7, ds≥4×Sin(360 / (N-1) / 2)-2, When N≥8, ds≤2-4×Sin(360 / (N-1) / 2), Where d is the distance between any two adjacent side windings, and s is the distance between the main winding and any one of the side windings.

5. The coupled inductor as described in claim 1, characterized in that, The winding wound around the outer periphery of the side column is the side winding, and the winding wound around the outer periphery of the center column is the main winding. When N=4, ds≥1.46WC+1.46R, When N=5, ds≥0.83WC+0.83R, When N=6, ds≥0.35WC+0.35R, Wherein, d is the distance between any two adjacent side windings, s is the distance between the main winding and any one of the side windings, the cross-sectional dimension of the winding is WC, and the radius of the magnetic column is R.

6. The coupled inductor as described in any one of claims 1 to 5, characterized in that, Each of the magnetic pillars is connected to at least one of the two magnetic core cover plates.

7. The coupled inductor as described in claim 6, characterized in that, The magnetic column includes two sub-columns spaced apart along its length, with an air gap between the two sub-columns.

8. The coupled inductor as described in claim 6, characterized in that, One end of the magnetic column is connected to the magnetic core cover plate, and an air gap is provided between the other end of the magnetic column and another magnetic core cover plate.

9. The coupled inductor as described in claim 6, characterized in that, The magnetic column includes an inductance adjustment section, which is filled with a material whose permeability is lower than that of the magnetic core cover plate.

10. The coupled inductor as described in claim 9, characterized in that, The sensitivity adjustment part is disposed at one end of the magnetic column, the sensitivity adjustment part abuts against the magnetic core cover plate, and the other end of the magnetic column is connected to another magnetic core cover plate.

11. A DC-DC converter, characterized in that, The DC-DC converter includes: a coupled inductor, a capacitor, and a plurality of switching devices as described in any one of claims 1 to 10.

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