Magnetic integrated inductor and inductor assembly thereof

Abstract

The magnetic integrated inductor comprises center pillar magnetic cores, coils, yoke iron magnetic cores and partition plate magnetic cores, the center pillar magnetic cores are arranged in parallel, the coils are wound on the center pillar magnetic cores, the two ends of each center pillar magnetic core are in contact connection with the yoke iron magnetic cores respectively, the partition plate magnetic cores are arranged between every two adjacent center pillar magnetic cores, and the yoke iron magnetic cores are arranged on the partition plate magnetic cores. The side faces of the partition plate magnetic cores are clamped and make contact with the bottom faces of the adjacent yoke iron magnetic cores, the side faces of the partition plate magnetic cores and the bottom faces of the yoke iron magnetic cores are parallel to the axes of the middle column magnetic cores, and the middle column magnetic cores, the yoke iron magnetic cores and the partition plate magnetic cores are all made of metal magnetic powder core materials. The inductor assembly comprises a magnetic integrated inductor and a shell, the shell is provided with a containing space, and the magnetic integrated inductor is placed in the containing space through an opening of the shell. According to the utility model, the magnetostriction coefficient of the material is small, the noise and saturation risks are avoided, the use amount of the iron core is reduced, and the cost is reduced and the efficiency is improved.

Description

Technical Field

[0001] The utility model relates to a magnetic integrated inductor and an inductor component thereof, in particular to a magnetic integrated inductor and an inductor component thereof prepared by using magnetic powder core materials. Background Art

[0002] Inductors are used in electronic devices to filter electromagnetic interference signals and suppress the outward radiation of electromagnetic waves generated by high-speed signal lines. Magnetic integrated inductors can integrate two or more discrete inductors by sharing the magnetic circuit, which can reduce the size and cost, reduce core loss, and improve power efficiency. Magnetic integrated inductors are widely used in situations such as MPPT circuits that need to implement maximum power point tracking in photovoltaic inverters, passive LC filter networks that realize three-phase AC inverter output, and boost circuits in high-power uninterruptible power supplies or rectifier power modules.

[0003] In these applications, the non-shared magnetic circuit of the magnetic integrated inductor generally uses metal magnetic powder core materials, and the shared magnetic circuit generally uses high permeability magnetic materials, so that the magnetic coupling between the inductors is very small and does not affect the independent control of the inductors. High permeability magnetic materials generally include laminated materials such as amorphous strips or ferrite materials. In industrial applications, laminated materials such as amorphous strips often have high-frequency noise problems due to their large magnetostriction coefficients; when ferrite materials are used as shared magnetic circuits, due to their small saturation magnetic density, when they come into contact with non-shared magnetic circuits such as metal magnetic powder core materials, the ferrite will often saturate prematurely, causing the inductance to suddenly drop. The inductance performance under DC current is not as good as that of amorphous materials, such as Figure 1 As shown, actual application will lead to increased ripple and difficult control. Utility Model Content

[0004] In order to solve the problems of noise and saturation, the utility model provides a magnetic integrated inductor. The technical solution of the utility model is as follows: it includes a middle column magnetic core, a coil, a yoke iron magnetic core and a partition magnetic core; the number of the middle column magnetic cores is at least two, and the multiple middle column magnetic cores are arranged in parallel; the coil is wound on the middle column magnetic core, and the two ends of the middle column magnetic core are respectively in contact with and connected to the yoke iron magnetic core; the partition magnetic core is arranged between two adjacent middle column magnetic cores and isolated from the coils on the two adjacent middle column magnetic cores, and the side surface of the partition magnetic core is clamped and contacted by the bottom surface of the adjacent yoke iron magnetic core; the side surface of the partition magnetic core and the bottom surface of the yoke iron magnetic core are parallel to the axis of the middle column magnetic core; the middle column magnetic core, the yoke iron magnetic core and the partition magnetic core are all made of metal magnetic powder core material.

[0005] The cross-sectional area of ​​the partition core is not less than 1.5 times the cross-sectional area of ​​the yoke core;

[0006] The magnetic permeability of the partition core is not less than 1.5 times the magnetic permeability of the yoke core;

[0007] The magnetic integrated inductor also includes two side column magnetic cores arranged in parallel with the partition magnetic core, and the side surfaces of the two side column magnetic cores are closely attached to the bottom surface of the outermost yoke iron magnetic core.

[0008] The utility model also provides an inductor assembly, comprising the magnetic integrated inductor and a shell, wherein the shell has a containing space, and the magnetic integrated inductor is placed in the containing space through an opening of the shell.

[0009] The beneficial effects of the utility model are: due to the adoption of the all-metal magnetic powder core solution, the magnetostriction coefficient of the material is very small compared to laminated amorphous materials or silicon steel sheet materials; the metal magnetic powder core has a soft saturation characteristic, and compared to ferrite materials, there is no saturation risk of sudden drop in inductance. The magnetic integrated inductor solution can control the coupling coefficient K between adjacent coils to be smaller, reduce the amount of iron core used, and help reduce costs and improve efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Relationship between inductance and DC current of different common magnetic circuit materials

[0011] Figure 2 Three-phase magnetic integrated inductor

[0012] Figure 3 Relationship between coupling coefficient and magnetic resistance ratio

[0013] Figure 4 Two-phase magnetic integrated inductor

[0014] Figure 5 Three-phase magnetic integrated inductor with grooves

[0015] Figure 6 Three-phase magnetic integrated inductor assembly.

[0016] In the figure,

[0017] 11-Middle column magnetic core

[0018] 12-Coil

[0019] 13-Yoke ferromagnetic core

[0020] 131- Bottom surface of yoke iron core

[0021] 14-Separator core

[0022] 141-Side of the separator core

[0023] 15-Side column core

[0024] 16-groove

[0025] 17- Shell

[0026] 171- Raised part inside the shell

[0027] R1-the magnetic resistance formed by the magnetic flux passing through the middle column core 11 and the partition core 14 R2-the magnetic resistance formed by the magnetic flux passing through the yoke iron core 13

[0028] Ae1- cross-sectional area of ​​yoke ferromagnetic core

[0029] Ae2-Separator core cross-sectional area

[0030] Ac-Contact surface between the diaphragm core and the yoke iron core

[0031] AX-center column magnetic core axis DETAILED DESCRIPTION

[0032] Embodiment 1:

[0033] The technical solution of the present utility model is now specifically described by taking two-phase and three-phase magnetic integrated inductors as examples.

[0034] like Figure 2 The utility model shows a three-phase magnetic integrated inductor, comprising a center column core 11, a coil 12, a yoke iron core 13 and a partition core 14; three center column cores 11 are arranged in parallel; three coils 12 are wound on the center column core 11, and two ends of the center column core 11 are respectively in contact with and connected to the yoke iron core 13; the partition core 14 is arranged between two adjacent center column cores 11 and isolated from the coils 12 on the two adjacent center column cores 11, and the side surface 141 of the partition core is clamped and contacted by the bottom surface 131 of the adjacent yoke iron core, and the side surface (141) of the partition core and the bottom surface (131) of the yoke iron core are parallel to the center column core axis AX; the center column core 11, the yoke iron core 13 and the partition core 14 are all made of metal magnetic powder core material. The inductor further comprises two side column cores 15 which are arranged in parallel with the partition core 14 , and the side surfaces of the two side column cores 15 are closely attached to the bottom surface of the outermost yoke iron core 13 of the inductor.

[0035] like Figure 2 As shown, the magnetic flux passing through the center column core 11 and the partition core 14 forms a magnetic resistance R1, and the magnetic flux passing through the yoke core 13 forms a magnetic resistance R2, Ae1 is the cross-sectional area of ​​the yoke core 13, and Ae2 is the cross-sectional area of ​​the partition core 14. The coupling coefficient K between adjacent coils 12 is related to the magnetic resistance ratio R2 / R1, as shown in Figure 3As shown, if the coupling coefficient K must be less than 10% to reduce mutual interference, the magnetic resistance ratio R2 / R1 should be less than 0.24, that is, the magnetic resistance R2 formed by the magnetic flux passing through the yoke iron core 13 should be minimized. According to the magnetic resistance formula, by reducing the magnetic path length le, increasing the magnetic permeability μ and the magnetic flux cross section Ae, a smaller magnetic resistance R can be obtained to achieve the decoupling function. A basic situation is that the magnetic permeability of the magnetic powder core itself is relatively low and cannot reach thousands like ferrite or amorphous materials, so in order to achieve the decoupling function, a larger magnetic flux cross section Ae is necessary. For the magnetic flux passing through the yoke iron core 13 to form the magnetic resistance R2, relative to R1, when the magnetic path length le is reduced to about 1 / 2 at most and the magnetic permeability μ is increased to 1.5 times, the cross-sectional area Ae2 of the partition core 14 is at least 1.5 times larger than the cross-sectional area Ae1 of the yoke iron core 13, so that the magnetic resistance ratio R2 / R1 can be reduced to less than 0.24.

[0036] Preferably, the saturation magnetic flux density Bs of the partition core 14 is less than the saturation magnetic flux density Bs of the yoke iron core 13. If a high-Bs magnetic powder core is used in combination with a high-Bs magnetic powder core, or a low-Bs magnetic powder core is used in combination with a low-Bs magnetic powder core, it does not make sense in terms of design, because when the Bs are similar, the magnetic flux cross-section will be roughly similar, so for a magnetic flux circuit that provides a multi-phase inductor decoupling function, it is difficult to reduce the magnetic resistance ratio R2 / R1 to below 0.24. Therefore, the saturation magnetic flux density Bs of the partition core is less than the saturation magnetic flux density Bs of the yoke iron core, so that the cross-sectional area Ae2 of the partition core 14 is greater than the cross-sectional area Ae1 of the yoke iron core 13, without causing material waste, and the magnetic resistance ratio R2 / R1 can be reduced to below 0.24, so as to achieve the function of reducing the coupling coefficient K.

[0037] It is particularly emphasized that the side surface 141 of the separator core must be clamped and contacted by the bottom surface 131 of the adjacent yoke core. Figure 4 The figure shows a two-phase magnetic integrated inductor, where Ac is the contact surface between the partition core 14 and the yoke core 13. In actual design, it is necessary to consider that the coupling coefficient K may change according to the load condition of the inductor. When the coil load current gradually increases, since the saturation magnetic flux density Bs of the yoke core 13 is greater than the saturation magnetic flux density Bs of the partition core 14, the contact surface Ac of the partition core 14 will saturate earlier, resulting in Figure 4 It can be seen from the figure that the saturation of the contact surface Ac of the partition core 14 will cause the magnetic permeability of the region to decrease and the magnetic resistance to increase, which will further hinder the magnetic flux from entering the adjacent winding, thereby reducing the coupling coefficient K between the two adjacent windings.

[0038] On the contrary, a bad practice is that the partition core 14 is pressed tightly by the upper and lower yoke iron cores 13. In this way, when the contact surface is saturated in advance, it is more difficult for the magnetic flux to follow the partition core magnetic path and easier to enter the adjacent winding, resulting in a larger coupling coefficient K.

[0039] Preferably, the separator core 14 is made of Sendust magnetic powder core, which has the characteristics of high magnetic permeability, low saturation magnetic flux density, and high cost performance, and is more suitable for use as a separator core.

[0040] Optionally, the separator core 14 is composed of a plurality of cores arranged in parallel along the direction of the parallel magnetic circuit. Figure 5 As shown, each partition core 14 is composed of two magnetic cores arranged in parallel along the direction of parallel magnetic circuits. This method helps to reduce the volume of the partition core formed in one step and improve the magnetic permeability of the partition core. On the contrary, if multiple magnetic cores are arranged in parallel along the direction perpendicular to the magnetic circuit, the assembly air gap will cause the overall magnetic permeability of the partition core to decrease, which is not conducive to reducing the coupling coefficient K between two adjacent windings.

[0041] Preferably, the middle column magnetic core 11 and the yoke iron magnetic core 13 are made of the same material, both of which are metal magnetic powder cores with a magnetic permeability of no more than 60.

[0042] Preferably, the partition core 14 and the side column core 15 are made of the same material, both of which are metal magnetic powder cores with a magnetic permeability of not less than 90.

[0043] Preferably, after the side surface of the partition core 14 is clamped and contacted by the bottom surface of the adjacent yoke core 13, a groove 16 is formed at the end of the partition core 14. Figure 5 As shown, the length of the separator core 14 is slightly shorter, and a groove 16 is formed on the end surface, which helps to form a better fit with the internal protrusion 171 of the housing 17 during assembly (such as Figure 6 shown).

[0044] In actual use, the magnetic flux generated by adjacent coils will try to produce a canceling effect on the partition core 14, and appropriate adjustments can be made according to different applications; for example, in applications such as the multi-channel MPPT circuit of a photovoltaic inverter or the dual boost circuit of a communication power supply, the magnetic flux directions of adjacent middle column cores 11 are required to be opposite. In the three-phase inverter inductor of the energy storage inverter, the magnetic flux directions of adjacent middle column cores 11 can be the same, and the magnetic flux generated by adjacent coils can be canceled on the partition core 14. The shape of the yoke iron core 13 can be a runway shape, and the side curvature of the partition core 14 matches the runway shape, which will make it easier to follow the shape of the circular coil and reduce the volume of the magnetic integrated inductor. The above can be adjusted accordingly as needed.

[0045] Embodiment 2:

[0046] The utility model also provides an inductor assembly, comprising the magnetic integrated inductor and a housing 17. The housing 17 has a containing space, and the magnetic integrated inductor is placed in the containing space through an opening of the housing 17. Figure 6As shown, the middle column magnetic core 11 and the upper and lower yoke iron magnetic cores 13 are made of iron silicon alloy powder cores with a magnetic permeability of 60, and three coils 12 are wound on the middle column magnetic core 11; the partition magnetic core 14 is made of sendustine alloy powder core with a magnetic permeability of 125; the side of the partition magnetic core 14 is clamped and contacted by the bottom surface of the adjacent yoke iron magnetic core 13. For better three-phase balance, the side column magnetic core 15 is made of sendustine alloy powder core with a magnetic permeability of 125, just like the partition magnetic core 14. The maximum magnetic density of the middle column core of the magnetic integrated inductor is calculated to be 1.0T when the maximum current is 55A. From the material property table, it can be seen that the magnetic permeability of the iron silicon alloy powder core is about 21 at this time; the magnetic flux cross section Ae of the partition core is twice the magnetic flux cross section of the yoke iron core, so the maximum magnetic density of the partition core is 0.5T when the maximum current is 55A. From the material property table, it can be seen that the magnetic permeability of the iron silicon aluminum alloy powder core is about 56 at this time, and the coupling coefficient can be controlled below 5%. The length of the partition core 14 is slightly shorter, and a groove 16 is formed on the end face, which helps to form a better match with the internal protrusion 171 of the shell when assembled with the shell 17. The protrusion 171 is provided with a threaded hole to facilitate the locking connection between the inductor component and the mechanism.

[0047] The above-mentioned specific implementation methods are only exemplary and are intended to better enable those skilled in the art to understand this patent. They should not be understood as limiting the scope of this patent. Any changes or modifications that are essentially the same or equivalent to the technical content made according to the technical solution disclosed in this patent shall fall within the scope of this patent.

Claims

1. A magnetic integrated inductor, comprising a center column magnetic core (11), a coil (12), a yoke iron magnetic core (13) and a partition magnetic core (14); characterized in that: The number of the middle column magnetic cores (11) is at least two, and the middle column magnetic cores (11) are arranged in parallel; the coil (12) is wound on the middle column magnetic core (11), and the two ends of the middle column magnetic core (11) are respectively in contact with the yoke iron magnetic core (13); the partition magnetic core (14) is arranged between two adjacent middle column magnetic cores (11) and isolated from the coils on the two adjacent middle column magnetic cores (11), and the side surface (141) of the partition magnetic core is clamped and contacted by the bottom surface (131) of the adjacent yoke iron magnetic core, and the side surface (141) of the partition magnetic core and the bottom surface (131) of the yoke iron magnetic core are parallel to the axis (AX) of the middle column magnetic core; the middle column magnetic core (11), the yoke iron magnetic core (13) and the partition magnetic core (14) are all made of metal magnetic powder core material.

2. The magnetic integrated inductor according to claim 1, characterized in that: It also includes two side column magnetic cores (15) arranged in parallel with the partition magnetic core (14), and the side surfaces of the side column magnetic cores are closely attached to the bottom surface of the outermost yoke iron magnetic core (13) of the inductor.

3. The magnetic integrated inductor according to claim 1, characterized in that: The cross-sectional area of ​​the partition magnetic core (14) is not less than 1.5 times the cross-sectional area of ​​the yoke iron magnetic core (13).

4. The magnetic integrated inductor according to claim 1, wherein the magnetic permeability of the partition core (14) is not less than 1.5 times the magnetic permeability of the yoke core (13).

5. The magnetic integrated inductor according to claim 1, characterized in that: The saturation magnetic flux density of the partition magnetic core (14) is smaller than the saturation magnetic flux density of the yoke iron magnetic core (13).

6. The magnetic integrated inductor according to claim 1, characterized in that: The material of the partition magnetic core (14) is a Sendust magnetic powder core.

7. The magnetic integrated inductor according to claim 1, characterized in that: The partition magnetic core (14) is composed of a plurality of magnetic cores arranged in parallel along the magnetic circuit direction.

8. The magnetic integrated inductor according to claim 1, characterized in that: The middle column magnetic core (11) and the yoke iron magnetic core (13) are made of the same material, both of which are metal magnetic powder cores with a magnetic permeability of no more than 60.

9. The magnetic integrated inductor according to claim 1, characterized in that: After the side surface of the partition core (14) is clamped and contacted by the bottom surface of the adjacent yoke iron core (13), a groove (16) is formed at the end of the partition core (14).

10. The magnetic integrated inductor according to claim 2, characterized in that: The partition magnetic core (14) and the side column magnetic core (15) are made of the same material, both of which are metal magnetic powder cores with a magnetic permeability of not less than 90.

11. An inductor component, characterized in that: There is a magnetic integrated inductor and a shell (17) as claimed in claim 1, wherein the shell (17) has a containing space, and the magnetic integrated inductor is placed into the containing space through an opening of the shell (17).

12. The inductor assembly according to claim 11, characterized in that: After the side surface of the partition core (14) of the magnetic integrated inductor is clamped and contacted by the bottom surface of the adjacent yoke iron core (13), a groove (16) is formed at the end of the partition core (14), and a protrusion (171) corresponding to the groove (16) is provided in the shell.

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