Magnetic integrated high frequency power inductor

Abstract

The utility model relates to power electronic device technical field more specifically, relate to a kind of magnetic integrated high-frequency power inductance, it includes magnetic core, and magnetic core includes: left core column, right core column and middle core column;Upper yoke, lower yoke, left side coil and right side coil;Wherein, middle core column is not wound coil, and is configured as the common return path of left side coil and right side coil magnetic flux, to realize the magnetic circuit decoupling between two coils;The utility model provides a kind of magnetic integrated high-frequency power inductance, it not only realizes the target of integrating two independent inductance functions in single device, more through a series of structural, material and electrical configuration optimization combination, provides a complete engineering solution, which is better in decoupling performance, stronger in manufacturability, and can further improve key electrical performance through magnetic flux cancellation technology.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, and more particularly to a magnetic component used in power conversion equipment such as switching power supplies, inverters, and converters. More specifically, it is a magnetically integrated high-frequency power inductor whose performance can be optimized through magnetic flux cancellation technology. Background Technology

[0002] High-frequency power inductors are indispensable core components in modern power electronic converters, and their performance directly determines the efficiency, power density, cost, and long-term reliability of the entire system. In many high-performance power electronic applications, such as multiphase DC-DC converters, active power filters (APF), photovoltaic inverters, and on-board chargers (OBCs) for new energy vehicles, it is common to integrate two or more power inductors on the same circuit board that require independent functions and no interference between them.

[0003] To address these needs, existing technologies mainly suffer from the following solutions and their inherent, irreconcilable contradictions:

[0004] Option 1: Discrete Independent Inductor Solution. This solution configures each inductor path with a completely independent magnetic core and coil. Physical isolation ensures that the magnetic circuits between inductors are completely independent, thus eliminating mutual magnetic coupling interference. This is the most traditional and direct design, but its shortcomings are becoming increasingly apparent in today's pursuit of high power density: First, the large number of components results in a large area occupied on the printed circuit board (PCB) and a bulky overall size, which runs counter to industry development trends; second, the procurement and management of multiple sets of magnetic cores, frames, and other materials increases the complexity of the supply chain, directly driving up material and manufacturing costs; finally, the handling, installation, and soldering of multiple discrete components also increases the complexity and time cost of automated production.

[0005] Option 2: Integrated Coupled Inductor Solution. To overcome the size and cost issues of discrete solutions, the industry has proposed a coupled inductor solution that integrates multiple coil windings onto a single magnetic core. This solution significantly reduces size and material costs by sharing the magnetic circuit. However, its design intent is to achieve strong magnetic coupling between coils, a characteristic that is only suitable for a few specific applications requiring the use of coupling effects (such as improving parallel current sharing performance). In most applications where the inductor needs to operate independently, magnetic coupling is a harmful parasitic effect that causes severe electromagnetic crosstalk, interfering with the normal or even stable operation of the circuit, thus greatly limiting its application scenarios.

[0006] Existing solutions have failed to provide a complete engineering solution that is structurally highly optimized, capable of handling complex operating conditions, and fully exploits the potential of magnetic integration.

[0007] Therefore, there is an urgent need in this field for a new type of magnetically integrated high-frequency power inductor that not only achieves basic decoupling integration, but also provides a structurally complete and high-performance solution to meet the stringent requirements of modern power electronics technology development. Utility Model Content

[0008] The purpose of this invention is to overcome the above-mentioned defects of the prior art and provide a magnetically integrated high-frequency power inductor. It not only achieves the goal of integrating the functions of two independent inductors into a single device, but also provides a complete engineering solution with better decoupling performance, stronger manufacturability, and the ability to further improve key electrical performance through a series of optimized combinations of structure, materials and electrical configurations.

[0009] To achieve the above objectives, this utility model provides the following technical solution:

[0010] A magnetically integrated high-frequency power inductor includes: a magnetic core comprising: a left core post, a right core post, and a middle core post disposed between and parallel to the left and right core posts; an iron yoke, the bottom surface of which is connected to the upper end faces of the left, middle, and right core posts; a lower iron yoke, the top surface of which is connected to the lower end faces of the left, middle, and right core posts; a left coil wound on the left core post; and a right coil wound on the right core post; wherein, no coil is wound on the middle core post, which is configured as a common return path for the magnetic flux of the left and right coils to achieve magnetic circuit decoupling between the two coils.

[0011] As a further optimization of this utility model, the lower yoke is formed by splicing together a first lower yoke and a second lower yoke that are physically separated from each other, and the lower end of the central core is embedded between the first lower yoke and the second lower yoke.

[0012] As a further optimization of this utility model, the central core is made of a soft magnetic material with higher permeability than the materials of the left and right cores.

[0013] As a further optimization of this utility model, it also includes a lower frame and an upper frame; after the lower frame and the upper frame are fastened together, they together form an internal cavity for accommodating the magnetic core, and together define the winding areas for winding the left coil and the right coil, respectively.

[0014] As a further optimization of this utility model, the bottom plate of the lower frame is integrally formed with an upwardly protruding slot base, which is configured to accommodate and position the lower ends of the left core column, the middle core column and the right core column respectively.

[0015] As a further optimization of this utility model, the winding polarities of the left coil and the right coil are configured such that when currents of the same direction flow into the left coil and the right coil respectively, the magnetic flux generated in the core column is in opposite directions.

[0016] As a further optimization of this invention, the winding polarity is configured to cancel the magnetic flux generated by the high-frequency ripple components in the currents of the two coils when operating in an interleaved parallel circuit.

[0017] As a further optimization of this invention, the winding polarity is configured to cancel the magnetic flux generated by the DC bias component in the current of the two coils when operating in an interleaved parallel circuit.

[0018] As a further optimization of this utility model, the cross-sectional area of ​​the central core column is configured to be greater than or equal to the cross-sectional area of ​​the left core column, and greater than or equal to the cross-sectional area of ​​the right core column.

[0019] As a further optimization of this utility model, the upper and lower end faces of the left core column, the middle core column and the right core column, as well as the areas in contact with the end faces of the core columns on the bottom surface of the upper yoke and the top surface of the lower yoke, are all flat grinding contact surfaces.

[0020] Compared with the prior art, the beneficial effects of this utility model are significant and multifaceted:

[0021] 1. This invention provides a complete engineering solution with superior decoupling performance: Going beyond theoretical decoupling, it physically severs potential coupling paths by introducing a "split-type lower yoke" and enhances the guiding effect of the common magnetic circuit by selecting a "high-permeability central column" material. This combination of specific structures and materials results in a magnetic decoupling effect far superior to a simple three-column core structure, leading to more stable and reliable performance.

[0022] 2. Significantly improved manufacturability and product consistency: This utility model innovatively adopts an upper and lower combined frame with a precision slot base. This design transforms the original cumbersome assembly process of multiple loose magnetic core components requiring alignment and bonding into a simple, efficient, and precise "building block" assembly process. This greatly reduces reliance on manual skills, improves production efficiency, and fundamentally ensures a high degree of consistency in the magnetic circuit structure of each product, thereby ensuring stable electrical performance.

[0023] 3. This invention deeply explores the performance potential of magnetic integration, achieving a breakthrough in electrical performance: Going beyond simple physical integration, this invention cleverly utilizes the inherent phase relationship of currents in interleaved parallel circuits by pre-setting the coil polarity, realizing vector cancellation of high-frequency or DC magnetic flux within a common core column. This flux cancellation technology can directly and significantly reduce core losses, improve system efficiency, or enhance the inductor's anti-saturation capability and strengthen system robustness. This performance gain is unattainable by any arrangement of two discrete inductors, and is the unique value of this invention's magnetic integration solution. Attached Figure Description

[0024] To enable those skilled in the art to more clearly and comprehensively understand the technical solution of this utility model, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be noted that the accompanying drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. In the accompanying drawings:

[0025] Figure 1 A three-dimensional structural schematic diagram of a magnetically integrated high-frequency power inductor provided for one embodiment of the present invention;

[0026] Figure 2 This is a three-dimensional structural diagram of the magnetic core portion of a magnetically integrated high-frequency power inductor provided in one embodiment of the present invention;

[0027] Figure 3 An exploded three-dimensional structural diagram of a magnetically integrated high-frequency power inductor provided as an embodiment of this utility model.

[0028] List of reference numerals in the attached diagram:

[0029] 1-Upper frame; 2-Left coil; 3-Right coil; 4-Left core column; 5-Middle core column; 6-Right core column; 7-Upper yoke; 8-Lower yoke; 81-First lower yoke; 82-Second lower yoke; 9-Inductor housing; 10-Lower frame; 100-Magnetic core. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings:

[0031] To make the objectives, technical solutions, and advantages of this utility model clearer, several preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the embodiments described herein are merely for explaining this utility model and do not constitute any limitation on its scope of protection. Any modifications, equivalent substitutions, or improvements made based on the spirit and principles of this utility model should be included within the scope of protection of this utility model.

[0032] Example 1

[0033] This embodiment aims to elaborate in detail on the specific physical structure of a magnetically integrated high-frequency power inductor and the synergistic technical effects it brings. This structure provides a complete engineering solution for achieving high-performance decoupled integration and high-efficiency manufacturing. Please also refer to... Figures 1-3 .

[0034] The magnetically integrated high-frequency power inductor of this embodiment includes a magnetic core 100, a left coil 2, and a right coil 3.

[0035] The magnetic core 100 is the foundation for constructing the entire inductor's magnetic circuit. Specifically, the magnetic core 100 includes a left core post 4, a right core post 6, and a middle core post 5 disposed between the left core post 4 and the right core post 6 and parallel to them.

[0036] The precise spatial relationship of "mutual parallelism" is the basis for ensuring the symmetry and performance consistency of the two magnetic circuits. These three core pillars are usually "I"-shaped magnetic cores with rectangular, circular, or elliptical cross-sections, and are made of soft magnetic materials with low loss and high saturation magnetic flux density.

[0037] To form a complete closed magnetic circuit, the magnetic core 100 also includes an upper yoke 7 and a lower yoke 8. The bottom surface of the upper yoke 7 is connected to the upper end faces of the left core post 4, the middle core post 5, and the right core post 6. Similarly, the top surface of the lower yoke 8 is connected to the lower end faces of the left core post 4, the middle core post 5, and the right core post 6.

[0038] The upper yoke 7 and lower yoke 8 are typically flat "I"-shaped magnetic core strips, long and wide enough to completely cover the end faces of the three core posts to ensure smooth magnetic flux flow. By applying a special magnetic core adhesive to the contact surfaces of the core posts and the yokes for bonding and fixing, a mechanically robust and magnetically continuous integral magnetic core frame can be formed, with an overall appearance similar to an "E"-shaped magnetic core.

[0039] The left coil 2 is specifically and uniquely wound on the left core post 4; the right coil 3 is specifically and uniquely wound on the right core post 6.

[0040] These two coils can be selected based on the requirements of rated current and inductance. Litz wire can be used to reduce the skin effect and proximity effect at high frequencies, or flat copper strip can be used to obtain higher current carrying capacity and better heat dissipation performance.

[0041] The core concept of this invention for achieving magnetic decoupling lies in the fact that no coil is wound on the central core column 5, making it electrically completely passive. Its sole function in the magnetic circuit is to be configured as the common return path for the magnetic flux of the left coil 2 and the right coil 3, thereby achieving magnetic decoupling between the two coils. Its working principle is as follows: When the left coil 2 is energized and generates magnetic flux, this flux travels along the left core column 4. Upon reaching the upper yoke 7, it naturally chooses the path with the lowest magnetic resistance to return. Because the central core column 5 provides a much lower magnetic resistance than air gaps or other long paths such as the right core column 6, most of the magnetic flux will be "captured" and guided to the central core column 5, then back to the left core column 4 via the lower yoke 8, forming an independent "left-side magnetic loop": left core column 4 - upper yoke 7 - central core column 5 - lower yoke 8. Similarly, the magnetic flux of the right coil 3 is also confined to the "right-side magnetic loop," i.e., right core column 6 - upper yoke 7 - central core column 5 - lower yoke 8. The central core 5 acts like a "public highway" for magnetic flux, effectively confining the two magnetic fields to their respective regions and avoiding crosstalk, thus achieving electrical independence of the two inductors on a physically integrated single magnetic core.

[0042] Preferably, in order to obtain more thorough decoupling performance, the structure of the lower yoke has been optimized in this embodiment; the lower yoke 8 is composed of a first lower yoke 81 and a second lower yoke 82 that are physically separated from each other, and the lower end of the central core 5 is embedded between the first lower yoke 81 and the second lower yoke 82.

[0043] This split design offers dual advantages. From a magnetic circuit perspective, it physically severs the direct magnetic connection between the left core post 4 and the right core post 6 at the bottom, eliminating any potential leakage and coupling of minute magnetic flux through the lower yoke. This results in greater independence of the two magnetic circuits and better decoupling. From a manufacturing perspective, this design greatly simplifies assembly. Workers can first fix the three core posts to the lower frame, and then easily insert and bond the two separate lower yokes from both sides. Compared to the requirement for precise alignment of a single, integrated lower yoke, this design is more convenient and has a higher tolerance for error.

[0044] Furthermore, in order to further enhance the decoupling effect from the material level, this embodiment proposes a preferred material configuration scheme; the central core 5 is made of a soft magnetic material with higher permeability than the materials of the left core 4 and the right core 6.

[0045] The distribution of magnetic flux follows the principle of minimum magnetic reluctance, and magnetic reluctance is inversely proportional to magnetic permeability. By selecting a material with extremely high initial magnetic permeability for the central core 5, such as permalloy, amorphous or nanocrystalline soft magnetic materials, while using conventional soft magnetic materials for the side cores, namely the left core 4 and the right core 6, a "magnetic reluctance cage" is artificially created in the magnetic circuit. This common return path, composed of high-permeability materials, has a strong attraction and binding ability for magnetic flux, which can more effectively "lock" the respective magnetic flux within the preset loop, minimize the outward leakage of magnetic field, and thus reduce the coupling coefficient between the two coils to an extremely low level, achieving near-perfect decoupling performance.

[0046] Preferably, to address the challenges of precision assembly and reliable fixation of multiple discrete magnetic core components and to provide a standardized winding platform for the coils, this embodiment introduces an innovative integrated frame system; the inductor also includes a lower frame 10 and an upper frame 1. When the lower frame 10 and upper frame 1 are engaged, they together form an internal cavity for accommodating the magnetic core 100 and jointly define the winding areas for winding the left coil 2 and the right coil 3, respectively. More specifically, to achieve precision assembly, the base plate of the lower frame 10 has three upwardly protruding slot bases integrally formed.

[0047] The shape, size, and relative position of these slot bases are precisely designed and molded to ensure that the three core posts can be positioned vertically and securely in their predetermined positions during assembly. The slot bases respectively accommodate and position the lower ends of the left core post 4, the middle core post 5, and the right core post 6. The upper frame 1 covers the lower frame 10 and is tightly secured to it via a snap-fit ​​structure, constraining the position of the magnetic cores from above. This integrated frame design transforms a complex, manually skill-dependent multi-part assembly process into a simple, standardized "building block" process, significantly improving production efficiency and product quality consistency.

[0048] Preferably, in order to prevent the core post 5, which serves as a common magnetic circuit, from saturating before the side posts, its geometry has been optimized in this embodiment. The cross-sectional area of ​​the core post 5 is designed to be greater than or equal to the cross-sectional area of ​​the left core post 4, and greater than or equal to the cross-sectional area of ​​the right core post 6.

[0049] Magnetic flux density B = Φ / A. The central core post 5, as a common path, needs to carry all the magnetic flux Φ from the coils on either side. To ensure that the magnetic flux density B of the central core post 5 does not exceed the saturation magnetic flux density B_sat of its material under extreme operating conditions, its cross-sectional area A must be sufficiently large. Designing it to be no less than the cross-sectional area of ​​the side posts is a robust and effective design principle to ensure it does not become a bottleneck in magnetic circuit performance.

[0050] Furthermore, in order to fundamentally ensure the low magnetic reluctance characteristics of the magnetic circuit, the contact surfaces of the magnetic core components in this embodiment have undergone process treatment. The upper and lower end faces of the left core post 4, the middle core post 5, and the right core post 6, as well as the areas in contact with the end faces of the core posts on the bottom surface of the upper yoke 7 and the top surface of the lower yoke 8, are all flat, ground contact surfaces.

[0051] In a magnetic circuit, even the smallest air gap can introduce enormous magnetic reluctance, severely impacting the performance and consistency of the inductor. By performing high-precision grinding on all magnetic core contact surfaces, the surface roughness can be reduced to an extremely low level. This allows for a molecular-level tight fit during component assembly, minimizing harmful air gaps and ensuring the continuity and low magnetic reluctance of the entire magnetic circuit. This is the prerequisite and guarantee for achieving high-performance magnetically integrated inductors.

[0052] Example 2

[0053] This embodiment, based on the physical structure described in Embodiment 1, provides a further technical solution through a specific configuration of the electrical characteristics of the coil windings. The physical structure of this embodiment is the same as that of Embodiment 1, the difference being that the winding polarities of the left coil 2 and the right coil 3 are specifically preset.

[0054] In specific power electronic applications, such as two-phase interleaved parallel converter circuits, the current flowing through the two inductors—that is, the left coil 2 and the right coil 3 of this invention—typically contains a DC bias component and a high-frequency ripple component. Due to the interleaved operation of the circuit, the current ripple components in the two coils have a 180-degree phase difference. Utilizing this characteristic, specific magnetic flux components can be made to interact within the central core 5, which serves as a common magnetic circuit, by different configurations of the coil winding polarities.

[0055] One technical solution is to set the winding polarity of the left coil 2 and the right coil 3 such that when currents of the same direction flow into the two coils respectively, the magnetic flux they generate within the core post 5 is in opposite directions. When this configuration is applied to the aforementioned interleaved parallel circuit, since the DC bias current components of the two coils are in the same direction, the DC magnetic flux they generate within the core post 5 is in opposite directions, thus canceling each other out. This solution is mainly used to cancel DC bias magnetic flux, effectively preventing the core post 5 from prematurely saturating due to a large DC bias, and improving the inductor's anti-saturation capability.

[0056] Another technical solution is to set the winding polarity of the left coil 2 and the right coil 3 such that when currents flow into the two coils in the same direction, the magnetic flux they generate within the core column 5 is in the same direction. When this configuration is applied to the aforementioned interleaved parallel circuit, because the high-frequency ripple current components of the two coils are in opposite directions (i.e., 180 degrees out of phase), the high-frequency AC magnetic flux they generate within the core column 5 is also in opposite directions, thus canceling each other out. This solution is mainly used to cancel high-frequency ripple magnetic flux, significantly reducing the magnetic flux swing within the core column 5, and greatly reducing the core loss of the core column 5 under high-frequency operation, thereby lowering the device operating temperature and improving system efficiency.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A magnetic integrated high frequency power inductor, characterized in that, include: A magnetic core (100), the magnetic core (100) comprising: Left core post (4), right core post (6), and a middle core post (5) disposed between the left core post (4) and the right core post (6) and parallel to them; Upper yoke (7), the bottom surface of which connects to the upper end faces of the left core post (4), the middle core post (5), and the right core post (6); and The lower yoke (8) has its top surface connected to the lower end surfaces of the left core column (4), the middle core column (5) and the right core column (6); as well as Left coil (2), the left coil (2) being wound on the left core post (4); and The right coil (3) is wound on the right core post (6); The central core column (5) is not wound with a coil and is configured as a common return path for the magnetic flux of the left coil (2) and the right coil (3) to achieve magnetic circuit decoupling between the two coils.

2. The magnetic integrated high frequency power inductor of claim 1, wherein, The lower yoke (8) is formed by splicing together a first lower yoke (81) and a second lower yoke (82) that are physically separated from each other, and the lower end of the central core (5) is embedded between the first lower yoke (81) and the second lower yoke (82).

3. The magnetic integrated high-frequency power inductor according to any one of claims 1 or 2, characterized in that, The central core (5) is made of a magnetic material with higher permeability than the materials of the left core (4) and the right core (6).

4. The magnetic integrated high frequency power inductor of claim 1, wherein, It also includes a lower frame (10) and an upper frame (1); after the lower frame (10) and the upper frame (1) are fastened together, they together form an internal cavity for accommodating the magnetic core (100) and together define the winding areas for winding the left coil (2) and the right coil (3) respectively.

5. The magnetic integrated high frequency power inductor of claim 4, wherein, The bottom plate of the lower frame (10) has an integrally formed upward protruding slot base, which is configured to accommodate and position the lower ends of the left core column (4), the middle core column (5) and the right core column (6) respectively.

6. The magnetic integrated high frequency power inductor of claim 1, wherein, The winding polarities of the left coil (2) and the right coil (3) are configured such that when currents of the same direction flow into the left coil (2) and the right coil (3) respectively, the magnetic flux generated in the core column (5) is in opposite directions.

7. The magnetic integrated high frequency power inductor of claim 6, wherein, The winding polarity is configured to cancel the magnetic flux generated by the high-frequency ripple components in the currents of the two coils when operating in an interleaved parallel circuit.

8. The magnetic integrated high frequency power inductor of claim 6, wherein, The winding polarity is configured to cancel the magnetic flux generated by the DC bias component in the current of the two coils when operating in an interleaved parallel circuit.

9. The magnetic integrated high frequency power inductor of claim 1, wherein, The cross-sectional area of ​​the central core column (5) is configured to be greater than or equal to the cross-sectional area of ​​the left core column (4) and greater than or equal to the cross-sectional area of ​​the right core column (6).

10. The magnetic integrated high frequency power inductor of claim 1, wherein, The upper and lower end faces of the left core (4), middle core (5) and right core (6), as well as the areas of the bottom surface of the upper yoke (7) and the top surface of the lower yoke (8) that contact the end face of the core are all flat grinding contact surfaces.

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