Balanced three-phase LC harmonic filter reactor
By adopting a metal magnetic powder core and a toroidal magnetic core assembly structure, the inductance accuracy and balance of the three-phase LC harmonic filter reactor are achieved, solving the problem of unbalanced inductance in traditional three-phase reactors and reducing production costs and processing difficulty.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN BOULDER ELECTRONIC CO LTD
- Filing Date
- 2025-05-23
- Publication Date
- 2026-08-04
AI Technical Summary
Existing three-phase LC harmonic filter reactors cannot meet design requirements for noise at high frequencies, and the inductance of the three circuits differs greatly, making it difficult to achieve an accuracy of less than 5%. Traditional coils are difficult to process and have high production costs.
The design employs a metal magnetic powder core, with the magnetic core components arranged in a ring. Each phase coil shares two magnetic core components, ensuring magnetic flux balance among the three phase coils. Adjacent magnetic core components are connected via a central core, resulting in identical turns for all three phase coils. This avoids the traditional figure-eight winding process and adjusts the magnetic circuit coupling method to achieve an inductance difference of less than 3%.
It achieves a difference of less than 3% in the inductance accuracy of the three circuits, reduces production costs and product size, reduces processing difficulty, saves copper material usage, and solves the problem of unbalanced three-phase inductance.
Smart Images
Figure CN224595348U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of electrical component technology, specifically to a balanced inductance three-phase LV harmonic filter reactor. Background Technology
[0002] Conventional three-phase LC harmonic filter reactors sometimes use silicon steel cores. However, since silicon steel cores operate at the power frequency, noise levels cannot meet design requirements when the applicable carrier frequency reaches 8kHz or higher. Others use iron-silicon cores, which can solve the noise problem at carrier frequencies of 8kHz or higher, but the accuracy for different inductance values across the three circuits is poor.
[0003] Currently, the three-phase inductors are arranged in a row and share the top magnetic core, which results in the inductance of the middle phase inductor being higher than that of the other two groups. Although the inductance of the middle phase can be adjusted by reducing the number of turns of the middle phase inductor coil (or reducing the length of the middle phase magnetic core to form an air gap), it is still difficult to meet the requirement that the difference in the inductance of the three circuits be less than 5%. Utility Model Content
[0004] To address the shortcomings of existing technologies, this invention provides a balanced inductance three-phase LC harmonic filter reactor. This structure allows the accuracy of the three inductance values to be within 3% of the difference. At the same time, each phase inductor has only one coil, avoiding the processing difficulty of figure-eight winding required by traditional coils. Furthermore, the number of turns of the three-phase coils is exactly the same, reducing the amount of time spent in the production process to adjust the number of coil turns or fill the air gap to meet the inductance balance requirements, saving copper material and reducing production costs.
[0005] A balanced inductance three-phase LC harmonic filter reactor includes three magnetic core assemblies and three center column magnetic cores, with the three magnetic core assemblies arranged in a ring.
[0006] The magnetic core assembly includes an upper cover magnetic core and a lower cover magnetic core. Adjacent magnetic core assemblies are connected by a central core. The top end of the central core is connected to both upper cover magnetic cores of the adjacent magnetic core assembly, and the bottom end of the central core is connected to the lower cover magnetic core of the adjacent magnetic core assembly. A coil is fitted onto the central core.
[0007] The upper cover magnetic core, lower cover magnetic core, and middle column magnetic core are all metal magnetic powder cores.
[0008] Preferably, the metal magnetic powder core is an iron-silicon-aluminum magnetic powder core, an iron-silicon magnetic powder core, an iron-nickel magnetic powder core, or a mixture of the above three types of magnetic powder cores.
[0009] Preferably, the three upper cover magnetic cores form a regular hexagonal ring.
[0010] Preferably, the three lower cover magnetic cores form a regular hexagonal ring.
[0011] Preferably, the annular central hole formed by the three top cover magnetic cores is a regular hexagon.
[0012] Preferably, the annular central hole formed by the three lower cover magnetic cores is a regular hexagon.
[0013] The beneficial effects of this utility model are reflected in the following: This technical solution employs a metal magnetic powder core, combined with a magnetic core assembly structure. The magnetic core assembly includes an upper cover magnetic core and a lower cover magnetic core, with the three magnetic core assemblies arranged in a ring. Adjacent magnetic core assemblies are connected via a central core, and a coil is mounted on the central core. Thus, each phase coil shares the effective cross-sectional area of two magnetic core assemblies, ensuring that the magnetic flux of the three phase coils is balanced and identical during operation. This adjusts the balance of the three-way magnetic circuit coupling, achieving an inductance accuracy within 3%. This technical solution uses only one coil per phase inductor, avoiding the complex figure-eight winding process required in traditional coils. This effectively reduces product size and weight, lowering costs. Especially in terms of three-phase inductance balance, the ring-shaped arrangement of the magnetic core assemblies results in a more reasonable balance than traditional solutions, resolving the significant defect of unbalanced three-phase inductance in traditional methods. Attached Figure Description
[0014] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.
[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0016] Figure 2 This is a schematic diagram of the overall structure of this utility model without the coil installed.
[0017] In the attached diagram, 1-upper cover magnetic core, 2-lower cover magnetic core, 3-middle column magnetic core, 4-coil. Detailed Implementation
[0018] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.
[0019] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this utility model pertains.
[0020] Example 1
[0021] like Figures 1-2 As shown, this embodiment provides a balanced inductance three-phase LC harmonic filter reactor, including three magnetic core assemblies and three central column magnetic cores 3. The three magnetic core assemblies are arranged in a ring.
[0022] The magnetic core assembly includes an upper cover magnetic core 1 and a lower cover magnetic core 2. Adjacent magnetic core assemblies are connected by a central column magnetic core 3. The top end of the central column magnetic core 3 is connected to both upper cover magnetic cores 1 of the adjacent magnetic core assembly, and the bottom end of the central column magnetic core 3 is connected to the lower cover magnetic core 2 of the adjacent magnetic core assembly. A coil 4 is sleeved on the central column magnetic core 3.
[0023] The upper cover magnetic core 1, the lower cover magnetic core 2, and the middle column magnetic core 3 are all metal magnetic powder cores.
[0024] In this embodiment, a metal magnetic powder core is used in conjunction with a magnetic core assembly structure. The magnetic core assembly includes an upper cover magnetic core 1 and a lower cover magnetic core 2, with the three magnetic core assemblies arranged in a ring. Adjacent magnetic core assemblies are connected by a central column magnetic core 3, and a coil 4 is mounted on the central column magnetic core 3. In this way, each phase coil 4 shares the effective cross-sectional area of two magnetic core assemblies, ensuring that the magnetic flux of the three phase coils 4 is balanced and identical during operation. This adjusts the balance of the three magnetic circuit coupling methods, allowing the accuracy of the three inductance values to achieve a difference within 3%. The structure designed in this application has only one coil 4 per phase inductor, avoiding the processing difficulty of the traditional figure-eight winding method for coils. This effectively reduces the product size and weight, and lowers costs. Especially in terms of three-phase inductance balance, because the magnetic core assemblies are arranged in a ring, the three-phase inductance balance is more reasonable than traditional solutions, solving the important defect of unbalanced three-phase inductance in traditional methods.
[0025] In this embodiment, coil 4 is mounted on the central core 3, and the magnetic circuit is integrated and coupled outside the coil.
[0026] In this embodiment, the number of turns of the three-phase coils can be exactly the same, which reduces the amount of time spent in the production process to adjust the number of coil turns or the air gap to meet the inductance balance, saves copper material usage, and reduces copper material cost, resulting in a lower overall cost.
[0027] In the actual production process, a plastic skeleton can be added between the magnetic core and the coil for isolation to meet the requirements of high voltage and safety creepage distance.
[0028] During assembly, the middle core 3 is connected to the lower cover core 2, the coil 4 is then placed on the middle core 3, and the upper cover core 1 is connected to the middle core 3 to complete the assembly.
[0029] In this embodiment, the metal magnetic powder core is a magnetic powder core composed of iron-silicon-aluminum magnetic powder core, iron-silicon magnetic powder core, iron-nickel magnetic powder core, or a mixture of the above three types of magnetic powder cores.
[0030] In this embodiment, the three upper cover magnetic cores 1 form a regular hexagonal ring.
[0031] In this embodiment, the three lower cover magnetic cores 2 form a regular hexagonal ring.
[0032] In this embodiment, the annular central hole formed by the three upper cover magnetic cores 1 is a regular hexagon.
[0033] In this embodiment, the annular central hole formed by the three lower cover magnetic cores 2 is a regular hexagon.
[0034] In this embodiment, the three magnetic core components are evenly distributed to achieve three-phase inductance balance.
[0035] 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 scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.
Claims
1. A balanced inductance three-phase LC harmonic filter reactor, characterized in that, It includes three magnetic core assemblies and three central cores (3), the three magnetic core assemblies being arranged in a ring. The magnetic core assembly includes an upper cover magnetic core (1) and a lower cover magnetic core (2). Adjacent magnetic core assemblies are connected by a central column magnetic core (3). The top of the central column magnetic core (3) is connected to both upper cover magnetic cores (1) of the adjacent magnetic core assembly, and the bottom of the central column magnetic core (3) is connected to the lower cover magnetic core (2) of the adjacent magnetic core assembly. A coil (4) is sleeved on the central column magnetic core (3). The upper cover magnetic core (1), the lower cover magnetic core (2), and the middle column magnetic core (3) are all metal magnetic powder cores.
2. A balanced inductance three-phase LC harmonic filter reactor according to claim 1, characterized in that, The metal magnetic powder core is an iron-silicon-aluminum magnetic powder core, an iron-silicon magnetic powder core, or an iron-nickel magnetic powder core.
3. A balanced inductance three-phase LC harmonic filter reactor according to claim 1, characterized in that, The three upper cover magnetic cores (1) form a regular hexagonal ring.
4. A balanced inductance three-phase LC harmonic filter reactor according to claim 1, characterized in that, The three lower cover magnetic cores (2) form a regular hexagonal ring.
5. A balanced inductance three-phase LC harmonic filter reactor according to claim 3, characterized in that, The annular central hole formed by the three top cover magnetic cores (1) is a regular hexagon.
6. A balanced inductance three-phase LC harmonic filter reactor according to claim 4, characterized in that, The annular central hole formed by the three lower cover magnetic cores (2) is a regular hexagon.