Multilayer adjustable reluctance type nested combined iron core transformer structure
By adopting a multi-layer adjustable magnetoresistive nested composite core structure, the problems of uneven flux density distribution and local overheating in medium and high-frequency transformers are solved, and a more uniform magnetic field distribution and higher space utilization are achieved.
Patent Information
- Application Number
- CN202510274245.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-10
- Publication Date
- 2025-05-02
AI Technical Summary
Existing medium and high frequency transformers face uneven flux density distribution and local overheating in high-power applications, and the core structure cannot meet the volume requirements.
The multi-layer adjustable magnetoresistive nesting combined core structure is adopted. Through the coordination of the inner and outer ring nesting structure and magnetic filling material, the equivalent magnetic permeability of the inner and outer ring core is adjusted to ensure the uniform magnetic resistance of the inner and outer rings, thereby improving the uniform distribution of magnetic flux density and reducing local heating.
It effectively improves the uniformity of the core magnetic field distribution, reduces local heating, improves space utilization, and saves 50% of the space while ensuring output power.
Smart Images
Figure CN119920597A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of transformers, and in particular to a multi-layer adjustable reluctance nested combined iron core transformer structure. Background Art
[0002] Medium and high frequency transformers are core components of high frequency power electronic systems. Their core functions are the same as those of conventional transformers (voltage conversion, current regulation, impedance matching, and electrical isolation). However, because the operating frequency is significantly higher than the industrial frequency (50 / 60Hz), they have unique characteristics in structure, materials, and application scenarios. Existing medium and high frequency transformers face the contradiction between high power demand and volume restrictions when used in offshore wind power generation, photovoltaic power generation and other fields. In addition, local oversaturation of the core can cause heating problems. As a key component of a new type of power electronic conversion device, medium and high frequency high power transformers need to comprehensively consider the product's electromagnetic performance, weight, insulation performance, and heat dissipation issues. This requires more attention to the uniformity of magnetic field density and volume requirements during design.
[0003] In existing medium and high frequency transformers, when the transformer power increases, the wound core requires a larger core cross-sectional area. Under the condition that the strip width cannot be increased, the number of winding layers of the core increases, resulting in oversaturation of the inner layer of the core, while the outer layer is still in a low magnetic density state, resulting in uneven distribution of the core magnetic flux density, which is prone to local overheating problems and affects product reliability. In addition, with the increase in the requirements for temperature rise and power density in the application scenarios of medium and high frequency transformers, the existing medium and high frequency transformer core structure can no longer meet the volume requirements, so it needs further improvement. Summary of the invention
[0004] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a multi-layer adjustable reluctance nested combined core transformer structure, which effectively improves the uniformity of the core magnetic field distribution, reduces local heating, and improves space utilization.
[0005] The present invention is achieved through the following technical solutions:
[0006] A multi-layer adjustable reluctance nested composite core transformer structure comprises three groups of nested composite cores and two groups of winding structures relatively wound between the three groups of nested composite cores. The nested composite cores comprise an outer ring core and an inner ring core, and magnetic filling materials are respectively arranged in the inner ring cores of the nested composite cores.
[0007] According to the above technical solution, preferably, the three groups of nested composite cores are respectively a front layer composite core, a middle layer composite core, and a rear layer composite core, the front layer composite core includes a front layer outer ring core and a front layer inner ring core, the middle layer composite core includes a middle layer outer ring core and a middle layer inner ring core, and the rear layer composite core includes a rear layer outer ring core and a rear layer inner ring core.
[0008] According to the above technical solution, preferably, the magnetic filling material includes a front layer inner ring filling symmetrically arranged on the front layer inner ring core, a middle layer inner ring filling symmetrically arranged on the middle layer inner ring core, and a rear layer inner ring filling symmetrically arranged on the rear layer inner ring core.
[0009] According to the above technical solution, preferably, the front layer inner ring filling is located at the upper part of the front layer inner ring core, the middle layer inner ring filling is located in the middle part of the middle layer inner ring core, and the rear layer inner ring filling is located at the lower part of the rear layer inner ring core, and the front layer inner ring filling and the rear layer inner ring filling can be symmetrical about the middle layer inner ring filling.
[0010] According to the above technical solution, preferably, there are equal intervals between the front layer composite core, the middle layer composite core, and the rear layer composite core.
[0011] According to the above technical solution, preferably, the top of the middle outer ring iron core is sleeved with an upper fixer, and the bottom of the middle outer ring iron core is sleeved with a lower fixer, and the two sides of the upper fixer and the lower fixer are respectively fitted with the front layer combined iron core and the rear layer combined iron core, so that the spacing between the front layer combined iron core, the middle layer combined iron core, and the rear layer combined iron core is equal.
[0012] According to the above technical solution, preferably, the winding structure includes an inner winding frame tightly fitted and sleeved between three groups of nested combined iron cores, an inner winding wound outside the inner winding frame, an outer winding frame located outside the inner winding, and an outer winding wound outside the outer winding frame.
[0013] According to the above technical solution, preferably, the inner side of the inner winding skeleton is provided with a front layer fixer, a middle layer fixer, a rear layer fixer, a front fixer and a rear fixer, the front layer fixer is relatively arranged with two, and their positions are relative to the front layer inner circle filling arrangement, the middle layer fixer is relatively arranged with two, and their positions are relative to the middle layer inner circle filling arrangement, the rear layer fixer is relatively arranged with two, and their positions are relative to the rear layer inner circle filling arrangement, and the front fixer and the rear fixer are respectively abutted against the outer sides of the front layer combined iron core and the rear layer combined iron core.
[0014] According to the above technical solution, preferably, a plurality of heat dissipation holes are distributed on the inner winding skeleton.
[0015] According to the above technical solution, preferably, the magnetic filling material includes one or more of silicon steel, amorphous alloy or ferrite material.
[0016] The beneficial effects of the present invention are:
[0017] The present invention adopts a nested structure of inner and outer rings, and adjusts the magnetic resistance of the core with a short inner magnetic flux path. By controlling the number of winding layers of the inner and outer ring cores and adjusting the equivalent magnetic permeability of the inner ring core, the uniformity of the distribution of the magnetic flux density in the core is improved. An air gap is opened in the inner ring core, and a magnetic material with low magnetic permeability is filled to adjust the equivalent magnetic permeability of the inner ring core, so that the magnetic resistance of the inner and outer rings is consistent, thereby avoiding the oversaturation of the inner ring core and reducing the problem of local heating. In addition, after adjusting the magnetic resistance, the inner ring core can have the same output power as the outer ring core. While ensuring the output power, the inner and outer ring nested structure adopted saves 50% of space compared with other combined cores.
[0018] For high-voltage applications, the required transformer core has a large cross-sectional area, which leads to uneven distribution of magnetic flux density and inconvenience in transportation and installation. The combined core is used to divide the required core cross-sectional area into multiple cores with small cross-sectional areas and combine them in a nested and parallel manner, which can improve the uniformity of magnetic flux density distribution and reduce local heating. At the same time, the nesting method can reduce the number of parallels, thereby reducing the total volume of the transformer core. The number of layers of the combined core can be increased according to the design requirements, and the filling position of each layer can also be adjusted. Since the small air gap at the filling position will increase the leakage magnetic field and increase the core loss, in order to reduce the leakage magnetic field, the inner ring cores of each layer are staggered. Parallel to the filling position of the front inner ring core and the rear inner ring core is the high magnetic permeability part of the middle inner ring core, and part of the leakage magnetic field can return to the middle inner ring core. Similarly, part of the leakage magnetic field at the filling position of the middle inner ring core can return to the front inner ring core or the rear inner ring core to reduce the leakage magnetic field. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a three-dimensional structural schematic diagram of the present invention.
[0020] Figure 2 The three-dimensional structure of the nested composite core of the present invention is shown in FIG. Figure 1 .
[0021] Figure 3 The three-dimensional structure of the nested composite core of the present invention is shown in FIG. Figure 2 .
[0022] Figure 4 The three-dimensional structure of the nested composite core of the present invention is shown in FIG. Figure 3 .
[0023] Figure 5 It is a three-dimensional structural schematic diagram of the upper fixing part and the lower fixing part of the present invention.
[0024] Figure 6 It is a three-dimensional structural schematic diagram of the winding structure part of the present invention.
[0025] Figure 7 It is a three-dimensional structural cross-sectional view of the winding structure part of the present invention.
[0026] Figure 8 The three-dimensional structure of the inner winding frame of the present invention is shown in FIG. Figure 1 .
[0027] Fig. 9 The three-dimensional structure of the inner winding frame of the present invention is shown in FIG. Figure 2 .
[0028] In the figure: 1. front layer composite core; 2. middle layer composite core; 3. back layer composite core; 4. upper fixation; 5. inner winding skeleton; 6. outer winding skeleton; 7. outer winding; 8. front layer outer ring core; 9. front layer inner ring core; 10. front layer inner ring filling; 11. middle layer outer ring core; 12. middle layer inner ring core; 13. middle layer inner ring filling; 14. back layer outer ring core; 15. back layer inner ring core; 16. back layer inner ring filling; 17. lower fixation; 18. front layer fixation; 19. middle layer fixation; 20. back layer fixation; 21. front fixation; 22. back fixation; 23. heat dissipation hole; 24. inner winding output terminal; 25. outer winding output terminal; 26. inner winding. DETAILED DESCRIPTION
[0029] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and the best embodiment. Based on the embodiments in the invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the invention.
[0030] In the description of the invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the invention.
[0031] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0032] As shown in the figure, the present invention includes three groups of nested composite cores and two groups of winding structures relatively wound between the three groups of nested composite cores, wherein the nested composite cores include an outer ring core and an inner ring core, and the inner ring cores of each nested composite core are respectively provided with magnetic filling materials. The three groups of nested composite cores are respectively a front layer composite core 1, a middle layer composite core 2, and a rear layer composite core 3, wherein the front layer composite core 1 includes a front layer outer ring core 8 and a front layer inner ring core 9, the middle layer composite core 2 includes a middle layer outer ring core 11 and a middle layer inner ring core 12, and the rear layer composite core 3 includes a rear layer outer ring core 14 and a rear layer inner ring core 15. An upper fixing 4 is sleeved on the top of the middle outer ring core 11, and a lower fixing 17 is sleeved on the bottom of the middle outer ring core 11. The upper fixing 4 and the lower fixing 17 are both hollow aluminum structures with a certain wall thickness. The two sides of the upper fixing 4 and the lower fixing 17 are respectively fitted with the front layer combined core 1 and the rear layer combined core 3. By changing the wall thickness of the upper fixing 4 and the lower fixing 17, the spacing between the front layer combined core 1, the middle layer combined core 2, and the rear layer combined core 3 is controlled to be equal.
[0033] Among them, the magnetic filling material can be selected from magnetic filling materials with low magnetic permeability such as silicon steel, amorphous alloy or ferrite material, and specifically includes a front layer inner ring filling 10 symmetrically arranged on the front layer inner ring core 9, a middle layer inner ring filling 13 symmetrically arranged on the middle layer inner ring core 12, and a rear layer inner ring filling 16 symmetrically arranged on the rear layer inner ring core 15. Specifically, the front layer inner ring filling 10 is located at the upper part of the front layer inner ring core 9, the middle layer inner ring filling 13 is located in the middle part of the middle layer inner ring core 12, and the rear layer inner ring filling 16 is located at the lower part of the rear layer inner ring core 15, and the front layer inner ring filling 10 and the rear layer inner ring filling 16 can be symmetrical about the middle layer inner ring filling 13. In this example, the front layer inner ring filling 10 is preferably located at a position larger than 1 / 2 of the window of the front layer inner ring core 9, and the specific position can be adjusted according to actual needs. The middle layer inner ring filling 13 is located at 1 / 2 of the window height of the middle layer inner ring core 12, and the rear layer inner ring filling 16 is located at a position smaller than 1 / 2 of the window of the rear layer inner ring core 15 and is symmetrical with the front layer inner ring filling 10 about the middle layer inner ring filling 13.
[0034] At the same time, the winding structure includes an inner winding skeleton 5 that is tightly fitted and sleeved between three groups of nested combined cores, an inner winding 26 wound outside the inner winding skeleton 5, an outer winding skeleton 6 located outside the inner winding, and an outer winding 7 wound outside the outer winding skeleton 6. Specifically, the inner winding skeleton 5 is respectively located on the left and right core columns of the three-layer nested combined core, the inner winding 26 is tightly wound on the inner winding skeleton 5, and the output terminal is led out through the inner winding output terminal 24. The outer winding skeleton 6 is located in the outer layer of the inner winding and maintains a certain distance for heat dissipation. The outer winding 7 is tightly wound on the outer winding skeleton 6, and the output terminal is led out through the outer winding output terminal 25.
[0035] In addition, the inner side of the inner winding skeleton 5 is provided with a front layer fixing 18, a middle layer fixing 19, a rear layer fixing 20, a front fixing 21, and a rear fixing 22, which are formed into one piece by pouring or 3D printing. The front layer fixing 18 is relatively arranged with two, and the position is arranged relative to the front layer inner ring filling 10, the middle layer fixing 19 is relatively arranged with two, and the position is arranged relative to the middle layer inner ring filling 13, and the rear layer fixing 20 is relatively arranged with two, and the position is arranged relative to the rear layer inner ring filling 16, wherein the width of the front layer fixing 18, the middle layer fixing 19, and the rear layer fixing 20 on both sides needs to match the length of the inner winding skeleton 5 and the single-side core column width of the front layer composite core 1, the middle layer composite core 2, and the rear layer composite core 3. The front fixing 21 and the rear fixing 22 are respectively abutted against the outer sides of the front layer composite core 1 and the rear layer composite core 3. The thickness of the front fixing 21 and the rear fixing 22 is matched with the width of the inner winding skeleton 5, the strip width of the front layer composite core 1, the middle layer composite core 2, and the rear layer composite core 3, and the spacing between the front, middle, and rear layers of the composite core 3. The height of the inner winding skeleton 5 is equal to the height of the composite core window, and the heat dissipation hole 23 is located in the inner winding skeleton 5 for heat dissipation. Specifically, in this example, preferably, the inner winding skeleton 5 is closely fitted with the front layer inner ring filling 10, the middle layer inner ring filling 13, and the rear layer inner ring filling 16 of the inner ring of the front, middle, and rear layers of the composite core 3 structure through the front layer fixing 18, the middle layer fixing 19, and the rear layer fixing 20, respectively, and the other side is closely fitted with the outer ring of the front, middle, and rear layers of the composite core 3 structure through the front layer fixing 18, the middle layer fixing 19, and the rear layer fixing 20, respectively, and the front and rear sides are closely fitted with the front layer composite core 1 and the rear layer composite core 3 through the front fixing 21 and the rear fixing 22, respectively.
[0036] The working principle of the present invention to achieve its technical effect is as follows:
[0037] The inner winding skeleton 5 plays the role of support, insulation and heat dissipation. It applies voltage excitation to the inner winding, generates magnetic fields in the front layer composite core 1, the middle layer composite core 2, and the back layer composite core 3, and induces voltage in the outer winding. Since the front layer inner ring core 9, the middle layer inner ring core 12, and the back layer inner ring core 15 respectively include the front layer inner ring filling 10, the middle layer inner ring filling 13, and the back layer inner ring filling 16 in different positions, the front layer inner ring filling 10 is located at a position greater than 1 / 2 of the window of the front layer inner ring core 9, and the specific position can be adjusted according to actual needs, the middle layer inner ring filling 13 is located at 1 / 2 of the window height of the middle layer inner ring core 12, and the back layer inner ring filling 16 is located at a position less than 1 / 2 of the window of the back layer inner ring core 15 and is symmetrical with the front layer inner ring filling 10 about the middle layer inner ring filling 13. Except for the filling position, the composite core adopts nanocrystalline alloy material, and the filling material can be selected from silicon steel, amorphous alloy and ferrite material according to calculation requirements. The equivalent magnetic permeability of the inner core is adjusted by filling the inner core with magnetic material whose magnetic permeability is lower than that of the outer core. Magnetic resistance calculation formula:
[0038]
[0039] Where R is the magnetic resistance, l is the length of the magnetic flux path, μ0 is the vacuum permeability, and μ r is the relative magnetic permeability of the magnetic material, S i is the cross-sectional area of the core.
[0040] In order to ensure uniform magnetic flux distribution, the thickness of the inner and outer core laminations is selected according to the ratio of the width of the outermost circle to the innermost circle of the wound core not exceeding 1.2, and the magnetic path length l and the cross-sectional area S can be determined. i (Wherein, the length of the magnetic path is the circumference of the core window plus twice the thickness of the core laminations; the cross-sectional area is the core lamination thickness multiplied by the width of the core strip). Since the magnetic permeability of the outer core is fixed, the magnetic resistance of each layer of the outer core can be obtained. Select the filling material according to the actual situation and calculate the filling thickness according to the magnetic permeability of the selected material and the equivalent magnetic permeability of the inner ring required to keep the magnetic resistance of the inner and outer rings the same, so that the inner core of each layer of the combined core structure has the same magnetic resistance as the outer core (specifically, use the magnetic resistance calculation formula to calculate the outer core magnetic resistance R1. If the magnetic resistance of the inner core is the same as R1, the equivalent magnetic permeability of the inner ring can be calculated, and the filling thickness can be calculated based on the equivalent magnetic permeability of the inner ring). The equivalent magnetic permeability of the inner core after filling the material can be expressed as:
[0041] μ ref = l all μ1μ2 / (l2μ1+l1μ2)
[0042] Among them, l all is the total magnetic path length of the inner ring, μ1 is the relative magnetic permeability of the magnetic material of the inner ring core excluding the filling material, μ2 is the relative magnetic permeability of the filling part, l1 is the path length of the inner ring core excluding the filling material, l2 is the thickness of the filling material, and l1=l all -l2.
[0043] Since the inner and outer cores of each layer of the composite core structure have the same magnetic resistance, the induced magnetic field in the inner and outer rings of the three-layer composite core is uniform, reducing the local heating of the inner core. The output power of the inner and outer cores after magnetic resistance adjustment is the same, and the nested structure allows the space of one transformer core to accommodate two transformer cores, thereby improving the power density.
[0044] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A multi-layer adjustable reluctance nested composite core transformer structure, characterized in that: It includes three sets of nested combined iron cores and two sets of winding structures relatively wound between the three sets of nested combined iron cores. The nested composite core comprises an outer core and an inner core, and magnetic filling materials are respectively arranged in the inner core of each nested composite core.
2. According to claim 1, a multi-layer adjustable reluctance nested composite core transformer structure is characterized in that: The three groups of nested composite cores are respectively a front layer composite core (1), a middle layer composite core (2), and a rear layer composite core (3). The front layer composite core (1) comprises a front layer outer ring core (8) and a front layer inner ring core (9), the middle layer composite core (2) comprises a middle layer outer ring core (11) and a middle layer inner ring core (12), and the rear layer composite core (3) comprises a rear layer outer ring core (14) and a rear layer inner ring core (15).
3. According to claim 2, a multi-layer adjustable reluctance nested composite core transformer structure is characterized in that: The magnetic filling material comprises a front layer inner ring filling (10) symmetrically arranged on the front layer inner ring core (9), a middle layer inner ring filling (13) symmetrically arranged on the middle layer inner ring core (12), and a rear layer inner ring filling (16) symmetrically arranged on the rear layer inner ring core (15).
4. According to claim 3, a multi-layer adjustable reluctance nested composite core transformer structure is characterized in that: The front layer inner ring filling (10) is located at the upper part of the front layer inner ring core (9), the middle layer inner ring filling (13) is located at the middle part of the middle layer inner ring core (12), and the rear layer inner ring filling (16) is located at the lower part of the rear layer inner ring core (15). Furthermore, the front layer inner ring filling (10) and the rear layer inner ring filling (16) can be symmetrical with respect to the middle layer inner ring filling (13).
5. The multi-layer adjustable reluctance nested composite core transformer structure according to claim 2 is characterized in that: There is an equal distance between the front layer composite iron core (1), the middle layer composite iron core (2), and the rear layer composite iron core (3).
6. The multi-layer adjustable reluctance nested composite core transformer structure according to claim 5, characterized in that: An upper fixing (4) is sleeved on the top of the middle outer ring core (11), and a lower fixing (17) is sleeved on the bottom of the middle outer ring core (11). The two sides of the upper fixing (4) and the lower fixing (17) are respectively fitted with the front layer composite iron core (1) and the rear layer composite iron core (3), so that the spacing between the front layer composite iron core (1), the middle layer composite iron core (2), and the rear layer composite iron core (3) is equal.
7. The multi-layer adjustable reluctance nested composite core transformer structure according to claim 2, characterized in that: The winding structure comprises an inner winding frame (5) tightly fitted and sleeved between three groups of nested combined iron cores, an inner winding (26) wound outside the inner winding frame (5), an outer winding frame (6) located outside the inner winding (26), and an outer winding (7) wound outside the outer winding frame (6).
8. The multi-layer adjustable reluctance nested composite core transformer structure according to claim 7, characterized in that: The inner side of the inner winding frame (5) is provided with a front layer fixing (18), a middle layer fixing (19), a rear layer fixing (20), a front fixing (21), and a rear fixing (22). The front layer fixing (18) is relatively arranged with two and is positioned relative to the front layer inner ring filling (10), the middle layer fixing (19) is relatively arranged with two and is positioned relative to the middle layer inner ring filling (13), and the rear layer fixing (20) is relatively arranged with two and is positioned relative to the rear layer inner ring filling (16). The front fixing (21) and the rear fixing (22) are respectively in contact with the outer sides of the front layer composite iron core (1) and the rear layer composite iron core (3).
9. The multi-layer adjustable reluctance nested composite core transformer structure according to claim 7, characterized in that: A plurality of heat dissipation holes (23) are distributed on the inner winding frame (5).
10. The multi-layer adjustable reluctance nested composite core transformer structure according to any one of claims 1 to 9, characterized in that: The magnetic filling material includes one or more of silicon steel, amorphous alloy or ferrite material.