A magnetic core air gap skeleton structure

Abstract

The utility model discloses a kind of magnetic core air gap skeleton structures, including skeleton, first magnetic core and second magnetic core being arranged in the inside of skeleton, coil assembly being wound on skeleton, preset gap h between first magnetic core and second magnetic core;The coil boss being arranged on skeleton separates the coil recess for coil assembly into first wire slot and second wire slot, the distance between top surface and bottom surface on coil boss is wire slot width A, wire slot width A is equal to 3~5 times interval preset gap h;The distance between the bottom of coil boss and the bottom of first coil recess is wire slot thickness B, wire slot thickness B is equal to 1.5~2.5 times preset gap h.The structure of multi-slot layering and small winding area in middle slot makes the winding turns number of middle slot close to air gap less, the layer far from air gap increases turns number, the skeleton of the utility model reduces the influence of magnetic core edge magnetic flux to winding, balances the eddy current loss of each layer, thereby reduce the eddy current loss of entire device, improve circuit conversion efficiency.

Description

Technical Field

[0001] This utility model relates to a magnetic core air gap skeleton structure, and more particularly to a magnetic core air gap skeleton structure that reduces the influence of magnetic core edge flux on winding and has low eddy current loss. Background Technology

[0002] Driven by the global shift towards a low-carbon energy structure and the upgrading of electronic devices towards "high efficiency and energy saving," the efficiency of inductors and transformers, as core components of "energy storage and transmission" in power systems, has become a key bottleneck restricting the overall system energy efficiency. From consumer electronics (such as fast charging for mobile phones and laptop power supplies) to industrial equipment (such as servo drives and energy storage converters) and new energy fields (such as photovoltaic inverters and vehicle power supplies), in almost all power conversion scenarios, the losses of inductors and transformers account for 20%-40% of the total system losses. Traditional devices have high core losses (eddy current and hysteresis losses) and winding losses (copper losses and eddy current losses), which not only cause a lot of energy waste, but also increase heat dissipation costs due to excessive heat generation, limit the power density of equipment, and even shorten the service life of the whole machine.

[0003] When an air gap is created in the magnetic core, as the main magnetic flux enters the air gap from the core, the sudden increase in air gap reluctance causes some of the flux to deviate from the original main magnetic path and diffuse into the space surrounding the air gap. This portion of flux is commonly referred to as edge flux. The larger the air gap, the greater the reluctance, the larger the space for flux diffusion, and the greater the intensity and coverage of the edge flux. This portion of flux passes through the winding, and according to the law of electromagnetic induction, alternating magnetic flux cutting the conductor induces a circular current, or "eddy current," within the conductor. The eddy current does work on the conductor's resistance, converting it into heat, forming "winding eddy current loss"—this loss does not exist in a core without an air gap and is an additional loss introduced by the air gap; moreover, the stronger the edge flux, the larger the eddy current, and the higher the loss.

[0004] Conventional bobbins do not consider avoiding the air gap in the magnetic core. When high-power circuits use inductors / transformers made with this type of bobbin, the large air gap in the core leads to high device losses, high temperature rise, and low circuit efficiency. In more serious cases, the high temperature can cause device burn-out. Dividing the large air gap in the core into several smaller air gaps to reduce edge flux effects and lower winding eddy current losses would increase costs. Increasing the grinding depth of the magnetic core requires adding magnetic pillars and air gap laminations, which also complicates the assembly process. Thickening the bottom of the bobbin (i.e., thickening the walls of the bobbin winding slots) to keep the windings away from the air gap in the core and reduce the impact of the air gap on the windings would also increase costs.

[0005] In view of the above-mentioned problems, this utility model urgently needs to provide a magnetic core air gap skeleton structure that overcomes the above problems. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a magnetic core air gap skeleton structure, which has the characteristics of reducing the influence of magnetic flux at the edge of the magnetic core on the winding and low eddy current loss.

[0007] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows: a magnetic core air gap skeleton structure, the innovation of which is: the magnetic core air gap skeleton structure includes a skeleton, a first magnetic core and a second magnetic core disposed inside the skeleton and stacked on top of each other, and a coil assembly wound on the skeleton. The central axis of the coil assembly is arranged parallel to the extension line of the length direction of the first magnetic core and the second magnetic core. A preset gap h is provided between the first magnetic core and the second magnetic core. The preset gap h is the air gap depth of the magnetic core column. The frame is provided with a first coil groove for the coil assembly to be placed in. The coil groove is provided with a coil boss extending to the position of the frame busbar. The coil boss divides the coil groove into a first groove and a second groove. The coil boss is directly opposite the junction of the first magnetic core and the second magnetic core. The distance between the top surface and the bottom surface of the coil boss is the groove width A. The groove width A is equal to 3 to 5 times the preset gap h. The coil boss is provided with a second coil groove for the coil assembly to be placed in. The distance between the bottom of the second coil groove and the bottom of the first coil groove is the groove thickness B. The groove thickness B is equal to 1.5 to 2.5 times the preset gap h.

[0008] Preferably, the coil boss and the skeleton are integrally injection molded.

[0009] Preferably, the coil boss is located in the middle of the skeleton along the length direction of the skeleton.

[0010] Preferably, at least one coil boss is provided on the skeleton along the length direction of the skeleton.

[0011] Preferably, at least one second coil groove is provided on the coil boss along the length direction of the skeleton.

[0012] Preferably, the second coil groove is provided with at least one groove baffle extending to the position of the skeleton busbar, and the groove baffle does not extend beyond the coil boss.

[0013] Preferably, when a groove baffle extending to the position of the skeleton busbar is provided on the second coil groove, the groove baffle divides the second coil groove into a third groove and a fourth groove.

[0014] Preferably, the groove baffle and the coil boss are integrally injection molded.

[0015] Preferably, the width A of the groove is equal to 4 times the preset gap h; the thickness B of the groove is equal to 1.5 times the preset gap h.

[0016] The advantages of this invention are as follows: This invention utilizes a multi-slot skeleton structure with the thickness of the middle slot being greater than that of the other slots to increase the distance between the winding and the air gap of the magnetic core. It also adopts a multi-slot layered structure with a small winding area in the middle slot, which results in fewer winding turns in the middle slot near the air gap and more turns in the layers farther from the air gap. The skeleton of this invention reduces the influence of the magnetic flux at the edge of the magnetic core on the winding, balances the eddy current losses of each layer, thereby reducing the eddy current losses of the entire device and improving the circuit conversion efficiency. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 This is a schematic diagram of a magnetic core air gap skeleton structure according to the present invention.

[0019] Figure 2 This is a schematic diagram of a magnetic core air gap skeleton structure (coilless assembly) according to the present invention.

[0020] Figure 3 This is a schematic diagram of magnetic flux diffusion at the edge of the magnetic core in a magnetic core air gap skeleton structure of this utility model.

[0021] In the diagram: 1-frame, 2-first magnetic core, 3-second magnetic core, 4-coil assembly, 5-coil boss, 6-first groove, 7-second groove, 8-groove baffle, 9-third groove, 10-fourth groove. Detailed Implementation

[0022] The magnetic core air gap skeleton structure of this utility model includes a skeleton 1, a first magnetic core 2 and a second magnetic core 3 stacked inside the skeleton 1, and a coil assembly 4 wound on the skeleton 1. The central axis of the coil assembly 4 is parallel to the extension line of the length direction of the first magnetic core 2 and the second magnetic core 3. A preset gap h is formed between the first magnetic core 2 and the second magnetic core 3, which is the air gap depth of the magnetic core. The skeleton 1 is provided with a first coil groove for the coil assembly 4 to be placed in. A coil boss 5 extending to the position of the generatrix of the skeleton 1 is provided on the coil groove. The coil boss 5 divides the coil groove into a first groove 6 and a second groove 7. The coil boss 5 is directly opposite the junction of the first magnetic core 2 and the second magnetic core 3. The distance between the top surface and the bottom surface of the coil boss 5 is the groove width A, which is equal to 3 to 5 times the preset gap h. The coil boss 5 is provided with a second coil groove for the coil assembly 4 to be placed in. The distance between the bottom of the second coil groove and the bottom of the first coil groove is the groove thickness B. The groove thickness B is equal to 1.5 to 2.5 times the preset gap h.

[0023] This invention utilizes a multi-slot skeleton structure with the middle slot having a higher thickness than the other slots to increase the distance between the winding and the air gap of the magnetic core. It also employs a multi-slot layered structure with a small winding area in the middle slot, resulting in fewer winding turns in the middle slot near the air gap and more turns in the layers further away from the air gap. The skeleton 1 of this invention reduces the influence of the magnetic flux at the edge of the magnetic core on the winding, balances the eddy current losses of each layer, thereby reducing the eddy current losses of the entire device and improving the circuit conversion efficiency.

[0024] like Figure 1 As shown, this invention divides the winding area of ​​the frame 1 into several slots (taking four slots as an example), and the wall thickness of the middle slot is thicker than that of the other two winding slots to avoid the influence of the magnetic core air gap on the winding. The design of the frame 1 follows the following principle: when the winding is 1.5 times the air gap value in the horizontal direction and 1.5 to 2.5 times the air gap value in the vertical direction, the influence of the edge magnetic flux on the winding is very small. For example, if the air gap depth of the magnetic core column is h, then the thickness B of the slot is 1.5 to 2.5h. Since the air gap has vertical up and down directions, the width A of the slot is 3 to 5h.

[0025] To ensure strength and reasonable layout, the coil boss 5 is integrally injection molded with the frame 1. The coil boss 5 is located in the middle of the frame 1 along its length. At least one coil boss 5 is provided on the frame 1 along its length.

[0026] To ensure strength and proper layout, at least one second coil groove is provided on the coil boss 5 along the length of the frame 1. At least one groove baffle 8 extending to the busbar of the frame 1 is provided on the second coil groove, and the groove baffle 8 does not extend beyond the coil boss 5. When the second coil groove has a groove baffle 8 extending to the busbar of the frame 1, the groove baffle 8 divides the second coil groove into a third groove 9 and a fourth groove 10. The groove baffle 8 and the coil boss 5 are integrally injection molded.

[0027] Usage and testing results show that when the slot width A is equal to 4 times the preset gap h, and the slot thickness B is equal to 1.5 times the preset gap h, the winding can avoid edge flux diffusion caused by the air gap in the magnetic core, thus achieving the best effect in reducing winding losses. Figure 3 It can be seen that since the wall thickness of the third slot 9 and the fourth slot 10 is B, the number of turns and layers of these two slots that are close to the preset gap h of the magnetic core air gap are reduced, while the number of turns and layers of the first slot 6 and the second slot 7 that are far away from the air gap are increased. In this way, the eddy current loss of each slot winding can be balanced, thereby reducing the eddy current loss of the entire device and improving the circuit conversion efficiency.

[0028] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples; within the framework of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in the details for the sake of brevity.

[0029] This utility model is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A magnetically shielded core air gap frame structure, characterized in that: The magnetic core air gap skeleton structure includes a skeleton, a first magnetic core and a second magnetic core disposed inside the skeleton and stacked on top of each other, and a coil assembly wound on the skeleton. The central axis of the coil assembly is parallel to the extension line of the length direction of the first magnetic core and the second magnetic core. A preset gap h is between the first magnetic core and the second magnetic core. The preset gap h is the air gap depth of the magnetic core column. The frame is provided with a first coil groove for the coil assembly to be placed in. The coil groove is provided with a coil boss extending to the position of the frame busbar. The coil boss divides the coil groove into a first groove and a second groove. The coil boss is directly opposite the junction of the first magnetic core and the second magnetic core. The distance between the top surface and the bottom surface of the coil boss is the groove width A. The groove width A is equal to 3 to 5 times the preset gap h. The coil boss is provided with a second coil groove for the coil assembly to be placed in. The distance between the bottom of the second coil groove and the bottom of the first coil groove is the groove thickness B. The groove thickness B is equal to 1.5 to 2.5 times the preset gap h.

2. The magnetically shielded core air gap frame structure as described in claim 1, characterized in that: The coil boss is integrally injection molded with the skeleton.

3. The magnetically shielded core air gap frame structure as described in claim 2, characterized in that: The coil boss is located in the middle of the skeleton along the length direction.

4. The magnetically shielded core air gap frame structure as described in claim 1, characterized in that: At least one coil boss is provided on the skeleton along the length direction of the skeleton.

5. The magnetically shielded core air gap frame structure as described in claim 1, characterized in that: At least one second coil groove is provided on the coil boss along the length direction of the skeleton.

6. The magnetically shielded core air gap frame structure as described in claim 1, characterized in that: The second coil groove is provided with at least one groove baffle extending to the position of the skeleton busbar, and the groove baffle does not extend beyond the coil boss.

7. The magnetically shielded core air gap frame structure as described in claim 6, characterized in that: When a groove baffle extending to the position of the skeleton busbar is provided on the second coil groove, the groove baffle divides the second coil groove into a third groove and a fourth groove.

8. The magnetically shielded core air gap frame structure as described in claim 6, characterized in that: The groove baffle and the coil boss are integrally injection molded.

9. The magnetically shielded core air gap frame structure as described in claim 1, characterized in that: The width A of the groove is equal to 4 times the preset gap h; the thickness B of the groove is equal to 1.5 times the preset gap h.

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