Inductor, power converter and uninterruptible power supply

Abstract

The invention provides an inductor, a power converter and an uninterruptible power supply, the power converter comprises a first circuit board and a second circuit board, the first circuit board is provided with the inductor, the first inductor comprises a first pin and a second pin, the first pin is electrically connected with the first circuit board, and the second pin is electrically connected with the second circuit board. The first circuit board and the second circuit board are electrically connected through the inductor, the number of cables can be reduced, and the arc discharge risk is reduced.

Description

Technical Field

[0001] The present application relates to the field of power electronics, and in particular to an inductor, a power converter and an uninterruptible power supply. Background Art

[0002] With the high requirements for the density and efficiency of power electronic equipment, power electronic equipment generally includes multiple circuit boards, and the multiple circuit boards are mostly electrically connected through terminals. The pins of the inductor fixed to the circuit board need to be electrically connected to the terminals of the circuit board first, and then the terminals are electrically connected to the terminals of other circuit boards, resulting in too many circuit board terminals and low space utilization of power electronic equipment. Summary of the invention

[0003] The present application provides an inductor, a power converter and an uninterruptible power supply, which realize electrical connection between two circuit boards through the pins of the inductor, can save the number of terminals and the space of the circuit boards, and improve the energy density of the power converter.

[0004] In a first aspect, the present application provides a power converter, the power converter comprising a first circuit board and a second circuit board, the first circuit board being provided with an inductor, the first inductor comprising a first pin and a second pin, the first pin being electrically connected to the first circuit board, and the second pin being electrically connected to the second circuit board. The pins of the inductor are used as a medium for electrically connecting the first circuit board and the second circuit board, thereby avoiding the pins of the inductor being connected to the terminals of the first circuit board, and then connected to the terminals of the second circuit board through the terminals of the first circuit board, which can not only save the number of terminals, but also reduce the risk of insulation failure and arcing caused by the exposure of the copper busbar due to too many terminals.

[0005] In a possible implementation, the first circuit board and the second circuit board are arranged in parallel along the first direction, the first pin and the second pin are respectively arranged on two sides of the inductor that are arranged opposite to each other along the first direction, the length of the second pin is longer than the first pin, and the difference between the lengths of the second pin and the first pin is [5,20mm]. The second pin of the inductor is lengthened to facilitate the fixed connection between the second pin and the second circuit board, so that the assembly between the inductor and the second circuit board is simple and convenient.

[0006] In a possible implementation, the first circuit board and the second circuit board are arranged opposite to each other along the second direction, and the first pin and the second pin are respectively arranged on two sides of the inductor that are arranged opposite to each other along the second direction. Such a design is suitable for scenarios where the circuit boards are placed opposite to each other, and enriches the use scenarios of the inductor.

[0007] In a possible implementation, a first screw is provided on the first circuit board, a first pin is provided with a first screw hole, the first pin is screwed and connected with the first screw, a second screw is provided on the second circuit board, a second pin is provided with a second screw hole, the second pin is screwed and connected with the second screw, thereby realizing electrical connection between the first circuit board and the second circuit board. The electrical connection method of screws and screws can not only realize the electrical connection between the inductor and the circuit board, but also fix the inductor on the circuit board to prevent the inductor from loosening during assembly and then falling off the circuit board.

[0008] In a possible implementation, an insulating boss is provided around the periphery of the first pin and the second pin, and the insulating boss is fixedly connected to the base. On the one hand, the insulating boss protects the first pin and the second pin, preventing the first pin and the second pin from being exposed and causing arcing. On the other hand, the insulating boss can position the pins, fixing the first pin and the second pin so that they do not deviate from the mounting hole of the circuit board.

[0009] In a possible implementation, the inductor includes a base, a magnetic core, and a coil. The magnetic core includes an upper magnetic yoke, a middle column, and a lower magnetic yoke. The upper magnetic yoke and the lower magnetic yoke are respectively arranged on both sides of the middle column. The coil is wound on the middle column to form a winding. The base is provided with a hole. At least part of the lower magnetic yoke is located in the hole and fixedly connected to the inner wall of the hole. The lower magnetic yoke is directly sunk into the base through the hole on the base. The lower magnetic yoke and the inner wall of the hole can be connected by glue to achieve the fixation of the magnetic core on the base.

[0010] In a possible implementation, the inductor includes a stud and a cover plate, the cover plate is arranged above the upper yoke, the cover plate and the base are both provided with protrusions, the projections of the cover plate and the protrusions of the base in the arrangement direction of the cover plate and the base at least partially overlap, the protrusion of the cover plate is provided with a third screw hole, the protrusion of the base is provided with a fourth screw hole, and both ends of the stud are screwed and connected with the third screw hole and the fourth screw hole respectively. The base and the cover plate are fixedly connected by the stud, thereby enhancing the structural strength of the inductor.

[0011] In one possible implementation, insulating sheets are provided between the coil and the upper yoke, and between the coil and the upper yoke, to enhance the insulation performance between the coil and the upper yoke, and the lower yoke, and to prevent arcing due to insulation failure between the upper yoke, the lower yoke and the coil.

[0012] In a possible implementation, the inductor includes at least two magnetic cores arranged in parallel, and an insulating barrier is provided between at least two magnetic cores to ensure insulation performance between the magnetic cores.

[0013] In a possible implementation, the cross-section of the coil is rectangular, the length of the cross-section may be [5mm, 8mm], and the width may be [1.5mm, 3mm]. The use of a flat coil can increase the heat dissipation area of ​​the coil and prevent the inductor from failing due to excessive heat.

[0014] In a possible implementation, the turn spacing between the coils is [0.6, 2.5 mm] to increase the heat dissipation area of ​​the coils.

[0015] In a second aspect, the present application provides an uninterruptible power supply, which includes the above-mentioned power converter for connecting to an AC power supply, and the power converter is used to perform power conversion on the AC power output by the AC power supply and output it to a load.

[0016] In a third aspect, the present application provides an inductor, which includes a first pin and a second pin, wherein the first pin and the second pin are respectively used to electrically connect two circuit boards, and the two circuit boards are electrically connected through the inductor.

[0017] In a possible implementation, the first pin and the second pin are respectively arranged on two opposite sides of the inductor, the inductor is fixed to one of the two circuit boards, the first pin is electrically connected to one of the circuit boards, and the second pin is electrically connected to the other of the two circuit boards.

[0018] In one possible implementation, the inductor includes a base, a magnetic core, and a coil. The magnetic core includes an upper magnetic yoke, a middle column, and a lower magnetic yoke. The upper magnetic yoke and the lower magnetic yoke are respectively arranged on both sides of the middle column. The coil is wound on the middle column to form a winding. The base is provided with a hole. At least a portion of the lower magnetic yoke is located in the hole and is fixedly connected to the inner wall of the hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the structure of a power converter provided in an embodiment of the present application;

[0020] Figure 2 is a top view of an inductor provided in an embodiment of the present application;

[0021] Figure 3 is a schematic diagram of the structure of an inductor provided in an embodiment of the present application;

[0022] Figure 4 is another structural schematic diagram of an inductor provided in an embodiment of the present application;

[0023] Figure 5 is a structural explosion diagram of an inductor provided in an embodiment of the present application;

[0024] Figure 6 is a schematic diagram of the structure of another inductor provided in an embodiment of the present application;

[0025] Figure 7 yes Figure 6 An exploded diagram of the structure of another inductor is provided.

[0026] Reference numerals:

[0027] 100-first circuit board; 200-second circuit board; 300-inductor; 310-first pin; 311-first screw hole; 320-second pin; 321-second screw hole; 330-cover; 340-base; 341-first boss; 342-second boss; 343-hole; 350-magnetic core; 351-upper yoke, 352-middle column; 353-lower yoke; 360-coil; 370- Insulating sheet; 400-inductor; 410-first pin; 411-first screw hole; 420-second pin; 421-second screw hole; 430-cover; 431-first protrusion; 432-third screw hole; 440-base; 441-second protrusion; 442-fourth screw hole; 450-magnetic core; 451-upper yoke; 452-middle column; 453-lower yoke; 460-coil; 470-studding. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present application clearer, the embodiments of the present application will be further described in detail below in conjunction with the accompanying drawings. However, the example implementation can be implemented in various forms and should not be construed as being limited to the implementations set forth herein. The same reference numerals in the figures represent the same or similar structures, and thus their repeated description will be omitted. The words expressing position and direction described in the embodiments of the present application are all illustrated by taking the accompanying drawings as examples, but changes may be made as needed, and the changes made are all included in the scope of protection of the present application. The drawings of the embodiments of the present application are only used to illustrate the relative position relationship and do not represent the true proportion.

[0029] As the demand for high-power converters increases, power converters generally include multiple circuit boards, on which a variety of electronic devices such as switch tubes, capacitors, and inductors are arranged, and different power conversion functions are realized through different circuit topology designs. Multiple circuit boards are electrically connected through terminals. An inductor is a device used in a power converter to convert electrical energy into magnetic energy and store it. In practice, in order to realize the electrical connection between the inductor and the circuit board and the electrical connection between the circuit board and other circuit boards, the pins of the inductor need to be electrically connected to the terminals of the circuit board where it is located, and the terminals are then electrically connected to the terminals of other circuit boards to realize the electrical connection between the two circuit boards. This connection method will result in too many circuit board terminals and low space utilization of the power converter. In addition, a large number of terminals will have exposed copper bars, which increases the risk of arcing between the copper bars. Therefore, an embodiment of the present application provides a power converter, which uses the pins of the inductor to electrically connect the two circuit boards, reduce the size of the two circuit boards, save the number of terminals between the circuit boards, and improve the space utilization of the power converter.

[0030] Reference Figure 1 , the embodiment of the present application includes a power converter, the power converter includes a first circuit board 100 and a second circuit board 200, the first circuit board 100 is provided with an inductor 300, and the first circuit board 100 and the second circuit board 200 can be a printed circuit board (Printed Circuit Board, PCB). The inductor 300 includes a first pin 310 and a second pin 320, the first pin 310 is electrically connected to the first circuit board 100, and the second pin 320 is electrically connected to the second circuit board 200. That is to say, in this embodiment, the pins of the inductor 300 are used as a medium for the electrical connection between the first circuit board 100 and the second circuit board 200, thereby avoiding the pins of the inductor 300 first connecting the terminals of the first circuit board 100, and then connecting the terminals of the second circuit board 200 through the terminals of the first circuit board 100, thereby realizing the electrical connection between the first circuit board 100 and the second circuit board 200. The embodiment of the present application can not only save the number of terminals, but also reduce the risk of insulation failure and arcing caused by the bare copper busbar leakage due to too many terminals. The above-mentioned inductor 300 can be used in PFC circuits, and can also be used in inverter circuits or other power topologies.

[0031] It should be noted that the first pin 310 and the second pin 320 may be reserved portions of the winding of the inductor 300 , or external wires of the inductor 300 may serve as pins of the inductor 300 .

[0032] See also Figure 2 The top view of the inductor 300 is shown and Figure 3The three-dimensional structural diagram of the inductor 300 shown in FIG. 3 is shown. The first pin 310 is provided with a first screw hole 311. Accordingly, a screw is provided on the first circuit board 100. The first screw hole 311 of the first pin 310 is screwed and connected with the screw on the first circuit board 100, thereby realizing the electrical connection between the inductor 300 and the first circuit board 100, and fixing the inductor 300 on the first circuit board 100. The second pin 320 is provided with a second screw hole 321. Accordingly, a screw may be provided on the second circuit board 200. The second screw hole 321 of the second pin 320 is screwed and connected with the screw on the second circuit board 200. Thus, the electrical connection between the first circuit board 100 and the second circuit board 200 is realized. The electrical connection method using screws and screws can not only realize the electrical connection between the inductor 300 and the circuit board, but also fix the inductor 300 on the circuit board to prevent the inductor 300 from loosening during assembly and then falling off the circuit board.

[0033] It should be understood that in order to further strengthen the fixation of the inductor 300 on the circuit board, the base 340 of the inductor 300 can be fixed on the corresponding circuit board by using a fixing method such as glue dispensing or snap fastening.

[0034] In practical applications, there are multiple arrangements of the first circuit board 100 and the second circuit board 200. For example, when the first circuit board 100 and the second circuit board 200 are arranged side by side along the first direction, the inductor 300 is located at the edge of the second circuit board 200 close to the first circuit board 100. The first pin 310 and the second pin 320 can be located at two sides of the inductor 300 that are oppositely arranged along the first direction. Since the second pin 320 needs to extend to the second circuit board 200 to be electrically connected to the second circuit board 200, the length of the second pin 320 needs to be longer than the first pin 310. The difference between the length of the second pin 320 and the first pin 310 is [5,20mm], leaving a margin for the connection between the second pin 320 and the second circuit board 200.

[0035] In another example, the first circuit board 100 and the second circuit board 200 may also be arranged relative to each other along the second direction. In this case, the first pin 310 and the second pin 320 may be arranged at two sides relatively arranged along the second direction. In other words, the first pin 310 and the second pin 320 may be respectively located at two opposite sides in the height direction of the inductor 300, and then the first pin 310 and the second pin 320 are respectively fixed to the first circuit board 100 and the second circuit board 200 so that the first circuit board 100 and the second circuit board 200 are electrically connected through the inductor 300. In this case, the length between the first pin 310 and the second pin 320 is not limited.

[0036] Continue to refer Figure 4In the structural diagram of the inductor 300 shown in FIG. 3 , the first pin 310 and the second pin 320 are both surrounded by insulating bosses, and the insulating bosses are fixedly connected to the base 340 of the inductor 300. For example, a first boss 341 may be surrounded by the first pin 310, and a second boss 342 may be surrounded by the second pin 320. On the one hand, the insulating bosses protect the first pin 310 and the second pin 320, preventing the first pin 310 and the second pin 320 from being exposed and causing arcing. On the other hand, the insulating bosses can position the pins, fixing the first pin 310 and the second pin 320 so that they do not deviate from the mounting holes of the circuit board. The insulating boss can be a plastic boss, and the insulating boss can be integrally formed with the base 340 of the inductor 300. An opening can be provided at the bottom of the insulating boss corresponding to the screw hole of the pin, and the screw of the circuit board is screwed and connected with the screw hole of the pin through the opening. The pin of the inductor 300 is located in the groove, and the bottom of the groove can be fixed to the circuit board by means of glue, thereby enhancing the fixation of the inductor 300 to the circuit board.

[0037] The length and width of the first boss 341 are both greater than the length and width of the first pin 310 , and the length and width of the second boss 342 are both greater than the length and width of the second pin 320 .

[0038] It is understandable that the first boss 341 and the second boss 342 can be integrally formed with the base 340. The use of the integral forming process can not only enhance the fixed connection between the first boss 341 and the second boss 342 and the base 340, but also has a simple process and is easy to implement.

[0039] The base 340 may be made of plastic material, and the first boss 341 and the second boss 342 may also be made of plastic material, so as to reduce the weight of the base 340 and the bosses while ensuring the insulation performance of the base 340 , the first boss 341 and the second boss 342 , thereby achieving a lightweight design.

[0040] Continue to refer to Figure 5The exploded diagram of the structure of the inductor 300 shown. The inductor 300 includes a base 340, a magnetic core 350, a coil 360 and a cover plate 330. The magnetic core 350 includes an upper magnetic yoke 351, a middle column 352 and a lower magnetic yoke 353. The upper magnetic yoke 351 and the lower magnetic yoke 353 are respectively arranged on both sides of the middle column 352, and the coil 360 is wound on the middle column 352 to form a winding. The base is provided with a hole 343, and at least part of the lower magnetic yoke is located in the hole 343 and fixedly connected to the inner wall of the hole. The cover plate 330 and the base 340 are fixedly connected by a stud 470. In other words, the lower magnetic yoke of the magnetic core 350 is directly sunk into the hole 343 provided in the base 340 and is fixedly connected to the wall of the hole 343. The magnetic core 350 can be fixedly connected to the inner wall of the hole 343 by means of glue. Compared with the prior art method of fixing the inductor 300 to the circuit board with a rolled strip, directly fixing the magnetic core 350 to the base 340 can enhance the connection firmness of the magnetic core 350 to the base 340. The hole 343 can be a blind hole or a through hole. The cover plate 330 can be a layer of insulating paper wrapped around the outer surface of the upper magnetic yoke 351, or an insulating plate arranged above the upper magnetic yoke 351.

[0041] It should be noted that the current flow mode of the coil 360 can be single-phase, two-phase or three-phase, which is not limited in the embodiment of the present application.

[0042] In one example, an insulating sheet 370 is provided between the coil 360 and the upper yoke 351, and between the coil 360 and the lower yoke 353, replacing the practice of using a fiberglass tube sleeve to insulate the coil 360 and the base 340 in the prior art, to avoid uneven distribution of the coil 360 due to the thick fiberglass tube. The minimum turn spacing of the winding is effectively increased, thereby improving the heat dissipation capacity of the winding. Similarly, an insulating sheet 370 is provided between the coil 360 and the cover plate 330 to strengthen the insulation performance between the coil 360 and the cover plate 330, and to prevent arcing between the cover plate 330 and the coil 360 due to insulation failure.

[0043] In one example, the inductor 300 includes at least two magnetic cores 350 arranged in parallel, and an insulating barrier is provided between at least two magnetic cores 350 to ensure the insulation performance between the magnetic cores 350. The insulating barrier can be a plastic composite paper sheet, and the plastic barrier can be integrally formed with the base 340 or can be separated from the base 340.

[0044] The cross-sectional shape of the coil 360 is rectangular, with a length of [5mm, 8mm] and a width of [1.5mm, 3mm]. As a device with a relatively large heat generation in the power converter, the inductor 300 uses a flat coil 360 to increase the heat dissipation area of ​​the coil 360 and prevent the inductor 300 from failing due to excessive heat.

[0045] The turn spacing between the coils 360 is [0.6, 2.5 mm], and the turn spacing between the coils 360 is increased to increase the heat dissipation area of ​​the coils 360. The turn spacing can be set by glue dispensing, and the spacing between the coils 360 can be fixed by glue dispensing.

[0046] Figure 6 is a schematic diagram of the structure of another inductor 400 provided in an embodiment of the present application. Figure 7 for Figure 6 The exploded diagram of the structure of the inductor 400 shown. The inductor 400 includes a first pin 410 and a second pin 420. The first pin 410 is provided with a first screw hole 411, and the first screw hole 411 is electrically connected to the first screw on the first circuit board (not shown in the figure). The second pin 420 is provided with a second screw hole 421, and the second screw hole 421 is electrically connected to the second screw on the second circuit board (not shown in the figure), thereby avoiding the pin of the inductor 400 connecting to the terminal of the first circuit board, and then connecting to the terminal of the second circuit board through the terminal of the first circuit board. Not only can the number of terminals be saved, but also the risk of insulation failure and arcing caused by bare copper busbar leakage due to too many terminals can be reduced.

[0047] The inductor 400 includes a base 440, a magnetic core 450, and a coil 460. The magnetic core includes an upper magnetic yoke 451, a middle column 452, and a lower magnetic yoke 453. The upper magnetic yoke 451 and the lower magnetic yoke 453 are respectively arranged on both sides of the middle column 452. The coil 460 is wound around the middle column 452 to form a winding. The base 440 is provided with a hole (not shown in the figure). At least part of the lower magnetic yoke 453 is located in the hole and fixedly connected to the inner wall of the hole. Compared with the practice of fixing the inductor 400 to the circuit board with a rolled strip in the prior art, directly fixing the magnetic core 450 to the base 440 can enhance the firmness of the magnetic core 450 to the circuit board. The hole can be a blind hole or a through hole. The magnetic core 450 can be placed horizontally or vertically relative to the base 440.

[0048] The inductor 400 further includes a stud 470 and a cover plate 430. The cover plate 430 is disposed above the upper yoke 451. The cover plate 430 may also be wrapped around the outer periphery of the upper yoke 451. The material of the cover plate 430 is an insulating material, such as plastic, so as to enhance the insulation between the cover plate 430 and the upper yoke 451. The cover plate 430 and the base 440 are both provided with protrusions. The cover plate 430 is provided with a first protrusion 431, and the base 440 is provided with a second protrusion 441. The projections of the first protrusion 431 and the second protrusion 441 in the arrangement direction of the cover plate 430 and the protrusion at least partially overlap. The first protrusion 431 is provided with a third screw hole 432, and the second protrusion 441 is provided with a fourth screw hole 442. The two ends of the stud 470 are respectively screwed and connected with the third screw hole 432 and the fourth screw hole 442. The inductor 400 is prevented from falling off due to the inversion when it is inverted on the circuit board.

[0049] Based on the same inventive concept, the present application also provides an uninterruptible power supply, which includes the above-mentioned power converter, which is used to connect to an AC power supply, and the power converter is used to convert the AC power output by the AC power supply and output it to a load.

[0050] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A power converter, characterized in that: The power converter includes a first circuit board and a second circuit board. The first circuit board is provided with an inductor. The inductor includes a first pin and a second pin. The first pin is electrically connected to the first circuit board, and the second pin is electrically connected to the second circuit board.

2. The power converter according to claim 1, characterized in that: The first circuit board and the second circuit board are arranged side by side along a first direction, the first pin and the second pin are respectively arranged on two sides of the inductor that are opposite to each other along the first direction, the length of the second pin is longer than that of the first pin, and the difference in length between the second pin and the first pin is [5,20mm].

3. The power converter according to claim 1, characterized in that: The first circuit board and the second circuit board are arranged opposite to each other along a second direction, and the first pin and the second pin are respectively arranged on two sides of the inductor that are arranged opposite to each other along the second direction.

4. The power converter according to any one of claims 1 to 3, characterized in that: A first screw is provided on the first circuit board, the first pin is provided with a first screw hole, and the first pin is screwed together with the first screw; a second screw is provided on the second circuit board, the second pin is provided with a second screw hole, and the second pin is screwed together with the second screw.

5. The power converter according to claim 4, characterized in that: An insulating boss is disposed around the periphery of the first pin and the second pin, and the insulating boss is fixedly connected to the base of the inductor.

6. The power converter according to any one of claims 1 to 5, characterized in that: The inductor includes a base, a magnetic core, and a coil. The magnetic core includes an upper magnetic yoke, a middle column, and a lower magnetic yoke. The upper magnetic yoke and the lower magnetic yoke are respectively arranged on both sides of the middle column. The coil is wound on the middle column to form a winding. The base is provided with a hole. At least a part of the lower magnetic yoke is located in the hole and is fixedly connected to the inner wall of the hole.

7. The power converter according to claim 6, characterized in that: The inductor includes a stud and a cover plate, wherein the cover plate is arranged above the upper yoke, and the cover plate and the base are both provided with protrusions, and the projections of the protrusions of the cover plate and the protrusions of the base in the arrangement direction of the cover plate and the base at least partially overlap, the protrusion of the cover plate is provided with a third screw hole, and the protrusion of the base is provided with a fourth screw hole, and both ends of the stud are respectively screwed and connected with the third screw hole and the fourth screw hole.

8. The power converter according to claim 6 or 7, characterized in that: An insulating sheet is provided between the coil and the upper magnetic yoke, and between the coil and the upper magnetic yoke.

9. The power converter according to any one of claims 6 to 8, characterized in that: The inductor comprises at least two magnetic cores arranged in parallel, and an insulating barrier is arranged between at least two of the magnetic cores.

10. The power converter according to any one of claims 6 to 9, characterized in that: The cross-sectional shape of the coil is rectangular, the length of the cross-sectional shape is [5mm, 8mm], and the width of the cross-sectional shape is [1.5mm, 3mm].

11. The power converter according to claim 10, characterized in that: The turn spacing between the coils is [0.6, 2.5 mm].

12. An uninterruptible power supply, characterized in that: The uninterruptible power supply comprises a power converter as described in any one of claims 1 to 11, wherein the power converter is used to connect to an AC power source, and the power converter is used to convert the AC power output by the AC power source into power and then output it to a load.

13. An inductor, characterized in that: The inductor comprises a first pin and a second pin, wherein the first pin and the second pin are respectively used to electrically connect two circuit boards, and the two circuit boards are electrically connected through the inductor.

14. The inductor according to claim 13, characterized in that: The first pin and the second pin are respectively arranged on two opposite sides of the inductor, the inductor is fixed to one of the two circuit boards, the first pin is electrically connected to the one circuit board, and the second pin is electrically connected to the other circuit board.

15. The inductor according to claim 13 or 14, characterized in that: The inductor includes a base, a magnetic core, and a coil. The magnetic core includes an upper magnetic yoke, a middle column, and a lower magnetic yoke. The upper magnetic yoke and the lower magnetic yoke are respectively arranged on both sides of the middle column. The coil is wound on the middle column to form a winding. The base is provided with a hole. At least a part of the lower magnetic yoke is located in the hole and is fixedly connected to the inner wall of the hole.

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