Inductor, AC / DC converter and power supply equipment

Abstract

The invention discloses an inductor, an AC / DC converter and power equipment, and relates to the technical field of electronic devices, the inductor comprises an annular magnetic core and a coil winding, the annular magnetic core is used for being installed in an external shell, and the annular magnetic core comprises a first winding area and a second winding area which are symmetrically arranged on the two sides of the annular magnetic core; the coil winding comprises at least one layer of inner-layer winding and at least one layer of outer-layer winding which are sequentially wound from inside to outside in the circumferential direction of the annular magnetic core, and the at least one layer of inner-layer winding and the at least one layer of outer-layer winding are connected in series; wherein the outer layer winding comprises multiple turns of outer layer coils, the multiple turns of outer layer coils are distributed in the first winding area and / or the second winding area, and the number of turns of the outer layer coils distributed in the first winding area is different from the number of turns of the outer layer coils distributed in the second winding area. The resonance point is adjusted by adjusting the number of turns of the outer layer coil distributed in the first winding area and the number of turns of the outer layer coil distributed in the second winding area, and noise is suppressed.

Description

Technical Field

[0001] The present application relates to the technical field of electronic devices, and in particular to an inductor, an AC / DC converter and a power supply device. Background Art

[0002] The characteristics of inductance determine that resonance points will appear at certain frequencies, which reduces the filtering performance and makes it impossible to effectively suppress noise at certain frequencies. When applied to power supply equipment, noise will not only affect the EMC performance of the power supply equipment, but also spread through the power line, causing interference to the electrical equipment. Summary of the invention

[0003] The main purpose of this application is to propose an inductor, an AC / DC converter and a power supply device, aiming to solve the technical problem of being unable to effectively suppress noise.

[0004] To achieve the above purpose, the present application proposes an inductor, comprising: An annular magnetic core, used for installation in an external shell, the annular magnetic core comprising a first winding area and a second winding area symmetrically arranged on two sides of the annular magnetic core; The coil winding comprises at least one inner winding and an outer winding wound in sequence from the inside to the outside along the circumference of the annular magnetic core, wherein at least one inner winding and the outer winding are connected in series with each other; wherein: The outer winding includes a plurality of turns of an outer coil, which are distributed in the first winding area and / or the second winding area, and the number of turns of the outer coil distributed in the first winding area is different from the number of turns of the outer coil distributed in the second winding area.

[0005] In one embodiment, the turns ratio of the coil turns distributed in the first winding area to the coil turns distributed in the second winding area is adjustable, and the size of the capacitance to ground formed between the outer winding and the shell is adjusted by adjusting the turns ratio, thereby adjusting the resonance point of the resonant circuit formed by the outer winding and the capacitance to ground, so that the resonance point is equal to the preset resonance point.

[0006] In one embodiment, the coil winding includes a layer of the inner layer winding, the inner layer winding includes multiple turns of the inner layer coil, the multiple turns of the inner layer coil are distributed in the first winding area and / or the second winding area, and the number of turns of the inner layer coil distributed in the first winding area is equal to the number of turns of the inner layer coil distributed in the second winding area.

[0007] In one embodiment, the coil winding includes at least two layers of inner windings, each layer of the inner winding includes multiple turns of inner coils, and the multiple turns of inner coils are distributed in the first winding area and / or the second winding area, and the number of turns of the inner coils distributed in the first winding area is equal to the number of turns of the inner coils distributed in the second winding area.

[0008] The present application also proposes an AC / DC converter, comprising a shell and an AC / DC conversion circuit located in the shell, the AC / DC conversion circuit comprising a common-mode filter, a rectifier bridge, a PFC inductor, a PFC switch source and an output filter capacitor electrically connected in sequence; the PFC inductor adopts the inductor as described above, and the outer winding of the inductor is asymmetrically distributed on the annular magnetic core to form a ground capacitance between the outer winding and the shell, the ground capacitance and the outer winding constitute a resonant circuit, and the resonance point of the resonant circuit and the low-impedance resonance point of the common-mode filter offset each other.

[0009] In one embodiment, the shell is grounded, the annular magnetic core is installed in the shell, and the distance between the shell and the outer winding is no more than twice the coil wire diameter.

[0010] In one embodiment, the multi-turn outer coil of the outer winding includes a first coil distributed in a first winding area and a second coil distributed in a second winding area, a first distance is formed between the first coil and the shell, and a second distance is formed between the second coil and the shell, and the first distance is smaller than the second distance.

[0011] The present application also provides a power supply device, which includes the AC / DC converter as described above.

[0012] Compared with the prior art, this application has the following beneficial effects: The annular magnetic core of the inductor comprises a first winding area and a second winding area symmetrically arranged on both sides of the annular magnetic core; the coil winding comprises at least one inner winding and an outer winding wound in sequence from the inside to the outside along the circumference of the annular magnetic core, and at least one inner winding and an outer winding are connected in series with each other; at least one inner winding and an outer winding are wound in sequence from the inside to the outside along the circumference of the annular magnetic core to reduce the mutual influence between the coils, improve the stability of the inductor, reduce the parasitic effect between layers, and improve the high-frequency performance; The first winding area and the second winding area are symmetrically arranged on both sides of the annular magnetic core, which can reduce electromagnetic interference and make the magnetic field distribution more uniform; In the technical solution of the present application, the outer winding includes multiple turns of an outer coil, which are distributed in a first winding area and / or a second winding area, and the number of turns of the outer coil distributed in the first winding area is different from the number of turns of the outer coil distributed in the second winding area, and is used to construct the inductor into an asymmetric winding structure of the coil, and adjust the capacitance to ground formed between the outer winding and the shell by different numbers of turns of the outer coil distributed in the first winding area and / or the second winding area, and adjust the size of the resonance point formed by the outer winding and the capacitance to ground, thereby changing the resonant frequency of the inductor, optimizing the inductor performance, and suppressing noise; it is also used to provide more precise frequency selection, achieve fine-tuning of the resonance point, effectively suppress noise, simplify the circuit, and reduce product costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0014] Figure 1 A schematic structural diagram of an embodiment of an inductor provided in the present application; Figure 2 A schematic structural diagram of another embodiment of the inductor provided in the present application; Figure 3 A cross-sectional view of an embodiment of an inductor provided in the present application; Figure 4 A cross-sectional view of another embodiment of the inductor provided by the present application; Figure 5 A cross-sectional view of another embodiment of the inductor provided by the present application; Figure 6 A cross-sectional view of another embodiment of the inductor provided by the present application; Figure 7 A schematic diagram of double-layer winding of the inductor provided in this application; Figure 8 A circuit schematic diagram of an embodiment of an AC / DC conversion circuit provided by the present application; Fig. 9 for Figure 8 Equivalent circuit diagram of Fig.10 The noise waveform diagram of the inductor provided for this application; Fig.11 Schematic diagram of the inductor provided for this application; Fig.12 The figure is a schematic diagram of an inductor according to the related art.

[0015] Description of Figure Numbers: 10. Inductor; 100, annular magnetic core; 101, first winding region; 102, second winding region; 200, coil winding; 210, inner winding; 211, third coil; 212, fourth coil; 220, outer winding; 221, first coil; 222, second coil; 300. Shell.

[0016] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0018] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0019] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0020] The characteristics of inductance determine that resonance points will appear at certain frequencies, which reduces the filtering performance and makes it impossible to effectively suppress noise at certain frequencies. When applied to power supply equipment, noise will not only affect the EMC performance of the power supply equipment, but also spread through the power line and interfere with the electrical equipment. Adjusting the resonance point can improve the inductance performance and suppress common mode noise.

[0021] To adjust the resonance point, refer to Figures 1 to 11 The present application proposes an inductor 10, an AC / DC converter and a power supply device, wherein the inductor 10 includes a toroidal core 100 and a coil winding 200. The toroidal core 100 is used to be installed in an external housing, and the toroidal core 100 includes a first winding area 101 and a second winding area 102 symmetrically arranged on both sides of the toroidal core 100. The coil winding 200 includes at least one inner winding 210 and an outer winding 220 wound in sequence from inside to outside along the circumference of the toroidal core 100, and at least one inner winding 210 and an outer winding 220 are connected in series.

[0022] The outer winding 220 includes multiple turns of outer coils, which are distributed in the first winding area 101 and / or the second winding area 102 , and the number of turns of the outer coils distributed in the first winding area 101 is different from the number of turns of the outer coils distributed in the second winding area 102 .

[0023] Specifically, the outer coil may be distributed only in the first winding area 101; or, the outer coil may be distributed only in the second winding area 102; or, different numbers of turns of the outer coil may be distributed in the first winding area 101 and the second winding area 102. The number of turns of the outer coil distributed in the first winding area 101 is different from the number of turns of the outer coil distributed in the second winding area 102, so as to construct the inductor 10 into an asymmetric winding structure of the coil. By distributing different numbers of turns of the outer coil in the first winding area 101 and / or the second winding area 102, the capacitance to ground formed between the outer winding 220 and the housing 300 (the parasitic capacitance between the winding and the housing 300) is adjusted, and the size of the resonance point of the resonant circuit formed by the outer winding 220 and the capacitance to ground is adjusted. The first winding area 101 and the second winding area 102 are symmetrically arranged on both sides of the annular magnetic core 100, which can reduce electromagnetic interference and make the magnetic field distribution more uniform.

[0024] In the application, the coil winding 200 includes at least one inner winding 210 and an outer winding 220 wound in sequence from the inside to the outside along the circumference of the annular magnetic core 100, and the multiple turns of the outer coil of the outer winding 220 are located on the same layer. The inductor 10 is wound in two or more layers, and the outermost outer winding 220 is wound in an asymmetric manner, so as to construct a high-impedance resonance point to the ground for the low-impedance resonance point of the common-mode filter when applied to AC / DC converters, AC / DC conversion circuits, and power supply equipment, so as to offset the low-impedance resonance point of the common-mode filter and suppress noise.

[0025] In the present application, the turns ratio of the coil turns distributed in the first winding area 101 to the coil turns distributed in the second winding area 102 is adjustable.

[0026] It can be understood that the outer coil of the outer winding 220 distributed in the first winding area 101 (and at least one inner coil of the inner winding 210 distributed in the first winding area 101) and the outer coil of the outer winding 220 distributed in the second winding area 102 (and at least one inner coil of the inner winding 210 distributed in the second winding area 102) are adjustable.

[0027] The size of the capacitance to ground formed between the outer winding 220 and the housing 300 is adjusted by adjusting the turns ratio, thereby adjusting the resonance point of the resonance circuit formed by the outer winding 220 and the capacitance to ground so that the resonance point is equal to the preset resonance point.

[0028] The turns ratio of the outer winding 220 distributed in the first winding area 101 and the outer winding 220 distributed in the second winding area 102 is adjustable, which is used to adjust the size of the ground capacitance formed between the outer winding 220 and the housing 300 during the process of adjusting the turns ratio, and then adjust the resonance point of the resonant circuit formed by the outer winding 220 and the ground capacitance, so that the resonance point of the resonant circuit formed by the outer winding 220 and the ground capacitance is equal to the preset resonance point, and more precise frequency selection can be provided without adding a level of inductance, and the fine adjustment of the resonance point can be achieved, and the corresponding filtering effect of using multi-level inductance can be achieved. Such a setting can also simplify the circuit and reduce product costs.

[0029] Optionally, the annular magnetic core 100 is made of magnetic material or magnetic conductive material, and the annular magnetic core can be optionally arranged into other regular or irregular annular structures such as a circular ring, a racetrack ring, etc.

[0030] When the annular magnetic core 100 is provided with a third winding area, a fourth winding area and multiple other winding areas in addition to the first winding area 101 and the second winding area 102, the multiple winding areas are distributed along the circumference of the annular magnetic core 100, and the sizes of the multiple winding areas may be the same or different; the multiple winding areas may be optionally arranged to be spaced apart from each other or to be connected; at least one other winding area in addition to the first winding area 101 and the second winding area 102 may be optionally arranged between the first winding area 101 and the second winding area 102; the specific arrangement may be based on actual conditions and is not limited here.

[0031] The coils of the inner winding 210 and the outer winding 220 have the same winding direction to form a magnetic field in the same direction. Specifically, the winding direction of the annular winding can be set to be wound from the inside of the ring to the outside of the ring, or from the outside of the ring to the inside of the ring. When the inner winding 210 includes multiple turns of inner coils and the outer winding 220 includes multiple turns of outer coils, the distances between the coils can be the same or different; the wire diameters of the inner coils and the outer coils can be the same or different; when multiple coil layers are provided from the inside to the outside of each winding area, the outermost coil is used as the outer winding 220, and the other coils except the outer winding 220 are used as the inner winding 210. The coils of the next layer can be optionally provided between at least two adjacent turns of the coils of the previous layer, or overlapped on the coils of the previous layer; the coil density of the coils of the next layer can be the same or different from the coil density, occupied space, etc. of the coils of the previous layer; the coil parameters of the coil winding 200 and the winding method of the coil can be set according to actual conditions, which are not limited here.

[0032] In some optional embodiments of the present application, the inner winding 210 and the outer winding 220 are wound by the same wire, one end of the wire is led out from the inside of the ring of the annular magnetic core 100, and the other end of the wire is led out from the outside of the ring of the annular magnetic core 100. The coil winding 200 includes at least one layer of inner winding 210 and outer winding 220 wound in sequence from the inside to the outside along the circumference of the annular magnetic core 100. Specifically, the outer winding 220 can be wound after the inner winding 210 is wound. This winding scheme can optimize the current distribution of the coil and improve the AC efficiency; it can also simplify the winding process and improve the winding efficiency.

[0033] Reference Fig.11 , this winding method of the present application can be used to adjust the resonance of the leakage inductance and capacitance of the housing 300 (that is, the common mode noise ground); there is also a winding method in the related art that requires the coils in different winding areas to be connected in series after the winding of the coils in different winding areas is completed separately, but Fig.12 As shown, this method can only adjust the resonance of inductance and parasitic capacitance and the problem of inconvenient adjustment, and cannot adjust the resonance of leakage inductance and capacitance of the housing 300 (that is, the common mode noise ground). Compared with this solution, the present application can not only effectively adjust the resonance of leakage inductance and capacitance of the housing 300 (that is, the common mode noise ground), but also make it more convenient to adjust the resonance point, and it is convenient to adjust the resonance point by adjusting the number of coil turns of the inner winding 210 and the outer winding 220, adjusting the ratio of the number of coil turns of different coils in the same layer, etc., so as to meet different usage requirements.

[0034] In the present application, the outer layer winding 220 includes an outer layer coil with a preset first number of turns. The outer layer coil of the outer layer winding 220 distributed in the first winding area 101 is defined as a first coil 221, and the outer layer coil of the outer layer winding 220 distributed in the second winding area 102 is defined as a second coil 222. The number of coil turns of the first coil 221 and the second coil 222 are not equal. By arranging coils with different numbers of turns in the first winding area 101 and the second winding area 102, respectively, to form an asymmetrically distributed winding structure, and by adjusting the coil turn ratio of the first coil 221 distributed in the first winding area 101 and the second coil 222 distributed in the second winding area 102 of the outer winding 220, the resonant frequency of the inductor 10 can be changed to avoid the resonant frequency of the inductor 10 from coinciding with the resonant vibration point of the common mode filter. When the low-resistance resonance point of the common mode filter appears at an undesirable frequency, the resonant frequency can be adjusted to avoid the resonance point to offset or suppress the low-resistance resonance point, thereby optimizing the performance of the inductor 10 and improving the stability when the inductor 10 is applied to power supply equipment or other application fields, thereby reducing interference to the equipment system.

[0035] Coils with different numbers of turns have different inductances and can produce different impedance characteristics. By reasonably designing the number of coil turns in the first winding area 101 and the second winding area 102, the filter response curve of the inductor 10 can be adjusted to match the impedance between the input and output ends of the inductor 10, so as to help reduce the influence of parasitic capacitance and optimize the signal transmission efficiency and high-frequency performance of the inductor 10, so as to avoid the inability to effectively suppress noise at certain frequencies, affecting the EMC (Electromagnetic Compatibility) performance of the power supply equipment and causing interference to the electrical equipment.

[0036] In the embodiment of the present application, the coil winding 200 includes at least one inner winding 210 .

[0037] When the coil winding 200 includes an inner winding 210, the inner winding 210 includes multiple turns of inner coils, and the multiple turns of inner coils are distributed in the first winding area 101 and / or the second winding area 102, and the number of turns of the inner coils distributed in the first winding area 101 is equal to the number of turns of the inner coils distributed in the second winding area 102.

[0038] When the coil winding 200 includes at least two layers of inner windings 210, each layer of inner windings 210 includes multiple turns of inner coils, and the multiple turns of inner coils are distributed in the first winding area 101 and / or the second winding area 102, and the number of turns of the inner coils distributed in the first winding area 101 is equal to the number of turns of the inner coils distributed in the second winding area 102.

[0039] It can be understood that the number of turns of the inner coil can be distributed only in the first winding area 101; or the number of turns of the inner coil can be distributed only in the second winding area 102; or the inner coil can be distributed in the first winding area 101 and the second winding area 102. When the inner coil is distributed in both the first winding area 101 and the second winding area 102, the number of turns of the inner coil distributed in the first winding area 101 is equal to the number of turns of the inner coil distributed in the second winding area 102.

[0040] The inner coil of the inner winding 210 distributed in the first winding area 101 is defined as a third coil 211, and the inner coil of the inner winding 210 distributed in the second winding area 102 is defined as a fourth coil 212. The inner winding 210 includes the third coil 211 distributed in the first winding area 101 and the fourth coil 212 distributed in the second winding area 102, and the number of coil turns of the third coil 211 and the fourth coil 212 are equal. The outer winding 220 serves as the outermost coil. The resonance point is adjusted by adjusting the number of turns of the outer winding 220 in the first winding area 101 and the second winding area 102. That is, when the number of turns of the third coil 211 and the fourth coil 212 of the inner winding 210 are equal, the coil turn ratio of the first coil 221 and the second coil 222 of the outer winding 220 is adjusted so that the resonant circuit of the outer winding 220 (that is, the first coil 221 and the second coil 222 of the outer winding 220) and the ground capacitance (parasitic capacitance between the outer winding 220 and the shell 300) has a set resonance point (preset resonance point).

[0041] For example, the outer winding 220 includes a first coil 221 distributed in the first winding area 101 and a second coil 222 distributed in the second winding area 102, and the inner winding 210 includes a third coil 211 distributed in the first winding area 101 and a fourth coil 212 distributed in the second winding area 102. Specifically, after the inner winding 210 is wound, the third coil 211 and the fourth coil 212 of the inner winding 210 are separated corresponding to the first winding area 101 and the second winding area 102; then the outer winding 220 is wound, and the first coil 221 and the second coil 222 of the outer winding 220 are separated corresponding to the first winding area 101 and the second winding area 102. This connection method can reduce the mutual influence between the coils, improve the stability of the inductor 10, reduce the interlayer parasitic effect, and improve the high-frequency performance.

[0042] When applied to power supply equipment and other application scenarios that need to process high-frequency signals or complex electromagnetics, in order to suppress the noise of noise sources such as power supplies and signal sources, and avoid noise interference with loads and other electrical equipment, the aforementioned winding connection scheme is used to enhance coupling, and the coils on the same layer act together on the noise, which can suppress common-mode noise and avoid introducing electromagnetic interference problems. In this way, more flexible current distribution and magnetic field control are allowed between different windings, which facilitates adjusting the resonance point according to the different requirements of actual application scenarios by adjusting the number of coil turns of the inner winding 210 and the outer winding 220, the ratio of the number of coil turns of different windings on the same layer, etc., to meet different usage requirements.

[0043] When a certain inductance is required, the number of turns of the coil winding 200 is fixed, that is, the number of turns of the inner winding 210 and the outer winding 220 is fixed.

[0044] When a certain inductance is required, the number of coil turns of the outer winding 220 is fixed, the number of coil turns of the first coil 221 distributed in the first winding area 101 and the number of coil turns of the second coil 222 distributed in the second winding area 102 are not equal, so that the coils in the first winding area 101 and the second winding area 102 are asymmetric, and by changing the number of coil turns distributed in the first winding area 101 and the second winding area 102, the size of the capacitance to the ground formed between the coil winding 200 (especially the outer winding 220) and the shell 300 is adjusted, thereby adjusting the resonance point of the resonant circuit formed by the outer coil and the capacitance to the ground.

[0045] For example, when the coil winding 200 is set to use a 60-turn coil, the inner winding 210 can be specifically set to have 40 turns, and the number of turns of the third coil 211 distributed in the first winding area 101 and the fourth coil 212 distributed in the second winding area 102 of the inner winding 210 are equal and both are 20 turns; the outer winding 220 has 20 turns, and the number of turns of the first coil 221 distributed in the first winding area 101 and the second coil 222 distributed in the second winding area 102 of the outer winding 220 are not equal. By adjusting the number of turns of the first coil 221 and the second coil 222 of the outer winding 220, the coil turns ratio of the first coil 221 and the second coil 222 is made to be 9:1, 8:2, 7:3, 6:4, etc., which can be specifically set according to actual conditions to achieve the adjustment of the resonance point, which will not be elaborated here.

[0046] In some specific embodiments of the present application, the number of turns of the inner winding 210 is not less than the number of turns of the outer winding 220. This configuration can simplify the structure of the inductor 10, facilitate the allocation of the outer winding 220 to different winding areas, and further facilitate the adjustment of the resonance point to suppress common mode noise.

[0047] As a specific embodiment of the present application, refer to Figures 8 to 10 In the figure, the greater the impedance of the PFC switch source or other noise source ZMOS+PFC to ground, the greater the impedance of the inductor Zfilter, and the smaller the noise on the AC / DC converter (AC / DC converter, converting AC power into DC power) ZLISN. At the resonance point of the inductor Zfilter, the impedance is reduced, and by constructing the anti-resonance point of the noise source ZMOS+PFC, high-impedance noise suppression is achieved at the low impedance point of the inductor Zfilter.

[0048] Specifically, the inductor 10 is connected to the measuring device, and the Fig.10 The noise waveform diagram, Fig.10 The noise waveform diagram is used to indicate that when the number of coil turns of the third coil 211 and the fourth coil 212 is equal (that is, the number of inner coil turns distributed in the first winding area 101 is equal to the number of inner coil turns distributed in the second winding area 102), and the ratio of the number of coil turns of the first coil 221 to the second coil 222 is 12:16 (that is, the ratio of the number of outer coil turns distributed in the first winding area 101 to the number of outer coil turns distributed in the second winding area 102 is 12:16), the anti-resonance point constructed by the asymmetric structure.

[0049] When the number of turns of the third coil 211 and the fourth coil 212 is equal, the outer winding 220 (i.e., the first coil 221 and the second coil 222 of the outer winding 220) and the ground capacitance (the parasitic capacitance formed between the outer winding 220 and the housing 300) have a set resonance point by adjusting the coil turn ratio of the first coil 221 and the second coil 222. Specifically, the number of turns can be preset and the number of turns of the outer coil of the outer winding 220 allocated to the first winding area 101 and the second winding area 102 can be adjusted according to different use requirements such as the actual required inductance, which is not limited here.

[0050] Reference Figure 1 The present application also proposes an AC / DC converter (AC / DC converter, converting AC power into DC power), the AC / DC converter includes a housing 300 and an AC / DC conversion circuit located in the housing 300, the AC / DC conversion circuit includes a common mode filter, a rectifier bridge, a PFC inductor (Power Factor Correction, power factor correction), a PFC switch source and an output filter capacitor electrically connected in sequence; the PFC inductor adopts the inductor 10 of the above embodiment, the outer winding 220 of the inductor 10 is asymmetrically distributed on the annular magnetic core 100, so that a ground capacitance is formed between the outer winding 220 and the housing 300, and the ground capacitance and the outer winding 220 form a resonant circuit, and the resonance point of the resonant circuit and the low-impedance resonance point of the common mode filter offset each other.

[0051] Since the AC / DC converter adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0052] It should be noted that when the inductor 10 itself is provided with the inductor 10 , the power supply device, etc. including the housing 300 , the housing 300 may not be separately provided on the AC / DC converter.

[0053] Reference Figures 2 to 7 In one embodiment, the housing 300 is grounded, and the annular magnetic core 100 is installed in the housing 300 .

[0054] The shell 300 is used to provide support and mechanical protection for the coil winding 200 and optimize the heat dissipation effect. The shell 300 is grounded to introduce common mode noise into the ground wire to reduce the interference of noise on the signal. It is also used to protect the coil winding 200. By forming a ground capacitor, the ability of the inductor 10 to suppress electromagnetic interference can be improved and electromagnetic compatibility can be optimized.

[0055] The closer the distance between the coil winding 200, especially the outer winding 220 (the outermost coil) of the coil winding 200 and the housing 300, the greater the capacitance to ground formed between the housing 300 and the coil winding 200; the farther the distance between the outer winding 220 of the coil winding 200 and the housing 300, the smaller the capacitance to ground formed between the housing 300 and the coil winding 200. By properly designing the distance between the housing 300 and the coil winding 200, the frequency characteristics of the inductor 10 can be adjusted to avoid being too far away to effectively suppress noise and too close to cause an increase in electromagnetic coupling and parasitic parameters, so as to minimize the influence of parasitic capacitance while achieving adjustment of the resonance point and optimize the performance of the inductor 10.

[0056] The annular magnetic core 100 is installed in the housing 300. Furthermore, the distance between the housing 300 and the outer winding 220 is not greater than twice the diameter of the coil wire. This is to avoid the housing 300 and the coil winding 200 being too far away from each other, which would affect the noise suppression capability of the inductor 10. It is also used to reduce the space occupied by the inductor 10 and reduce the production and processing costs.

[0057] In one embodiment, the multi-turn outer coil of the outer winding 220 includes a first coil 221 distributed in the first winding area 101 and a second coil 222 distributed in the second winding area 102, a first distance is formed between the first coil 221 and the shell 300, and a second distance is formed between the second coil 222 and the shell 300, and the first distance is smaller than the second distance.

[0058] In order to adjust the resonance point, the first distance can be made smaller than the second distance by optionally setting the number of coil turns of the first coil 221 distributed in the first winding area 101 among the multiple turns of the outer coil of the outer winding 220 to be greater than the number of coil turns of the second coil 222 distributed in the second winding area 102; or, by setting the multiple turns of the outer coil to be distributed in the first winding area 101, the first distance can be made smaller than the second distance; or, when the coil winding 200 includes at least two layers of inner windings 210, the number of coil layers of the inner coils distributed in the first winding area 101 among the at least two layers of inner windings 210 is set to be greater than the number of coil layers of the inner coils distributed in the second winding area 102, so that the first distance is smaller than the second distance; the specific settings can be made according to actual conditions and are not limited here.

[0059] In the related art, due to the leakage inductance to the ground between the coil winding 200 and the housing 300, this part of the leakage inductance will resonate with the capacitor. The adjustment of the resonance point of the present application is mainly for the leakage inductance formed between the coil winding 200 and the housing 300, and the capacitance to the ground formed between the outer winding 220 of the coil winding 200 and the housing 300. The resonance point is controlled by adjusting the number of coil turns of the inner winding 210 and the outer winding 220, and the inductance performance is optimized mainly by adjusting the coil turn ratio of the first coil 221 and the second coil 222 of the outer winding 220.

[0060] Taking a product with a fixed inductance requirement as an example, in order to ensure that the overall inductance remains unchanged, the number of coil turns of the coil winding 200 is limited.

[0061] As a specific implementation scheme of the present application, the coil winding 200 includes a coil with a preset number of turns. Specifically, the number of coil turns can be determined by simulation experiments, empirical formulas, etc. according to the requirements of the total inductance. Taking the determination by empirical formula as an example, specifically, by formula (wherein: N is the number of turns of the coil; A is the cross-sectional area of ​​the coil; μ is the magnetic permeability; l is the average length of the coil) etc. are calculated and determined, and the determined number of turns of the coil is used as the preset number of turns to adjust the resonance point through the coil winding 200 with a fixed number of turns of the coil.

[0062] The coil winding 200 includes at least one inner winding 210 and an outer winding 220 wound in sequence from the inside to the outside along the circumference of the annular magnetic core 100, with the outermost coil as the outer winding, and the other coils other than the outer winding as the inner winding, the third coil 211 of the inner winding 210 is wound in the first winding area 101, and the fourth coil 212 of the inner winding 210 is wound in the second winding area 102; the first coil 221 of the outer winding 220 is wound in the first winding area 101, and the second coil 222 of the outer winding 220 is wound in the second winding area 102, and the first winding area 101 and the second winding area 102 are symmetrically arranged on both sides of the annular magnetic core 100. When the total inductance of the inductor 10 is constant, it can be achieved by the following two or more methods: First, the coil winding 200 includes at least two layers of inner windings 210 .

[0063] When the inner winding 210 is set to have two layers, three layers or other multiple layers, the inner winding 210 is wound in sequence from the inside to the outside along the circumference of the annular magnetic core 100, and the number of turns of the inner coil of each layer of the inner winding 210 can be the same or different. According to the different winding areas, the inner winding is divided into a third coil 211 and a fourth coil 212, and the number of turns of the third coil 211 and the fourth coil 212 are equal. The outer winding includes a first coil 221 distributed in the first winding area 101 and a second coil 222 distributed in the second winding area 102. The first coil 221 and the second coil 222 are distributed in the same layer. The turns ratio of the first coil 221 of the outer winding 220 distributed in the first winding area 101 to the second coil 222 distributed in the second winding area 102 is adjustable. By adjusting the number of coil turns allocated in the first winding area 101 and the number of coil turns allocated in the second winding area 102, specifically, by adjusting the number of coil turns allocated to the first coil 221 and the second coil 222, the size of the ground capacitance formed between the outer winding 220 and the shell 300 is adjusted, and then the resonance point of the resonant circuit formed by the outer coil and the ground capacitance is adjusted, so as to achieve fine adjustment of the resonance point, so that the resonant circuit formed by the outer coil and the ground capacitance has a set resonance point (preset resonance point), and the low-impedance resonance point of the common mode filter is offset by the resonance point.

[0064] Reference Figures 3 to 5 , secondly: the coil winding 200 includes an inner winding 210 .

[0065] The coil winding 200 includes an inner winding 210 and an outer winding 220 which are sequentially wound from the inside to the outside along the circumference of the annular magnetic core 100 . The inner winding 210 and the outer winding 220 are connected in series. Among them, the inner winding 210 includes a third coil 211 distributed in the first winding area 101 and a fourth coil 212 distributed in the second winding area 102, and the number of turns of the third coil 211 and the fourth coil 212 arranged in the same layer are equal; the outer winding includes a first coil 221 distributed in the first winding area 101 and a second coil 222 distributed in the second winding area 102, and the first coil 221 and the second coil 222 are distributed in the same layer. The turns ratio of the first coil 221 of the outer winding 220 distributed in the first winding area 101 to the second coil 222 distributed in the second winding area 102 is adjustable, which is used to adjust the capacitance to ground formed between the outer winding 220 and the shell 300 (parasitic capacitance between the winding and the shell 300) during the process of adjusting the turns ratio, and adjust the size of the resonance point formed by the outer winding 220 and the capacitance to ground.

[0066] By adjusting the number of coil turns allocated to the first coil 221 and the second coil 222, the size of the capacitance to ground formed between the outer winding 220 and the shell 300 is adjusted, and then the resonance point of the resonant circuit formed by the outer coil and the capacitance to ground is adjusted, so as to achieve fine adjustment of the resonance point, so that the resonant circuit formed by the outer coil and the capacitance to ground has a set resonance point (preset resonance point), and the low-impedance resonance point of the common mode filter is offset by the resonance point.

[0067] Reference Figure 6 Thirdly, in other optional embodiments of the present application, it is also possible to set the coil winding 200 to include only the outer winding 220 .

[0068] In this embodiment, in order to change the overall capacitance to ground, the magnetic core is set to be replaceable and the number of coil turns is adjustable. By using toroidal magnetics with different dielectric constants, changing the number of coil turns of the outer winding 220, and further changing the number of coil turns of the first coil 221 allocated in the first winding area 101 and the second coil 222 allocated in the second winding area 102 of the outer winding 220, the resonance point can be adjusted, so that the resonant circuit formed by the outer coil and the capacitance to ground has a set resonance point, and the low-impedance resonance point of the common mode filter is offset by the resonance point.

[0069] The present application also proposes a power supply device, which includes the AC / DC converter as described in the above embodiment. The specific structure of the AC / DC converter refers to the above embodiment.

[0070] Specifically, the PFC switch source is used as a noise source, and the inductor 10 is applied to the AC / DC conversion circuit to reduce electromagnetic interference (EMI), especially the electromagnetic interference generated by the noise in the power supply equipment such as the switching action, current change and voltage fluctuation, and reduce the influence of these interferences on the power supply itself and the load and other electrical equipment. Specifically, the turns ratio of the number of coil turns of the outer winding 220 distributed in the first winding area 101 and the number of coil turns of the outer winding 220 distributed in the second winding area 102 is set to be adjustable, which is used to adjust the capacitance to ground formed between the outer winding 220 and the housing 300 (the parasitic capacitance between the winding and the housing 300) and adjust the size of the resonance point of the resonance circuit formed by the outer winding 220 and the capacitance to ground during the adjustment of the turns ratio. By adjusting the turns ratio of the number of coil turns of the outer winding 220 distributed in the first winding area 101 and the number of coil turns of the outer winding 220 distributed in the second winding area 102, the influence of noise on the load is reduced and the power quality is improved.

[0071] In one embodiment, the distance between the housing 300 and the outer winding 220 of the coil winding 200 is not greater than twice the diameter of the coil wire, so as to avoid the housing 300 and the coil winding 200 being too far apart, thereby affecting the noise suppression capability of the inductor 10, and also to reduce the space occupied by the inductor 10 and reduce the production and processing costs.

[0072] In some other embodiments of the present application, the housing 300 is grounded, and the annular magnetic core 100 is used to be installed in the housing 300. The housing 300 is used to provide support and mechanical protection for the coil winding 200 and optimize the heat dissipation effect. The housing 300 is grounded to introduce common mode noise into the ground line to reduce the interference of noise on the signal, and is also used to protect the coil winding 200. By forming a capacitance to the ground, the ability of the inductor 10 to suppress electromagnetic interference can be improved, and the electromagnetic compatibility can be optimized.

[0073] By reasonably designing the distance between the shell 300 and the coil winding 200, the frequency characteristics of the inductor 10 can be adjusted to avoid being too far away to effectively suppress noise, and being too close to cause an increase in electromagnetic coupling and parasitic parameters. This is used to minimize the impact of parasitic capacitance while achieving adjustment of the resonance point and optimize the performance of the inductor 10.

[0074] In one embodiment, the multi-turn outer coil of the outer winding 220 includes a first coil 221 distributed in the first winding area 101 and a second coil 222 distributed in the second winding area 102, a first distance is formed between the first coil 221 and the shell 300, and a second distance is formed between the second coil 222 and the shell 300, and the first distance is smaller than the second distance.

[0075] In order to adjust the resonance point, the first distance can be made smaller than the second distance by optionally setting the number of coil turns of the first coil 221 distributed in the first winding area 101 among the multiple turns of the outer coil of the outer winding 220 to be greater than the number of coil turns of the second coil 222 distributed in the second winding area 102; or, by setting the multiple turns of the outer coil to be distributed in the first winding area 101, the first distance can be made smaller than the second distance; or, when the coil winding 200 includes at least two layers of inner windings 210, the number of coil layers of the inner coils distributed in the first winding area 101 among the at least two layers of inner windings 210 is set to be greater than the number of coil layers of the inner coils distributed in the second winding area 102, so that the first distance is smaller than the second distance; the specific settings can be made according to actual conditions and are not limited here.

[0076] Since the power supply device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0077] The above description is only an exemplary embodiment of the present application and does not limit the patent scope of the present application. All equivalent structural changes made by using the contents of the present application specification and drawings under the technical concept of the present application, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present application.

Claims

1. An inductor, characterized in that: include: An annular magnetic core, used for installation in an external shell, the annular magnetic core comprising a first winding area and a second winding area symmetrically arranged on two sides of the annular magnetic core; The coil winding comprises at least one inner winding and an outer winding wound in sequence from the inside to the outside along the circumference of the annular magnetic core, wherein at least one inner winding and the outer winding are connected in series with each other; wherein: The outer winding includes a plurality of turns of an outer coil, which are distributed in the first winding area and / or the second winding area, and the number of turns of the outer coil distributed in the first winding area is different from the number of turns of the outer coil distributed in the second winding area.

2. The inductor according to claim 1, characterized in that The turns ratio of the coil turns distributed in the first winding area to the coil turns distributed in the second winding area is adjustable. The size of the capacitance to ground formed between the outer winding and the shell is adjusted by adjusting the turns ratio, and then the resonance point of the resonant circuit formed by the outer winding and the capacitance to ground is adjusted so that the resonance point is equal to the preset resonance point.

3. The inductor according to claim 1 or 2, characterized in that: The coil winding includes a layer of inner winding, and the inner winding includes multiple turns of inner coils. The multiple turns of inner coils are distributed in the first winding area and / or the second winding area, and the number of turns of the inner coils distributed in the first winding area is equal to the number of turns of the inner coils distributed in the second winding area.

4. The inductor according to claim 1 or 2, characterized in that: The coil winding includes at least two layers of inner windings, each layer of the inner winding includes multiple turns of inner coils, and the multiple turns of inner coils are distributed in the first winding area and / or the second winding area. The number of turns of the inner coils distributed in the first winding area is equal to the number of turns of the inner coils distributed in the second winding area.

5. An AC / DC converter, comprising a housing and an AC / DC conversion circuit located in the housing, wherein the AC / DC conversion circuit comprises a common mode filter, a rectifier bridge, a PFC inductor, a PFC switch source and an output filter capacitor electrically connected in sequence; characterized in that: The PFC inductor adopts the inductor as described in any one of claims 1 to 4, and the outer winding of the inductor is asymmetrically distributed on the annular magnetic core to form a ground capacitance between the outer winding and the shell, and the ground capacitance and the outer winding constitute a resonant circuit, and the resonance point of the resonant circuit and the low-impedance resonance point of the common mode filter offset each other.

6. The AC / DC converter according to claim 5, characterized in that: The shell is grounded, the annular magnetic core is installed in the shell, and the distance between the shell and the outer winding is no more than twice the coil wire diameter.

7. The AC / DC converter according to claim 5, characterized in that: The multi-turn outer coil of the outer winding includes a first coil distributed in a first winding area and a second coil distributed in a second winding area, a first distance is formed between the first coil and the shell, and a second distance is formed between the second coil and the shell, and the first distance is smaller than the second distance.

8. A power supply device, characterized in that: The power supply device comprises an AC / DC converter as claimed in any one of claims 5 to 7.

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