Inductor, power factor correction circuit, power supply system and electronic server

Abstract

The present application discloses an inductor, a power factor correction circuit, a power supply system and an electronic server. The inductor includes at least two first solid air gaps with different effective magnetic core cross-sectional areas Ae, and controls the inductance of the inductor component through the magnetic saturation states of the at least two first solid air gaps under different load conditions, so as to enable the inductor to flexibly provide a suitable inductance according to the load under various different load conditions, such that the switching frequency of the PFC circuit in the CRM mode will not be too high to cause excessive switching losses, nor too low to cause abnormal noises. At the same time, it can also confine the magnetic induction lines passing through the first solid air gap in the magnetic medium of the first solid air gap, thereby reducing the eddy current losses generated by the leakage magnetic flux in the surrounding coils and improving the overall working efficiency of the circuit.

Description

Technical Field

[0001] The present application relates to the technical field of power supplies, and particularly to an inductor, a power factor correction circuit, a power supply system, and an electronic server. Background Art

[0002] The power factor is mainly used to characterize the utilization degree of electric energy by electronic devices. The larger the power factor value is, the higher the electric energy utilization rate is. The technology used to improve the power factor of electrical equipment is called power factor correction (PFC) technology.

[0003] In a power supply circuit, in order to improve the power supply efficiency, the PFC circuit is widely used. There are three common operating modes of the PFC circuit, namely continuous conduction mode (CCM), discontinuous conduction mode (DCM), and current critical mode (CRM). In the PFC circuit in the CRM mode, the inductance of the PFC inductor is usually a fixed value according to the circuit design and cannot be flexibly adjusted according to different loads. Summary of the Invention

[0004] The present application provides an inductor, a power factor correction circuit, a power supply system, and an electronic server. The inductor can flexibly provide a suitable inductance according to the load under various working conditions of different loads, and improve the overall working efficiency of the circuit.

[0005] In a first aspect, the present application provides an inductor that can be applied to a PFC circuit. The inductor includes a coil winding and a magnetic core. The magnetic core includes a first outer magnetic core, a second outer magnetic core, and a winding unit. The first outer magnetic core and the second outer magnetic core are oppositely arranged. The winding unit is arranged between the first outer magnetic core and the second outer magnetic core. The coil winding is wound around the winding unit. The winding unit includes a magnetic core middle column and at least three air gaps distributed along a reference direction. The axis line of the magnetic core middle column is parallel to the reference direction. The at least three air gaps include at least two first solid air gaps and at least one air air gap. The circumferential surfaces of the at least two first solid air gaps are flush with the circumferential surface of the magnetic core middle column. The at least two first solid air gaps have at least two different effective magnetic core cross-sectional areas.

[0006] Wherein, the material of the first solid air gap is a magnetic conductive material, and the first solid air gap has a hollow area penetrating the first solid air gap along the reference direction.

[0007] Among them, the effective cross-sectional area of the magnetic core of the first solid air gap is less than 36000 / N square millimeters, where N is the number of turns of the coil in the coil winding and N is greater than or equal to 1.

[0008] In this application, the inductance of the inductor device is controlled by the magnetic saturation state of the at least two first solid air gaps under different load conditions, so that the inductor can flexibly provide an appropriate inductance according to the load under various different load conditions, preventing the switching frequency of the PFC circuit in the CRM mode from being too high, resulting in excessive switching losses, or too low, resulting in abnormal noise. At the same time, by confining the magnetic induction lines of the first solid air gap within the magnetic medium of the first solid air gap, the eddy current loss generated by the leakage magnetic flux in the surrounding coils can be reduced, improving the overall working efficiency of the circuit.

[0009] In a possible implementation, the middle column of the magnetic core includes a plurality of inner magnetic cores; at least two first solid air gaps and at least one air gap are located between the plurality of inner magnetic cores; the circumferential surfaces of the at least two first solid air gaps are flush with the circumferential surface of the middle column of the magnetic core, including the circumferential surfaces of the at least two first solid air gaps being flush with the circumferential surfaces of the plurality of inner magnetic cores.

[0010] Among them, the shapes and areas of the cross-sections of the plurality of inner magnetic cores perpendicular to the reference direction are the same.

[0011] Among them, the circumferential surface of the at least the first solid air gap is flush with the circumferential surface of the adjacent inner magnetic core.

[0012] In this application, by defining that the circumferential surface of the first solid air gap is flush with the circumferential surface of the inner magnetic core, on the one hand, it is beneficial for the coil winding to be wound around the winding unit; on the other hand, the magnetic induction lines passing through the first solid air gap can be confined within the magnetic medium of the first solid air gap, thereby reducing the eddy current loss generated by the leakage magnetic flux in the surrounding coils.

[0013] In a possible implementation, the middle column of the magnetic core is connected to the first outer magnetic core, and the air gap is formed between the middle column of the magnetic core and the second outer magnetic core; or, the middle column of the magnetic core is connected to the second outer magnetic core, and the air gap is formed between the middle column of the magnetic core and the first outer magnetic core.

[0014] In a possible implementation, the hollowed-out area is one or more; the shapes and areas of any two cross-sections of the same hollowed-out area perpendicular to the reference direction are the same.

[0015] Among them, the same first solid air gap has one or more of the hollowed-out areas.

[0016] Among them, the cross-section of the hollowed-out area refers to the planar figure obtained by intercepting the geometric body formed by the hollowed-out area with a certain plane.

[0017] In this application, by providing a hollowed-out area with the same shape and area for any two cross-sections perpendicular to the reference direction, the effective cross-sectional area of the magnetic core of the first solid air gap can be better controlled, thereby better designing the air gap in the inductor.

[0018] In a possible implementation, the projection of the hollowed-out area on the plane perpendicular to the reference direction is located within the outer boundary of the projection of the first solid air gap on this plane.

[0019] In this application, by restricting the projection of the hollowed-out area on the plane perpendicular to the reference direction to be within the outer boundary of the projection of the first solid air gap on this plane, it is possible to prevent the appearance of holes on the circumferential surface of the first solid air gap caused by the setting of the hollowed-out area, resulting in an increase in leakage magnetic flux.

[0020] In a possible implementation, the winding unit further includes a second solid air gap, and the material of the second solid air gap is an insulating material.

[0021] In this application, by placing a second solid air gap made of an insulating material between two inner magnetic cores, a segmented design of the inductor air gap can be achieved, thereby reducing the leakage magnetic flux caused by an overly large air gap and reducing eddy current losses.

[0022] In a possible implementation, the first outer magnetic core includes a first base and two first side posts, and the two first side posts are fixed to the first base and extend towards the second outer magnetic core; the second outer magnetic core includes a second base and two second side posts, and the two second side posts are fixed to the second base and extend towards the first outer magnetic core; the two first side posts and the two second side posts are correspondingly connected in a one-to-one manner.

[0023] In a second aspect, this application provides a power factor correction circuit, and the power factor correction circuit includes an inductor as described in any one of the possible implementations in the first aspect above.

[0024] In a third aspect, this application provides a power supply system, and the power supply system includes the power factor correction circuit as described in the second aspect above.

[0025] In a fourth aspect, this application provides an electronic server, and the electronic server includes the power supply system as described in the third aspect above.

[0026] It should be understood that the implementations and beneficial effects of the above-mentioned multiple aspects can be mutually referred to. Description of the Drawings

[0027] Figure 1 It is a schematic structural diagram of a power supply system in an embodiment;

[0028] Figure 2 It is a schematic structural diagram of an AC-DC conversion circuit in an embodiment;

[0029] Figure 3 Schematic diagram of an inductance magnetic core provided by an embodiment of the present application;

[0030] Figure 4 Structural schematic diagram of an inductance magnetic core provided by an embodiment of the present application;

[0031] Figure 5 Structural schematic diagram of a first solid air gap provided by an embodiment of the present application;

[0032] Figure 6 Structural schematic diagram of another first solid air gap provided by an embodiment of the present application;

[0033] Figure 7 Structural schematic diagram of another first solid air gap provided by an embodiment of the present application;

[0034] Figures 8a to 8b Front view of another inductance magnetic core provided by an embodiment of the present application;

[0035] Figure 9 Front view of another inductance magnetic core provided by an embodiment of the present application;

[0036] Figure 10a and Figure 10b Front view of another inductance magnetic core provided by an embodiment of the present application;

[0037] Figure 11 Front view of another inductance magnetic core provided by an embodiment of the present application;

[0038] Figure 12 Front view of another inductance magnetic core provided by an embodiment of the present application. Detailed implementation manners

[0039] The embodiments of the present application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Those of ordinary skill in the art can understand that with the development of technology and the emergence of new scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present application.

[0040] In the embodiments of the present application, terms such as "first" and "second" do not have a logical or temporal dependency relationship, nor do they limit the quantity and execution order. It should also be understood that although the following description uses terms such as first and second to describe various elements, these elements should not be limited by the terms. These terms are only used to distinguish one element from another.

[0041] In the embodiments of the present application, the term "at least one" means one or more, and the term "a plurality" means two or more than two.

[0042] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. As used in the specification and claims of the present application, the singular forms "a", "an", "the", "above-mentioned", "said", and "this" are also intended to include expressions such as "one or more", unless the context clearly indicates otherwise.

[0043] Reference to "one embodiment" or "some embodiments" etc. described in this specification means that a specific feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of the present application. Thus, the statements "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "comprising", "including", "having" and their variants all mean "including but not limited to", unless otherwise specifically emphasized.

[0044] The inductance magnetic core and inductor device provided by the embodiments of the present application are applied to the PFC circuit in the CRM mode. Therefore, it can be understood that the PFC circuits mentioned in this application document all refer to the PFC circuits in the CRM mode.

[0045] It can be understood that the PFC circuit is widely used in the power supply system to improve the power factor of the circuit and reduce the interference and pollution of the power supply system to the power grid.

[0046] As Figure 1 shown, Figure 1 FIG. 19 is a schematic structural diagram of a power supply system in an embodiment. The power supply system 100 includes an AC-DC conversion circuit 110, a DC voltage conversion circuit 120, and a control circuit 130.

[0047] Among them, the AC-DC conversion circuit 110 is used to receive the alternating current provided by the AC power supply 200, convert the alternating current into direct current, and finally send the direct current to the DC voltage conversion circuit 120.

[0048] The DC voltage conversion circuit 120 is used to perform step-up or step-down processing on the direct current delivered by the AC-DC conversion circuit 110, and send the DC voltage after the conversion processing to the DC load 300.

[0049] The control circuit 130 is used to control the AC-DC conversion circuit 110 and the DC voltage conversion circuit 130 to perform current processing.

[0050] Among them, the DC load 300 may include DC power-consuming devices such as servers, data centers, base stations, or household appliances. The power supply system is used to supply power to the DC power-consuming devices in the corresponding power-consuming scenarios of the above-mentioned DC power-consuming devices.

[0051] As Figure 2 shown, Figure 2 is Figure 1 a schematic structural diagram of the AC-DC conversion circuit in the shown embodiment. As Figure 2 shown, the AC-DC conversion circuit 110 includes a rectifier circuit 111 and a PFC circuit 112; the input end of the AC-DC conversion circuit 110 is connected to the AC power supply 200, and the output end is connected to the direct voltage conversion circuit 120. Among them, the AC-DC conversion circuit 110 is also provided with an analog ground (AGND). The input end of the rectifier circuit 111 is connected to the AC power supply 200, and the output end is connected to the PFC circuit 112. Among them, the rectifier circuit 111 includes four diodes D1, D2, D3, and D4, and each diode can allow alternating current to flow through when flowing forward and block the current when the current flows backward. The PFC circuit 112 includes an inductor L1, a capacitor C, a diode D0, and a MOSFET switch Q1. Among them, one end of the inductor L1 is connected to the output end of the rectifier circuit 111 for receiving the output current of the rectifier circuit 111, and the other end of the inductor L1 is connected to the anode of the diode D0 and one end of the MOSFET switch Q1. The cathode of the diode D0 is connected to the input end of the DC voltage conversion circuit 120 and the capacitor C. It can be understood that the inductor L1 stores energy when the MOSFET switch Q1 is turned on, and charges the capacitor C through the diode D0 with the energy stored when the MOSFET switch Q1 is turned off.

[0052] The applicant's research found that there are the following implementation methods for the PFC inductor. One is that for all load conditions, the inductance value of the inductor device in the PFC circuit is a fixed value designed according to the maximum operating current of the circuit, which cannot meet the requirements of providing different inductance values for different load conditions; the other is to set a variable air gap to achieve variable inductance, but the current inductance design with variable inductance can only change the inductance value once when the load condition changes. Therefore, there is a problem that the change of the inductance is not flexible enough.

[0053] Therefore, there is an urgent need for an inductor that can provide different inductance values under different load conditions to improve the efficiency of the power supply.

[0054] The embodiment of the present application provides an inductor that can provide different inductance values under different load conditions, thereby improving the overall working efficiency of the circuit.

[0055] Figure 3Schematic diagram of an inductor provided by an embodiment of the present application, as Figure 3 shown, the inductor includes a magnetic core 10 and a coil winding 20; the magnetic core 10 includes a first outer magnetic core 1, a second outer magnetic core 2 and a winding unit R; the coil winding 20 is disposed around the winding unit R, the first outer magnetic core 1 and the second outer magnetic core 2 are oppositely disposed along a reference direction, and the winding unit R is disposed between the first outer magnetic core 1 and the second outer magnetic core 2.

[0056] Wherein, the reference direction includes the direction from the first outer magnetic core 1 to the second outer magnetic core 2, and also includes the direction from the second outer magnetic core 2 to the first outer magnetic core 1.

[0057] Specifically, the first outer magnetic core 1 includes a first base 11 and two first side posts 12, the two first side posts 12 are fixed on both sides of the first base 11, and the two first side posts 12 extend towards the second outer magnetic core 2; correspondingly, the second outer magnetic core 2 includes a second base 21 and two second side posts 22, the two second side posts 22 are fixed on both sides of the second base 21, and the two second side posts 22 extend towards the first outer magnetic core 1; the two first side posts 12 and the two second side posts 22 are correspondingly connected.

[0058] Optionally, the first base 11 and the two first side posts 12 are of an integral structure, the second base 21 and the two second side posts 22 are of an integral structure, and the two first side posts 12 and the two second side posts 22 can be connected and fixed by pasting or stacking.

[0059] Optionally, the first side post 12 and the corresponding second side post 22 are of an integral structure, the first side post 12 and the first base 11 can be connected and fixed by pasting or stacking, and the second side post 22 and the second base 21 can be connected and fixed by pasting or stacking.

[0060] It can be understood that Figure 2 the first outer magnetic core and the second outer magnetic core shown in

[0061] are only examples, and the first outer magnetic core and the second outer magnetic core can be any one of EE type, RP type, EQ type and RM type.

[0062] Figure 4 For Figure 3 the structural schematic diagram of the inductor provided by the shown embodiment, for the convenience of display, the coil winding 20 of the inductor is hidden in the figure. As Figure 3As shown, the winding unit R includes a central magnetic core column 30 and at least three air gaps. Specific examples of the at least three air gaps are at least two first solid air gaps 41 and at least one air gap 42. The axis line of the central magnetic core column 30 is parallel to the above reference direction, and the at least three air gaps are distributed along the reference direction. Continuing to refer to Figure 4 , both ends of the central magnetic core column 30 along the reference direction are respectively fixed to the first base 11 and the second base 21. The central magnetic core column 30 can be divided into at least four segments along the reference direction to form at least four inner magnetic cores (the first inner magnetic core 31, the second inner magnetic core 32, the third inner magnetic core 33, and the fourth inner magnetic core 34). Among them, the first inner magnetic core 31 is fixed to the first base 11, and the first inner magnetic core 31 and the first base 11 are of an integrated structure; the fourth inner magnetic core 34 is fixed to the second base 21, and the fourth inner magnetic core 34 and the second base 21 are of an integrated structure. Among them, the second inner magnetic core 32 and the third inner magnetic core 33 are arranged between the first inner magnetic core 31 and the fourth inner magnetic core 34.

[0063] In Figure 4 In a specific example, the air gap 42 is arranged between the first inner magnetic core 31 and the second inner magnetic core 32, and the two first solid air gaps 41 are arranged between the second inner magnetic core 32 and the third inner magnetic core 33, and between the third inner magnetic core 33 and the fourth inner magnetic core 34. The first solid air gap 41 and the air gap 42 here can achieve the segmentation of the central magnetic core column 30 and reduce the eddy current loss generated by the coil winding wound on the central magnetic core column 3. By arranging the air gap 42, a larger current is required for the magnetic core to reach the magnetic saturation state, which can prevent magnetic saturation to a certain extent; at the same time, the positive interaction force between the magnetic domains of the inductive magnetic core is weakened as a whole, and the residual magnetism is reduced.

[0064] In other embodiments of the present application, the air gap 42 can be arranged between the third inner magnetic core 33 and the fourth inner magnetic core 34, and the two first solid air gaps 41 can be respectively arranged between the first inner magnetic core 31 and the second inner magnetic core 32, and between the second inner magnetic core 32 and the third inner magnetic core 33. It can be understood that the first solid air gap 41 and the air gap 42 can be arranged between any two adjacent inner magnetic cores.

[0065] Among them, the material of the first solid air gap 41 can be the same as that of the central magnetic core column 30 or can be a different magnetic conductive material, and can specifically be other iron oxide mixtures such as ferromagnets, ferromagnetic powders, or iron silicon aluminum.

[0066] Among them, the first solid air gap 41 has a hollow area Q penetrating the first solid air gap 41 along the reference direction, and specifically can be as Figure 5 shown Figure 5Schematic diagram of the structure of a first solid air gap 41 provided by an embodiment of the present application. In this embodiment, the middle column of the magnetic core is cylindrical with a diameter of 30, the first solid air gap 41 is cylindrical, and the hollowed-out area Q is also cylindrical. The hollowed-out area Q is located at the center of the first solid air gap 41; the axis lines of the hollowed-out area Q, the first solid air gap 41, and the middle column 30 of the magnetic core are collinear.

[0067] Optionally, the hollowed-out area Q is arranged at the center of the first solid air gap 41.

[0068] Optionally, the shapes and areas of any two cross-sections of the hollowed-out area Q perpendicular to the reference direction are the same. Here, the cross-section of the hollowed-out area Q refers to the planar figure obtained by intercepting the geometric body formed by the hollowed-out area Q with a certain plane. In other words, in any two cross-sections of the first solid air gap 41 corresponding to the hollowed-out area Q perpendicular to the reference direction, the shapes and areas of the regions occupied by the hollowed-out area Q are the same.

[0069] It can be understood that by setting the shapes and areas of any two cross-sections of the hollowed-out area Q perpendicular to the reference direction to be the same, it is more convenient to control the effective cross-sectional area Ae of the magnetic core of the first solid air gap 41, thereby better designing the air gap in the inductor.

[0070] By arranging the hollowed-out area Q at the center of the first solid air gap 41, the magnetic flux lines passing through the first solid air gap 41 can be evenly distributed in the magnetic medium of the first solid air gap 41, so that the magnetic induction intensities of all parts of the first solid air gap 41 increase synchronously with the increase of the current until the first solid air gap 41 is completely in the magnetic saturation state. The synchronous change of the magnetic induction intensities of all parts of the first solid air gap 41 can prevent the magnetic medium of the first solid air gap 41 from being unevenly distributed in the magnetic field, so that some magnetic media reach the magnetic saturation state even under the condition of light load, and then leakage magnetic flux is generated.

[0071] It can be understood that the hollowed-out area Q can also be arranged in a non-center area of the first solid air gap 41, and the hollowed-out area does not communicate with the outer boundary of the first solid air gap. By setting a hollowed-out area with a uniform shape inside the outer boundary of the solid air gap, eddy current losses generated by leakage magnetic flux in the surrounding coil at the solid air gap boundary can be prevented, thereby improving the working efficiency under light load.

[0072] Optionally, the number of the hollowed-out areas Q is one or more; when the number of the hollowed-out areas Q is multiple, the sizes of the multiple hollowed-out areas Q can be different. Specifically, the same first solid air gap 41 can have one or more hollowed-out areas Q. As Figure 6 shown, the first solid air gap 41 is cylindrical, and the hollowed-out areas Q1 and Q2 are cylindrical with different diameters.

[0073] It can be understood that when the shapes of the multiple hollow regions Q are the same, the calculation of the effective cross-sectional area of the magnetic core of the first solid air gap 41 and the air gap design of the inductor are more convenient.

[0074] Optionally, the hollow region Q and the first solid air gap 41 can have different shapes.

[0075] Among them, the circumferential surface of the first solid air gap 41 is flush with the circumferential surface of the middle column 30 of the magnetic core. That is to say, the radial dimension of the first solid air gap 41 perpendicular to the reference direction is equal to the radial dimension of the middle column 30 of the magnetic core perpendicular to the reference direction. It can be understood that in some embodiments where the middle column of the magnetic core is not cylindrical, the cross-section of the first solid air gap 41 perpendicular to the reference direction is the first cross-section, and the cross-section of the middle column 30 of the magnetic core perpendicular to the reference direction is the second cross-section, and the shapes and outer boundaries of the first cross-section and the second cross-section are the same.

[0076] In a possible implementation, when the middle column 30 of the magnetic core includes multiple inner magnetic cores, the shapes and areas of the cross-sections of the multiple inner magnetic cores perpendicular to the reference direction are the same; further, when the at least two first solid air gaps 41 and the at least one air gap 42 are located between the multiple inner magnetic cores, the circumferential surfaces of the at least two first solid air gaps are flush with the circumferential surfaces of the multiple inner magnetic cores.

[0077] Among them, the radial dimensions of the multiple inner magnetic cores perpendicular to the reference direction are the same.

[0078] By designing the circumferential surface of the first solid air gap 41 to be flush with the circumferential surface of the middle column 30 of the magnetic core, on the one hand, it can make the circumferential surface of the first solid air gap 41 and the circumferential surface of the middle column 30 of the magnetic core flat, which is beneficial to the coil winding 20 to be wound around the winding unit R; on the other hand, it can also confine the magnetic induction lines passing through the first solid air gap 41 in the magnetic medium of the first solid air gap 41, thereby reducing the eddy current loss generated by the leakage magnetic flux in the surrounding coils.

[0079] In a possible implementation, the projection of the hollow region Q in the plane perpendicular to the reference direction is located within the outer boundary of the projection of the first solid air gap 41 where it is located in this plane.

[0080] By restricting the projection of the hollow region in the plane perpendicular to the reference direction to be within the outer boundary of the projection of the first solid air gap in this plane, it is possible to prevent the hollow region from causing holes in the circumferential surface of the first solid air gap, resulting in an increase in leakage magnetic flux.

[0081] Among them, the at least two first solid air gaps 41 have at least two effective cross-sectional areas of the magnetic core, that is, the winding unit R at least includes two first solid air gaps 41 with different effective cross-sectional areas of the magnetic core, and the number of each first solid air gap 41 is at least one. The effective cross-sectional area of the magnetic core refers to the effective cross-sectional area through which the magnetic flux passes. Please refer to againFigure 5 , Figure 5 The shaded part in Figure 5 is the effective cross-sectional area of the magnetic core of the first solid air gap 41, and the cross-section corresponding to this effective cross-sectional area of the magnetic core is perpendicular to Figure 5 the reference direction shown.

[0082] It should be noted that the smaller the effective cross-sectional area of the magnetic core of the first solid air gap 41, the easier it is for the magnetic flux to reach the magnetic saturation state.

[0083] In an achievable manner, the effective cross-sectional area of the magnetic core of the first solid is less than 36000 / N square millimeters, where N is the number of turns of the coil in the coil winding 20 and N is greater than or equal to 1. With such a setting, it is possible to ensure that the first solid air gap is still in an unsaturated state as much as possible under a light load condition, such as under a 40% load condition; at this time, there is only an air gap in the inductor, and the inductance is in the maximum state. As the load gradually increases, the solid air gap is continuously saturated and acts as an air gap, and the overall air gap amount of the inductor gradually increases, causing the inductance to gradually decrease.

[0084] It should be noted that after the shape of the coil winding and the magnetic core of the inductor are selected, with the number of turns of the inductor coil and the effective cross-sectional area of the magnetic core remaining unchanged, the magnitude of the inductance of the inductor is inversely proportional to the size of the air gap.

[0085] Under different load conditions, the magnitude of the current in the inductor is different, so the saturation degrees of the middle column 30 of the magnetic core and the first solid air gap 41 are different, and the saturation degrees of the first solid air gaps 41 with different effective cross-sectional areas of the magnetic core are also different. Under a light load condition, the current in the coil winding 20 of the inductor is relatively small, and the magnetic flux of the first solid air gap 41 does not reach saturation. The first solid air gap 41 can play a similar magnetic conduction role as the inner magnetic core (31, 32, 33). At this time, the air gap of the entire middle column 30 of the magnetic core is the air gap 42, the air gap is small, and the inductance is large, thereby reducing the switching frequency of the switching tube in the PFC circuit and reducing the switching loss. As the load gradually increases, the current in the coil winding 20 of the inductor gradually increases, and the at least two first solid air gaps 41 are saturated one by one according to the effective cross-sectional area of the magnetic core from small to large. For the entire middle column 30 of the magnetic core, its air gap is composed of the air gap 42 and the first solid air gap 41 that reaches the magnetic saturation state. Therefore, as the first solid air gap 41 that reaches the magnetic saturation state continuously increases, the overall air gap of the middle column 30 of the magnetic core also increases; in the heavy load / full load scenario, after all the first solid air gaps 41 are fully saturated, the first solid air gap 41 acts as an air gap. As the current in the coil winding of the inductor increases, the inductance gradually decreases. At this time, the total air gap size of the magnetic core 10 is equivalent to the sum of all the first solid air gaps 41 and the air gap 42. The air gap is large and the inductance is small, thereby increasing the switching frequency of the switching tube in the PFC circuit and avoiding abnormal sounds.

[0086] In this embodiment, a multi-step inductor design is implemented for different load conditions. In different stages of load conditions, different numbers of first solid air gaps 41 act as air gaps to match the air gap requirements under the current load condition, and can more accurately meet the different inductance requirements of various PFC circuits in actual application scenarios.

[0087] Optionally, at least two first solid air gaps 41 can correspond to at least two different shapes, and the circumferential surfaces of one or more of the at least two different shapes are not flush with the middle column 30 of the magnetic core. It can be understood that first solid air gaps 41 with different shapes but the same effective cross-sectional area of the magnetic core can be used as the same step in a multi-stage stepped inductor. By constructing a stepped air gap with magnetic core components of different shapes, when there is a need for multiple air gaps in the inductor design, some first solid air gaps 41 with a smaller effective cross-sectional area of the magnetic core can be used to replace the air gaps for the connection of components between inductors; in addition, it can also make the selection more diverse during inductor design and the design method more flexible.

[0088] For example, the shape of the middle column 30 of the magnetic core in this embodiment can also be a hexagonal column or a quadrilateral column. Correspondingly, the first solid air gap 41 can be a Figure 7 closed hollow hexagonal column or a closed hollow quadrilateral column as shown.

[0089] It can be understood that the outer magnetic core part of the inductor provided in the following embodiments is similar to the outer magnetic core part of the inductor in the Figure 3 embodiment shown, and will not be described in detail specifically.

[0090] In the embodiment of the present application, the inductance of the inductor device is controlled by the magnetic saturation states of at least two first solid air gaps with different effective cross-sectional areas of the magnetic core under different load conditions, so that the inductor can provide an appropriate inductance under various different load conditions, preventing the switching frequency of the PFC circuit from being too high resulting in excessive switching losses, nor too low resulting in abnormal noises. At the same time, the magnetic induction lines of the first solid air gap can be confined in the magnetic medium of the first solid air gap, thereby reducing the eddy current loss generated by the leakage magnetic flux in the surrounding coils and improving the overall working efficiency of the circuit.

[0091] Figure 8a and Figure 8b are the front views of another inductor provided in the embodiment of the present application. For the convenience of display, the coil winding 20 of the inductor is hidden in the figure. As Figure 8a and Figure 8bAs shown, the magnetic core 10 includes a first outer magnet 1, a second outer magnet 2, and a winding unit R. The first outer magnet 1 and the second outer magnet 2 are arranged opposite to each other. The winding unit R includes a magnetic core middle column 30 and at least three air gaps. Specific examples of the at least three air gaps are an air gap 42 and at least two first solid air gaps 41. Among them, the at least two first solid air gaps 41 have at least two different effective cross-sectional areas of the magnetic core. The axis line of the magnetic core middle column is parallel to the above reference direction. The at least three air gaps are distributed along the reference direction. The magnetic core middle column 30 can be divided into at least three segments along the reference direction to form at least three inner magnetic cores (a first inner magnetic core 31, a second inner magnetic core 32, and a third inner magnetic core 33). In Figure 8a In, the first inner magnetic core 31 is fixed to the first base 11. The first inner magnetic core 31 and the first base 11 are of an integrated structure. The second inner magnetic core 32 is arranged between the first inner magnetic core 31 and the third inner magnetic core 33. At least two first solid air gaps 41 are respectively arranged between two adjacent inner magnetic cores. An air gap 42 is formed between the third inner magnetic core 33 and the second base 21. In Figure 8b In, the third inner magnetic core 33 is fixed to the second base 21. The third inner magnetic core 33 and the second base 21 are of an integrated structure. The second inner magnetic core 32 is arranged between the first inner magnetic core 31 and the third inner magnetic core 33. At least two first solid air gaps 41 are respectively arranged between two adjacent inner magnetic cores. An air gap 42 is formed between the first inner magnetic core 31 and the first base 11.

[0092] Figure 9 The front view of another inductor provided by an embodiment of the present application is shown. For the convenience of display, the coil winding 20 of the inductor is hidden in the figure. As Figure 9 shown, the magnetic core 10 includes a first outer magnet 1, a second outer magnet 2, and a winding unit R. The first outer magnet 1 and the second outer magnet 2 are arranged opposite to each other. The winding unit R includes a magnetic core middle column 30 and at least three air gaps. Specific examples of the at least three air gaps are an air gap 42 and at least two first solid air gaps 41. Among them, the at least two first solid air gaps 41 have at least two different effective cross-sectional areas of the magnetic core. The axis line of the magnetic core middle column 30 is parallel to the above reference direction. The at least three air gaps are distributed along the reference direction. The magnetic core middle column 30 can be divided into at least three segments along the reference direction to form at least three inner magnetic cores (a first inner magnetic core 31, a second inner magnetic core 32, and a third inner magnetic core 33). Among them, the first inner magnetic core 31 is fixed to the first base 11. The first inner magnetic core 31 and the first base 11 are of an integrated structure; the third inner magnetic core 33 is fixed to the second base 21, and the third inner magnetic core 33 and the second base 21 are of an integrated structure; the second inner magnetic core 32 is arranged between the first inner magnetic core 31 and the third inner magnetic core 33. In Figure 9In a specific example, two first solid air gaps 41 with different effective cross-sectional areas of the magnetic cores are adjacently arranged between the second inner magnetic core 32 and the third inner magnetic core 33, and an air gap 42 is arranged between the first inner magnetic core 31 and the second inner magnetic core 32.

[0093] Figure 10a and Figure 10b FIG. is the front view of another inductor provided by the embodiment of the present application. For the convenience of display, the coil winding 20 of the inductor is hidden in the figure. As Figure 10a and Figure 10b shown, the magnetic core 10 includes a first outer magnet 1, a second outer magnet 2 and a winding unit R, and the first outer magnet 1 and the second outer magnet 2 are arranged oppositely. The winding unit R includes a magnetic core middle column 30 and at least three air gaps. The at least three air gaps are specifically exemplified as an air gap 42 and at least two first solid air gaps 41; wherein, the at least two first solid air gaps 41 have at least two different effective cross-sectional areas of the magnetic cores. The axis line of the magnetic core middle column is parallel to the above reference direction, the at least three air gaps are distributed along the reference direction, and the magnetic core middle column 30 can be divided into at least two segments along the reference direction to form at least two inner magnetic cores (the first inner magnetic core 31 and the second inner magnetic core 32). In Figure 10a a specific example, the first inner magnetic core 31 is fixed to the first base 11, the first inner magnetic core 31 and the first base 11 are an integrated structure, and two first solid air gaps 41a and 41b with different effective cross-sectional areas of the magnetic cores are adjacently arranged between the first inner magnetic core 31 and the second inner magnetic core 32, and an air gap 42 is formed between the second inner magnetic core 32 and the second base 21. In Figure 10b a specific example, the second inner magnetic core 32 is fixed to the second base 21, the second inner magnetic core 32 and the second base 21 are an integrated structure, and two first solid air gaps 41a and 41b with different effective cross-sectional areas of the magnetic cores are adjacently arranged between the first inner magnetic core 31 and the second inner magnetic core 32, and an air gap 42 is formed between the first inner magnetic core 31 and the first base 11.

[0094] Figure 11 FIG. is the front view of another inductor provided by the embodiment of the present application. For the convenience of display, the coil winding 20 of the inductor is hidden in the figure. As Figure 11 shown, the magnetic core 10 includes a first outer magnet 1, a second outer magnet 2 and a winding unit R, and the first outer magnet 1 and the second outer magnet 2 are arranged oppositely. The winding unit R includes a magnetic core middle column 30 and at least four air gaps. The at least four air gaps are specifically exemplified as at least one air gap 42, at least two first solid air gaps 41 and at least one second solid air gap 43. The axis line of the magnetic core middle column 30 is parallel to the above reference direction, and the at least four air gaps are distributed along the reference direction. Continuing to refer to Figure 11, both ends of the middle column 30 of the magnetic core along the reference direction are respectively fixed to the first base 11 and the second base 21. The middle column 30 of the magnetic core can be divided into at least five segments along the reference direction to form at least five inner magnetic cores (the first inner magnetic core 31, the second inner magnetic core 32, the third inner magnetic core 33, the fourth inner magnetic core 34, and the fifth inner magnetic core 35). Among them, the first inner magnetic core 31 is fixed to the first base 11, and the first inner magnetic core 31 and the first base 11 are of an integral structure; the fifth inner magnetic core 35 is fixed to the second base 21, and the fifth inner magnetic core 35 and the second base 21 are of an integral structure. Among them, the second inner magnetic core 32, the third inner magnetic core 33, and the fourth inner magnetic core 34 are arranged between the first inner magnetic core 31 and the fifth inner magnetic core 35.

[0095] In Figure 11 specific examples, an air gap 42 is arranged between the first inner magnetic core 31 and the second inner magnetic core 32, a second solid gap 43 is arranged between the second inner magnetic core 32 and the third inner magnetic core 33, a first solid gap 41 is arranged between the third inner magnetic core 33 and the fourth inner magnetic core 34, and between the fourth inner magnetic core 34 and the fifth inner magnetic core 35.

[0096] Among them, the second solid gap 43 is an insulating material, specifically an epoxy resin board.

[0097] Among them, the circumferential surface of the second solid gap 43 is flush with the circumferential surface of the middle column of the magnetic core, which is beneficial to the coil winding 20 being wound around the winding unit R.

[0098] By placing the second solid gap 43 made of an insulating material between two inner magnetic cores, a segmented design of the inductance gap can be realized, and thus the leakage magnetic flux caused by an excessive gap can be reduced, and the eddy current loss can be lowered.

[0099] Among them, the at least two first solid gaps 41 have at least two different effective cross-sectional areas of the magnetic core.

[0100] Figure 12 is the front view of another inductor provided by the embodiment of the present application. For the convenience of display, the coil winding 20 of the inductor is hidden in the figure. As Figure 12 shown, the magnetic core 10 includes a first outer magnet 1, a second outer magnet 2, and a winding unit R. The first outer magnet 1 and the second outer magnet 2 are arranged opposite to each other. The winding unit R includes a middle column 30 of the magnetic core and at least four gaps. Specific examples of the at least four gaps are at least one air gap 42, at least two first solid gaps 41, and at least one second solid gap 43. The at least two first solid gaps 41 have at least two different effective cross-sectional areas of the magnetic core. The axis line of the middle column 30 of the magnetic core is parallel to the above reference direction, and the at least four gaps are distributed along the reference direction. Continue to refer to Figure 9, both ends of the middle column 30 of the magnetic core along the reference direction are respectively fixed to the first base 11 and the second base 21. The middle column 30 of the magnetic core can be divided into at least four segments along the reference direction, forming at least four inner magnetic cores (the first inner magnetic core 31, the second inner magnetic core 32, the third inner magnetic core 33, and the fourth inner magnetic core 34). Among them, the first inner magnetic core 31 is fixed to the first base 11, and the first inner magnetic core 31 and the first base 11 are of an integrated structure; the fourth inner magnetic core 34 is fixed to the second base 21, and the fourth inner magnetic core 34 and the second base 21 are of an integrated structure. Among them, the second inner magnetic core 32 and the third inner magnetic core 33 are arranged between the first inner magnetic core 31 and the fourth inner magnetic core 34.

[0101] In Figure 12 In a specific example, the air gap 42 is arranged between the first inner magnetic core 31 and the second inner magnetic core 32, the second solid gap 43 is arranged between the second inner magnetic core 32 and the third inner magnetic core 33, and two first solid gaps 41 with different effective cross-sectional areas of the magnetic core are adjacently arranged between the third inner magnetic core 33 and the fourth inner magnetic core 34.

[0102] The air gap of the inductor provided by the embodiment of the present application includes a combination of at least two first solid gaps with different effective cross-sectional areas of the magnetic core and an air gap, or a combination of at least two first solid gaps, an air gap, and a second solid gap with different effective cross-sectional areas of the magnetic core; among them, the air gap of the inductor includes at least two first solid gaps with different effective cross-sectional areas of the magnetic core and at least one air gap.

[0103] Optionally, the at least two first solid gaps with different effective cross-sectional areas of the magnetic core in the embodiment of the present application can be adjacently arranged; further, the two at least first solid gaps can be adjacently arranged with the air gap; the at least two first solid gaps can be adjacently arranged with the second solid gap; it is also possible that at least one first solid gap is adjacently arranged with the air gap, and the other first solid gap is adjacently arranged with the second solid gap; it is also possible to arrange the above at least two first solid gaps, the air gap, and the second solid gap adjacently.

[0104] Specifically, the above-mentioned multiple adjacently arranged air gaps can be arranged between two adjacent inner magnetic cores, or can be adjacently arranged between the inner magnetic core and the base.

[0105] Optionally, one air gap is arranged between any two adjacent inner magnetic cores in the embodiment of the present application.

[0106] The inductor provided by the embodiment of the present application can control the inductance of the inductor component through the magnetic saturation state of at least two first solid gaps under different load conditions, so that the inductor can provide a suitable inductance under various different load conditions, improve the overall working efficiency of the circuit, and avoid abnormal sounds of the inductor.

[0107] The inductor provided by the embodiment of the present application is applied to a PFC circuit, an AC-DC conversion circuit, and a power supply system, and can improve the working efficiency of the PFC circuit, the AC-DC conversion circuit, and the power supply system.

[0108] The embodiment of the present application also provides a PFC circuit, which includes any one of the inductors provided by the above embodiment. Specifically, the structure of the PFC circuit can refer to Figure 2 the PFC circuit 112 in Figure 2 wherein the inductor L1 is replaced by any one of the inductors provided by the above embodiment.

[0109] The embodiment of the present application also provides a power supply system, the structure of which can refer to the power supply system 100 as shown in Figure 1 wherein the difference is that Figure 1 the AC-DC conversion circuit 110 in

[0110] In the CRM mode, when the power supply system provided by the embodiment of the present application operates under light load conditions, the current passing through the inductor in the AC-DC conversion circuit is small, that is, the current in the winding coil of the inductor is small, and the first solid air gaps in the inductor do not reach the magnetic saturation state. The first solid air gaps all conduct magnetism as good magnetic conduction materials, and the total air gap size of the inductor is the size of the air gap or the sum of the size of the air gap and the size of the second solid air gap. At this time, the inductor has a small air gap and a large inductance, which can effectively reduce the switching frequency, reduce the switching loss, and improve the power supply efficiency.

[0111] As the load increases, some of the first solid air gaps do not reach the magnetic saturation state and conduct magnetism as good magnetic conduction materials; the other part of the first solid air gaps has reached the magnetic saturation state; after the magnetic flux rapidly decays, it acts as an air gap, and the total air gap size of the inductor is the total air gap size under light load conditions plus the size of the part of the first solid air gap that has reached the magnetic saturation state. At this time, by controlling the size of the total air gap of the inductor, a suitable inductance is provided for the inductor, so that the switching frequency of the PFC circuit is not too high to cause excessive switching loss, nor too low to cause abnormal noise.

[0112] Under heavy load conditions, the first solid air gaps of the inductor all reach the magnetic saturation state, and the first solid air gaps all act as air gaps, and the total air gap size of the inductor is the sum of the sizes of all air gaps. At this time, the inductor has a large air gap and a small inductance, which can effectively increase the switching frequency and avoid abnormal noise caused by too low switching frequency.

[0113] The power supply system provided by the embodiment of the present application can provide a suitable inductance according to different load conditions, improve the working efficiency of the power supply system under various load conditions, and thus meet the energy efficiency requirements of the power supply system.

[0114] An embodiment of the present application further provides an electronic server, and the electronic server includes the power supply system provided in the above embodiment.

[0115] As described above, the foregoing is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, and all of them should be covered by the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An inductor, comprising a coil winding and a magnetic core, wherein the magnetic core includes a first outer magnetic core, a second outer magnetic core and a winding unit; the first outer magnetic core and the second outer magnetic core are oppositely arranged, the winding unit is arranged between the first outer magnetic core and the second outer magnetic core, and the coil winding is wound around the winding unit; Characterized in that, the winding unit includes a magnetic core middle column and at least three air gaps distributed along a reference direction, the axis line of the magnetic core middle column is parallel to the reference direction, and the at least three air gaps include at least two first solid air gaps and at least one air air gap; the circumferential surfaces of the at least two first solid air gaps are flush with the circumferential surface of the magnetic core middle column; wherein, the material of the first solid air gap is a magnetic conductive material, and the first solid air gap has a hollowed-out area penetrating through the first solid air gap along the reference direction; the at least two first solid air gaps have at least two different effective magnetic core cross-sectional areas; wherein, the effective magnetic core cross-sectional area of the first solid air gap is less than 36000 / N square millimeters; wherein, N is the number of turns of the coil in the coil winding.

2. The inductor according to claim 1, Characterized in that, the magnetic core middle column includes a plurality of inner magnetic cores; the at least two first solid air gaps and the at least one air air gap are located between the plurality of inner magnetic cores; the circumferential surfaces of the at least two first solid air gaps being flush with the circumferential surface of the magnetic core middle column includes the circumferential surfaces of the at least two first solid air gaps being flush with the circumferential surfaces of the plurality of inner magnetic cores.

3. The inductor according to claim 1, Characterized in that, the magnetic core middle column is connected to the first outer magnetic core, and the air air gap is formed between the magnetic core middle column and the second outer magnetic core; or, the magnetic core middle column is connected to the second outer magnetic core, and the air air gap is formed between the magnetic core middle column and the first outer magnetic core.

4. The inductor according to any one of claims 1-3, Characterized in that, the hollowed-out area is one or more; and the shapes and areas of any two cross-sections perpendicular to the reference direction of the same hollowed-out area are the same.

5. The inductor according to any one of claims 1-3, Characterized in that, the projection of the hollowed-out area on a plane perpendicular to the reference direction is located within the outer boundary of the projection of the first solid air gap on the plane.

6. The inductor according to any one of claims 1-3, Characterized in that, the winding unit further includes a second solid air gap, and the material of the second solid air gap is an insulating material.

7. The inductor according to any one of claims 1-3, Characterized in that, the first outer magnetic core includes a first base and two first side columns, the two first side columns are fixed to the first base and extend towards the second outer magnetic core; the second outer magnetic core includes a second base and two second side columns, the two second side columns are fixed to the second base and extend towards the first outer magnetic core; the two first side columns and the two second side columns are correspondingly connected one by one.

8. A power factor correction circuit, Characterized in that, The power factor correction circuit includes an inductor as described in any one of claims 1 to 7.

9. A power supply system, characterized in that the power supply system includes a power factor correction circuit as described in claim 8.

10. An electronic server, characterized in that the electronic server includes a power supply system as described in claim 9.

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