CN115359997A - Inductance, power factor correction circuit, power supply system and electronic server - Google Patents

Abstract

The application discloses an inductor, a power factor correction circuit, a power supply system and an electronic server. The inductor comprises at least two first solid air gaps with different magnetic core effective sectional areas Ae, the inductance of the inductor device is controlled through the magnetic saturation states of the at least two first solid air gaps under different load working conditions, the inductor can flexibly provide proper inductance according to loads under various different load working conditions, and the switching frequency of a PFC circuit in a CRM mode is not too high to cause too large switching loss and is not too low to cause abnormal sound. Meanwhile, the magnetic induction lines passing through the first solid air gap can be constrained in the magnetic medium of the first solid air gap, so that the eddy current loss generated by leakage magnetic flux at the peripheral coil is reduced, and the overall working efficiency of the circuit is improved.

Description

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

Technical Field

The application relates to the technical field of power supplies, in particular to an inductor, a power factor correction circuit, a power supply system and an electronic server.

Background

The power factor (power factor) is mainly used for representing the utilization degree of the electronic equipment on electric energy, and the larger the power factor value is, the higher the electric energy utilization rate is represented. A technique for improving the power factor of a power consumption device is called a Power Factor Correction (PFC) technique.

In a power supply circuit, a PFC circuit is widely used in order to improve power supply efficiency. The PFC circuit has three common operation modes, namely, a Continuous Conduction Mode (CCM), a Discontinuous Conduction Mode (DCM) and a current critical conduction mode (CRM). In the CRM mode of the PFC circuit, the inductance of the PFC inductor is usually a fixed value according to the circuit design. And can not be flexibly adjusted according to different loads.

Disclosure of Invention

The application provides an inductance, power factor correction circuit, electrical power generating system and electronic server, and this inductance can provide suitable inductance according to the load is nimble under the operating mode of multiple different loads, promotes the holistic work efficiency of circuit.

In a first aspect, the present application provides an inductor, which may be applied to a PFC circuit. The inductor comprises a coil winding and a magnetic core, wherein the magnetic core comprises 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 arranged around the winding unit; the winding unit comprises a magnetic core center pillar and at least three air gaps distributed along a reference direction, the axial lead of the magnetic core center pillar is parallel to the reference direction, and the at least three air gaps comprise at least two first solid air gaps and at least one air gap; the circumferential surfaces of the at least two first solid air gaps and the circumferential surface of the magnetic core center leg are flush; the at least two first solid air gaps have at least two different magnetic core effective cross-sectional areas.

The first solid air gap is made of a magnetic conductive material and is provided with a hollow area penetrating through the first solid air gap along the reference direction.

The effective sectional area of the magnetic core of the first solid air gap is less than 36000/N square millimeters, N is the number of turns of the coil in the coil winding, and N is more than or equal to 1.

The inductance of the inductance device is controlled through the magnetic saturation states of the at least two first solid air gaps under different load working conditions, the inductance can be flexibly provided with appropriate inductance according to the load under various different load working conditions, the switching frequency of the PFC circuit in the CRM mode is not too high, switching loss is not too large, and abnormal sound is not caused due to too low switching frequency. Simultaneously, can also be through retraining the magnetic induction line of first solid air gap in the magnetic medium of first solid air gap, and then reduce the eddy current loss that the leakage magnetic flux produced at peripheral coil, promote the holistic work efficiency of circuit.

In one possible implementation, the core center leg includes a plurality of inner 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 and the circumferential surfaces of the center pillars of the magnetic core are flush, and the circumferential surfaces of the at least two first solid air gaps and the circumferential surfaces of the plurality of inner magnetic cores are flush.

Wherein the plurality of inner magnetic cores have the same shape and area of a cross section perpendicular to the reference direction.

Wherein a circumferential surface of the at least a first solid air gap is flush with a circumferential surface of an adjacently disposed inner magnetic core.

In the application, the circumferential surface of the first solid air gap and the circumferential surface of the inner magnetic core are flush, so that on one hand, the coil winding is favorably arranged around the winding unit; on the other hand, the magnetic induction lines passing through the first solid air gap can be restrained in the magnetic medium of the first solid air gap, and therefore the eddy current loss generated by the leakage magnetic flux on the peripheral coil is reduced.

In one possible implementation, the center leg of the magnetic core connects the first outer magnetic core, the air gap being formed between the center leg of the magnetic core and the second outer magnetic core; or the magnetic core center pillar is connected with the second outer magnetic core, and the air gap is formed between the magnetic core center pillar and the first outer magnetic core.

In one possible implementation, the hollowed-out area is one or more; any two sections of the same hollowed-out area, which are perpendicular to the reference direction, are the same in shape and area.

Wherein the same first solid air gap has one or more hollow areas.

The cross section of the hollow area is a plane figure obtained by cutting a geometric body formed by the hollow area by a certain plane.

In the application, the effective sectional area of the magnetic core of the first solid air gap can be better controlled by arranging the hollow-out areas with the same shape and area of any two cross sections perpendicular to the reference direction, so that the air gap in the inductor can be better designed.

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

In the application, the projection of the hollow area on the plane perpendicular to the reference direction is limited to be located in the outer boundary of the projection of the first solid air gap on the plane, so that the situation that the arrangement of the hollow area causes the circumferential surface of the first solid air gap to generate a cavity and the leakage magnetic flux is increased can be prevented.

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.

In this application, through place insulating material's second solid air gap between two sections interior magnetic cores, can realize the segmentation design of inductance air gap, and then can reduce because of the too big magnetic leakage flux that causes of air gap, reduce the eddy current loss.

In one possible implementation, the first outer magnetic core includes a first base and two first side legs fixed to the first base and extending toward the second outer magnetic core; the second outer magnetic core comprises a second base and two second side columns, and the two second side columns are fixed on the second base and extend towards the first outer magnetic core; the two first side columns and the two second side columns are correspondingly matched and connected one by one.

In a second aspect, the present application provides a power factor correction circuit comprising an inductor as described in any one of the possible implementations of the first aspect.

In a third aspect, the present application provides a power supply system comprising a power factor correction circuit as described in the second aspect above.

In a fourth aspect, the present application provides an electronics server comprising a power supply system as described in the third aspect above.

It should be understood that the implementations and advantages of the various aspects described above may be referenced to one another.

Drawings

FIG. 1 is a schematic diagram of a power supply system in one embodiment;

FIG. 2 is a schematic diagram of an embodiment of an AC/DC converter circuit;

fig. 3 is a schematic diagram of an inductor core according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of an inductor core according to an embodiment of the present disclosure;

FIG. 5 is a schematic illustration of a first solid air gap provided in an embodiment of the present application;

FIG. 6 is a schematic structural view of another first solid air gap provided in an embodiment of the present application;

FIG. 7 is a schematic structural view of another first solid air gap provided in an embodiment of the present application;

fig. 8a to 8b are front views of another inductor core provided in the embodiments of the present application;

fig. 9 is a front view of another inductor core provided in an embodiment of the present application;

fig. 10a and 10b are front views of another inductor core provided in the embodiments of the present application;

fig. 11 is a front view of another inductor core provided in an embodiment of the present application;

fig. 12 is a front view of another inductor core according to an embodiment of the present application.

Detailed Description

Embodiments of the present application will now be described with reference to the accompanying drawings, and it is to be understood that the described embodiments are merely illustrative of some, but not all, embodiments of the present application. As can be known to those skilled in the art, with the development of technology and the emergence of new scenarios, the technical solution provided in the embodiments of the present application is also applicable to similar technical problems. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the scope of protection of the present application.

In the embodiments of the present application, the terms "first", "second", and the like do not have any logical or temporal dependency, and do not limit the number and execution order. It will be further understood that, although the following description uses the terms first, second, etc. to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

The term "at least one" in the embodiments of the present application means one or more, and the term "a plurality" in the embodiments of the present application means two or more.

The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification of this application and the appended claims, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, such as "one or more", unless the context clearly indicates otherwise.

Reference throughout this specification to "one embodiment" or "some embodiments," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather "one or more but not all embodiments" unless specifically stated otherwise. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless expressly specified otherwise.

The inductor core and the inductor device provided in the embodiment of the present application are applied to a PFC circuit in a CRM mode, and therefore it can be understood that the PFC circuit mentioned in the present application document refers to a PFC circuit in the CRM mode.

It can be understood that the PFC circuit is widely applied to a 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.

As shown in fig. 1, fig. 1 is a schematic structural diagram of a power supply system in an embodiment, and the power supply system 100 includes an ac-dc conversion circuit 110, a dc transformation circuit 120, and a control circuit 130.

The ac/dc conversion circuit 110 is configured to receive ac power provided by the ac power supply 200, convert the ac power into dc power, and finally transmit the dc power to the dc transformer circuit 120.

The dc transformer circuit 120 is configured to boost or buck the dc power supplied from the ac/dc converter circuit 110, and to supply the dc power after the transformation to the dc load 300.

The control circuit 130 is used to control the ac/dc conversion circuit 110 and the dc/dc transformation circuit 130 to perform current processing.

The dc load 300 may include a server, a data center, a base station, or a dc power device such as a household appliance. The power supply system is used for supplying power to the direct-current electric equipment in an electric utilization scene corresponding to the direct-current electric equipment.

As shown in fig. 2, fig. 2 is a schematic structural diagram of the ac-dc conversion circuit in the embodiment shown in fig. 1. As shown in fig. 2, the ac-dc conversion circuit 110 includes a rectification 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 transformation circuit 120. The ac/dc conversion circuit 110 is further provided with an Analog Ground (AGND). The input end of the rectifying circuit 111 is connected to the ac power supply 200, and the output end is connected to the PFC circuit 112. The rectifying circuit 111 includes four diodes D1, D2, D3, and D4, each of which is capable of allowing an alternating current to flow when a current flows in a forward direction and blocking the current when the current flows in a reverse direction. PFC circuit 112 includes an inductor L1, a capacitor C, a diode D0, and a mosfet switch Q1. One end of the inductor L1 is connected to the output end of the rectifying circuit 111, and is configured to receive an output current of the rectifying 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 terminal of the dc transformer 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 the capacitor C is charged by the diode D0 with the capacity of storing energy when the mosfet switch Q1 is turned off.

The applicant researches and discovers that the conventional PFC inductor has the following implementation mode, one mode is that for all load conditions, the inductance of an inductor of a PFC circuit is designed according to the maximum working current of the circuit, so that the PFC inductor can not adapt to different load working conditions and can not meet the requirements of different inductance values; the other is to provide a variable air gap to realize the inductance variable, but the inductance value can be changed only once when the load condition is changed in the current inductance variable design. There is a problem that the inductance change is not flexible enough.

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

The embodiment of the application provides an inductor, and the inductor can provide different inductance values under different load conditions, so that the overall working efficiency of a circuit is improved.

Fig. 3 is a schematic diagram of an inductor according to an embodiment of the present application, where, as shown in fig. 3, 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 wound around a 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.

Wherein the reference direction comprises a direction in which the first outer magnetic core 1 points to the second outer magnetic core 2, and also comprises a direction in which the second outer magnetic core 2 points to the first outer magnetic core 1.

Specifically, the first outer magnetic core 1 includes a first base 11 and two first side legs 12, the two first side legs 12 are fixed to two sides of the first base 11, and the two first side legs 12 extend toward the second outer magnetic core 2; correspondingly, the second outer magnetic core 2 comprises a second base 21 and two second side columns 22, the two second side columns 22 are fixed on two sides of the second base 21, and the two second side columns 22 extend towards the first outer magnetic core 1; the two first side columns 12 and the two second side columns 22 are correspondingly connected.

Optionally, the first base 11 and the two first side columns 12 are of an integrated structure, the second base 21 and the two second side columns 22 are of an integrated structure, and the two first side columns 12 and the two second side columns 22 may be connected and fixed in a sticking or stacking manner.

Optionally, the first side column 12 and the corresponding second side column 22 are of an integrated structure, the first side column 12 and the first base 11 may be fixed by being adhered or stacked, and the second side column 22 and the second base 21 may be fixed by being adhered or stacked.

It is to be understood that the first and second outer cores shown in fig. 2 are only examples, and the first and second outer cores may be any one of EE type, RP type, EQ type, and RM type.

The outer magnetic core portion of the inductor provided in the embodiments of the present application is described above, and the winding unit portion of the inductor provided in the embodiments of the present application is described below.

Fig. 4 is a schematic diagram of the inductor structure provided in the embodiment shown in fig. 3, and the coil winding 20 of the inductor is hidden in the diagram for convenience of illustration. As shown in fig. 3, the winding unit R includes the core center leg 30 and at least three air gaps, specifically exemplified by at least two first solid air gaps 41 and at least one air gap 42. The center axis of the core leg 30 is parallel to the reference direction, and the at least three air gaps are distributed along the reference direction. With continued reference to fig. 4, the core leg 30 is fixed to the first base 11 and the second base 21 at both ends in the reference direction, respectively. The core leg 30 may be divided into at least four sections in the reference direction to form at least four inner cores (a first inner core 31, a second inner core 32, a third inner core 33, and a fourth inner core 34). The first inner magnetic core 31 is fixed on 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 on the second base 21, and the fourth inner magnetic core 34 and the second base 21 are of an integrated structure. Wherein the second inner magnetic core 32 and the third inner magnetic core 33 are disposed between the first inner magnetic core 31 and the fourth inner magnetic core 34.

In the particular example of fig. 4, an air gap 42 is provided between the first inner magnetic core 31 and the second inner magnetic core 32, two first solid air gaps 41 are provided 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 can realize the segmentation of the leg 30 of the magnetic core, and reduce the eddy current loss generated by the coil winding wound on the leg 3 of the magnetic core. By providing the air gap 42, the magnetic core requires a larger current to reach the magnetic saturation state, which can prevent the magnetic saturation to a certain extent; meanwhile, the positive interaction force among the magnetic domains of the inductance magnetic core is weakened integrally, and the residual magnetism is reduced.

In other embodiments of the present application, an air gap 42 may be disposed between the third inner magnetic core 33 and the fourth inner magnetic core 34, and two first solid air gaps 41 may be disposed 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, respectively. It will be appreciated that the first solid air gap 41 and the air gap 42 may be disposed between any adjacent two inner magnetic cores.

The material of the first solid air gap 41 may be the same as that of the magnetic core center pillar 30, or may be a different magnetic conductive material, specifically, may be ferromagnetic material, ferromagnetic powder, or other iron oxide mixture such as sendust.

Specifically, as shown in fig. 5, fig. 5 is a schematic structural diagram of the first solid air gap 41 provided in the embodiment of the present application. In this embodiment, the center pillar of the magnetic core is 30 cylindrical, the first solid air gap 41 is cylindrical, and the hollow area Q is also cylindrical, and the hollow area Q is located at the center of the first solid air gap 41; the axis of the hollowed region Q, the axis of the first solid air gap 41, and the axis of the core center leg 30 are collinear.

Optionally, the hollowed-out area Q is disposed in the center of the first solid air gap 41.

Optionally, any two cross sections of the hollow-out area Q perpendicular to the reference direction have the same shape and area. The cross section of the hollow area Q is a planar figure obtained by cutting a geometric body formed by the hollow area Q by a certain plane. On the other hand, in any two cross sections perpendicular to the reference direction corresponding to the hollow regions Q in the first solid air gaps 41, the shapes and areas of the regions occupied by the hollow regions Q are the same.

It can be understood that, by setting the shape and area of any two cross sections perpendicular to the reference direction of the hollow-out region Q to be the same, the effective cross-sectional area Ae of the magnetic core of the first solid air gap 41 can be controlled more conveniently, so as to better design the air gap in the inductor.

By disposing the hollow-out region 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 uniformly distributed in the magnetic medium of the first solid air gap 41, so that the magnetic induction intensity of each part of the first solid air gap 41 rises 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 intensity of each part of the first solid air gap 41 can avoid the magnetic medium of the first solid air gap 41 from being distributed unevenly in a magnetic field, so that part of the magnetic medium reaches a magnetic saturation state under the working condition of light load, and further magnetic leakage flux is generated.

It is understood that the hollowed-out region Q may also be disposed in a non-central region of the first solid air gap 41, and the hollowed-out region is not communicated with the outer boundary of the first solid air gap. The hollow areas with uniform shapes are arranged inside the outer boundary of the solid air gap, so that eddy current loss generated by leakage magnetic flux on the peripheral coil at the boundary of the solid air gap is prevented, and the light-load working efficiency is improved.

Optionally, the number of the hollow areas Q is one or more; when the number of the hollow-out areas Q is plural, the sizes of the plural hollow-out areas Q may be different. Specifically, the same first solid air gap 41 may have one or more hollow areas Q. As shown in fig. 6, the first solid air gap 41 is cylindrical, and the hollow areas Q1 and Q2 are cylindrical with different diameters.

It can be understood that, when the plurality of hollow-out regions Q have the same shape, 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.

Alternatively, the hollowed-out region Q and the first solid air gap 41 may be of different shapes.

Wherein the circumferential surface of the first solid air gap 41 is flush with the circumferential surface of the core leg 30. That is, the first solid air gap 41 is perpendicular to the reference direction equal to the radial dimension of the core leg 30 perpendicular to the reference direction. It will be appreciated that in other embodiments where the legs of the core are not cylindrical, the cross-section of the first solid air gap 41 perpendicular to the reference direction is a first cross-section, and the cross-section of the leg 30 of the core perpendicular to the reference direction is a second cross-section, the first cross-section and the second cross-section having the same shape and outer boundary.

In one possible implementation, when the core center leg 30 includes a plurality of inner cores, the shapes and areas of the sections of the plurality of inner 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 plurality of inner magnetic cores, the circumferential surfaces of the at least two first solid air gaps and the circumferential surfaces of the plurality of inner magnetic cores are flush.

Wherein the plurality of inner magnetic cores have the same radial dimension perpendicular to the reference direction.

By designing the circumferential surface of the first solid air gap 41 to be flush with the circumferential surface of the core leg 30, on one hand, the circumferential surfaces of the first solid air gap 41 and the core leg 30 can be kept flat, which is beneficial to the coil winding 20 to be arranged around the winding unit R; on the other hand, the magnetic induction lines passing through the first solid air gap 41 can be constrained in the magnetic medium of the first solid air gap 41, so that the eddy current loss generated by the leakage magnetic flux in the peripheral coil can be reduced.

In a possible implementation, the projection of the hollow area Q on the plane perpendicular to the reference direction is located within the outer boundary of the projection of the plane of the first solid air gap 41 on which it is located.

The projection of the hollow area on the plane vertical to the reference direction is limited to be positioned in the outer boundary of the projection of the first solid air gap on the plane, so that the situation that the arrangement of the hollow area causes the appearance of a cavity on the circumferential surface of the first solid air gap and the leakage magnetic flux is increased is prevented.

Wherein, the at least two first solid air gaps 41 have at least two magnetic core effective cross-sectional areas, that is, the winding unit R at least includes two first solid air gaps 41 with different magnetic core effective cross-sectional areas, and the number of each first solid air gap 41 is at least one. Referring to fig. 5 again, the cross section of the magnetic core is the cross section of the first solid air gap 41, and the cross section of the magnetic core is perpendicular to the reference direction of fig. 5.

Note that the smaller the effective cross-sectional area of the magnetic core of the first solid air gap 41 is, the easier the magnetic flux reaches the magnetic saturation state.

In one realizable manner, the first solid has a magnetic core effective cross-sectional area of less than 36000/N square millimeters, where N is the number of turns in the coil winding 20 and N is greater than or equal to 1. By setting in this way, the first solid air gap can be ensured to be still in a non-saturated state under the condition of light load as much as possible, such as under the condition of 40% load; at this time, only air gap exists in the inductor, and the inductance is in the maximum state. And as the load is gradually increased, the solid air gap is continuously saturated to serve as an air gap, and the whole air gap amount of the inductor is gradually increased, so that the inductance is gradually reduced.

After the shapes of the coil winding and the magnetic core of the inductor are selected, the number of turns of the inductor coil and the effective sectional area of the magnetic core are unchanged, and the inductance of the inductor is inversely proportional to the size of the air gap.

Under different load conditions, the current in the inductor is different, and then the saturation degrees of the magnetic core center pillar 30 and the first solid air gap 41 are different, and the saturation degrees of the first solid air gaps 41 with different magnetic core effective cross-sectional areas are also different. Under the condition of light load, the current of the coil winding 20 of the inductor is relatively low, 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 function with an internal magnetic core (31,32,33), and at the moment, the air gap of the column 30 in the whole magnetic core is an air gap 42 which is small in air gap and large in inductance, so that the switching frequency of a switching tube in a PFC circuit is reduced, and the switching loss is reduced. As the load is gradually increased, the current of the coil winding 20 of the inductor is gradually increased, and the at least two first solid air gaps 41 are gradually saturated from small to large according to the effective sectional area of the magnetic core, for the whole center pillar 30 of the magnetic core, the air gap thereof is composed of the air gap 42 and the first solid air gap 41 reaching the magnetic saturation state, so as the first solid air gap 41 reaching the magnetic saturation state is continuously increased, the whole air gap of the center pillar 30 of the magnetic core is also increased; in a heavy load/full load scene, after all the first solid air gaps 41 are completely saturated, the first solid air gaps 41 serve as air gaps, inductance is gradually reduced along with the increase of current of a coil winding of an inductor, the total size of the air gaps of the magnetic core 10 is equal to the sum of all the first solid air gaps 41 and the air gaps 42, the air gaps are large, the inductance is small, and therefore the switching frequency of a switching tube in a PFC circuit is improved, and abnormal sounds are avoided.

The embodiment realizes the design of the multi-step inductor for different load working conditions, and in the load working conditions of different stages, the first solid air gaps 41 with different numbers serve as air gaps to match the air gap requirements under the current load working conditions, so that different inductance requirements of various PFC circuits in practical application scenes can be met more accurately.

Alternatively, the at least two first solid air gaps 41 may correspond to at least two different shapes, one or more of which have a circumferential surface that is not flush with the core leg 30. It will be appreciated that first solid air gaps 41 of different shapes but of the same core effective cross-sectional area may be provided as the same step in a multi-step inductor. By constructing the stepped air gaps with magnetic core components of different shapes, when the inductor is designed with a plurality of air gaps, the air gaps can be replaced by the first solid air gaps 41 with smaller effective sectional areas of the magnetic cores, so that the components between the inductors can be connected; in addition, the selection in the process of designing the inductor can be diversified, and the design mode is more flexible.

For example, the shape of the leg 30 in the magnetic core in the present embodiment may also be a hexagonal cylinder or a quadrangular cylinder, and accordingly, the first solid air gap 41 may be a closed hollow hexagonal cylinder or a closed hollow quadrangular cylinder as shown in fig. 7.

It is understood that the outer magnetic core portion of the inductor provided in the following embodiments is similar to that of the inductor in the embodiment shown in fig. 3, and detailed description thereof will be omitted.

The inductance of the inductance device is controlled through the magnetic saturation states of at least two first solid air gaps with different effective sectional areas of the magnetic core under different load working conditions, the inductance can provide appropriate inductance under the working conditions of various different loads, the switching frequency of the PFC circuit is not too high, the switching loss is too large, and the abnormal sound is not caused to be too low. Meanwhile, the magnetic induction lines of the first solid air gap can be constrained in the magnetic medium of the first solid air gap, so that the eddy current loss generated by leakage magnetic flux at the peripheral coil is reduced, and the overall working efficiency of the circuit is improved.

Fig. 8a and 8b are front views of another inductor provided in the embodiments of the present application, and the coil winding 20 of the inductor is hidden in the drawings for convenience of illustration. As shown in fig. 8a and 8b, 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 being disposed opposite to each other. The winding unit R includes the core center leg 30 and at least three air gaps, specifically exemplified by one 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 magnetic core effective cross-sectional areas. The center axis of the core leg is parallel to the reference direction, the at least three air gaps are distributed along the reference direction, and the core leg 30 may be divided into at least three sections 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 fig. 8a, a first inner magnetic core 31 is fixed to a first base 11, the first inner magnetic core 31 and the first base 11 are of an integrated structure, a second inner magnetic core 32 is disposed between the first inner magnetic core 31 and a third inner magnetic core 33, at least two first solid air gaps 41 are respectively disposed between two adjacent inner magnetic cores, and an air gap 42 is formed between the third inner magnetic core 33 and the second base 21. In fig. 8b, a 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 disposed between the first inner magnetic core 31 and the third inner magnetic core 33, at least two first solid air gaps 41 are respectively disposed between two adjacent inner magnetic cores, and an air gap 42 is formed between the first inner magnetic core 31 and the first base 11.

Fig. 9 is a front view of another inductor provided in the embodiments of the present application, in which the coil winding 20 of the inductor is hidden for convenience of illustration. As shown in fig. 9, 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 being disposed opposite to each other. The winding unit R includes the core center leg 30 and at least three air gaps, specifically exemplified by one 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 magnetic core effective cross-sectional areas. The center axis of the core leg 30 is parallel to the reference direction, the at least three air gaps are distributed along the reference direction, and the core leg 30 may be divided into at least three sections along the reference direction to form at least three inner cores (a first inner core 31, a second inner core 32, and a third inner core 33). The first inner magnetic core 31 is fixed on the first base 11, and the first inner magnetic core 31 and the first base 11 are of an integrated structure; the third inner magnetic core 33 is fixed on 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 disposed between the first inner magnetic core 31 and the third inner magnetic core 33. In the specific example of fig. 9, a first solid air gap 41, having two cores of different effective cross-sectional areas, is disposed adjacent between the second inner core 32 and the third inner core 33, and an air gap 42 is disposed between the first inner core 31 and the second inner core 32.

Fig. 10a and 10b are front views of another inductor provided in the embodiments of the present application, and the coil winding 20 of the inductor is hidden in the drawings for convenience of illustration. As shown in fig. 10a and 10b, 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 being disposed opposite to each other. The winding unit R includes the core center leg 30 and at least three air gaps, specifically exemplified by one 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 magnetic core effective cross-sectional areas. The center axis of the core leg is parallel to the reference direction, the at least three air gaps are distributed along the reference direction, and the core leg 30 can be divided into at least two sections along the reference direction to form at least two inner cores (a first inner core 31 and a second inner core 32). In the specific example of fig. 10a, 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, first solid air gaps 41a and 41b with different effective cross-sectional areas of the two 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 the specific example of fig. 10b, 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 of an integrated structure, two first solid air gaps 41a and 41b with different magnetic core effective cross-sectional areas 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.

Fig. 11 is a front view of another inductor provided in the embodiments of the present application, in which the coil winding 20 of the inductor is hidden for convenience of illustration. As shown in fig. 11, 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 being disposed opposite to each other. The winding unit R includes the core center leg 30 and at least four air gaps, specifically exemplified by at least one air gap 42, at least two first solid air gaps 41, and at least one second solid air gap 43. The center axis of the core leg 30 is parallel to the reference direction, and the at least four air gaps are distributed along the reference direction. With continued reference to fig. 11, the core leg 30 is fixed to the first base 11 and the second base 21 at both ends in the reference direction, respectively. The core leg 30 may be divided into at least five sections in the reference direction, forming at least five inner cores (a first inner core 31, a second inner core 32, a third inner core 33, a fourth inner core 34, and a fifth inner core 35). The first inner magnetic core 31 is fixed on the first base 11, and the first inner magnetic core 31 and the first base 11 are of an integrated structure; the fifth inner magnetic core 35 is fixed on the second base 21, and the fifth inner magnetic core 35 and the second base 21 are of an integrated structure. Wherein the second inner magnetic core 32, the third inner magnetic core 33, and the fourth inner magnetic core 34 are disposed between the first inner magnetic core 31 and the fifth inner magnetic core 35.

In the particular example of fig. 11, an air gap 42 is provided between the first inner magnetic core 31 and the second inner magnetic core 32, a second solid air gap 43 is provided between the second inner magnetic core 32 and the third inner magnetic core 33, a first solid air gap 41 is provided 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.

The second solid air gap 43 is made of an insulating material, and may be an epoxy resin plate.

Wherein the circumferential surface of the second solid air gap 43 is flush with the circumferential surface of the center pillar of the magnetic core, facilitating the coil winding 20 to be disposed around the winding unit R.

The second solid air gap 43 made of insulating materials is arranged between the two sections of inner magnetic cores, so that the sectional design of the inductance air gap can be realized, the leakage magnetic flux caused by overlarge air gaps can be reduced, and the eddy current loss is reduced.

Wherein the at least two first solid air gaps 41 have at least two different magnetic core effective cross-sectional areas.

Fig. 12 is a front view of another inductor provided in the embodiment of the present application, in which the coil winding 20 of the inductor is hidden for convenience of illustration. As shown in fig. 12, 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 being disposed opposite to each other. The winding unit R includes the core leg 30 and at least four air gaps, specifically exemplified by at least one air gap 42, at least two first solid air gaps 41 and at least one second solid air gap 43, the at least two first solid air gaps 41 having at least two different core effective cross-sectional areas. The center axis of the core leg 30 is parallel to the reference direction, and the at least four air gaps are distributed along the reference direction. With continued reference to fig. 9, the core leg 30 is fixed to the first base 11 and the second base 21 at both ends in the reference direction, respectively. The core leg 30 may be divided into at least four sections in the reference direction to form at least four inner cores (a first inner core 31, a second inner core 32, a third inner core 33, and a fourth inner core 34). The first inner magnetic core 31 is fixed on 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 on the second base 21, and the fourth inner magnetic core 34 and the second base 21 are of an integrated structure. Wherein the second inner magnetic core 32 and the third inner magnetic core 33 are disposed between the first inner magnetic core 31 and the fourth inner magnetic core 34.

In the specific example of fig. 12, an air gap 42 is provided between the first inner magnetic core 31 and the second inner magnetic core 32, a second solid air gap 43 is provided between the second inner magnetic core 32 and the third inner magnetic core 33, and two first solid air gaps 41 having different core effective cross-sectional areas are adjacently provided between the third inner magnetic core 33 and the fourth inner magnetic core 34.

The air gap of the inductor provided by the embodiment of the application comprises a combination of at least two first solid air gaps and air gaps with different magnetic core effective sectional areas, or a combination of at least two first solid air gaps, air gaps and second solid air gaps with different magnetic core effective sectional areas; wherein, the air gap of the inductor at least comprises at least two first solid air gaps with different magnetic core effective sectional areas and at least one air gap.

Optionally, at least two first solid air gaps with different magnetic core effective cross-sectional areas in the embodiments of the present application may be adjacently disposed; further, two at least first solid air gaps may be disposed adjacent to the air gap; at least two first solid air gaps may be disposed adjacent to the second solid air gap; at least one first solid air gap and an air gap can be adjacently arranged, and another first solid air gap and a second solid air gap are adjacently arranged; the at least two first solid air gaps, the air gap and the second solid air gap can also be adjacently arranged.

Specifically, the plurality of air gaps arranged adjacently may be arranged between two adjacent inner magnetic cores, or may be arranged adjacently between the inner magnetic core and the base.

Optionally, an air gap is arranged between any two adjacent inner magnetic cores in the embodiment of the application.

The inductance that this application embodiment provided can be through the inductance volume of two at least first solid air gaps magnetic saturation state control inductance devices under different load operating modes, realizes that the inductance can provide suitable inductance volume under the operating mode of multiple different loads, promotes the holistic work efficiency of circuit, avoids the inductance abnormal sound to appear.

The inductor provided by the embodiment of the 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.

The embodiment of the application also provides a PFC circuit, which comprises any inductor provided by the embodiment. Specifically, the structure of the PFC circuit can refer to the PFC circuit 112 in fig. 2, except that the inductor L1 in fig. 2 is replaced by any one of the inductors provided in the above embodiments.

The embodiment of the present application further provides a power supply system, which can be referred to as the power supply system 100 shown in fig. 1, and is different in that the ac-dc conversion circuit 110 in fig. 1 employs any one of the inductors provided in the above embodiments.

In the CRM mode, when the power supply system provided in this application embodiment operates under a light-load working condition, the current passing through the inductor in the ac-dc conversion circuit is small, that is, the current of the winding coil of the inductor is small, the first solid air gap in the inductor does not reach a magnetic saturation state, the first solid air gap is magnetically conducted as a good magnetic conductive material, 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 the moment, the air gap of the inductor is small, the inductance is large, the switching frequency can be effectively reduced, the switching loss is reduced, and the power efficiency is improved.

With the increase of the load, part of the first solid air gap does not reach a magnetic saturation state and is used as a good magnetic conductive material for magnetic conduction; the other part of the first solid air gap reaches a magnetic saturation state; the magnetic flux is quickly attenuated and then acts as an air gap, and the total air gap of the inductor is the sum of the total air gap under the light-load working condition and the size of the first solid air gap when the part reaches the magnetic saturation state. At this time, the inductor provides a proper inductance by controlling the size of the total air gap of the inductor, so that the switching frequency of the PFC circuit is not too high to cause too large switching loss, and is not too low to cause abnormal sound.

Under the heavy-load working condition, the first solid air gaps of the inductor reach a magnetic saturation state, the first solid air gaps all play a role as air gaps, and the total size of the air gaps of the inductor is the sum of the sizes of all the air gaps. At the moment, the air gap of the inductor is large, the inductance is small, the switching frequency can be effectively improved, and abnormal sound caused by too low switching frequency is avoided.

The power supply system that this application embodiment provided can provide suitable inductance according to the load operating mode of difference, improves power supply system work efficiency under various load operating modes, and then satisfies power supply system's energy efficiency demand.

The embodiment of the application also provides an electronic server which comprises the power supply system provided by the embodiment.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. An inductor comprises a coil winding and a magnetic core, wherein the magnetic core comprises 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 arranged around the winding unit; it is characterized in that the preparation method is characterized in that,

the winding unit comprises a magnetic core center pillar and at least three air gaps distributed along a reference direction, the axis of the magnetic core center pillar is parallel to the reference direction, and the at least three air gaps comprise at least two first solid air gaps and at least one air gap; the circumferential surfaces of the at least two first solid air gaps and the circumferential surface of the magnetic core center pillar are flush;

the first solid air gap is made of a magnetic conductive material and is provided with a hollow-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 magnetic core effective cross-sectional areas; wherein the magnetic core effective cross-sectional area of the first solid air gap is less than 36000/N square millimeters; and N is the number of turns of the coil in the coil winding.

2. The inductor as claimed in claim 1 wherein the core legs comprise a plurality of inner cores; the at least two first solid air gaps and the 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 and the circumferential surfaces of the magnetic core center pillars are flush, including the circumferential surfaces of the at least two first solid air gaps and the circumferential surfaces of the plurality of inner magnetic cores.

3. The inductor as claimed in claim 1, wherein the core leg connects the first outer core, and the air gap is formed between the core leg and the second outer core; or the magnetic core center pillar is connected with the second outer magnetic core, and the air gap is formed between the magnetic core center pillar and the first outer magnetic core.

4. The inductor according to any one of claims 1 to 3, wherein the number of the hollowed-out areas is one or more; and the shape and the area of any two sections of the same hollowed-out area, which are perpendicular to the reference direction, are the same.

5. The inductor according to any of claims 1-4, wherein a projection of the hollowed-out area onto a plane perpendicular to the reference direction is located within an outer boundary of a projection of the first solid air gap onto the plane.

6. The inductor according to any one of claims 1 to 5, wherein the winding unit further comprises a second solid air gap, and the second solid air gap is made of an insulating material.

7. An inductor according to any one of claims 1-6, characterised in that the first outer core comprises a first base and two first side legs, which are fixed to the first base and extend towards the second outer core; the second outer magnetic core comprises a second base and two second side columns, and the two second side columns are fixed on the second base and extend towards the first outer magnetic core; the two first side columns and the two second side columns are correspondingly matched and connected one by one.

8. A power factor correction circuit, characterized in that it comprises an inductance according to any one of claims 1 to 7.

9. A power supply system characterized in that it comprises a power factor correction circuit as claimed in claim 8.

10. An electronic server, characterized in that the electronic server comprises the power supply system according to claim 9.

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