Power inductor and power device

Abstract

This application provides a power inductor and a power device. The power inductor includes a magnetic core and at least two windings, the magnetic core includes two first cover plates, at least one second cover plate, and at least two groups of middle pillars, each group of middle pillars includes two middle pillars, and each winding is wound around two middle pillars of one group of middle pillars. The two first cover plates are disposed opposite to each other, and the at least one second cover plate and the at least two groups of middle pillars are located between the two first cover plates. Each first cover plate is connected to end parts of one adjacent group of middle pillars, each second cover plate is located between two adjacent groups of middle pillars, and each second cover plate is connected to end parts of the two adjacent groups of middle pillars. In the power inductor provided in this application, two adjacent groups of middle pillars of the magnetic core share the second cover plate, so that magnetic fluxes generated by two windings wound around the two groups of middle pillars can be conducted through the same second cover plate, to implement magnetic circuit sharing. This helps reduce a volume of the power inductor, and helps implement a miniaturization design of the power device.

Description

TECHNICAL FIELD

[0001] This application relates to the field of energy technologies, and in particular, to a power inductor and a power device.BACKGROUND

[0002] Currently, a magnetic element in a power device such as a photovoltaic inverter or a power supply is increasingly widely used. To adapt to a development trend of high efficiency and miniaturization, the power device imposes a higher requirement on a miniaturization design of the magnetic element. A power inductor is a main magnetic element in the power device, and a decrease in a volume of the power inductor is essential for implementing a miniaturization design of the power device.

[0003] The power inductor usually includes a magnetic core and a winding, the magnetic core includes two cover plates and a middle pillar disposed between the two cover plates, and the winding is wound on the middle pillar. When the power device includes two or more power inductors, the two or more power inductors may be fastened to an insulation bottom plate through an adhesive, so that the two or more power inductors may be arranged in the power device as a whole. However, to avoid mutual interference between the power inductors, there is a specific gap between any two adjacent power inductors. Consequently, the two or more power inductors occupy a large area and space in the power device. This is inconducive to implementing the miniaturization design of the power device.SUMMARY

[0004] This application provides a power inductor and a power device, to improve integration of the power inductor, thereby facilitating a miniaturization design of the power device.

[0005] According to a first aspect, this application provides a power device. The power device includes at least one circuit board and a plurality of direct current conversion circuits disposed on the at least one circuit board, and each direct current conversion circuit includes at least one switch module and a power inductor. When the power inductor is specifically disposed, the power inductor includes a magnetic core and at least two windings, the magnetic core includes two first cover plates, at least one second cover plate, and at least two groups of middle pillars, each group of middle pillars includes two middle pillars, and each winding is wound around two middle pillars of one group of middle pillars. The two first cover plates are disposed opposite to each other, and the at least one second cover plate and the at least two groups of middle pillars are located between the two first cover plates. Each first cover plate is connected to end parts of one group of middle pillars, each second cover plate is located between two adjacent groups of middle pillars, and each second cover plate is connected to end parts of the two adjacent groups of middle pillars. In addition, the at least two groups of windings are respectively connected to the at least one switch module in different direct current conversion circuits in the plurality of direct current conversion circuits. In the power device provided in this application, because two adjacent groups of middle pillars of the magnetic core of the power inductor are connected to a same second cover plate, the magnetic core may be considered as integration of at least two magnetic core structures. In addition, magnetic fluxes generated by two windings wound around the two adjacent groups of middle pillars may be conducted through the same second cover plate, to implement magnetic circuit sharing. This can effectively improve integration of the power inductor. Compared with a conventional power inductor in which a plurality of magnetic core structures are separately disposed, the power inductor of the power device provided in this application can effectively reduce a volume while meeting a same use requirement, thereby helping reduce a volume of an overall structure of the power inductor. In this way, the power inductor occupies small space on a circuit board. This helps reduce an area of the circuit board, and helps implement a miniaturization design of the power device. In addition, when the area of the circuit board of the power device remains unchanged, a requirement of disposing more components on the circuit board may be further met. This helps improve function diversification of the power device.

[0006] In a possible implementation of this application, a pillar shaft of each middle pillar is perpendicular to plate surfaces of the two first cover plates. In this way, structural reliability of the magnetic core can be improved, and a volume of the magnetic core can be reduced, thereby helping reduce a volume of an overall structure of the power inductor.

[0007] In addition, an air gap sheet is disposed between the second cover plate and at least one adjacent group of middle pillars. In this way, an air gap between the second cover plate and the adjacent middle pillars can be effectively increased. This helps improve effect of offsetting or superimposing magnetic fluxes that are generated by parts of the power inductor and that are conducted through a same second cover plate, and further reduces mutual impact between the parts of the power inductor.

[0008] In a possible implementation of this application, a magnetic permeability of each second cover plate is higher than a magnetic permeability of each first cover plate, and the magnetic permeability of each second cover plate is higher than a magnetic permeability of each adjacent middle pillar. In this way, after magnetic fluxes generated by the windings of the power inductor pass through the middle pillars, most of the magnetic fluxes are conducted through the adjacent second cover plate, so that mutual impact of the magnetic fluxes generated by the windings in the power inductor can be reduced, and a use requirement of the power inductor for local magnetic conduction or overall magnetic conduction of the magnetic core can be met.

[0009] In this application, there may be a plurality of implementations in which the magnetic permeability of each second cover plate is higher than the magnetic permeability of each first cover plate. For example, a material of the second cover plate may be different from a material of the first cover plate. The material of the second cover plate is a high magnetic permeability material such as ferrite, nanocrystalline, or nanoamorphous, and the material of the first cover plate is a metal powder core. This helps control costs of the power inductor.

[0010] In addition, a material of the middle pillar may also be a metal powder core. This helps control the costs of the power inductor. Materials of the first cover plate and the middle pillar may be the same or different. This is not limited in this application.

[0011] In a possible implementation of this application, the magnetic permeability of each second cover plate is twice or more than twice the magnetic permeability of each first cover plate. In this way, the magnetic permeability of the second cover plate can be obviously different from the magnetic permeability of the first cover plate, so that after magnetic fluxes generated by the windings pass through the middle pillars, most of the magnetic fluxes can be conducted through the adjacent second cover plate. This can reduce mutual impact of the magnetic fluxes generated by the windings in the power inductor, and help implement magnetic circuit sharing.

[0012] Similarly, the magnetic permeability of each second cover plate is twice or more than twice the magnetic permeability of each adjacent middle pillar. In this way, the magnetic permeability of the second cover plate may be obviously different from the magnetic permeability of the middle pillar, so that after magnetic fluxes generated by the windings pass through the middle pillars, most of the magnetic fluxes can be conducted through the adjacent second cover plate. This can reduce mutual impact of the magnetic fluxes generated by the windings in the power inductor, and help implement magnetic circuit sharing.

[0013] In this application, based on use requirements of the power inductor in different application scenarios, winding directions of the windings of the power inductor and directions of currents passing through the windings may be adjusted, to adjust directions of magnetic fluxes generated by the two windings disposed adjacent to the second cover plate. For example, in a possible implementation of this application, in an arrangement direction of the two first cover plates, when winding directions of two adjacent windings are the same and directions of currents passing through the two adjacent windings are opposite, magnetic fluxes generated by the two adjacent windings are offset at the second cover plate located between the two adjacent windings; or in an arrangement direction of the two first cover plates, when winding directions of two adjacent windings are opposite and directions of currents passing through the two adjacent windings are the same, magnetic fluxes generated by the two adjacent windings are offset at the second cover plate located between the two adjacent windings. In this application scenario, the magnetic fluxes generated by the two adjacent windings are offset at the second cover plate between the two adjacent windings, so that a loss of the magnetic core can be effectively reduced, thereby helping improve efficiency of the power inductor.

[0014] In another possible implementation of this application, magnetic fluxes generated by two adjacent windings may be superimposed at the second cover plate located between the two adjacent windings based on a use requirement of an application scenario. Specifically, in an arrangement direction of the two first cover plates, when winding directions of the two adjacent windings are opposite and directions of currents passing through the two adjacent windings are opposite, the magnetic fluxes generated by the two adjacent windings are superimposed at the second cover plate located between the two adjacent windings; or in an arrangement direction of the two first cover plates, when winding directions of the two adjacent windings are the same and directions of currents passing through the two adjacent windings are the same, the magnetic fluxes generated by the two adjacent windings are superimposed at the second cover plate located between the two adjacent windings.

[0015] In a possible implementation of this application, the at least one circuit board includes a main power board and a first circuit board, the at least one switch module is disposed on the main power board, the power inductor is disposed on the first circuit board, and the power inductor is connected to a circuit trace of the main power board through a cable, to implement an electrical connection to the switch module. This helps reduce a size of the main power board can be reduced, thereby reducing costs of the main power board. Moreover, this can improve layout flexibility, in the power device, of components in the direct current conversion circuit, thereby improving internal space utilization of the power device, and helping implement an overall miniaturization design of the power device.

[0016] According to a second aspect, this application further provides a power device. The power device includes a circuit board and an inverter circuit disposed on the circuit board, and the inverter circuit includes at least two inverter bridge arms and a filter inductor. The filter inductor includes a magnetic core and at least two windings, the magnetic core includes two first cover plates, at least one second cover plate, and at least two groups of middle pillars, each group of middle pillars includes two middle pillars, and each winding is wound around two middle pillars of one group of middle pillars. The two first cover plates are disposed opposite to each other, and the at least one second cover plate and the at least two groups of middle pillars are located between the two first cover plates. Each first cover plate is connected to end parts of one adjacent group of middle pillars, each second cover plate is located between two adjacent groups of middle pillars, and each second cover plate is connected to end parts of the two adjacent groups of middle pillars. In addition, the at least two windings are respectively connected to output ends of different inverter bridge arms in the at least two inverter bridge arms. In the power device provided in this application, because two adjacent groups of middle pillars of the magnetic core of the filter inductor are connected to a same second cover plate, the magnetic core may be considered as integration of at least two magnetic core structures. In addition, magnetic fluxes generated by two windings wound around the two adjacent groups of middle pillars may be conducted through the same second cover plate, to implement magnetic circuit sharing, and effectively improve integration of the filter inductor. Compared with a conventional filter inductor in which a plurality of magnetic core structures are separately disposed, the filter inductor of the power device provided in this application can effectively reduce a volume while meeting a same use requirement, thereby helping reduce a volume of an overall structure of the filter inductor. In this way, the filter inductor occupies small space on a circuit board. This helps reduce an area of the circuit board, and helps implement a miniaturization design of the power device. In addition, when the area of the circuit board of the power device remains unchanged, a requirement of disposing more components on the circuit board may be further met. This helps improve function diversification of the power device.

[0017] According to a third aspect, this application further provides a power inductor. The power inductor includes a magnetic core and at least two windings, the magnetic core includes two first cover plates, at least one second cover plate, and at least two groups of middle pillars, each group of middle pillars includes two middle pillars, and each winding is wound around two middle pillars of one group of middle pillars. The two first cover plates are disposed opposite to each other, and the at least one second cover plate and the at least two groups of middle pillars are located between the two first cover plates. Each first cover plate is connected to end parts of one group of middle pillars, each second cover plate is located between two adjacent groups of middle pillars, and each second cover plate is connected to end parts of the two adjacent groups of middle pillars. In the power inductor provided in this application, because two adjacent groups of middle pillars of the magnetic core are connected to a same second cover plate, the magnetic core may be considered as integration of at least two magnetic core structures. In addition, magnetic fluxes generated by two windings wound around the two adjacent groups of middle pillars may be conducted through the same second cover plate, to implement magnetic circuit sharing. This can effectively improve integration of the power inductor. Compared with a conventional power inductor in which a plurality of magnetic core structures are separately disposed, the power inductor provided in this application can effectively reduce a volume while meeting a same use requirement, thereby helping reduce a volume of an overall structure of the power inductor.

[0018] In a possible implementation of this application, a magnetic permeability of each second cover plate is higher than a magnetic permeability of each first cover plate, and the magnetic permeability of each second cover plate is higher than a magnetic permeability of each adjacent middle pillar. In this way, after magnetic fluxes generated by the windings of the power inductor pass through the middle pillars, most of the magnetic fluxes are conducted through the adjacent second cover plate, so that mutual impact of the magnetic fluxes generated by the windings in the power inductor can be reduced, and a use requirement of the power inductor for local magnetic conduction or overall magnetic conduction of the magnetic core can be met.

[0019] In a possible implementation of this application, a pillar shaft of each middle pillar is perpendicular to plate surfaces of the two first cover plates. In this way, structural reliability of the magnetic core can be improved, and a volume of the magnetic core can be reduced, thereby helping reduce a volume of an overall structure of the power inductor.

[0020] In a possible implementation of this application, the power inductor further includes an air gap sheet, and the air gap sheet is disposed between the second cover plate and at least one adjacent group of middle pillars. In this way, an air gap between the second cover plate and the adjacent middle pillars can be effectively increased. This helps improve effect of offsetting or superimposing magnetic fluxes that are generated by parts of the power inductor and that are conducted through a same second cover plate, and further reduces mutual impact between the parts of the power inductor.

[0021] In this application, there may be a plurality of implementations in which the magnetic permeability of each second cover plate is higher than the magnetic permeability of each first cover plate. For example, a material of the second cover plate may be different from a material of the first cover plate. The material of the second cover plate is a high magnetic permeability material such as ferrite, nanocrystalline, or nanoamorphous, and a material of the first cover plate is a metal powder core. This helps control costs of the power inductor.

[0022] In addition, a material of the middle pillar may also be a metal powder core. This helps control the costs of the power inductor. Materials of the first cover plate and the middle pillar may be the same or different. This is not limited in this application.

[0023] In a possible implementation of this application, the magnetic permeability of each second cover plate is twice or more than twice the magnetic permeability of each first cover plate. In this way, the magnetic permeability of the second cover plate can be obviously different from the magnetic permeability of the first cover plate, so that after magnetic fluxes generated by the windings pass through the middle pillars, most of the magnetic fluxes can be conducted through the adjacent second cover plate. This can reduce mutual impact of the magnetic fluxes generated by the windings in the power inductor, and help implement magnetic circuit sharing.

[0024] Similarly, the magnetic permeability of each second cover plate is twice or more than twice the magnetic permeability of each adjacent middle pillar. In this way, the magnetic permeability of the second cover plate may be obviously different from the magnetic permeability of the middle pillar, so that after magnetic fluxes generated by the windings pass through the middle pillars, most of the magnetic fluxes can be conducted through the adjacent second cover plate. This can reduce mutual impact of the magnetic fluxes generated by the windings in the power inductor, and help implement magnetic circuit sharing.

[0025] In this application, a winding direction of each winding in the power inductor is not limited. For example, in an arrangement direction of the two first cover plates, winding directions of two windings located on two sides of each second cover plate are the same; or in an arrangement direction of the two first cover plates, winding directions of two windings located on two sides of each second cover plate are opposite. In this way, winding directions of windings of the power inductor and directions of currents passing through the windings of the power inductor may be adjusted based on use requirements of the power inductor in different application scenarios, to adjust directions of magnetic fluxes generated by two windings disposed adjacent to the second cover plate, so that magnetic flux offsetting or magnetic flux superposition is implemented at the second cover plate.

[0026] In a possible implementation of this application, the power inductor further includes an insulation bottom plate, and at least one of the two first cover plates and the at least one second cover plate is fastened to the insulation bottom plate. In this way, the insulation bottom plate can be used as a support structure of the entire power inductor, to improve structural reliability of the power inductor, and facilitate movement and mounting of the entire power inductor.BRIEF DESCRIPTION OF DRAWINGS

[0027] FIG. 1 is a diagram of a structure of a photovoltaic power generation system according to an embodiment of this application; FIG. 2 is a simplified schematic of a circuit topology structure of an inverter according to an embodiment of this application; FIG. 3 is a design manner of two boost inductors in a conventional inverter according to an embodiment of this application; FIG. 4 is a diagram of a structure of a magnetic core of a power inductor according to an embodiment of this application; FIG. 5 is a diagram of a structure of a power inductor according to an embodiment of this application; FIG. 6 is a diagram of a structure of a winding according to an embodiment of this application; FIG. 7 is a diagram of a structure of an inverter according to an embodiment of this application; FIG. 8 is a diagram of another structure of a power inductor according to an embodiment of this application; and FIG. 9 is a diagram of another structure of a power inductor according to an embodiment of this application. Reference numerals:

[0028] 1000: photovoltaic module; 2000: inverter; 2001: direct current conversion circuit; 2001a: first boost circuit; 2001b: second boost circuit; 20001: boost inductor; 2002: inverter circuit; 20002: output end of an inverter bridge arm; 20003: filter inductor; 2003: main power board; 2004: switch module; 2005: first circuit board; 2006: second circuit board; 3000: load; 100: power inductor; 1: magnetic core; 101: first cover plate; 102: second cover plate; 103a: first group of middle pillars; 103b: second group of middle pillars; 103: middle pillar; 2: winding; 201: winding part; 2a: first winding; 2b: second winding; 2c: third winding; 2d: fourth winding; 2e: fifth winding; 3: air gap sheet; and 4: insulation bottom plate. DESCRIPTION OF EMBODIMENTS

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the following further describes this application in detail with reference to accompanying drawings. However, example implementations may be implemented in a plurality of forms, and it should not be understood as being limited to the example implementations described herein. Same reference numerals in the accompanying drawings represent same or similar structures. Therefore, repeated descriptions thereof are omitted. Words that express locations and directions and that are described in embodiments of this application are described by using the accompanying drawings as an example. However, changes may also be made as required, and all the changes fall within the protection scope of this application. The accompanying drawings in embodiments of this application are merely used to illustrate relative location relationships and do not represent an actual scale.

[0030] It should be noted that specific details are described in the following descriptions to facilitate understanding of this application. However, this application can be implemented in a plurality of manners different from those described herein, and a person skilled in the art can make similar inferences without departing from the connotation of this application. Therefore, this application is not limited to the following disclosed specific implementations.

[0031] To facilitate understanding of a power inductor provided in this application, the following first describes an application scenario of the power inductor. The power inductor may be used in a scenario such as an energy storage system, a photovoltaic power generation system, a photovoltaic energy storage system, or a charging network. For example, the power inductor may be used in a component configured to implement power conversion, such as a power conversion system, a transformer, a photovoltaic inverter, an uninterruptible power supply (uninterruptible power supply, UPS), or a power supply. A photovoltaic power generation system scenario is used as an example. FIG. 1 is a diagram of a structure of a photovoltaic power generation system according to an embodiment of this application. The photovoltaic power generation system is a system that converts solar energy into electric energy through photovoltaic effect of a semiconductor material. The photovoltaic power generation system may usually include a photovoltaic module 1000, an inverter 2000, and a load 3000. The photovoltaic module 1000 may be configured to convert solar energy into electric energy, and a direct current input end of the inverter 2000 is configured to connect to the photovoltaic module 1000. In addition, an alternating current output end of the inverter 2000 is connected to the load 3000. The load 3000 may be an electrical device or a power grid, for example, a three-phase load. The inverter 2000 may be configured to perform power conversion on a current of a direct current from the photovoltaic module 1000, or may be configured to perform power conversion on a voltage of a direct current from the photovoltaic module 1000, so that power output by the inverter 2000 matches power of the load 3000.

[0032] FIG. 2 is a simplified schematic of a circuit topology structure of the inverter 2000 according to an embodiment of this application. FIG. 2 shows a scenario in which a direct current input end of a direct current conversion circuit 2001 of the inverter 2000 is connected to two direct currents converted by the photovoltaic module. In this case, the direct current conversion circuit 2001 of the inverter 2000 includes a first boost circuit 2001a and a second boost circuit 2001b, and the first boost circuit 2001a and the second boost circuit 2001b each are connected to a boost inductor 20001.

[0033] In addition, in FIG. 2, the inverter 2000 further includes an inverter circuit 2002, and a direct current input end of the inverter circuit 2002 is connected to direct current output ends of the first boost circuit 2001a and the second boost circuit 2001b. The inverter circuit 2002 includes output ends 20002 of three inverter bridge arms, and each output end 20002 of an inverter bridge arm is connected to a filter inductor 20003. In this case, the inverter circuit 2002 may be configured to connect to a three-phase load.

[0034] It may be understood that, when the direct current input end of the direct current conversion circuit 2001 of the inverter 2000 is connected to three or more direct currents, the direct current input end of the direct current conversion circuit 2001 of the inverter 2000 may further include three or more boost inductors 20001. In addition, when the inverter 2000 is connected to a three-phase four-wire load, the inverter circuit 2002 of the inverter 2000 may be connected to four filter inductors 20003.

[0035] It can be learned that there are a large quantity of power inductors in the inverter 2000. When the plurality of power inductors are specifically arranged in the inverter 2000, the plurality of power inductors may be fastened to an insulation bottom plate 4 through an adhesive. For example, FIG. 3 shows a design manner of two boost inductors 20001 in a conventional inverter according to an embodiment of this application. As shown in FIG. 3, the two boost inductors 20001 are fastened to the insulation bottom plate 4, so that the two boost inductors 20001 may be arranged in the power device as a whole.

[0036] In addition, the three filter inductors 20003 in the inverter 2000 may be fastened to another insulation bottom plate, so that the three filter inductors 20003 may be arranged in the inverter 2000 as a whole. This helps improve convenience of moving and mounting the power inductors in the inverter 2000.

[0037] However, to avoid mutual interference between the power inductors, still refer to FIG. 3. A specific interval d needs to be maintained between the power inductors disposed on the same insulation bottom plate 4. In addition, each power inductor is independently disposed, and a volume of each power inductor is large. As a result, the power inductor occupies large arrangement space in the inverter 2000. This is inconducive to implementing a miniaturization design of the inverter 2000.

[0038] In view of this, the power inductor provided in embodiments of this application is designed in a manner of integrating cover plates, so that adjacent inductors share a cover plate, to implement sharing of a magnetic circuit by a plurality of inductors. In such a design manner, the power inductor can meet a power conversion requirement of the power device, and space occupied by the power inductor can be effectively reduced, thereby helping implement a miniaturization design of the power device. To facilitate understanding of the power inductor provided in this application, the following describes the power inductor in detail with reference to specific embodiments.

[0039] The power inductor may usually include a magnetic core and a winding. The magnetic core is usually used as a magnetic conductive material of the power inductor. The winding is a coil made of a copper wire or an aluminum wire, and the winding is configured to conduct a current in the inductor.

[0040] FIG. 4 is a diagram of a structure of a magnetic core 1 of a power inductor according to an embodiment of this application. In this application, the magnetic core 1 of the power inductor includes two first cover plates 101, at least one second cover plate 102, and at least two groups of middle pillars 103, and each group of middle pillars 103 includes two middle pillars 103. For example, in FIG. 4, the magnetic core includes two first cover plates 101, one second cover plate 102, and two groups of middle pillars 103, the two first cover plates 101 are disposed opposite to each other, the second cover plate 102 and the two groups of middle pillars 103 are located between the two first cover plates 101, and the second cover plate 102 is located between the two groups of middle pillars 103.

[0041] In this application, each first cover plate 101 is connected to end parts of one group of middle pillars 103, and a connection manner may be but is not limited to bonding, to help improve processing efficiency of the magnetic core 1. Similarly, the second cover plate 102 is connected to end parts of the two adjacent groups of middle pillars 103 through bonding.

[0042] In the magnetic core 1 shown in FIG. 4, one first cover plate 101, one adjacent group of middle pillars 103, and the second cover plate 102 may be considered as one magnetic core structure, and the other first cover plate 101, the other adjacent group of middle pillars 103, and the second cover plate 102 may be considered as the other magnetic core structure. In other words, in a design manner of the magnetic core 1 provided in this application, the two adjacent groups of middle pillars 103 may share the second cover plate 102, to integrate the two magnetic core structures. Compared with a conventional solution in which two magnetic core structures are separately disposed, this manner can effectively reduce a volume of the magnetic core 1, and reduce materials used by the magnetic core 1, thereby helping reduce costs of the magnetic core 1.

[0043] FIG. 5 is a diagram of a structure of the power inductor 100 according to an embodiment of this application. The power inductor 100 further includes at least two windings 2. It may be understood that a quantity of windings 2 should be equal to a quantity of groups of middle pillars 103, and each winding 2 is wound around two middle pillars 103 in one group of middle pillars 103. For example, when the power inductor 100 includes the magnetic core 1 shown in FIG. 4, the power inductor 100 may include two windings 2, and the two windings 2 are wound around two groups of middle pillars 103 in a one-to-one correspondence. In other words, one winding 2 is correspondingly wound around each group of middle pillars 103.

[0044] It should be noted that, because each group of middle pillars 103 includes two middle pillars 103, and each winding 2 needs to be wound around the two middle pillars 103 at the same time, each winding 2 includes two winding parts 201. FIG. 6 is a diagram of a structure of the winding 2 according to an embodiment of this application. It can be seen from FIG. 6 that winding directions of the two winding parts 201 of the winding 2 are opposite, and wire heads of the winding parts 201 are located on a same side of the entire winding 2. In this way, when a current passes through the winding 2, directions of magnetic fluxes generated by the two winding parts 201 of the winding 2 may be the same.

[0045] Still refer to FIG. 5. In the power inductor 100 shown in FIG. 5, winding directions of the two windings 2 are opposite. For ease of description, in a Y direction in FIG. 5, that is, in an arrangement direction of the two first cover plates 101, the two windings 2 may be respectively defined as a first winding 2a and a second winding 2b, and the two groups of middle pillars are respectively defined as a first group of middle pillars 103a and a second group of middle pillars 103b. In this case, winding directions of the first winding 2a on two middle pillars 103 of the first group of middle pillars 103a are different, and winding directions of the second winding 2b on two middle pillars 103 of the second group of middle pillars 103b are different. In addition, as shown in FIG. 5, the second cover plate 102 is located between the first winding 2a and the second winding 2b.

[0046] In the power inductor 100 shown in FIG. 5, one first cover plate 101, the first group of middle pillars 103a, the second cover plate 102, and the first winding 2a may be considered as one inductor unit, and the other first cover plate 101, the second group of middle pillars 103b, the second cover plate 102, and the second winding 2b may be considered as the other inductor unit. In other words, in the design manner of the power inductor 100 provided in this application, two adjacent groups of middle pillars 103 may share the second cover plate 102, to integrate the two inductor units. Compared with a conventional solution in which two inductors are separately disposed, this manner can effectively reduce a volume of an overall structure of the power inductor 100.

[0047] In addition, when currents in a same direction respectively pass through the first winding 2a and the second winding 2b of the power inductor 100 shown in FIG. 5, for example, a current in an X direction passes through the first winding 2a, and a current in the X direction passes through the second winding 2b, the first winding 2a generates a magnetic flux in a clockwise direction, and the second winding 2b generates a magnetic flux in a counterclockwise direction. The X direction is an arrangement direction of two middle pillars 103 in a same group of middle pillars 103.

[0048] In this application, both the magnetic flux generated by the first winding 2a and the magnetic flux generated by the second winding 2b are conducted through the second cover plate 102, and directions of the magnetic fluxes generated by the first winding 2a and the second winding 2b are opposite. Therefore, the magnetic fluxes generated by the two windings 2 may be offset at the second cover plate 102.

[0049] Because a part of energy of the magnetic core 1 is irreversibly converted into heat in a magnetization process and an anti-magnetization process, an energy loss is caused, and the energy loss becomes a magnetic loss. Based on this, it may be understood that, in this application, the magnetic fluxes generated by the two windings 2 are offset at the second cover plate 102, so that a loss of the magnetic core 1 can be reduced, thereby helping improve efficiency of the power inductor 100.

[0050] Based on the design of the power inductor 100 shown in FIG. 5, in some possible application scenarios, the magnetic fluxes generated by the first winding 2a and the second winding 2b need to be superimposed at the second cover plate 102. In this case, currents in opposite directions may pass through the two windings 2, so that directions of the magnetic fluxes generated by the two windings 2 are the same, to implement magnetic flux superposition at the second cover plate 102.

[0051] In the power inductor 100 provided in this application, in the arrangement direction of the two first cover plates 101, winding directions of two adjacent windings 2 are the same; or in the arrangement direction of the two first cover plates 101, winding directions of two adjacent windings 2 are opposite. This is not limited in this application.

[0052] Therefore, it may be understood that, in this application, the winding directions of the two adjacent windings 2 of the power inductor 100 and directions of currents passing through the two adjacent windings 2 may be adjusted based on use requirements of the power inductor 100 in different application scenarios, to adjust directions of magnetic fluxes generated by the two adjacently disposed windings 2, so that magnetic flux offsetting or magnetic flux superposition is implemented at the second cover plate 102. Specifically, in the arrangement direction of the two first cover plates, when the winding directions of the two adjacent windings are the same and the directions of the currents passing through the two adjacent windings are opposite, magnetic fluxes generated by the two adjacent windings are offset at the second cover plate located between the two adjacent windings; or in the arrangement direction of the two first cover plates, when the winding directions of the two adjacent windings are opposite and the directions of the currents passing through the two adjacent windings are the same, magnetic fluxes generated by the two adjacent windings are offset at the second cover plate located between the two adjacent windings. In addition, in the arrangement direction of the two first cover plates, when the winding directions of the two adjacent windings are opposite and the directions of the currents passing through the two adjacent windings are opposite, magnetic fluxes generated by the two adjacent windings are superimposed at the second cover plate located between the two adjacent windings; or in the arrangement direction of the two first cover plates, when the winding directions of the two adjacent windings are the same and the directions of the currents passing through the two adjacent windings are the same, magnetic fluxes generated by the two adjacent windings are superimposed at the second cover plate located between the two adjacent windings.

[0053] However, in some possible application scenarios, a current needs to pass through only some windings 2 of the power inductor 100. In other words, only the some windings 2 are in a working state. For example, in the power inductor 100 shown in FIG. 5, a current passes through only the first winding 2a, and no current passes through the second winding 2b. To prevent a magnetic flux generated by a winding 2 in the working state from generating a high voltage on the other winding 2 through which no current passes, in the power inductor 100 provided in embodiments of this application, a magnetic permeability of the second cover plate 102 is higher than a magnetic permeability of each first cover plate 101, and the magnetic permeability of the second cover plate 102 is higher than a magnetic permeability of each adjacent middle pillar 103. In this way, the magnetic flux generated by the winding 2 through which the current passes may be conducted to the adjacent second cover plate 102 through the middle pillars 103, to form a magnetic flux loop. This can effectively reduce impact of the other winding 2 through which no current passes on the winding 2 in the working state, and help improve efficiency of the power inductor 100.

[0054] In this application, a material of the first cover plate 101 is different from a material of the second cover plate 102. Specifically, the material of the first cover plate 101 may be a metal powder core, and the material of the second cover plate 102 may be a material with a high magnetic permeability such as ferrite, nanocrystalline, or nanoamorphous. In addition, a material of the middle pillar 103 may also be a metal powder core, but materials of the first cover plate 101 and the middle pillar 103 may be the same or different. This is not limited in this application.

[0055] It may be understood that a proportional relationship between the magnetic permeability of the second cover plate 102 and the magnetic permeability of the first cover plate 101 may be specifically designed based on a specific application scenario. For example, in a possible embodiment of this application, the magnetic permeability of the second cover plate 102 may be twice or more than twice the magnetic permeability of the first cover plate 101, so that the magnetic permeability of the second cover plate 102 is obviously different from the magnetic permeability of the first cover plate 101, and after a magnetic flux generated by the winding 2 passes through the middle pillars 103, most of the magnetic flux can be conducted through the adjacent second cover plate 102. This can reduce mutual impact of magnetic fluxes generated by the windings in the power inductor 100, and help implement magnetic circuit sharing.

[0056] In addition, in this application, the magnetic permeability of the second cover plate 102 is also twice or more than twice the magnetic permeability of the adjacent middle pillar 103, so that the magnetic permeability of the second cover plate 102 is obviously different from the magnetic permeability of the middle pillar 103. This helps improve efficiency of the power inductor 100.

[0057] Still refer to FIG. 5. The power inductor 100 provided in embodiments of this application further includes an air gap sheet 3, and the air gap sheet 3 may be disposed between the second cover plate 102 and at least one adjacent group of middle pillars 103. For example, an air gap sheet 3 may be disposed between the second cover plate 102 and one adjacent group of middle pillars 103, and no air gap sheet 3 is disposed between the second cover plate 102 and the other adjacent group of middle pillars 103. In this case, a thickness of the air gap sheet 3 disposed between the second cover plate 102 and the adjacent group of middle pillars 103 may be, for example, 0.5 mm. Alternatively, an air gap sheet 3 may be disposed between the second cover plate 102 and each of two adjacent groups of middle pillars 103. In this case, thicknesses of air gap sheets 3 disposed on two sides of the second cover plate 102 may be the same or may be different. For example, an air gap sheet 3 of 0.25 mm may be disposed between the second cover plate 102 and each of the two adjacent groups of middle pillars 103. In embodiments of this application, the air gap sheet 3 is disposed between the second cover plate 102 and adjacent middle pillars 103, so that an air gap between the second cover plate 102 and the adjacent middle pillars 103 can be effectively increased. This can further reduce a risk that a magnetic flux generated by a winding 2 in the working state generates a high voltage on the other winding 2 through which no current passes, and help improve efficiency of the power inductor 100.

[0058] In this application, for example, the air gap sheet 3 may be in a regular shape such as a circle, a rectangle, or a rhombus, or may be in some possible irregular shapes. A specific shape of the air gap sheet 3 is not limited in this application. In addition, the air gap sheet 3 may be but is not limited to a non-metal film like a polyester film. A quantity of air gap sheets 3 disposed between the second cover plate 102 and each middle pillar 103 may be selected based on a requirement of a specific application scenario.

[0059] As shown in FIG. 5, the power inductor 100 provided in this application further includes the insulation bottom plate 4, at least one of the two first cover plates 101 and the second cover plate 102 is fastened to the insulation bottom plate 4, and a connection manner may be but is not limited to bonding. The insulation bottom plate 4 may be used as a support structure of the entire power inductor 100, to improve structural reliability of the power inductor 100, and facilitate movement and mounting of the entire power inductor 100.

[0060] In FIG. 5, the structure of the power inductor 100 provided in this application is specifically described by using an example in which the magnetic core 1 includes two first cover plates 101, one second cover plate 102, and two groups of middle pillars 103. For example, the power inductor 100 may be used in the inverter, and the power inductor 100 may be used in the plurality of direct current conversion circuits 2001 of the inverter. Specifically, the plurality of direct current conversion circuits 2001 in the inverter include the first boost circuit and the second boost circuit, the first winding 2a of the power inductor 100 is connected to the first boost circuit and is used as a boost inductor of the first boost circuit, and the second winding 2b is connected to the second boost circuit and is used as a boost inductor of the second boost circuit.

[0061] It may be understood that, in the design manner of the power inductor 100 provided in this application, the two boost inductors in the direct current conversion circuit 2001 of the inverter may be integrated into an integrated structure. Compared with a conventional solution in which two boost inductors are independently designed, this design manner can significantly reduce a volume.

[0062] In addition, FIG. 7 is a diagram of a structure of an inverter according to an embodiment of this application. The inverter further includes at least one circuit board, and the plurality of direct current conversion circuits 2001 are disposed on the at least one circuit board. In addition to the power inductor 100, the direct current conversion circuit 2001 further includes at least one switch module 2004, and the two windings of the power inductor 100 are respectively connected to the at least one switch module 2004 in different direct current conversion circuits in the plurality of direct current conversion circuits 2001. In the inverter shown in FIG. 7, the at least one circuit board includes a main power board 2003 and a first circuit board 2005, the at least one switch module 2004 is disposed on the main power board 2003, and the power inductor 100 is disposed on the first circuit board 2005. In this way, the power inductor 100 may be connected to a circuit trace of the main power board 2003 through a cable, to implement an electrical connection to the switch module 2004. In this application, components in the direct current conversion circuit 2001 are disposed in different boards, so that a size of the main power board 2003 can be reduced, thereby reducing costs of the main power board 2003. In addition, layout flexibility, in the power device, of the components in the direct current conversion circuit 2001 can be improved, thereby improving internal space utilization of the power device, and helping implementing a miniaturization design of the entire power device.

[0063] It should be noted that, in some other possible embodiments of this application, the power inductor 100 may alternatively be directly disposed on the main power board 2003. This helps improve integration of the inverter.

[0064] It may be understood that, in this application, the power inductor of the direct current conversion circuit 2001 uses the design manner of the power inductor 100 provided in this application, so that space occupied by the power inductor 100 on the main power board 2003 is small, thereby helping reduce an area of the main power board 2003, and implementing a miniaturization design of the power device. In addition, when the area of the main power board 2003 of the power device remains unchanged, a requirement of disposing more components on the main power board 2003 may be further met. This helps improve function diversification of the power device.

[0065] In this application, a quantity of second cover plates 102 and a quantity of middle pillars 103 in the power inductor 100 may be selected based on a requirement of a specific application scenario. For example, when the power inductor 100 is used in the alternating current output end of the direct current conversion circuit of the inverter, the power inductor 100 may be used to implement an integrated design of three filter inductors. During specific implementation, FIG. 8 is a diagram of another structure of the power inductor 100 according to this application. In FIG. 8, the magnetic core 1 of the power inductor 100 includes two first cover plates 101, two second cover plates 102, and three groups of middle pillars 103. A specific disposing manner of the magnetic core 1 is similar to a specific disposing manner in the power inductor 100 shown in FIG. 5. Details are not described herein again. In addition, the power inductor 100 includes three windings 2, and the three windings 2 are wound around the three groups of middle pillars 103 in a one-to-one correspondence.

[0066] The power inductor 100 shown in FIG. 8 may be used in an inverter circuit of an inverter. For ease of description, the three windings in FIG. 8 may be respectively defined as a third winding 2c, a fourth winding 2d, and a fifth winding 2e. In this case, one second cover plate 102 is located between the third winding 2c and the fourth winding 2d, and the other second cover plate 102 is located between the fourth winding 2d and the fifth winding 2e. In addition, the foregoing three windings are respectively connected to output ends of different inverter bridge arms in three inverter bridge arms of the inverter circuit, so that each winding may be used as a filter inductor of an output end of a correspondingly connected inverter bridge arm. The filter inductor of the inverter circuit is disposed in the manner of disposing the power inductor provided in this application. Compared with a conventional solution in which filter inductors are separately disposed, this manner can achieve same filtering effect while reducing space occupied by the filter inductors of the inverter circuit, thereby helping implement a miniaturization design of the inverter.

[0067] In addition, when the inverter is a three-phase four-wire inverter, the inverter circuit includes four inverter bridge arms. To meet a power conversion requirement of an alternating current output end of the inverter, the power inductor 100 may be disposed with reference to FIG. 9, and the magnetic core 1 of the power inductor 100 includes two first cover plates 101, three second cover plates 102, and four groups of middle pillars 103. In addition, the power inductor 100 includes four windings 2, and the four windings 2 are wound around the four groups of middle pillars 103 in a one-to-one correspondence. A specific disposing manner of the power inductor 100 is similar to that of the power inductor 100 shown in FIG. 8. Details are not described herein again.

[0068] It should be noted that, as shown in FIG. 7, in this application, the inverter circuit 2002 may alternatively be disposed on the main power board 2003. In addition, in the inverter circuit 2002, the power inductor 100 may be separately disposed on a second circuit board 2006 with a small area, so that the power inductor 100 may be connected to another part that is of the inverter circuit 2002 and that is disposed on the main power board 2003 through a cable. This helps reduce a size of the main power board 2003, thereby reducing costs of the main power board 2003. Moreover, this further helps improve layout flexibility, in the power device, of components in the inverter circuit 2002, thereby improving internal space utilization of the power device, and helping implement a miniaturization design of the entire power device. In another possible embodiment of this application, the power inductor 100 in the inverter circuit 2002 may alternatively be directly disposed on the main power board 2003. This helps improve integration of the inverter. In addition, in some other possible embodiments of this application, the direct current conversion circuit 2001 and the inverter circuit 2002 may alternatively be separately disposed on different circuit boards.

[0069] Other structures of the power inductor 100 shown in FIG. 8 and FIG. 9 may be disposed with reference to any one of the foregoing embodiments. Details are not described herein again.

[0070] The foregoing merely describes, with reference to specific application scenarios, some examples of specific structures of the power inductor 100 provided in this application. However, in some other possible embodiments of this application, some adaptive variations may be further made to the specific structure of the power inductor 100 based on a specific power conversion requirement. The variations are not enumerated herein, but should be understood as falling within the protection scope of this application.

[0071] In the power inductor 100 provided in embodiments of this application, two groups of middle pillars 103 that are disposed adjacently share one second cover plate 102, so that magnetic fluxes generated by a plurality of windings 2 share a magnetic circuit. In this way, a multi-inductor use requirement of the power device can be met, and space occupied by the power inductor 100 in the power device can be effectively reduced, thereby helping implement a miniaturization design of the power device.

[0072] The foregoing embodiments of this application are described by using use of the power inductor 100 in the inverter. It may be understood that the power inductor 100 provided in this application may be further used in other power devices, and a specific manner of disposing the power inductor 100 in various power devices is similar to the foregoing manner of disposing the power inductor 100 in the inverter. Details are not described herein again. However, it should be understood that this shall fall within the protection scope of this application.

[0073] Because a volume of the power inductor 100 provided in embodiments of this application is small, when the power inductor 100 is disposed in the power device, space occupied by the power inductor 100 on a circuit board of the power device is small. This helps reduce an area of the circuit board, and helps implement a miniaturization design of the power device. In addition, when the area of the circuit board of the power device remains unchanged, a requirement of disposing more components on the circuit board may be further met. This helps improve function diversification of the power device.

[0074] The foregoing descriptions are merely specific implementations of this application, but are not intended to limit the protection scope of this application. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in this application shall fall within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims

1. A power device, comprising at least one circuit board and a plurality of direct current conversion circuits disposed on the at least one circuit board, wherein the direct current conversion circuit comprises at least one switch module and a power inductor; the power inductor comprises a magnetic core and at least two windings, the magnetic core comprises two first cover plates, at least one second cover plate, and at least two groups of middle pillars, and each group of middle pillars comprises two middle pillars; each winding is wound around two middle pillars of one group of middle pillars; the two first cover plates are disposed opposite to each other, the at least one second cover plate and the at least two groups of middle pillars are located between the two first cover plates, each first cover plate is connected to end parts of one group of middle pillars, each second cover plate is located between two adjacent groups of middle pillars, and each second cover plate is connected to end parts of the two adjacent groups of middle pillars; and the at least two windings are respectively connected to the at least one switch module in different direct current conversion circuits in the plurality of direct current conversion circuits.

2. The power device according to claim 1, wherein a pillar shaft of each middle pillar is perpendicular to plate surfaces of the two first cover plates, and an air gap sheet is disposed between the second cover plate and at least one adjacent group of middle pillars.

3. The power device according to claim 1 or 2, wherein a magnetic permeability of each second cover plate is higher than a magnetic permeability of each first cover plate, and the magnetic permeability of each second cover plate is higher than a magnetic permeability of each adjacent middle pillar.

4. The power device according to claim 3, wherein the magnetic permeability of the second cover plate is twice or more than twice the magnetic permeability of the first cover plate.

5. The power device according to claim 4, wherein a material of the second cover plate is ferrite, nanocrystalline, or nanoamorphous, and a material of the first cover plate and a material of the middle pillar are metal powder cores.

6. The power device according to any one of claims 1 to 5, wherein in an arrangement direction of the two first cover plates, when winding directions of two adjacent windings are the same and directions of currents passing through the two adjacent windings are opposite, magnetic fluxes generated by the two adjacent windings are offset at the second cover plate located between the two adjacent windings; or in an arrangement direction of the two first cover plates, when winding directions of two adjacent windings are opposite and directions of currents passing through the two adjacent windings are the same, magnetic fluxes generated by the two adjacent windings are offset at the second cover plate located between the two adjacent windings.

7. The power device according to any one of claims 1 to 5, wherein in an arrangement direction of the two first cover plates, when winding directions of two adjacent windings are opposite and directions of currents passing through the two adjacent windings are opposite, magnetic fluxes generated by the two adjacent windings are superimposed at the second cover plate located between the two adjacent windings; or in an arrangement direction of the two first cover plates, when winding directions of two adjacent windings are the same and directions of currents passing through the two adjacent windings are the same, magnetic fluxes generated by the two adjacent windings are superimposed at the second cover plate located between the two adjacent windings.

8. The power device according to any one of claims 1 to 5, wherein the at least one circuit board comprises a main power board and a first circuit board, the at least one switch module is disposed on the main power board, the power inductor is disposed on the first circuit board, and the power inductor is connected to a circuit trace of the main power board through a cable, to implement an electrical connection to the switch module.

9. A power device, comprising a circuit board and an inverter circuit disposed on the circuit board, wherein the inverter circuit comprises at least two inverter bridge arms and a filter inductor; the filter inductor comprises a magnetic core and at least two windings, the magnetic core comprises two first cover plates, at least one second cover plate, and at least two groups of middle pillars, and each group of middle pillars comprises two middle pillars; each winding is wound around two middle pillars of one group of middle pillars; the two first cover plates are disposed opposite to each other, the at least one second cover plate and the at least two groups of middle pillars are located between the two first cover plates, each first cover plate is connected to end parts of one group of middle pillars, each second cover plate is located between two adjacent groups of middle pillars, and each second cover plate is connected to end parts of the two adjacent groups of middle pillars; and the at least two windings are respectively connected to output ends of different inverter bridge arms in the at least two inverter bridge arms.

10. A power inductor, comprising a magnetic core and at least two windings, wherein the magnetic core comprises two first cover plates, at least one second cover plate, and at least two groups of middle pillars, and each group of middle pillars comprises two middle pillars; each winding is wound around two middle pillars of one group of middle pillars; and the two first cover plates are disposed opposite to each other, the at least one second cover plate and the at least two groups of middle pillars are located between the two first cover plates, each first cover plate is connected to end parts of one group of middle pillars, each second cover plate is located between two adjacent groups of middle pillars, and each second cover plate is connected to end parts of the two adjacent groups of middle pillars.

11. The power inductor according to claim 10, wherein a magnetic permeability of each second cover plate is higher than a magnetic permeability of each first cover plate, and the magnetic permeability of each second cover plate is higher than a magnetic permeability of each adjacent middle pillar.

12. The power inductor according to claim 10 or 11, wherein the power inductor further comprises an air gap sheet, and the air gap sheet is disposed between the second cover plate and at least one adjacent group of middle pillars.

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