Power conversion device

Abstract

The embodiment of the invention provides a power conversion device, and relates to the technical field of power supplies, the power conversion device is used for power conversion between direct current and alternating current, the power conversion device comprises a device shell, a circuit board and a power inductor, the device shell comprises a top cover and a bottom shell which are fixedly connected, and the top cover and the bottom shell define a containing cavity; the circuit board is located in the containing cavity. The power inductor is located in the containing cavity and fixed between the circuit board and the bottom shell. The power inductor comprises an installation base, a magnetic core, a magnetic ring, a first winding and a second winding. The mounting seat is fixed on the circuit board, the magnetic core and the magnetic ring are both fixed on the mounting seat, the first winding and the second winding are both wound on the magnetic core, one pin of the first winding and one pin of the second winding both penetrate through the magnetic ring, and at least one pin of the first winding and at least one pin of the second winding are both connected with the circuit board. According to the technical scheme, unified installation of the inductor and the magnetic ring is facilitated, installation procedures are reduced, and the risk that the magnetic ring is damaged is also reduced.

Description

Technical Field

[0001] This application relates to the technical field of power supplies, and particularly to a power conversion device. Background Art

[0002] In a power conversion device (for example, a photovoltaic inverter), a magnetic core is provided on the input side or the output side of an inductor to suppress common-mode current through the magnetic core.

[0003] In the related art, a winding is led out by an electronic wire, and a magnetic core for suppressing common mode is sleeved outside the electronic wire. However, with the solution of the related art, the inductor and the magnetic core need to be separately installed. During the process of manually installing the magnetic core, the magnetic core may be knocked and there is also a risk of incorrect installation of the magnetic core, which affects the normal use of the magnetic core. In addition, the installation process is increased. Moreover, the magnetic core can move relative to the electronic wire, and there is a greater risk of damage to the magnetic core during the installation and handling of the power conversion device. Summary of the Invention

[0004] This application provides a power conversion device, which facilitates the unified installation of the inductor and the magnetic core, reduces the installation process, and also reduces the risk of damage to the magnetic core.

[0005] To achieve the above object, this application adopts the following technical solutions:

[0006] In a first aspect of this application, a power conversion device is provided. The power conversion device is used for power conversion between direct current and alternating current. Among them, the power conversion device includes a device housing, a circuit board, and a power inductor. The device housing includes a top cover and a bottom case that are fixedly connected. The top cover and the bottom case enclose a receiving cavity. Heat dissipation fins are provided on the outer side of the bottom case. The bottom case is an integrally formed structural member; the circuit board is located in the receiving cavity, and the board surface of the circuit board is perpendicular to the arrangement direction of the top cover and the bottom case; the power inductor is located in the receiving cavity and fixed between the circuit board and the bottom case. The power inductor includes: a mounting seat, a magnetic core, a magnetic ring, a first winding, and a second winding; the mounting seat is fixed to the circuit board, the magnetic core and the magnetic ring are both fixed to the mounting seat, the first winding and the second winding are both wound around the magnetic core, one lead of the first winding and one lead of the second winding both pass through the magnetic ring, and at least one lead of the first winding and at least one lead of the second winding are both connected to the circuit board.

[0007] The receiving cavity of the device housing is used to receive a circuit board and some electronic components (such as a power module, a power inductor, etc.). Among them, the heat dissipation fins can assist the device housing in heat dissipation and reduce the possibility of the temperature inside the device housing being too high. Among them, the power inductor integrates a magnetic core, windings (a first winding and a second winding), and a magnetic ring. The magnetic core and the magnetic ring are both fixed on the mounting seat, so that the first winding and the second winding are wound around the magnetic core, and each of the first winding and the second winding has a pin passing through the magnetic ring. When a common-mode current flows through the first winding and the second winding, the magnetic fluxes generated by the first winding and the second winding on the magnetic ring are superimposed on each other, so as to have a larger inductance and play an inhibitory role on the common-mode current. By integrating the magnetic core, the windings, and the magnetic ring, the power inductor of the present application facilitates the unified installation of the magnetic core and the magnetic ring during the installation process of the power inductor, reducing the installation process. Moreover, the magnetic ring is fixed to the mounting seat, that is, the position of the magnetic ring is relatively fixed, and the magnetic ring will not move randomly inside the device housing, reducing the possibility of the magnetic ring bumping into other electronic components inside the device housing and also reducing the possibility of the magnetic ring falling off, thereby reducing the risk of damage to the magnetic ring.

[0008] In addition, both the first winding and the second winding of the power inductor are connected to the circuit board, so that the power inductor exists in the device housing in the form of a board-mounted inductor, without the need to additionally reserve space for installing the power inductor around the circuit board, nor the need to pot the installation position of the power inductor, saving the potting cost of the power inductor and reducing the process complexity of installing the power inductor.

[0009] In an optional implementation manner, the power inductor further includes a "U"-shaped first metal row and a "U"-shaped second metal row. The openings of the first metal row and the second metal row both face the mounting seat; one end of the first metal row passes through the magnetic ring and is connected to the circuit board, and the other end of the first metal row is located outside the magnetic ring and is electrically connected to the pin of the first winding passing through the magnetic ring; one end of the second metal row passes through the magnetic ring and is connected to the circuit board, and the other end of the second metal row is located outside the magnetic ring and is electrically connected to the pin of the second winding passing through the magnetic ring.

[0010] Set the first metal row and the second metal row, and make the first metal row and the second metal row cross-connected on the magnetic core. Among them, the end of the first metal row located outside the magnetic core is connected to the pin of the first winding passing through the magnetic core. Equivalently, the first winding, the first metal row, and the structure connecting the two together form a coil wound around the magnetic core for two turns (the impedance is about 4 times that of a single turn); the end of the second metal row located outside the magnetic core is connected to the pin of the second winding passing through the magnetic core. Equivalently, the second winding, the second metal row, and the structure connecting the two together form a coil wound around the magnetic core for two turns (the impedance is about 4 times that of a single turn). Under the same impedance requirement, the cross-sectional area of the magnetic core can be reduced, that is, the height of the magnetic core is reduced, the height of the power inductor itself is reduced, and the volume of the power inductor and the area occupied on the circuit board are reduced.

[0011] In an alternative embodiment, the other end of the first metal row and the pin of the first winding passing through the magnetic core are electrically connected through the traces on the circuit board; the other end of the second metal row and the pin of the second winding passing through the magnetic core are electrically connected through the traces on the circuit board.

[0012] Connect both ends of the first metal row and both pins of the first winding to the circuit board, and realize the connection between the first metal row and the first winding through the traces on the circuit board. The current passes through the first winding, the first metal row, and the traces on the circuit board used to connect the two, which is equivalent to the current passing through a coil wound around the magnetic core for two turns. Similarly, connect both ends of the second metal row and both pins of the second winding to the circuit board, and realize the connection between the second metal row and the second winding through the traces on the circuit board. The current passes through the second winding, the second metal row, and the traces on the circuit board used to connect the two, which is equivalent to the current passing through a coil wound around the magnetic core for two turns. Through this design method, the impedance of the magnetic core can be improved.

[0013] In an alternative embodiment, the mounting base is located between the magnetic core and the circuit board. Both pins of the first winding, both pins of the second winding, both ends of the first metal row, and both ends of the second metal row pass through the mounting base and are inserted into the circuit board.

[0014] Set the mounting base between the magnetic core and the circuit board, make the mounting base serve as the base of the magnetic core, and make the first winding, the second winding, the first metal row, and the second metal row all pass through the mounting base. During the installation of the power inductor, just move the mounting base of the power inductor close to the circuit board, and make the parts of the first winding, the second winding, the first metal row, and the second metal row extending between the mounting base and the circuit board be inserted into the circuit board.

[0015] In an alternative embodiment, the mounting base has opposite first and second sides, and the distance between the magnetic ring and the first side is less than the distance between the magnetic ring and the second side; the other ends of the first metal row and the second metal row are both located between the magnetic ring and the second side.

[0016] Compared with the distance from the second side, the magnetic ring is closer to the first side, and the ends of the first metal row connected to the first winding and the ends of the second metal row connected to the second winding are both located between the magnetic ring and the second side. In this way, the ends of the first metal row not connected to the first winding (the ends passing through the magnetic ring) and the ends of the second metal row not connected to the second winding (the ends passing through the magnetic ring) are both close to the first side, facilitating the layout of the traces on the circuit board.

[0017] In an alternative embodiment, the power inductor further includes a plurality of metal sheets fixed to the mounting base; the other end of the first metal row and the pin of the first winding passing through the magnetic ring are electrically connected through one metal sheet; the other end of the second metal row and the pin of the second winding passing through the magnetic ring are electrically connected through another metal sheet.

[0018] The connection between the first metal row and the first winding is achieved through the metal sheet on the mounting base. The current passes through the first winding, the first metal row, and the metal sheet connecting the two, which is equivalent to the current passing through a coil wound around the magnetic ring for two turns. Similarly, the connection between the second metal row and the second winding can also be achieved through the metal sheet on the mounting base. The current passes through the second winding, the second metal row, and the metal sheet connecting the two, which is equivalent to the current passing through a coil wound around the magnetic ring for two turns. Through this design method, the impedance of the magnetic ring can be increased.

[0019] In an alternative embodiment, the power inductor further includes a first coil and a second coil wound around the magnetic ring; one pin of the first coil is located outside the magnetic ring and is electrically connected to the pin of the first winding passing through the magnetic ring, and the other pin of the first coil passes through the magnetic ring and is connected to the circuit board; one pin of the second coil is located outside the magnetic ring and is electrically connected to the pin of the second winding passing through the magnetic ring, and the other pin of the second coil passes through the magnetic ring and is connected to the circuit board.

[0020] The first coil is connected to the pin of the first winding passing through the magnetic core. The part of the first winding passing through the magnetic core is equivalent to adding one turn to the first coil. Similarly, the second coil is connected to the pin of the second winding passing through the magnetic core, and the part of the second winding passing through the magnetic core is equivalent to adding one turn to the second coil. This increases the impedance of the magnetic core. Under the same impedance requirement, the cross-sectional area of the magnetic core can be reduced, that is, the height of the magnetic core is reduced, the height of the power inductor itself is reduced, and the volume and the board (printed circuit board) area of the power inductor are reduced.

[0021] In an alternative embodiment, the magnetic core is in a "mouth" shape, and the first winding and the second winding are respectively wound around two opposite magnetic posts of the magnetic core.

[0022] With a "mouth"-shaped magnetic core, both the first winding and the second winding can be wound around the magnetic core, which improves the integration of the power inductor and reduces the volume of the power inductor, reducing the board area of the power inductor on the printed circuit board. There is more area on the printed circuit board available for installing other electronic components, improving the power rating of the power conversion device.

[0023] In an alternative embodiment, the power inductor further includes a bracket. The bracket is fixed to the surface of the mounting base facing the magnetic core. The bracket supports the magnetic core, and the magnetic ring is located in the gap between the magnetic core and the mounting base.

[0024] The bracket can support the magnetic core, forming a gap for accommodating the magnetic ring between the magnetic core and the mounting base, facilitating the pins of the first winding and the second winding to pass through the magnetic ring. Moreover, installing the magnetic ring between the magnetic core and the mounting base reduces the occupation of the mounting space on the printed circuit board by the power inductor.

[0025] In an alternative embodiment, the power inductor further includes a first protective cover. The first protective cover covers the magnetic ring and is fixed to the mounting base. The first protective cover has a guiding hole, and the pins of the first winding passing through the magnetic ring and the pins of the second winding passing through the magnetic ring both pass through the guiding hole.

[0026] In some cases, the magnetic ring is vulnerable to damage. For example, the magnetic ring can be a nanocrystalline magnetic ring. Covering the magnetic ring with the first protective cover can protect the magnetic ring and reduce the possibility of the magnetic ring being damaged. Since both the first winding and the second winding pass through the magnetic ring, when the first protective cover is covered outside the magnetic ring, the guiding hole is provided to guide the pins of the first winding and the second winding, reducing the impact of installing the first protective cover on the assembly of the first winding and the second winding.

[0027] In an alternative embodiment, the power inductor further includes a second protective cover. The second protective cover is fixed to the surface of the mounting base facing the magnetic core. The second protective cover has a groove recessed away from the magnetic core, and the magnetic ring is installed in the groove. The first protective cover covers the magnetic ring and is cooperatively connected with the second protective cover.

[0028] The second protective cover can be integrally connected to the mounting base, or it can be an independent structure fixed to the mounting base by adhesion (or other means). Limiting the magnetic ring through the groove in the second protective cover is beneficial to the installation of the magnetic ring. After the magnetic ring is installed in the second protective cover, the first protective cover is cooperatively connected to the second protective cover, and the magnetic ring is protected by the first protective cover and the second protective cover, reducing the possibility of damage to the magnetic ring.

[0029] In an alternative embodiment, the power conversion device further includes a DC-AC power conversion circuit disposed on a circuit board. The input pins of the first winding pins and the input pins of the second winding pins are both connected to the output terminal of the DC-AC power conversion circuit. The output pins of the first winding pins and the output pins of the second winding pins are both used to connect to a load; the input pins of the first winding and the input pins of the second winding both pass through the magnetic ring; or, the output pins of the first winding and the output pins of the second winding both pass through the magnetic ring.

[0030] The DC-AC power conversion circuit can convert direct current into alternating current. For example, when the power conversion device is used as an inverter, it can convert the direct current from a photovoltaic module or a storage battery into alternating current and output it to the power grid or a load. Among them, the first pin and the second pin of the power inductor are both connected to the output terminal of the DC-AC power conversion circuit. For example, the power inductor serves as the L1 inductor in an LCL filter circuit. Making the input pins of the first winding and the input pins of the second winding both pass through the magnetic ring, or making the output pins of the first winding and the output pins of the second winding both pass through the magnetic ring, the magnetic ring plays a role in suppressing the common-mode current.

[0031] In an alternative embodiment, the DC-AC power conversion circuit includes a first arm and a second arm disposed between the positive DC bus and the negative DC bus. The first arm includes a first switching tube and a second switching tube connected in series, and the second arm includes a third switching tube and a fourth switching tube connected in series; the input pin of the first winding is connected to the midpoint of the first arm, and the input pin of the second winding is connected to the midpoint of the second arm.

[0032] Through the first switching tube and the second switching tube in the first arm, and the third switching tube and the fourth switching tube in the second arm, direct current can be converted into alternating current to achieve power conversion.

[0033] In an alternative embodiment, the power inductor is thermally connected to the bottom case.

[0034] Thermally connect the power inductor to the bottom case. When the temperature of the power inductor is relatively high, the heat of the power inductor can be transferred to the bottom case, and heat exchange is carried out with the outside air through the heat dissipation fins on the bottom case, realizing the heat dissipation of the power inductor.

[0035] In a second aspect of the present application, another power conversion device is provided. The power conversion device is used for power conversion between direct current and alternating current. Wherein, the power conversion device includes a device case, a circuit board, and a power inductor. The device case includes a top case and a bottom case fixedly connected. The top case and the bottom case enclose a receiving cavity. Heat dissipation fins are arranged on the outside of the bottom case, and the bottom case is an integrally formed structural member; the circuit board is located in the receiving cavity, and the plane of the circuit board is perpendicular to the arrangement direction of the top case and the bottom case; the power inductor is located in the receiving cavity and fixed between the circuit board and the bottom case. The power inductor includes: a mounting base, a magnetic core, a magnetic ring, and a winding; the mounting base is fixed to the circuit board, both the magnetic core and the magnetic ring are fixed to the mounting base, the winding is wound around the magnetic core, one lead of the winding passes through the magnetic ring, and at least one lead of the winding is connected to the circuit board.

[0036] The receiving cavity of the device case is used to receive the circuit board and some electronic components (for example, power modules, power inductors, etc.). Among them, the heat dissipation fins can assist the device case in heat dissipation and reduce the possibility of overheating inside the device case. Among them, the magnetic core, winding, and magnetic ring are integrated in the power inductor. Both the magnetic core and the magnetic ring are fixed on the mounting base, the winding is wound around the magnetic core, and one lead of the winding passes through the magnetic ring. During the installation process of the power inductor, it is convenient for the unified installation of the magnetic core and the magnetic ring, reducing the installation process. In addition, the winding of the power inductor is connected to the circuit board, so that the power inductor exists in the device case in the form of a board-mounted inductor, without the need to additionally reserve space for the installation of the power inductor outside the circuit board, and there is no need to pot the installation position of the power inductor, saving the potting cost of the power inductor and reducing the process complexity of installing the power inductor.

[0037] In an optional implementation manner, the power conversion device further includes a DC-AC power conversion circuit. The DC-AC power conversion circuit is arranged on the circuit board. The input lead of the winding leads is used to connect to a DC source, and the output lead of the winding leads is connected to the input end of the DC-AC power conversion circuit. The input lead of the winding or the output lead of the winding passes through the magnetic ring.

[0038] Among them, the power inductor can be a Boost inductor and is used in a Boost circuit (DC-DC power conversion circuit). In this case, the power inductor is connected between a DC source (for example, a photovoltaic module, an energy storage battery, etc.) and the DC-AC power conversion circuit. Description of the Drawings

[0039] Figure 1 It is a schematic diagram of a photovoltaic energy storage system provided by an embodiment of the present application;

[0040] Figure 2 Schematic diagram of the structure of a power conversion device provided by an embodiment of the present application;

[0041] Figure 3 Topological diagram of a power conversion device provided by an embodiment of the present application;

[0042] Figure 4 Schematic diagram of the internal structure of a power conversion device provided by an embodiment of the present application;

[0043] Figure 5 Schematic diagram of the structure of a power inductor provided by an embodiment of the present application;

[0044] Figure 6 Schematic diagram of the structure of a magnetic core provided by an embodiment of the present application;

[0045] Figure 7 Schematic diagram of the structure of a magnetic ring provided by an embodiment of the present application;

[0046] Figure 8 Topological diagram of a DC-AC power conversion circuit provided by an embodiment of the present application;

[0047] Figure 9 Schematic diagram of the structure of another power inductor provided by an embodiment of the present application;

[0048] Figure 10 Schematic diagram of the split structure of a magnetic core and a magnetic ring provided by an embodiment of the present application;

[0049] Figure 11 Schematic diagram of the structures of multiple metal buses provided by an embodiment of the present application;

[0050] Figure 12 Schematic diagram of the structure of the traces on a circuit board provided by an embodiment of the present application;

[0051] Figure 13 Schematic diagram of the position of a magnetic ring provided by an embodiment of the present application;

[0052] Figure 14 Schematic diagram of the position of another magnetic ring provided by an embodiment of the present application;

[0053] Figure 15 Schematic diagram of the structure of yet another power inductor provided by an embodiment of the present application;

[0054] Figure 16 Schematic diagram of the split structure of another magnetic core and magnetic ring provided by an embodiment of the present application;

[0055] Figure 17Schematic diagram of yet another power inductor provided by an embodiment of the present application;

[0056] Figure 18 Schematic diagram of yet another power inductor provided by an embodiment of the present application;

[0057] Figure 19 Schematic diagram of a structure of a first protective cover and a second protective cover provided by an embodiment of the present application;

[0058] Figure 20 Schematic diagram of another structure of a first protective cover and a second protective cover provided by an embodiment of the present application;

[0059] Figure 21 Schematic diagram of another structure of a power conversion device provided by an embodiment of the present application.

[0060] Reference numerals:

[0061] 100 - Photovoltaic and energy storage system; 10 - Photovoltaic module; 20 - Power conversion device; 201 - Inverter; 30 - Power grid or load; 40 - Energy storage battery; 1 - Device housing; 11 - Top cover; 12 - Bottom case; 121 - Heat dissipation fins; 13 - Receiving cavity; 14 - Thermal pad; 2 - Terminal; 3 - DC - DC power conversion circuit; 4 - DC - AC power conversion circuit; 5 - Circuit board; 51 - First trace; 52 - Second trace; 53 - Third trace; 54 - Fourth trace; 55 - Fifth trace; 56 - Sixth trace; 6 - Power inductor; 61 - Mounting base; 611 - First side; 612 - Second side; 62 - Magnetic core; 63 - Magnetic ring; 64 - First winding; 65 - Second winding; 66 - Bracket; 67 - Metal strip; 671 - First metal strip; 672 - Second metal strip; 68 - Metal sheet; 691 - First coil; 692 - Second coil; 7 - Second protective cover; 71 - Groove; 8 - First protective cover; 81 - Guide hole; 811 - First sub - guide hole; 812 - Second sub - guide hole; 821 - First through - hole; 822 - Second through - hole. Detailed implementation manners

[0062] Next, the technical solutions in the embodiments of the present application will be described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments.

[0063] In the present application, terms such as "first" and "second" are only used for descriptive purposes, to distinguish one element from another, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features.

[0064] In this application, unless otherwise clearly specified or limited, the meaning of "a plurality of" is two or more than two.

[0065] In addition, in this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in this application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0066] In the drawings of the embodiments of this application, entity structures such as components and assemblies are represented by guide lines; structures composed of multiple components are represented by brackets or guide lines with solid arrows; hollow structures such as openings, holes, spaces, and cavities are represented by guide lines with hollow arrows; reference lines for directions, dimensions, etc. are all represented by straight lines with hollow arrows.

[0067] Figure 1 Exemplarily, the structure of a photovoltaic energy storage system 100 (solar photovoltaic energy storage power generation system) is shown, including a photovoltaic system and an energy storage system. Referring to Figure 1 , in the photovoltaic system, the photovoltaic module 10 directly converts solar energy into electrical energy by the photovoltaic effect. Among them, the photovoltaic module 10 usually includes a plurality of solar cells connected in series or in parallel to achieve a certain output power. The inverter 201 is used to convert the direct current from the photovoltaic module 10 into alternating current and deliver the alternating current to the power grid or the load 30. Alternatively, the inverter 201 sends the alternating current into the corresponding box-type substation for voltage transformation. The box-type substation corresponding to the inverter 201 can convert the low-voltage alternating current output by the inverter 201 into medium-voltage alternating current and then deliver the alternating current to the booster station and transmit it to the power grid or the load 30.

[0068] Referring to Figure 1 , in the energy storage system, the energy storage battery 40 can store unstable electrical energy and convert the direct current into alternating current through the inverter 201 to deliver stable electrical energy to the power grid or the load 30. Alternatively, the energy storage battery 40 converts the direct current into alternating current through a power conversion system (PCS), and after passing through the box-type substation corresponding to the energy storage battery 40, delivers stable electrical energy to the power grid or the load 30. In addition, through the energy storage converter, the alternating current of the power grid can also be converted into direct current to charge the energy storage battery 40, and then the electrical energy is stored in the energy storage battery 40.

[0069] The embodiments of this application provide a power conversion device 20, Figure 2Exemplarily, the structure of a power conversion device 20 is shown, where the power conversion device 20 is used to convert one of alternating current and direct current into the other. In one embodiment, the power conversion device 20 may be an inverter 201 (auxiliary reference Figure 1 ), in this embodiment, the power conversion device 20 can be used in a photovoltaic system, and the power conversion device 20 is used to convert the direct current from the photovoltaic module 10 into alternating current and output it to the power grid or the load 30. The power conversion device 20 can also be used in an energy storage system, and the power conversion device 20 is used to convert the direct current from the energy storage battery 40 into alternating current and output it to the power grid or the load 30. In another embodiment, the power conversion device 20 can also be an energy storage inverter.

[0070] Referring to Figure 2 , the power conversion device includes a device housing 1 and terminals 2 for external connection cables. The terminals 2 are fixed to the device housing 1. For example, the terminals 2 are fixed to the bottom of the device housing 1. The device housing 1 includes a top cover 11 and a bottom case 12, where the top cover 11 and the bottom case 12 are fixedly connected. For example, the top cover 11 and the bottom case 12 are fixedly connected by bolts or screws. The space enclosed by the top cover 11 and the bottom case 12 is used to accommodate structures such as a printed circuit board (PCB) and electronic components. Among them, heat dissipation fins 121 for heat dissipation are provided on the outer side of the bottom case 12. The heat generated by the electronic components inside the device housing 1 will be transferred to the bottom case 12 and dissipated through the heat dissipation fins 121 on the bottom case 12. It should be noted that in this application, the bottom case 12 is an integrally formed structural member, that is, the bottom case 12 cannot be disassembled into multiple parts and then spliced together.

[0071] Figure 3 Exemplarily, a topology diagram of a power conversion device 20 is shown. Referring to Figure 3 , the power conversion device 20 (a two-stage mode power conversion device 20) includes a DC-DC power conversion circuit 3 and a DC-AC power conversion circuit 4. The input end of the DC-DC power conversion circuit 3 is used to connect to the photovoltaic module 10 or the energy storage battery 40 (auxiliary reference Figure 1 ), the output end of the DC-DC power conversion circuit 3 is electrically connected to the input end of the DC-AC power conversion circuit 4, and the output end of the DC-AC power conversion circuit 4 is used to connect to the power grid or the load 30 (auxiliary reference Figure 1 ). Among them, the DC-DC power conversion circuit 3 is used to perform power conversion on direct current (DC). For example, the DC-DC power conversion circuit 3 is used for boosting or bucking, and the DC-AC power conversion circuit 4 is used to convert direct current into alternating current (AC).

[0072] In some other examples, the power conversion device 20 (the power conversion device 20 in single-stage mode) includes a DC-AC power conversion circuit 4 and does not include a DC-DC power conversion circuit 3. In such an embodiment, the input terminal of the DC-AC power conversion circuit 4 is used to connect to the photovoltaic module 10 or the energy storage battery 40, and the output terminal of the DC-AC power conversion circuit 4 is used to connect to the power grid or the load 30.

[0073] Taking Figure 3 the power conversion device 20 in Figure 3 as an example, the power conversion device 20 further includes a filter circuit. For example,

[0074] Figure 4 An exemplary internal structure diagram of a power conversion device 20 is shown. Referring to Figure 4 , the top cover 11 and the bottom case 12 enclose a receiving cavity 13 (a cavity inside the device case 1). The power conversion device 20 further includes a circuit board 5 and a power inductor 6. The circuit board 5 is located inside the receiving cavity 13, and the plane of the circuit board 5 (any one of the planes) is perpendicular to the arrangement direction of the top cover 11 and the bottom case 12. The power inductor 6 is located inside the receiving cavity 13 and fixed to the circuit board 5. Among them, the power inductor 6 is located between the circuit board 5 and the bottom case 12. In some embodiments, the power inductor 6 is thermally connected to the bottom case 12. For example, the power inductor 6 is thermally connected to the bottom case 12 through a thermal pad 14. Through this design, when the temperature of the power inductor 6 is relatively high, the heat of the power inductor 6 can be transferred to the bottom case 12, and heat exchange with the outside air is carried out through the heat dissipation fins 121 on the bottom case 12, which is beneficial to the heat dissipation of the power inductor 6.

[0075] Among them, Figure 4 aiming to show the position of the power inductor 6, other electronic components are omitted. For example, Figure 4 the electronic components included in the DC-AC power conversion circuit 4 provided on the circuit board 5 are omitted in Figure 4 The omitted electronic components are represented by a dashed box.

[0076] Figure 5 An exemplary structure of a power inductor 6 is shown. Referring to Figure 5 , the power inductor 6 includes a mounting base 61, a magnetic core 62, a magnetic ring 63, a first winding 64, and a second winding 65. Among them, the mounting base 61 is fixed to the circuit board 5, and both the magnetic core 62 and the magnetic ring 63 are fixed to the mounting base 61. In Figure 5 the embodiment shown, the magnetic core 62 is a "mouth"-shaped structure. Figure 6The structure of the magnetic core 62 is exemplarily shown, and the first winding 64 and the second winding 65 are both wound around the magnetic core 62. For example, referring to Figure 6 , the first winding 64 and the second winding 65 are respectively wound around two opposite magnetic posts of the magnetic core 62. By this design method, the integration degree of the power inductor 6 can be improved, and the volume of the power inductor 6 can be reduced. In some other embodiments, when the magnetic core 62 is in a "mouth" shape, the first winding 64 and the second winding 65 are both wound around the same magnetic post of the magnetic core 62. In some other embodiments, the magnetic core 62 may include a first sub-magnetic core 62 and a second sub-magnetic core 62. Among them, the first sub-magnetic core 62 and the second sub-magnetic core 62 are two independent magnetic cores. The first winding 64 is wound around the first sub-magnetic core 62, and the second winding 65 is wound around the second sub-magnetic core 62.

[0077] Among them, one pin of the first winding 64 and one pin of the second winding 65 both pass through the magnetic ring 63. Figure 7 The structure of a magnetic ring 63 is exemplarily shown. Referring to Figure 7 , the magnetic ring 63 is sleeved outside one pin of the first winding 64 and one pin of the second winding 65. For example, the magnetic ring 63 is sleeved outside the input pins of the first winding 64 and the second winding 65; for another example, the magnetic ring 63 is sleeved outside the output pins of the first winding 64 and the second winding 65; for another example, the magnetic ring 63 is sleeved outside the input pins of the first winding 64 and the second winding 65, and moreover, the magnetic ring 63 is also sleeved outside the output pins of the first winding 64 and the second winding 65.

[0078] Regarding the pins of the first winding 64 and the pins of the second winding 65, in one embodiment, the first winding 64 is a wound coil, and the two pins of the first winding 64 are the two ends of itself. In another embodiment, the first winding 64 includes a wound coil part and two pins. For example, the pins can be hard probes or other structures that can serve as pins. The two ends of the coil part of the first winding 64 are each connected to one pin of the first winding 64. Similarly, in one embodiment, the second winding 65 is a wound coil, and the two pins of the second winding 65 are the two ends of itself. In another embodiment, the second winding 65 includes a wound coil part and two pins. For example, the pins can be hard probes or other structures that can serve as pins. The two ends of the coil part of the second winding 65 are each connected to one pin of the second winding 65. In addition, the pins of the first winding 64 can be strip-shaped or bent; and the pins of the second winding 65 can also be strip-shaped or bent.

[0079] Among them, the input pin of the first winding 64 is the pin where the first winding 64 is connected to the output end of the DC-AC power conversion circuit 4, the output pin of the first winding 64 is the pin where the first winding 64 is connected to the power grid or the load 30, the input pin of the second winding 65 is the pin where the first winding 64 is connected to the output end of the DC-AC power conversion circuit 4, and the output pin of the second winding 65 is the pin where the first winding 64 is connected to the power grid or the load 30. Figure 8 An exemplary topology of a DC-AC power conversion circuit 4 is shown, with reference to Figure 8 , the DC-AC power conversion circuit 4 includes a first bridge arm and a second bridge arm disposed between the positive DC bus and the negative DC bus. The DC-AC power conversion circuit 4 further includes a third bridge arm connected between the midpoint of the first bridge arm and the midpoint of the second bridge arm. The first bridge arm includes a first switching tube Q1 and a second switching tube Q2 connected in series (two switching tubes with the same freewheeling direction). The second bridge arm includes a third switching tube Q3 and a fourth switching tube Q4 connected in series (two switching tubes with the same freewheeling direction). The third bridge arm includes a fifth switching tube Q5 and a sixth switching tube Q6 (two switching tubes with opposite freewheeling directions). The drain or collector of the fifth switching tube Q5 is connected to the drain or collector of the sixth switching tube Q6, or the source or emitter of the fifth switching tube Q5 is connected to the source or emitter of the sixth switching tube Q6.

[0080] With reference to Figure 8 , the input pin of the first winding 64 is connected to the midpoint of the first bridge arm, and the input pin of the second winding 65 is connected to the midpoint of the second bridge arm. In one embodiment, the input pins of both the first winding 64 and the second winding 65 pass through the magnetic core 63 (the magnetic core 63 represented by the solid line). In another embodiment, the output pins of both the first winding 64 and the second winding 65 pass through the magnetic core 63 (the magnetic core 63 represented by the dashed line). In another embodiment, there are multiple magnetic cores 63. The input pins of both the first winding 64 and the second winding 65 pass through one magnetic core 63, and the output pins of both the first winding 64 and the second winding 65 pass through another magnetic core 63. When common-mode current flows through the first winding 64 and the second winding 65, the magnetic fluxes generated by the first winding 64 and the second winding 65 on the magnetic core 63 are superimposed on each other, so as to have a relatively large inductance and play a role in suppressing the common-mode current.

[0081] Return to reference Figure 5, the power inductor 6 of the present application integrates the magnetic core 62, the first winding 64, the second winding 65 and the magnetic ring 63. During the installation of the power inductor 6, it is convenient for the unified installation of the magnetic core 62 and the magnetic ring 63, reducing the installation process. Moreover, compared with the solution in the related art (the magnetic ring 63 can move relative to the electronic wire), in the present application, the magnetic ring 63 is fixed to the mounting base 61, and the position of the magnetic ring 63 is relatively fixed. The magnetic ring 63 will not move randomly inside the device housing 1, reducing the possibility of the magnetic ring 63 bumping into other electronic components inside the device housing 1, and also reducing the possibility of the magnetic ring 63 detaching from the outside of the first winding 64 and the second winding 65, reducing the risk of damage to the magnetic ring 63.

[0082] In addition, at least one pin of the first winding 64 and at least one pin of the second winding 65 are both connected to the circuit board 5. For example, referring to Figure 5 , the mounting base 61 is located between the magnetic core 62 and the circuit board 5. Two pins of the first winding 64 and two pins of the second winding 65 both pass through the mounting base 61 and are inserted and fixed to the circuit board 5. Again, for example, at least one pin of the first winding 64 and at least one pin of the second winding 65 are not inserted into the circuit board 5, but are connected to the surface of the circuit board 5 by means such as soldering.

[0083] Through the above design method, the power inductor 6 is connected to the circuit board 5, and the power inductor 6 exists in the device housing 1 in the form of a board-mounted inductor. There is no need to additionally reserve space for the installation of the power inductor 6 around the circuit board 5, nor is it necessary to pot the installation position of the power inductor 6. The heat of the power inductor 6 is transferred to the heat dissipation fins 121 through the bottom case 12 for heat dissipation, saving the potting cost of the power inductor 6 and reducing the process complexity of installing the power inductor 6.

[0084] In some embodiments, referring to Figure 5 , the power inductor 6 further includes a bracket 66. The bracket 66 is fixed to the surface of the mounting base 61 facing the magnetic core 62. The bracket 66 can support the magnetic core 62. Through the bracket 66, the magnetic core 62 can be supported, forming a gap for accommodating the magnetic ring 63 between the magnetic core 62 and the mounting base 61. The magnetic ring 63 is installed in the gap between the magnetic core 62 and the mounting base 61, facilitating the pins of the first winding 64 and the second winding 65 to pass through the magnetic ring 63. Moreover, installing the magnetic ring 63 between the magnetic core 62 and the mounting base 61 can also reduce the occupation of the installation space on the circuit board 5 by the power inductor 6.

[0085] In addition, referring to Figure 5 , when the bracket 66 supports the magnetic core 62, a profiling groove for accommodating the magnetic core 62 can be provided on the bracket 66, so that a part of the magnetic core 62 extends into the profiling groove. And in some embodiments, the magnetic core 62 can be adhesively fixed to the bracket 66.

[0086] In another embodiment, the power inductor 6 may further include some other structures. For example, Figure 9 An exemplary structure of another power inductor 6 is shown. The power inductor 6 further includes a "U"-shaped first metal row 671 and a "U"-shaped second metal row 672. The openings of the first metal row 671 and the second metal row 672 both face the mounting base 61. Among them, the cross-sections of the first metal row 671 and the second metal row 672 may both be flat or circular. For example, the first metal row 671 and the second metal row 672 may both be copper rows (a copper row with a flat cross-section or a copper row with a circular cross-section), or the first metal row 671 and the second metal row 672 may both be other metal structures capable of conducting electricity. The present application does not make specific limitations on this.

[0087] Figure 10 An exemplary structure after the magnetic core 62 and the magnetic ring 63 are split is shown. Refer to Figure 9 and Figure 10 , one end of the first metal row 671 passes through the magnetic ring 63 and is connected to the circuit board 5, and the other end of the first metal row 671 is located outside the magnetic ring 63. And, one end of the second metal row 672 passes through the magnetic ring 63 and is connected to the circuit board 5, and the other end of the second metal row 672 is located outside the magnetic ring 63.

[0088] It should be noted that the "U" shape in the present application refers to any shape similar to "U". For example, Figure 11 Exemplary structures of various "U"-shaped metal rows 67 are shown. The metal row 67 may be the first metal row 671 or the second metal row 672. Among them, Figure 11 in (a) is a "U"-shaped metal row 67, and the structure of this metal row 67 is Figure 10 the structure adopted by the first metal row 671 and the second metal row 672 in, among which, Figure 11 the part of the metal row 67 shown in (a) in that is surrounded by a dotted line frame is the two ends of the metal row 67, and the opening of the metal row 67 is located between the two ends. Figure 11 in (b) is another "U"-shaped metal row 67, among which, Figure 11 the part of the metal row 67 shown in (b) in that is surrounded by a dotted line frame is the two ends of the metal row 67. It can be understood that the two ends of the metal row 67 are bent. Figure 11 in (c) is yet another "U"-shaped metal row 67, among which, Figure 11 the part of the metal row 67 shown in (c) in that is surrounded by a dotted line frame is the two ends of the metal row 67. It can be understood that the two ends of the metal row 67 are inclined towards the inside. Figure 11 in (d) is yet another "U"-shaped metal row 67, among which,Figure 11 The part of the bus bar 67 shown in (d) in is surrounded by a dashed line frame, and the two ends of the bus bar 67 are the two ends of the bus bar 67. It can be understood that the two ends of the bus bar 67 are inclined outward.

[0089] Among them, the end of the first bus bar 671 located outside the magnetic core 62 is electrically connected to the pin of the first winding 64 passing through the magnetic ring 63. Equivalently, the first winding 64, the first bus bar 671, and the structure connecting the two together form a coil wound around the magnetic ring 63 for two turns (the impedance is about 4 times that of a single turn). Similarly, the end of the second bus bar 672 located outside the magnetic core 62 is electrically connected to the pin of the second winding 65 passing through the magnetic ring 63. Equivalently, the second winding 65, the second bus bar 672, and the structure connecting the two together form a coil wound around the magnetic ring 63 for two turns (the impedance is about 4 times that of a single turn). Under the same impedance requirement, the cross-sectional area of the magnetic ring 63 can be reduced, that is, the height of the magnetic ring 63 is reduced, the height of the power inductor 6 itself is reduced, and the volume of the power inductor 6 and the area occupied on the circuit board 5 are reduced.

[0090] The first bus bar 671 can be electrically connected to the first winding 64 in any suitable manner, and the second bus bar 672 can also be electrically connected to the second winding 65 in any suitable manner. In one embodiment, the trace on the circuit board 5 can assist in electrically connecting the first bus bar 671 to the first winding 64, and the trace on the circuit board 5 can also assist in electrically connecting the second bus bar 672 to the second winding 65. Among them, both ends of the first bus bar 671 are fixedly connected to the circuit board 5 (for example, plugged in), both pins of the first winding 64 are fixedly connected to the circuit board 5 (for example, plugged in), and the end of the first bus bar 671 located outside the magnetic ring 63 is electrically connected to the pin of the first winding 64 passing through the magnetic ring 63 through the trace on the circuit board 5; the end of the second bus bar 672 located outside the magnetic ring 63 is electrically connected to the pin of the second winding 65 passing through the magnetic ring 63 through the trace on the circuit board 5.

[0091] Figure 12 Exemplarily shows a trace of a circuit board 5, referring to Figure 12, the traces on the circuit board 5 include a first trace 51, a second trace 52, a third trace 53, a fourth trace 54, a fifth trace 55, and a sixth trace 56. Among them, one pin of the first winding 64 is connected to the first trace 51, and the other pin of the first winding 64 (the pin passing through the magnetic ring 63) is connected to the end of the first metal row 671 outside the magnetic core 62 through the second trace 52. The end of the first metal row 671 passing through the magnetic core 62 is connected to the third trace 53. One pin of the second winding 65 is connected to the fourth trace 54, and the other pin of the second winding 65 (the pin passing through the magnetic ring 63) is connected to the end of the second metal row 672 outside the magnetic core 62 through the fifth trace 55. The end of the second metal row 672 passing through the magnetic core 62 is connected to the sixth trace 56.

[0092] In Figure 12 the illustrated embodiment, the connection between the first metal row 671 and the first winding 64 is achieved through the second trace 52 on the circuit board 5. The current passes through the first winding 64, the second trace 52, and the first metal row 671, which is equivalent to the current passing through a coil wound around the magnetic ring 63 for two turns. Similarly, the connection between the second metal row 672 and the second winding 65 is achieved through the fifth trace 55 on the circuit board 5. The current passes through the second winding 65, the fifth trace 55, and the second metal row 672, which is equivalent to the current passing through a coil wound around the magnetic ring 63 for two turns. Through this design method, the impedance of the magnetic ring 63 can be increased.

[0093] In addition, in Figure 12 the illustrated embodiment, the mounting seat 61 has opposite first side 611 and second side 612. The distance between the magnetic ring 63 and the first side 611 is less than the distance between the magnetic ring 63 and the second side 612. That is, compared with the second side 612, the magnetic ring 63 is closer to the first side 611. Moreover, the ends of the first metal row 671 connected to the first winding 64 and the ends of the second metal row 672 connected to the second winding 65 are both located between the magnetic ring 63 and the second side 612. In this way, the ends of the first metal row 671 connected to the first winding 64 and the ends of the second metal row 672 connected to the second winding 65 can be both located on the side of the magnetic ring 63 close to the second side 612. Then, the ends of the first metal row 671 not connected to the first winding 64 (the ends passing through the magnetic ring 63) and the ends of the second metal row 672 not connected to the second winding 65 (the ends passing through the magnetic ring 63) are both close to the first side 611, which is beneficial to the connection between the first metal row 671 and the third trace 53 and is also beneficial to the connection between the second metal row 672 and the sixth trace 56.

[0094] If the ends of the first metal row 671 connected to the first winding 64 and the ends of the second metal row 672 connected to the second winding 65 are both located between the magnetic core 63 and the first side surface 611, then both the third trace 53 and the sixth trace 56 need to be bent multiple times to extend from the side where the first side surface 611 is located, making the layout of the traces on the circuit board 5 more complex. Therefore, the embodiment shown by Figure 12 is convenient for the layout of the traces on the circuit board 5.

[0095] Regarding the distance between the magnetic core 63 and the first side surface 611 and the distance between the magnetic core 63 and the second side surface 612, it should be noted that the distance between the magnetic core 63 and the first side surface 611 refers to the minimum distance between the magnetic core 63 and the first side surface 611, and the distance between the magnetic core 63 and the second side surface 612 refers to the minimum distance between the magnetic core 63 and the second side surface 612. For example, Figure 13 an exemplary position of a magnetic core 63 is shown. Referring to Figure 13 , L1 represents the distance between the magnetic core 63 and the first side surface 611, and L2 represents the distance between the magnetic core 63 and the second side surface 612. Among them, L1 < L2, making the magnetic core 63 closer to the first side surface 611. For example, Figure 14 another exemplary position of a magnetic core 63 is shown. Referring to Figure 14 , L1 represents the distance between the magnetic core 63 and the first side surface 611, and L2 represents the distance between the magnetic core 63 and the second side surface 612. Among them, L1 < L2, making the magnetic core 63 closer to the first side surface 611.

[0096] In addition, referring back to Figure 9 , in order to connect the first winding 64 and the first metal row 671 through the traces on the circuit board 5, and also in order to connect the second winding 65 and the second metal row 672 through the traces on the circuit board 5, the two pins of the first winding 64, the two pins of the second winding 65, the two ends of the first metal row 671, and the two ends of the second metal row 672 are all inserted into the circuit board 5. When the mounting base 61 is located between the magnetic core 62 and the circuit board 5, the two pins of the first winding 64, the two pins of the second winding 65, the two ends of the first metal row 671, and the two ends of the second metal row 672 all pass through the mounting base 61 and are inserted into the circuit board 5.

[0097] In some other embodiments, when the power inductor 6 is fixed on the circuit board 5, the first metal row 671 can be electrically connected to the first winding 64 in other ways, and the second metal row 672 can also be electrically connected to the second winding 65 in other ways. For example, Figure 15 an exemplary structure of another power inductor 6 is shown. Referring to Figure 15, the power inductor 6 further includes a plurality of metal sheets 68 (e.g., copper sheets), and the plurality of (e.g., two) metal sheets 68 are all fixed to the mounting base 61. For example, the plurality of metal sheets 68 are bonded to the surface of the mounting base 61. The end of the first metal row 671 located outside the magnetic ring 63 is electrically connected to the pin of the first winding 64 passing through the magnetic ring 63 through a metal sheet 68, and the end of the second metal row 672 located outside the magnetic ring 63 is electrically connected to the pin of the second winding 65 passing through the magnetic ring 63 through another metal sheet 68.

[0098] In Figure 15 the illustrated embodiment, the current passes through the first winding 64, the first metal row 671, and the metal row 67 for connecting the two, which is equivalent to the current passing through a coil wound two turns around the magnetic ring 63. Similarly, the current passes through the second winding 65, the second metal row 672, and the metal row 67 for connecting the two, which is also equivalent to the current passing through a coil wound two turns around the magnetic ring 63. By this design method, the impedance of the magnetic ring 63 can be increased.

[0099] In some other embodiments, the first metal row 671 and the second metal row 672 can both be replaced by coils. For example, Figure 16 an exemplary split structure of another magnetic core 62 and magnetic ring 63 is shown. Referring to Figure 16 , the power inductor 6 does not include the first metal row 671 and the second metal row 672. The power inductor 6 further includes a first coil 691 and a second coil 692 wound around the magnetic ring 63. One pin of the first coil 691 is located outside the magnetic ring 63 and is electrically connected to the pin of the first winding 64 passing through the magnetic ring 63 ( Figure 16 the dotted line in Figure 9 ) represents electrical connection), and the other pin of the first coil 691 passes through the magnetic ring 63 and is connected to the circuit board 5 (the circuit board 5 is for auxiliary reference Figure 16 ); one pin of the second coil 692 is located outside the magnetic ring 63 and is electrically connected to the pin of the second winding 65 passing through the magnetic ring 63 ( Figure 9 the dotted line in

[0100] represents electrical connection), and the other pin of the second coil 692 passes through the magnetic ring 63 and is connected to the circuit board 5 (the circuit board 5 is for auxiliary reference

[0101] Among them, the first coil 691 can be electrically connected to the first winding 64 in any suitable manner, and the second coil 692 can also be electrically connected to the second winding 65 in any suitable manner. For example, the first coil 691 and the first winding 64 can be electrically connected through the traces on the circuit board 5 (the traces of the circuit board 5 are for auxiliary reference Figure 12 ), and the first coil 691 and the first winding 64 can also be electrically connected through the metal sheet 68 on the mounting base 61 (the metal sheet 68 is for auxiliary reference Figure 15 ), which will not be elaborated here. And the second coil 692 and the second winding 65 can be electrically connected through the traces on the circuit board 5 (the traces of the circuit board 5 are for auxiliary reference Figure 12 ), and the second coil 692 and the second winding 65 can also be electrically connected through the metal sheet 68 on the mounting base 61 (the metal sheet 68 is for auxiliary reference Figure 15 ), which will not be elaborated here.

[0102] In some embodiments, the power inductor 6 may further include a structure for accommodating the magnetic ring 63. For example, Figure 17 An exemplary schematic diagram of another structure of the power inductor 6 is shown. Referring to Figure 17 , the mounting base 61 may further include a second protective cover 7. The second protective cover 7 is fixed to the surface of the mounting base 61 facing the magnetic core 62. The second protective cover 7 has a groove 71 recessed away from the magnetic core 62, and the magnetic ring 63 is installed in the groove 71. The groove 71 can be annular or other shapes capable of accommodating the magnetic ring 63. Among them, the second protective cover 7 can be integrally connected to the mounting base 61 (for example, integrally injection-molded), that is, the second protective cover 7 and the mounting base 61 form a complete structure. The second protective cover 7 can also be an independent structure fixed to the mounting base 61 by adhesion (or other means). Limiting the magnetic ring 63 through the groove 71 in the second protective cover 7 is beneficial to the installation of the magnetic ring 63.

[0103] In addition, in some embodiments, after the magnetic ring 63 is installed in the groove 71, the magnetic ring 63 can be fixed to the inner wall surface of the groove 71 by means of dotting, reducing the possibility of the magnetic ring 63 moving randomly in the groove 71.

[0104] In some embodiments, the magnetic ring 63 is vulnerable to damage. For example, the magnetic ring 63 can be a nanocrystalline magnetic ring. The power inductor 6 may further include a structure for further protecting the magnetic ring 63. For example, Figure 18 An exemplary schematic diagram of another structure of the power inductor 6 is shown. Referring to Figure 18, the power inductor 6 further includes a first protective cover 8. The first protective cover 8 cooperates with the second protective cover 7. The first protective cover 8 covers the magnetic core 63 and is connected to the second protective cover 7 in a cooperative manner (for example, bonding, snap - connection or plug - connection). That is, after the magnetic core 63 is installed in the second protective cover 7, the first protective cover 8 is covered outside the magnetic core 63. The magnetic core 63 is protected by the first protective cover 8 and the second protective cover 7, reducing the possibility of damage to the magnetic core 63.

[0105] In some other embodiments, the mounting base 61 does not include an obvious structure similar to the second protective cover 7. A groove 71 for mounting the magnetic core 63 can be formed on the mounting base 61. Or, the magnetic core 63 is directly fixed on the surface of the mounting base 61 facing the magnetic core 62. Then, the first protective cover 8 is covered outside the magnetic core 63, and the first protective cover 8 is fixed to the mounting base 61. By wrapping the magnetic core 63 with the first protective cover 8, the magnetic core 63 can also be protected, reducing the possibility of damage to the magnetic core 63.

[0106] Among them, since both the first winding 64 and the second winding 65 pass through the magnetic core 63, therefore, referring to Figure 18 , the first protective cover 8 has a guiding hole 81. When the first protective cover 8 is covered outside the magnetic core 63, the guiding hole 81 is provided to guide the first winding 64 and the second winding 65. The pins of the first winding 64 passing through the magnetic core 63 and the pins of the second winding 65 passing through the magnetic core 63 both pass through the guiding hole 81, and after passing through the guiding hole 81, they pass through the second protective cover 7 and the mounting base 61, realizing the assembly of the magnetic core 62, the first winding 64, the second winding 65 and the mounting base 61, reducing the influence of setting the first protective cover 8 on the assembly of the first winding 64 and the second winding 65.

[0107] In Figure 18 the illustrated embodiment, the guiding hole 81 includes a first sub - guiding hole 811 and a second sub - guiding hole 812. The pin of the first winding 64 passing through the magnetic core 63 passes through the first sub - guiding hole 811, and the pin of the second winding 65 passing through the magnetic core 63 passes through the second sub - guiding hole 812. In some other embodiments, the guiding hole 81 is a complete through - hole, and both the pin of the first winding 64 passing through the magnetic core 63 and the pin of the second winding 65 passing through the magnetic core 63 pass through the guiding hole 81.

[0108] When the guiding hole 81 is provided on the first protective cover 8, after the first winding 64 and the second winding 65 pass through the guiding hole 81, the first winding 64 and the second winding 65 can be fixed by dot - gluing at the guiding hole 81.

[0109] In the case where the power inductor 6 further includes a first metal row 671 (or a first coil 691) and a second metal row 672 (or a second coil 692), in one embodiment, the first protective cover 8 can cover the first metal row 671 (or the first coil 691) and the second metal row 672 (or the second coil 692). For example, Figure 19 An exemplary structure of the first protective cover 8 and the second protective cover 7 is shown. Referring to Figure 19 , a part of the first metal row 671 and a part of the second metal row 672 are located between the first protective cover 8 and the second protective cover 7, and the first metal row 671 and the second metal row 672 can both be fixed (e.g., adhesively bonded or integrally injection-molded) to the first protective cover 8. During the installation of the first protective cover 8, the first metal row 671 and the second metal row 672 can be installed together, reducing the installation process of the power inductor 6.

[0110] In another embodiment, the first metal row 671 (or the first coil 691) and the second metal row 672 (or the second coil 692) are installed or wound outside the first protective cover 8 and the second protective cover 7. For example, Figure 20 An exemplary structure of another first protective cover 8 and second protective cover 7 is shown. Referring to Figure 20 , the first protective cover 8 is further provided with a first through-hole 821 for the first metal row 671 to pass through and a second through-hole 822 for the second metal row 672 to pass through. Among them, the first metal row 671 and the second metal row 672 can be fixedly connected to the first protective cover 8. During the installation of the first protective cover 8, the first metal row 671 and the second metal row 672 can be installed together, reducing the installation process of the power inductor 6.

[0111] The present application also provides another structure of the power conversion device 20. Figure 21 An exemplary structure of this power conversion device 20 is shown. Referring to Figure 21 , the power conversion device includes a device housing 1 and terminals 2. Among them, the structure of the device housing 1 can be the same as that of the device housing 1 in Figure 2 , and the structures of the device housing 1 and the terminals 2 will not be elaborated here.

[0112] Among them, referring to Figure 21 , the power conversion device 20 further includes a circuit board 5 and a power inductor 6. The power inductor 6 is installed on the circuit board 5. For example, with reference to Figure 3 , the power inductor 6 can be a Boost inductor and is used in a Boost boost circuit (DC-DC power conversion circuit 3). The power inductor 6 includes a mounting base 61, a magnetic core 62, a magnetic ring 63, and a winding (e.g., a first winding 64). Among them, the mounting base 61 is fixed to the circuit board 5, and the magnetic core 62 and the magnetic ring 63 are both fixed to the mounting base 61. In Figure 21In the illustrated embodiment, the magnetic core 62 is an annular structure, and the first winding 64 is wound around a magnetic pole of the magnetic core 62.

[0113] Among them, a pin of the first winding 64 (the pin referred to by Y1) passes through the magnetic ring 63. For example, when the power inductor 6 is a Boost inductor, the input pin among the two pins of the first winding 64 is used to connect to a DC source (the photovoltaic module 10 or the energy storage battery 40), and the output pin among the two pins of the first winding 64 is connected to the input end of the DC-AC power conversion circuit 4. The input pin or the output pin of the first winding 64 passes through the magnetic ring 63. That is, when the power inductor 6 is a Boost inductor, the power inductor 6 is connected between the DC source and the DC-AC power conversion circuit 4.

[0114] By integrating the magnetic core 62, the first winding 64, and the magnetic ring 63 of the power inductor 6, during the installation process of the power inductor 6, it is convenient to install the magnetic core 62 and the magnetic ring 63 uniformly, reducing the installation process.

[0115] As described above, it is only the specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claimed rights.

Claims

1. A power conversion device for power conversion between direct current and alternating current, characterized in that The power conversion device includes: A device housing, which includes a top cover and a bottom case fixedly connected. The top cover and the bottom case enclose a receiving cavity. Heat dissipation fins are provided on the outer side of the bottom case, and the bottom case is an integrally formed structural member; A circuit board, which is located in the receiving cavity, and the plane of the circuit board is perpendicular to the arrangement direction of the top cover and the bottom case; A power inductor, which is located in the receiving cavity and fixed between the circuit board and the bottom case. The power inductor includes: a mounting seat, a magnetic core, a magnetic ring, a first winding, and a second winding; The mounting seat is fixed to the circuit board, both the magnetic core and the magnetic ring are fixed to the mounting seat, both the first winding and the second winding are wound around the magnetic core, one pin of the first winding and one pin of the second winding both pass through the magnetic ring, and at least one pin of the first winding and at least one pin of the second winding are both connected to the circuit board.

2. The power conversion device according to claim 1, characterized in that The power inductor further includes a "U"-shaped first metal row and a "U"-shaped second metal row, and the openings of the first metal row and the second metal row both face the mounting seat; One end of the first metal row passes through the magnetic ring and is connected to the circuit board, and the other end of the first metal row is located outside the magnetic ring and is electrically connected to the pin of the first winding passing through the magnetic ring; One end of the second metal row passes through the magnetic ring and is connected to the circuit board, and the other end of the second metal row is located outside the magnetic ring and is electrically connected to the pin of the second winding passing through the magnetic ring.

3. The power conversion device according to claim 2, characterized in that, The other end of the first metal row and the pin of the first winding passing through the magnetic ring are electrically connected through the trace of the circuit board; The other end of the second metal row and the pin of the second winding passing through the magnetic ring are electrically connected through the trace of the circuit board.

4. The power conversion device according to claim 3, characterized in that, The mounting seat is located between the magnetic core and the circuit board. Two pins of the first winding, two pins of the second winding, two ends of the first metal row, and two ends of the second metal row all pass through the mounting seat and are inserted into the circuit board.

5. The power conversion device according to any one of claims 2-4, characterized in that, The mounting seat has opposite first and second side faces, and the distance between the magnetic ring and the first side face is less than the distance between the magnetic ring and the second side face; The other ends of the first metal row and the second metal row are both located between the magnetic ring and the second side face.

6. The power conversion device according to claim 2, characterized in that, The power inductor further includes a plurality of metal sheets, and the plurality of metal sheets are fixed to the mounting seat; The other end of the first metal row and the pin of the first winding passing through the magnetic ring are electrically connected through one of the metal sheets; The other end of the second metal row and the pin of the second winding passing through the magnetic ring are electrically connected through another one of the metal sheets.

7. The power conversion device according to claim 1, characterized in that, The power inductor further includes a first coil and a second coil wound around the magnetic ring; One pin of the first coil is located outside the magnetic ring and is electrically connected to the pin of the first winding passing through the magnetic ring, and the other pin of the first coil passes through the magnetic ring and is connected to the circuit board; One pin of the second coil is located outside the magnetic ring and is electrically connected to the pin of the second winding passing through the magnetic ring, and the other pin of the second coil passes through the magnetic ring and is connected to the circuit board.

8. The power conversion device according to any one of claims 1-7, characterized in that, The magnetic core is in a "mouth" shape, and the first winding and the second winding are respectively wound around two opposite magnetic posts of the magnetic core.

9. The power conversion device according to any one of claims 1-8, characterized in that, The power inductor further includes a bracket fixed to the surface of the mounting seat facing the magnetic core. The bracket supports the magnetic core, and the magnetic ring is located in the gap between the magnetic core and the mounting seat.

10. The power conversion device according to any one of claims 1-9, characterized in that, The power inductor further includes a first protective cover covering the magnetic ring and fixed to the mounting seat. The first protective cover has a guiding hole, and the pins of the first winding passing through the magnetic ring and the pins of the second winding passing through the magnetic ring both pass through the guiding hole.

11. The power conversion device according to claim 10, characterized in that, The power inductor further includes a second protective cover fixed to the surface of the mounting seat facing the magnetic core. The second protective cover has a groove recessed away from the magnetic core, and the magnetic ring is installed in the groove. The first protective cover covers the magnetic ring and is cooperatively connected with the second protective cover.

12. The power conversion device according to any one of claims 1 to 11, characterized in that The power conversion device further includes a DC-AC power conversion circuit provided on the circuit board. The input pins of the first winding and the input pins of the second winding are both connected to the output terminal of the DC-AC power conversion circuit, and the output pins of the first winding and the output pins of the second winding are both used to connect to the power grid or a load; The input pins of the first winding and the input pins of the second winding both pass through the magnetic ring; Alternatively, the output pins of the first winding and the output pins of the second winding both pass through the magnetic ring.

13. The power conversion device according to claim 12, characterized in that, The DC-AC power conversion circuit includes a first bridge arm and a second bridge arm arranged between the positive DC bus and the negative DC bus. The first bridge arm includes a first switch tube and a second switch tube connected in series, and the second bridge arm includes a third switch tube and a fourth switch tube connected in series; The input pin of the first winding is connected to the midpoint of the first bridge arm, and the input pin of the second winding is connected to the midpoint of the second bridge arm.

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