Power conversion device
Patent Information
- Application Number
- PCT/CN2026/076460
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-02-19
- Filing Date
- 2026-01-31
- Publication Date
- 2026-08-27
Smart Images
Figure CN2026076460_27082026_PF_FP_ABST
Abstract
Description
Power conversion device
[0001] This application claims priority to Chinese patent application No. 202510187199.1, filed on February 19, 2025, entitled "Power Conversion Device", the entire contents of which are incorporated herein by reference. Technical Field
[0002] This application relates to the field of power supply technology, and in particular to a power conversion device. Background Technology
[0003] In power conversion devices (e.g., photovoltaic inverters), magnetic rings are placed on the input or output side of the inductor to suppress common-mode current.
[0004] In related technologies, windings are led out via electronic wires, and a magnetic ring for common-mode suppression is fitted around the electronic wires. However, with this approach, the inductor and magnetic ring need to be installed separately. Manual installation of the magnetic ring carries the risk of impacts and incorrect installation, affecting its normal operation. Furthermore, it adds to the installation process. Moreover, the magnetic ring can move relative to the electronic wires, posing a significant risk of damage during the installation and handling of the power conversion device. Summary of the Invention
[0005] This application provides a power conversion device that facilitates the unified installation of inductors and magnetic rings, reduces installation steps, and lowers the risk of magnetic ring damage.
[0006] To achieve the above objectives, this application adopts the following technical solution:
[0007] A first aspect of this application provides a power conversion device for power conversion between direct current and alternating current. The power conversion device includes a housing, a circuit board, and a power inductor. The housing includes a top cover and a bottom cover fixedly connected together, forming a receiving cavity. Heat dissipation fins are provided on the outer side of the bottom cover, which is an integrally formed structural component. The circuit board is located within the receiving cavity, with its surface perpendicular to the arrangement direction of the top cover and bottom cover. The power inductor is located within the receiving cavity and fixed between the circuit board and the bottom cover. The power inductor includes a mounting base, a magnetic core, a magnetic ring, a first winding, and a second winding. The mounting base is fixed to the circuit board, and both the magnetic core and the magnetic ring are fixed to the mounting base. 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 pass through the magnetic ring. At least one pin of the first winding and at least one pin of the second winding are connected to the circuit board.
[0008] The housing cavity of the device is used to house the circuit board and some electronic components (e.g., power modules, power inductors, etc.). Heat sink fins assist in heat dissipation, reducing the possibility of excessively high internal temperatures. The power inductor integrates a magnetic core, windings (first and second windings), and a magnetic ring. The magnetic core and magnetic ring are fixed to a mounting base. The first and second windings are wound around the magnetic core, with one lead from each winding passing through the magnetic ring. When a common-mode current flows through the first and second windings, the magnetic flux generated on the magnetic ring by the first and second windings superimposes, resulting in a large inductance and suppressing the common-mode current. This application's power inductor integrates the magnetic core, windings, and magnetic ring, facilitating unified installation of the core and magnetic ring during power inductor mounting and reducing installation steps. Furthermore, the magnetic ring is fixed to the mounting base, meaning its position is relatively fixed and it will not move freely inside the device housing. This reduces the possibility of the magnetic ring bumping into other electronic components inside the housing and also reduces the possibility of the magnetic ring falling off, thus lowering the risk of damage to the magnetic ring.
[0009] In addition, both the first and second windings of the power inductor are connected to the circuit board, so that the power inductor exists in the device housing as an onboard inductor. There is no need to reserve additional space for the installation of the power inductor on the outside of the circuit board, nor is there a need to pot the mounting position of the power inductor. This saves the potting cost of the power inductor and reduces the process complexity of installing the power inductor.
[0010] In one optional embodiment, the power inductor further includes a U-shaped first metal busbar and a U-shaped second metal busbar, the openings of the first metal busbar and the second metal busbar both facing the mounting base; one end of the first metal busbar passes through the magnetic ring and is connected to the circuit board, and the other end of the first metal busbar 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 busbar passes through the magnetic ring and is connected to the circuit board, and the other end of the second metal busbar is located outside the magnetic ring and is electrically connected to the pin of the second winding passing through the magnetic ring.
[0011] A first metal busbar and a second metal busbar are configured and connected across a magnetic ring. The end of the first metal busbar located on the outer side of the magnetic ring is connected to the pin of the first winding that passes through the magnetic ring. Essentially, the first winding, the first metal busbar, and the connecting structure together form a coil with two turns wound around the magnetic ring (impedance approximately four times that of a single turn). Similarly, the end of the second metal busbar located on the outer side of the magnetic ring is connected to the pin of the second winding that passes through the magnetic ring. This also means that the second winding, the second metal busbar, and the connecting structure together form a coil with two turns wound around the magnetic ring (impedance approximately four times that of a single turn). Under the same impedance requirement, the cross-sectional area of the magnetic ring can be reduced, which means reducing the height of the magnetic ring, thus lowering the height of the power inductor itself and reducing its volume and area occupied on the circuit board.
[0012] In one optional embodiment, the other end of the first metal busbar is electrically connected to the pin of the first winding passing through the magnetic ring via a trace on the circuit board; the other end of the second metal busbar is electrically connected to the pin of the second winding passing through the magnetic ring via a trace on the circuit board.
[0013] Both ends of the first metal busbar and both pins of the first winding are connected to the circuit board. The connection between the first metal busbar and the first winding is achieved through traces on the circuit board. Current flows through the first winding, the first metal busbar, and the traces on the circuit board used to connect the two, which is equivalent to current flowing through a coil wound two turns on a magnetic ring. Similarly, both ends of the second metal busbar and both pins of the second winding are connected to the circuit board. The connection between the second metal busbar and the second winding is achieved through traces on the circuit board. Current flows through the second winding, the second metal busbar, and the traces on the circuit board used to connect the two, which is equivalent to current flowing through a coil wound two turns on a magnetic ring. This design improves the impedance of the magnetic ring.
[0014] In one alternative embodiment, the mounting base is located between the magnetic core and the circuit board, and the two pins of the first winding, the two pins of the second winding, the two ends of the first metal busbar and the two ends of the second metal busbar all pass through the mounting base and are inserted into the circuit board.
[0015] The mounting base is placed between the magnetic core and the circuit board, serving as the base of the magnetic core. The first winding, the second winding, the first metal busbar, and the second metal busbar all pass through the mounting base. During the installation of the power inductor, simply move the mounting base of the power inductor toward the circuit board and insert the portions of the first winding, the second winding, the first metal busbar, and the second metal busbar that extend between the mounting base and the circuit board onto the circuit board.
[0016] In one optional embodiment, the mounting base has a first side and a second side opposite to each other, and the distance between the magnetic ring and the first side is smaller than the distance between the magnetic ring and the second side; the other end of the first metal bar and the other end of the second metal bar are both located between the magnetic ring and the second side.
[0017] Compared to the distance to the second side, the magnetic ring is closer to the first side. Furthermore, the ends of the first metal busbar connected to the first winding and the second metal busbar connected to the second winding are both located between the magnetic ring and the second side. This design ensures that the ends of the first metal busbar connected to the first winding and the second metal busbar connected to the second winding are both located on the side of the magnetic ring closer to the second side. Based on this design, the ends of the first metal busbar not connected to the first winding (the ends passing through the magnetic ring) and the ends of the second metal busbar not connected to the second winding (the ends passing through the magnetic ring) are both close to the first side, which facilitates the arrangement of traces on the circuit board.
[0018] In one optional embodiment, the power inductor further includes a plurality of metal plates fixed to a mounting base; the other end of the first metal bar is electrically connected to the pin of the first winding passing through the magnetic ring via a metal plate; the other end of the second metal bar is electrically connected to the pin of the second winding passing through the magnetic ring via another metal plate.
[0019] The first metal busbar and the first winding are connected via a metal plate on the mounting base. Current flows through the first winding, the first metal busbar, and the metal plate connecting them, equivalent to current flowing through a coil wound two turns around a magnetic ring. Similarly, the second metal busbar and the second winding can be connected via the metal plate on the mounting base. Current flows through the second winding, the second metal busbar, and the metal plate connecting them, equivalent to current flowing through a coil wound two turns around a magnetic ring. This design increases the impedance of the magnetic ring.
[0020] In one optional embodiment, the power inductor further includes a first coil and a second coil wound around a magnetic ring; one pin of the first coil is located outside the magnetic ring and electrically connected to a 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 a circuit board; one pin of the second coil is located outside the magnetic ring and electrically connected to a 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 a circuit board.
[0021] The first coil is connected to the pin of the first winding through the magnetic ring. The portion of the first winding passing through the magnetic ring effectively adds one turn to the first coil. Similarly, the second coil is connected to the pin of the second winding through the magnetic ring. The portion of the second winding passing through the magnetic ring effectively adds one turn to the second coil. By increasing the impedance of the magnetic ring, the cross-sectional area of the magnetic ring can be reduced under the same impedance requirement, which means reducing the height of the magnetic ring. This reduces the height of the power inductor itself, thereby reducing the volume of the power inductor and the area it occupies on the board (circuit board).
[0022] In one alternative implementation, the magnetic core is U-shaped, and the first winding and the second winding are respectively wound on two opposing magnetic pillars of the magnetic core.
[0023] By using a "U"-shaped magnetic core, both the first and second windings can be wound around the core, which improves the integration of the power inductor and reduces its size. This reduces the area occupied by the power inductor on the circuit board, allowing more space on the board for other electronic components to be installed, thus increasing the power rating of the power conversion device.
[0024] In one alternative embodiment, the power inductor further includes a bracket fixed to the surface of the mounting base facing the magnetic core, the bracket supporting the magnetic core, and a magnetic ring located within the gap between the magnetic core and the mounting base.
[0025] The bracket supports the magnetic core, creating a gap between the core and the mounting base to accommodate the magnetic ring, allowing the leads of the first and second windings to pass through the ring. Furthermore, mounting the magnetic ring between the core and the mounting base reduces the space occupied by the power inductor on the circuit board.
[0026] In one optional embodiment, the power inductor further includes a first protective cover, which covers a magnetic ring and is fixed to a mounting base. The first protective cover has a guide hole, through which the pins of the first winding and the pins of the second winding pass through the magnetic ring.
[0027] In some cases, magnetic rings are easily damaged. For example, the magnetic ring may be a nanocrystalline magnetic ring. Placing a first protective cover over the magnetic ring can protect it and reduce the possibility of damage. Since both the first and second windings pass through the magnetic ring, the presence of a first protective cover allows for the provision of guide holes to guide the pins of both windings, reducing the impact of the first protective cover on the assembly of the first and second windings.
[0028] In one optional embodiment, the power inductor further includes a second protective cover, which is fixed to the surface of the mounting base facing the magnetic core. The second protective cover has a groove that is recessed away from the magnetic core, and a magnetic ring is installed in the groove. A first protective cover covers the magnetic ring and is connected to the second protective cover.
[0029] The second protective cover can be integrally connected to the mounting base, or it can be a separate structure bonded (or fixed to the mounting base using other methods). The groove within the second protective cover limits the movement of the magnetic ring, facilitating its installation. After the magnetic ring is installed inside the second protective cover, the first and second protective covers are then connected together. The first and second protective covers protect the magnetic ring, reducing the possibility of damage.
[0030] In one optional embodiment, the power conversion device further includes a DC-AC power conversion circuit, which is disposed on a circuit board. The input pins of the first winding pin and the input pins of the second winding pin are both connected to the output terminal of the DC-AC power conversion circuit. The output pins of the first winding pin and the output pins of the second winding pin are both used to connect to the load. The input pins of the first winding and the input pins of the second winding both pass through a magnetic ring; or, the output pins of the first winding and the output pins of the second winding both pass through a magnetic ring.
[0031] DC-AC power conversion circuits convert direct current (DC) to alternating current (AC). For example, when the power conversion device acts as an inverter, it can convert DC power from photovoltaic modules or energy storage batteries into AC power and output it to the grid or load. The first and second pins of the power inductor are both connected to the output of the DC-AC power conversion circuit; for example, the power inductor acts as the L1 inductor in an LCL filter circuit. The input pins of both the first and second windings pass through a magnetic ring, or the output pins of both the first and second windings pass through a magnetic ring, which helps suppress common-mode current.
[0032] In one optional implementation, the DC-AC power conversion circuit includes a first bridge arm and a second bridge arm disposed between a positive DC bus and a negative DC bus. The first bridge arm includes a first switch and a second switch connected in series, and the second bridge arm includes a third switch and a fourth switch 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.
[0033] Through the first and second switching transistors in the first bridge arm, and the third and fourth switching transistors in the second bridge arm, direct current can be converted into alternating current, thus realizing power conversion.
[0034] In one alternative implementation, the power inductor is thermally connected to the bottom case.
[0035] By thermally connecting the power inductor to the base, the heat from the power inductor can be transferred to the base when the power inductor temperature is high. The heat is then exchanged with the outside air through the heat dissipation fins on the base, thus achieving heat dissipation for the power inductor.
[0036] A second aspect of this application provides another power conversion device for power conversion between direct current and alternating current. The power conversion device includes a housing, a circuit board, and a power inductor. The housing includes a top cover and a bottom cover fixedly connected together, forming a receiving cavity. Heat dissipation fins are provided on the outer side of the bottom cover, which is an integrally formed structural component. The circuit board is located within the receiving cavity, with its surface perpendicular to the arrangement direction of the top cover and bottom cover. The power inductor is located within the receiving cavity and fixed between the circuit board and the bottom cover. 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, and both the magnetic core and the magnetic ring are fixed to the mounting base. The winding is wound around the magnetic core, with one pin of the winding passing through the magnetic ring, and at least one pin of the winding connected to the circuit board.
[0037] The housing cavity of the device is used to house the circuit board and some electronic components (e.g., power modules, power inductors, etc.). Heat sink fins assist in heat dissipation, reducing the possibility of excessively high internal temperatures. The power inductor integrates a magnetic core, winding, and magnetic ring. The core and ring are fixed to the mounting base, and the winding is wound around the core, with one lead of the winding passing through the magnetic ring. This facilitates unified installation of the core and ring during power inductor installation, reducing installation steps. Furthermore, the power inductor winding is connected to the circuit board, making the power inductor an onboard inductor within the device housing. This eliminates the need for additional space around the circuit board for power inductor installation and avoids the need for potting compound at the mounting location, saving potting costs and reducing the complexity of the power inductor installation process.
[0038] In one optional embodiment, the power conversion device further includes a DC-AC power conversion circuit, which is disposed on a circuit board. The input pin of the winding pin is used to connect to a DC source, and the output pin of the winding pin is connected to the input terminal of the DC-AC power conversion circuit. The input pin or the output pin of the winding passes through a magnetic ring.
[0039] The power inductor can be a boost inductor used in a boost circuit (DC-DC power conversion circuit). In this case, the power inductor is connected between the DC source (e.g., photovoltaic module, energy storage battery, etc.) and the DC-AC power conversion circuit. Attached Figure Description
[0040] Figure 1 is a schematic diagram of a photovoltaic energy storage system provided in an embodiment of this application;
[0041] Figure 2 is a schematic diagram of a power conversion device provided in an embodiment of this application;
[0042] Figure 3 is a topology diagram of a power conversion device provided in an embodiment of this application;
[0043] Figure 4 is a schematic diagram of the internal structure of a power conversion device provided in an embodiment of this application;
[0044] Figure 5 is a schematic diagram of the structure of a power inductor provided in an embodiment of this application;
[0045] Figure 6 is a schematic diagram of a magnetic core provided in an embodiment of this application;
[0046] Figure 7 is a schematic diagram of a magnetic ring provided in an embodiment of this application;
[0047] Figure 8 is a topology diagram of a DC-AC power conversion circuit provided in an embodiment of this application;
[0048] Figure 9 is a schematic diagram of another power inductor provided in an embodiment of this application;
[0049] Figure 10 is a schematic diagram of the disassembled structure of a magnetic core and a magnetic ring provided in an embodiment of this application;
[0050] Figure 11 is a schematic diagram of the structure of various metal bars provided in the embodiments of this application;
[0051] Figure 12 is a schematic diagram of the wiring structure of a circuit board provided in an embodiment of this application;
[0052] Figure 13 is a schematic diagram of the position of a magnetic ring provided in an embodiment of this application;
[0053] Figure 14 is a schematic diagram showing the position of another magnetic ring provided in an embodiment of this application;
[0054] Figure 15 is a schematic diagram of another power inductor provided in an embodiment of this application;
[0055] Figure 16 is a schematic diagram of another disassembled structure of magnetic core and magnetic ring provided in an embodiment of this application;
[0056] Figure 17 is a schematic diagram of another power inductor provided in an embodiment of this application;
[0057] Figure 18 is a schematic diagram of another power inductor provided in an embodiment of this application;
[0058] Figure 19 is a structural schematic diagram of a first protective cover and a second protective cover provided in an embodiment of this application;
[0059] Figure 20 is a schematic diagram of another first protective cover and second protective cover provided in an embodiment of this application;
[0060] Figure 21 is a schematic diagram of another power conversion device provided in an embodiment of this application.
[0061] Reference numerals: 100-Photovoltaic-Storage System; 10-Photovoltaic Module; 20-Power Conversion Device; 201-Inverter; 30-Grid or Load; 40-Storage Battery; 1-Device Housing; 11-Top Cover; 12-Bottom Housing; 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 busbar; 671-First metal busbar; 672-Second metal busbar; 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 passage; 822-Second passage. Detailed Implementation
[0062] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.
[0063] In this application, the terms "first," "second," etc., are used for descriptive purposes only to distinguish one element from another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.
[0064] In this application, unless otherwise expressly stated and limited, "multiple" means two or more.
[0065] Furthermore, in this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.
[0066] In the accompanying drawings of the embodiments of this application, solid structures such as components and assemblies are represented by guide lines; structures composed of multiple components are represented by guide lines with brackets or solid arrows; hollow structures such as openings, holes, spaces, and cavities are represented by guide lines with hollow arrows; and reference lines such as directions and dimensions are represented by straight lines with hollow arrows.
[0067] Figure 1 illustrates an exemplary structure of a photovoltaic energy storage system 100 (solar photovoltaic energy storage power generation system), including a photovoltaic system and an energy storage system. Referring to Figure 1, in the photovoltaic system, photovoltaic modules 10 directly convert solar energy into electrical energy using the photovoltaic effect. The photovoltaic modules 10 typically include multiple cells connected in series or parallel to achieve a certain output power. An inverter 201 converts the direct current (DC) from the photovoltaic modules 10 into alternating current (AC) and transmits the AC to the power grid or load 30. Alternatively, the inverter 201 sends the AC to a corresponding prefabricated substation for voltage transformation. The prefabricated substation can convert the low-voltage AC output from the inverter 201 into medium-voltage AC, and then transmit the AC to a step-up substation and to the power grid or load 30.
[0068] Referring to Figure 1, in the energy storage system, the energy storage battery 40 can store unstable electrical energy and convert DC power into AC power via the inverter 201 to deliver stable electrical energy to the grid or load 30. Alternatively, the energy storage battery 40 can convert DC power into AC power via a power conversion system (PCS), and after passing through a prefabricated substation corresponding to the energy storage battery 40, deliver stable electrical energy to the grid or load 30. Furthermore, the power conversion system can also convert AC power from the grid into DC power to charge the energy storage battery 40, and then store the electrical energy within the energy storage battery 40.
[0069] This application provides a power conversion device 20. FIG2 exemplarily illustrates the structure of a power conversion device 20, wherein the power conversion device 20 is used to convert one of alternating current (AC) and direct current (DC) to the other. In one embodiment, the power conversion device 20 may be an inverter 201 (refer to FIG1 for supplementary details). In this embodiment, the power conversion device 20 may be used in a photovoltaic system, and the power conversion device 20 is used to convert DC power from photovoltaic module 10 into AC power and output it to the grid or load 30. The power conversion device 20 may also be used in an energy storage system, and the power conversion device 20 is used to convert DC power from energy storage battery 40 into AC power and output it to the grid or load 30. In another embodiment, the power conversion device 20 may also be an energy storage converter.
[0070] Referring to Figure 2, the power conversion device includes a housing 1 and terminals 2 for connecting external cables. Terminals 2 are fixed to the housing 1, for example, to the bottom of the housing 1. The housing 1 includes a top cover 11 and a bottom cover 12, which are fixedly connected, for example, by bolts or screws. The space enclosed by the top cover 11 and the bottom cover 12 is used to house printed circuit boards (PCBs), electronic components, and other structures. The bottom cover 12 has heat dissipation fins 121 on its outer side. Heat generated by the electronic components inside the housing 1 is transferred to the bottom cover 12 and dissipated through the heat dissipation fins 121. It should be noted that in this application, the bottom cover 12 is a one-piece structure; that is, the bottom cover 12 cannot be disassembled into multiple parts and then assembled.
[0071] Figure 3 illustrates an exemplary topology of a power conversion device 20. Referring to Figure 3, the power conversion device 20 (a two-stage power conversion device 20) includes a DC-DC power conversion circuit 3 and a DC-AC power conversion circuit 4. The input terminal of the DC-DC power conversion circuit 3 is used to connect to a photovoltaic module 10 or an energy storage battery 40 (refer to Figure 1 for reference). The output terminal of the DC-DC power conversion circuit 3 is electrically connected to the input terminal of the DC-AC power conversion circuit 4. The output terminal of the DC-AC power conversion circuit 4 is used to connect to the power grid or a load 30 (refer to Figure 1 for reference). The DC-DC power conversion circuit 3 is used to convert direct current (DC) power, for example, to boost or buck the voltage. The DC-AC power conversion circuit 4 is used to convert direct current to alternating current (AC).
[0072] In some other examples, the power conversion device 20 (single-stage mode power conversion device 20) includes a DC-AC power conversion circuit 4 but does not include a DC-DC power conversion circuit 3. In this embodiment, the input 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 of the DC-AC power conversion circuit 4 is used to connect to the power grid or the load 30.
[0073] Taking the power conversion device 20 in Figure 3 as an example, the power conversion device 20 also includes a filter circuit. For example, Figure 3 shows the power inductor 6 in the LCL filter circuit (that is, the L1 inductor in the LCL filter circuit). The power inductor 6 can be located at any suitable position within the device housing 1 of the power conversion device 20.
[0074] Figure 4 illustrates an exemplary internal structure diagram of a power conversion device 20. Referring to Figure 4, the top cover 11 and the bottom shell 12 form a receiving cavity 13 (a cavity located within the device housing 1). The power conversion device 20 also includes a circuit board 5 and a power inductor 6. The circuit board 5 is located within the receiving cavity 13, and any one of its surfaces is perpendicular to the arrangement direction of the top cover 11 and the bottom shell 12. The power inductor 6 is located within the receiving cavity 13 and fixed to the circuit board 5, wherein the power inductor 6 is located between the circuit board 5 and the bottom shell 12. In some embodiments, the power inductor 6 is thermally connected to the bottom shell 12. For example, the power inductor 6 is thermally connected to the bottom shell 12 through a thermal pad 14. With this design, when the temperature of the power inductor 6 is high, the heat of the power inductor 6 can be transferred to the bottom shell 12 and exchanged with the outside air through the heat dissipation fins 121 on the bottom shell 12, which is beneficial for the heat dissipation of the power inductor 6.
[0075] Figure 4 is intended to show the location of the power inductor 6, so other electronic components are omitted. For example, the electronic components included in the DC-AC power conversion circuit 4 set on the circuit board 5 are omitted in Figure 4. The omitted electronic components in Figure 4 are represented by dashed boxes.
[0076] Figure 5 illustrates an exemplary structure of a power inductor 6. 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. 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 the embodiment shown in Figure 5, the magnetic core 62 has a U-shaped structure. Figure 6 illustrates this structure of the magnetic core 62. 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 on two opposite magnetic pillars of the magnetic core 62. This design improves the integration density of the power inductor 6 and reduces its size. In other embodiments, when the magnetic core 62 is U-shaped, the first winding 64 and the second winding 65 are both wound on the same magnetic pillar of the magnetic core 62. In some other embodiments, the magnetic core 62 may include a first sub-core 62 and a second sub-core 62, wherein the first sub-core 62 and the second sub-core 62 are two independent magnetic cores, a first winding 64 is wound on the first sub-core 62, and a second winding 65 is wound on the second sub-core 62.
[0077] In this configuration, one pin of the first winding 64 and one pin of the second winding 65 both pass through the magnetic ring 63. Figure 7 exemplarily illustrates the structure of one type of magnetic ring 63. 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 pin of the first winding 64 and the input pin of the second winding 65; another example is that the magnetic ring 63 is sleeved outside the output pin of the first winding 64 and the output pin of the second winding 65; yet another example is that the magnetic ring 63 is sleeved outside the input pin of the first winding 64 and the input pin of the second winding 65, and the magnetic ring 63 is also sleeved outside the output pin of the first winding 64 and the output pin of the second winding 65.
[0078] Regarding the pins of the first winding 64 and 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 its two ends. In another embodiment, the first winding 64 includes a wound coil portion and two pins; for example, the pins can be rigid probes or other structures that can serve as pins, and each end of the coil portion of the first winding 64 is 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 its two ends. In another embodiment, the second winding 65 includes a wound coil portion and two pins; for example, the pins can be rigid probes or other structures that can serve as pins, and each end of the coil portion of the second winding 65 is connected to one pin of the second winding 65. Furthermore, the pins of the first winding 64 can be elongated or bent; and the pins of the second winding 65 can also be elongated or bent.
[0079] The input pin of the first winding 64 is the pin that connects the first winding 64 to the output terminal of the DC-AC power conversion circuit 4, and the output pin of the first winding 64 is the pin that connects the first winding 64 to the power grid or the load 30. The input pin of the second winding 65 is the pin that connects the first winding 64 to the output terminal of the DC-AC power conversion circuit 4, and the output pin of the second winding 65 is the pin that connects the first winding 64 to the power grid or the load 30. Figure 8 illustrates an exemplary topology of a DC-AC power conversion circuit 4. Referring to Figure 8, the DC-AC power conversion circuit 4 includes a first bridge arm and a second bridge arm disposed between a positive DC bus and a negative DC bus. The DC-AC power conversion circuit 4 also 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 switch Q1 and a second switch Q2 (two switches with the same freewheeling direction) connected in series. The second bridge arm includes a third switch Q3 and a fourth switch Q4 (two switches with the same freewheeling direction) connected in series. The third bridge arm includes a fifth switch Q5 and a sixth switch Q6 (two switches with opposite freewheeling directions). The drain or collector of the fifth switch Q5 and the drain or collector of the sixth switch Q6 are connected, or the source or emitter of the fifth switch Q5 and the source or emitter of the sixth switch Q6 are connected.
[0080] Referring 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, both the input pins of the first winding 64 and the second winding 65 pass through a magnetic ring 63 (represented by the solid line). In another embodiment, both the output pins of the first winding 64 and the second winding 65 pass through a magnetic ring 63 (represented by the dashed line). In yet another embodiment, multiple magnetic rings 63 are provided, with the input pins of the first winding 64 and the second winding 65 passing through one magnetic ring 63, and the output pins of the first winding 64 and the second winding 65 passing through another magnetic ring 63. When a common-mode current flows through the first winding 64 and the second winding 65, the magnetic flux generated by the first winding 64 and the second winding 65 on the magnetic ring 63 is superimposed, resulting in a large inductance and suppressing the common-mode current.
[0081] Referring back to Figure 5, the power inductor 6 of this application integrates the magnetic core 62, the first winding 64, the second winding 65, and the magnetic ring 63. This facilitates the unified installation of the magnetic core 62 and the magnetic ring 63 during the installation of the power inductor 6, reducing installation steps. Furthermore, compared to related technologies where the magnetic ring 63 can move relative to the electronic wires, the magnetic ring 63 in this application is fixed to the mounting base 61. The position of the magnetic ring 63 is relatively fixed, preventing it from moving freely within the device housing 1. This reduces the possibility of the magnetic ring 63 bumping into other electronic components within the device housing 1 and also reduces the possibility of the magnetic ring 63 detaching from the outside of the first winding 64 and the second winding 65, thus lowering the risk of damage to the magnetic ring 63.
[0082] Furthermore, 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 FIG5, the mounting base 61 is located between the magnetic core 62 and the circuit board 5, and two pins of the first winding 64 and two pins of the second winding 65 pass through the mounting base 61 and are inserted and fixed to the circuit board 5. Alternatively, at least one pin of the first winding 64 and at least one pin of the second winding 65 may not be inserted into the circuit board 5, but may be connected to the surface of the circuit board 5 by means of soldering or other methods.
[0083] With the above design, the power inductor 6 is connected to the circuit board 5. The power inductor 6 exists in the device housing 1 as an onboard inductor. There is no need to reserve additional space for the installation of the power inductor 6 on the outside of the circuit board 5, nor is it necessary to pot the mounting position of the power inductor 6. The heat of the power inductor 6 is transferred to the heat dissipation fins 121 through the bottom shell 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 FIG5, the power inductor 6 further includes a bracket 66, which is fixed to the surface of the mounting base 61 facing the magnetic core 62. The bracket 66 supports the magnetic core 62, creating a gap between the magnetic core 62 and the mounting base 61 to accommodate a magnetic ring 63. The magnetic ring 63 is installed within this gap, allowing the leads of the first winding 64 and the second winding 65 to pass through it. Furthermore, installing the magnetic ring 63 between the magnetic core 62 and the mounting base 61 reduces the space occupied by the power inductor 6 on the circuit board 5.
[0085] Furthermore, referring to FIG5, when the support 66 supports the magnetic core 62, the support 66 may be provided with a contoured groove for accommodating the magnetic core 62, allowing a portion of the magnetic core 62 to extend into the contoured groove. In some embodiments, the magnetic core 62 can be adhesively fixed to the support 66.
[0086] In another embodiment, the power inductor 6 may also include some other structures. For example, Figure 9 exemplarily shows another structure of the power inductor 6, which also includes a "U"-shaped first metal busbar 671 and a "U"-shaped second metal busbar 672. The openings of the first metal busbar 671 and the second metal busbar 672 both face the mounting base 61. The cross-sections of the first metal busbar 671 and the second metal busbar 672 may both be flat or circular. For example, the first metal busbar 671 and the second metal busbar 672 may both be copper busbars (flat copper busbars or circular copper busbars). The first metal busbar 671 and the second metal busbar 672 may also both be other conductive metal structures. This application does not impose specific limitations on this.
[0087] Figure 10 illustrates the structure of the magnetic core 62 and the magnetic ring 63 after separation. Referring to Figures 9 and 10, one end of the first metal bar 671 passes through the magnetic ring 63 and is connected to the circuit board 5, and the other end of the first metal bar 671 is located outside the magnetic ring 63. In addition, one end of the second metal bar 672 passes through the magnetic ring 63 and is connected to the circuit board 5, and the other end of the second metal bar 672 is located outside the magnetic ring 63.
[0088] It should be noted that the "U" shape in this application refers to any shape similar to "U". For example, Figure 11 exemplarily shows the structures of various "U" shaped metal strips 67, which can be a first metal strip 671 or a second metal strip 672. Figure 11(a) shows a "U" shaped metal strip 67, the structure of which is the same as that used in the first metal strip 671 and the second metal strip 672 in Figure 10. In Figure 11(a), the portion of the metal strip 67 enclosed by the dashed frame represents the two ends of the metal strip 67, and the opening of the metal strip 67 is located between the two ends. Figure 11(b) shows another "U" shaped metal strip 67, where the portion of the metal strip 67 enclosed by the dashed frame represents the two ends of the metal strip 67. It can be understood that the two ends of the metal strip 67 are bent. Figure 11(c) shows another type of "U"-shaped metal bar 67. The portion of the metal bar 67 enclosed by the dashed frame in Figure 11(c) represents the two ends of the metal bar 67. It can be understood that the two ends of the metal bar 67 are inclined inwards. Figure 11(d) shows yet another type of "U"-shaped metal bar 67. The portion of the metal bar 67 enclosed by the dashed frame in Figure 11(d) represents the two ends of the metal bar 67. It can be understood that the two ends of the metal bar 67 are inclined outwards.
[0089] In this design, the end of the first metal busbar 671 located outside the magnetic core 62 is electrically connected to the pin of the first winding 64 passing through the magnetic ring 63. This means that the first winding 64, the first metal busbar 671, and the connecting structure together form a coil with two turns wound on the magnetic ring 63 (impedance approximately four times that of a single turn). Similarly, the end of the second metal busbar 672 located outside the magnetic core 62 is electrically connected to the pin of the second winding 65 passing through the magnetic ring 63. This means that the second winding 65, the second metal busbar 672, and the connecting structure together form a coil with two turns wound on the magnetic ring 63 (impedance approximately four times that of a single turn). Under the same impedance requirement, the cross-sectional area of the magnetic ring 63 can be reduced, which means the height of the magnetic ring 63 can be lowered, thus reducing the height of the power inductor 6 itself and shrinking its volume and the area it occupies on the circuit board 5.
[0090] The first metal busbar 671 can be electrically connected to the first winding 64 in any suitable manner, and the second metal busbar 672 can also be electrically connected to the second winding 65 in any suitable manner. In one embodiment, the first metal busbar 671 can be electrically connected to the first winding 64 via traces on the circuit board 5, and the second metal busbar 672 can also be electrically connected to the second winding 65 via traces on the circuit board 5. Both ends of the first metal busbar 671 are fixedly connected to the circuit board 5 (e.g., plugged in), both pins of the first winding 64 are fixedly connected to the circuit board 5 (e.g., plugged in), the end of the first metal busbar 671 outside the magnetic ring 63 is electrically connected to the pin of the first winding 64 passing through the magnetic ring 63 via traces on the circuit board 5; the end of the second metal busbar 672 outside the magnetic ring 63 is electrically connected to the pin of the second winding 65 passing through the magnetic ring 63 via traces on the circuit board 5.
[0091] Figure 12 illustrates an exemplary circuit board 5. Referring to Figure 12, the circuit board 5 includes 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. One pin of the first winding 64 is connected to the first trace 51. 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 busbar 671 outside the magnetic core 62 via the second trace 52. The end of the first metal busbar 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. 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 busbar 672 outside the magnetic core 62 via the fifth trace 55. The end of the second metal busbar 672 passing through the magnetic core 62 is connected to the sixth trace 56.
[0092] In the embodiment shown in Figure 12, the first metal busbar 671 and the first winding 64 are connected via the second trace 52 on the circuit board 5. Current flows through the first winding 64, the second trace 52, and the first metal busbar 671, which is equivalent to current flowing through a coil wound two turns on the magnetic ring 63. Similarly, the second metal busbar 672 and the second winding 65 are connected via the fifth trace 55 on the circuit board 5. Current flows through the second winding 65, the fifth trace 55, and the second metal busbar 672, which is equivalent to current flowing through a coil wound two turns on the magnetic ring 63. This design improves the impedance of the magnetic ring 63.
[0093] Furthermore, in the embodiment shown in FIG12, the mounting base 61 has a first side 611 and a second side 612 opposite to each other, and the distance between the magnetic ring 63 and the first side 611 is smaller than the distance between the magnetic ring 63 and the second side 612. That is, the magnetic ring 63 is closer to the first side 611 than to the second side 612. Furthermore, the ends of the first metal busbar 671 connected to the first winding 64 and the second metal busbar 672 connected to the second winding 65 are both located between the magnetic ring 63 and the second side surface 612. This allows the ends of the first metal busbar 671 connected to the first winding 64 and the second metal busbar 672 connected to the second winding 65 to be located on the side of the magnetic ring 63 closer to the second side surface 612. Thus, the ends of the first metal busbar 671 not connected to the first winding 64 (the ends passing through the magnetic ring 63) and the ends of the second metal busbar 672 not connected to the second winding 65 (the ends passing through the magnetic ring 63) are both close to the first side surface 611, which is beneficial for the first metal busbar 671 to connect to the third trace 53 and for the second metal busbar 672 to connect to the sixth trace 56.
[0094] If the ends of the first metal busbar 671 connected to the first winding 64 and the second metal busbar 672 connected to the second winding 65 are both located between the magnetic ring 63 and the first side surface 611, then the third trace 53 and the sixth trace 56 will both need to be bent multiple times to extend from the side where the first side surface 611 is located, making the arrangement of traces on the circuit board 5 more complex. Therefore, the embodiment shown in FIG12 is adopted to facilitate the arrangement of traces on the circuit board 5.
[0095] Regarding the spacing between the magnetic ring 63 and the first side 611, and the spacing between the magnetic ring 63 and the second side 612, it should be noted that the spacing between the magnetic ring 63 and the first side 611 refers to the minimum distance between them, and the spacing between the magnetic ring 63 and the second side 612 refers to the minimum distance between them. For example, Figure 13 exemplarily shows one position of the magnetic ring 63. Referring to Figure 13, L1 represents the spacing between the magnetic ring 63 and the first side 611, and L2 represents the spacing between the magnetic ring 63 and the second side 612, where L1 < L2, making the magnetic ring 63 closer to the first side 611. For example, Figure 14 exemplarily shows another position of the magnetic ring 63. Referring to Figure 14, L1 represents the spacing between the magnetic ring 63 and the first side 611, and L2 represents the spacing between the magnetic ring 63 and the second side 612, where L1 < L2, making the magnetic ring 63 closer to the first side 611.
[0096] Furthermore, referring back to FIG9, in order to connect the first winding 64 and the first metal busbar 671 via traces on the circuit board 5, and also to connect the second winding 65 and the second metal busbar 672 via traces on the circuit board 5, two pins of the first winding 64, two pins of the second winding 65, two ends of the first metal busbar 671, and two ends of the second metal busbar 672 are all inserted into the circuit board 5. With the mounting base 61 located between the magnetic core 62 and the circuit board 5, two pins of the first winding 64, two pins of the second winding 65, two ends of the first metal busbar 671, and two ends of the second metal busbar 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 to the circuit board 5, the first metal busbar 671 can be electrically connected to the first winding 64 in other ways, and the second metal busbar 672 can also be electrically connected to the second winding 65 in other ways. For example, FIG15 exemplarily illustrates another structure of the power inductor 6. Referring to FIG15, the power inductor 6 also includes a plurality of metal sheets 68 (e.g., copper sheets), which are fixed to the mounting base 61, for example, by bonding the plurality of metal sheets 68 to the surface of the mounting base 61. The end of the first metal busbar 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 one metal sheet 68, and the end of the second metal busbar 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 the embodiment shown in Figure 15, the current flowing through the first winding 64, the first metal busbar 671, and the metal busbar 67 connecting the two is equivalent to the current flowing through a coil wound two turns around the magnetic ring 63. Similarly, the current flowing through the second winding 65, the second metal busbar 672, and the metal busbar 67 connecting the two is also equivalent to the current flowing through a coil wound two turns around the magnetic ring 63. This design increases the impedance of the magnetic ring 63.
[0099] In some other embodiments, both the first metal busbar 671 and the second metal busbar 672 can be replaced by coils. For example, FIG16 exemplarily shows another split structure of the magnetic core 62 and the magnetic ring 63. Referring to FIG16, the power inductor 6 does not include the first metal busbar 671 and the second metal busbar 672. The power inductor 6 also 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 (the dashed line in FIG16 indicates the electrical connection). 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 shown in FIG9). 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 (the dashed line in FIG16 indicates the electrical connection). 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 shown in FIG9).
[0100] The pin of the first coil 691 located outside the magnetic ring 63 is connected to the pin of the first winding 64 passing through the magnetic ring 63. The portion of the first winding 64 passing through the magnetic ring 63 effectively adds one turn to the first coil 691. Similarly, the pin of the second coil 692 located outside the magnetic ring 63 is connected to the pin of the second winding 65 passing through the magnetic ring 63. The portion of the second winding 65 passing through the magnetic ring 63 effectively adds one turn to the second coil 692. This increases the impedance of the magnetic ring 63, allowing for a reduction in the cross-sectional area of the magnetic ring 63 under the same impedance requirements, thus reducing the size of the power inductor 6.
[0101] 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 via traces on the circuit board 5 (see Figure 12 for traces of the circuit board 5), or via a metal plate 68 on the mounting base 61 (see Figure 15 for metal plate 68), which will not be elaborated further here. Similarly, the second coil 692 and the second winding 65 can be electrically connected via traces on the circuit board 5 (see Figure 12 for traces of the circuit board 5), or via a metal plate 68 on the mounting base 61 (see Figure 15 for metal plate 68), which will not be elaborated further here.
[0102] In some embodiments, the power inductor 6 may further include a structure for housing the magnetic ring 63. For example, FIG17 exemplarily shows a schematic diagram of another power inductor 6. Referring to FIG17, the mounting base 61 may further include a second protective cover 7, which 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 may be annular or other shapes capable of accommodating the magnetic ring 63. The second protective cover 7 may be integrally connected to the mounting base 61 (e.g., integrally injection molded), that is, the second protective cover 7 and the mounting base 61 form a complete structure. Alternatively, the second protective cover 7 may be a separate structure bonded (or otherwise fixed to the mounting base 61). The groove 71 within the second protective cover 7 limits the position of the magnetic ring 63, facilitating its installation.
[0103] In addition, in some embodiments, after the magnetic ring 63 is installed in the groove 71, it can be fixed to the inner wall of the groove 71 by applying adhesive, which reduces the possibility of the magnetic ring 63 moving freely in the groove 71.
[0104] In some embodiments, the magnetic ring 63 is susceptible to damage. For example, the magnetic ring 63 may be a nanocrystalline magnetic ring. The power inductor 6 may also include a structure to further protect the magnetic ring 63. For example, FIG18 exemplarily shows a schematic diagram of another power inductor 6. Referring to FIG18, the power inductor 6 also includes a first protective cover 8, which cooperates with a second protective cover 7. The first protective cover 8 covers the magnetic ring 63 and is connected to the second protective cover 7 (e.g., by adhesive, snap-fit, or plug-in). That is, after the magnetic ring 63 is installed inside the second protective cover 7, the first protective cover 8 is placed over the magnetic ring 63. The magnetic ring 63 is protected by the first protective cover 8 and the second protective cover 7, reducing the possibility of damage to the magnetic ring 63.
[0105] In some other embodiments, the mounting base 61 does not include a structure that is obviously similar to the second protective cover 7. A groove 71 for mounting the magnetic ring 63 can be formed on the mounting base 61. Alternatively, the magnetic ring 63 can be directly fixed to the surface of the mounting base 61 facing the magnetic core 62, and then the first protective cover 8 can be placed over the magnetic ring 63 and fixed to the mounting base 61. By wrapping the magnetic ring 63 with the first protective cover 8, the magnetic ring 63 can also be protected, reducing the possibility of damage to the magnetic ring 63.
[0106] Since both the first winding 64 and the second winding 65 pass through the magnetic ring 63, as shown in Figure 18, the first protective cover 8 has a guide hole 81. With the first protective cover 8 covering the magnetic ring 63, the guide hole 81 guides the first winding 64 and the second winding 65. The pins of the first winding 64 and the second winding 65 passing through the magnetic ring 63 both pass through the guide hole 81, and after passing through the guide hole 81, they pass through the second protective cover 7 and the mounting base 61, thus realizing the assembly of the magnetic core 62, the first winding 64, the second winding 65 and the mounting base 61, reducing the impact of the first protective cover 8 on the assembly of the first winding 64 and the second winding 65.
[0107] In the embodiment shown in Figure 18, the guide hole 81 includes a first sub-guide hole 811 and a second sub-guide hole 812. The pin of the first winding 64 passing through the magnetic ring 63 passes through the first sub-guide hole 811, and the pin of the second winding 65 passing through the magnetic ring 63 passes through the second sub-guide hole 812. In some other embodiments, the guide hole 81 is a complete through hole through which the pins of the first winding 64 and the second winding 65 passing through the magnetic ring 63 both pass.
[0108] When the first protective cover 8 is provided with a guide hole 81, after the first winding 64 and the second winding 65 pass through the guide hole 81, the first winding 64 and the second winding 65 can be fixed by applying glue at the guide hole 81.
[0109] In the case where the power inductor 6 also includes a first metal busbar 671 (or a first coil 691) and a second metal busbar 672 (or a second coil 692), in one embodiment, the first protective cover 8 can cover the first metal busbar 671 (or the first coil 691) and the second metal busbar 672 (or the second coil 692). For example, FIG19 exemplarily shows the structure of a first protective cover 8 and a second protective cover 7. Referring to FIG19, a portion of the first metal busbar 671 and a portion of the second metal busbar 672 are located between the first protective cover 8 and the second protective cover 7. Furthermore, the first metal busbar 671 and the second metal busbar 672 can both be fixed (e.g., glued or integrally injection molded) on the first protective cover 8. During the installation of the first protective cover 8, the first metal busbar 671 and the second metal busbar 672 can be installed together, reducing the installation steps of the power inductor 6.
[0110] In another embodiment, the first metal busbar 671 (or the first coil 691) and the second metal busbar 672 (or the second coil 692) are mounted or wound around the first protective cover 8 and the second protective cover 7. For example, FIG20 exemplarily shows another structure of the first protective cover 8 and the second protective cover 7. Referring to FIG20, the first protective cover 8 is further provided with a first through-hole 821 for the first metal busbar 671 to pass through and a second through-hole 822 for the second metal busbar 672 to pass through. The first metal busbar 671 and the second metal busbar 672 can be fixedly connected to the first protective cover 8. During the installation of the first protective cover 8, the first metal busbar 671 and the second metal busbar 672 can be installed together, reducing the installation steps of the power inductor 6.
[0111] This application also provides another structure of power conversion device 20. FIG21 shows the structure of such power conversion device 20 by way of example. Referring to FIG21, the power conversion device includes device housing 1 and terminal 2. The structure of device housing 1 can be the same as that of device housing 1 in FIG2. The structure of device housing 1 and terminal 2 will not be described in detail here.
[0112] Referring to Figure 21, the power conversion device 20 also includes a circuit board 5 and a power inductor 6. The power inductor 6 is mounted on the circuit board 5. For example, referring to Figure 3, the power inductor 6 can be a boost inductor and used in a boost converter 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). 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 the embodiment shown in Figure 21, the magnetic core 62 has a ring-shaped structure, and the first winding 64 is wound around a magnetic post of the magnetic core 62.
[0113] In this circuit, one 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 of the two pins of the first winding 64 is used to connect to the DC source (photovoltaic module 10 or energy storage battery 40), and the output pin of the two pins of the first winding 64 is connected to the input terminal of the DC-AC power conversion circuit 4. The input pin or 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, the installation of the magnetic core 62 and the magnetic ring 63 is facilitated during the installation of the power inductor 6, reducing the number of installation steps.
[0115] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A power conversion device for power conversion between direct current and alternating current, characterized by, The power conversion device includes: The device housing includes a top cover and a bottom cover that are fixedly connected. The top cover and the bottom cover form a receiving cavity. Heat dissipation fins are provided on the outer side of the bottom cover. The bottom cover is an integrally formed structural component. A circuit board, located within the receiving cavity, with the surface of the circuit board perpendicular to the arrangement direction of the top cover and the bottom shell; A power inductor is located within the receiving cavity and fixed between the circuit board and the bottom shell. The power inductor includes: a mounting base, a magnetic core, a magnetic ring, a first winding, and a second winding. The mounting base is fixed to the circuit board, the magnetic core and the magnetic ring are both fixed to the mounting base, the first winding and the second winding are both 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 of claim 1, wherein, The power inductor also includes a U-shaped first metal busbar and a U-shaped second metal busbar, with the openings of the first metal busbar and the second metal busbar both facing the mounting base; One end of the first metal bar passes through the magnetic ring and is connected to the circuit board, and the other end of the first metal bar is located outside the magnetic ring and is electrically connected to the pin of the first winding that passes through the magnetic ring; One end of the second metal busbar passes through the magnetic ring and is connected to the circuit board, while the other end of the second metal busbar is located outside the magnetic ring and is electrically connected to the pin of the second winding that passes through the magnetic ring.
3. The power conversion device of claim 2, wherein, The other end of the first metal busbar is electrically connected to the pin of the first winding that passes through the magnetic ring via the traces on the circuit board; The other end of the second metal busbar is electrically connected to the pin of the second winding through the magnetic ring via the wiring of the circuit board.
4. The power conversion device of claim 3, wherein, The mounting base is located between the magnetic core and the circuit board. The two pins of the first winding, the two pins of the second winding, the two ends of the first metal busbar, and the two ends of the second metal busbar all pass through the mounting base and are inserted into the circuit board.
5. A power conversion device according to any one of claims 2-4, characterized in that, The mounting base has a first side and a second side opposite to each other, and the distance between the magnetic ring and the first side is smaller than the distance between the magnetic ring and the second side. The other end of the first metal bar and the other end of the second metal bar are both located between the magnetic ring and the second side.
6. The power conversion device of claim 2, wherein, The power inductor also includes a plurality of metal plates, which are fixed to the mounting base; The other end of the first metal busbar is electrically connected to the pin of the first winding that passes through the magnetic ring via a metal sheet; The other end of the second metal bar is electrically connected to the pin of the second winding through the magnetic ring via another metal sheet.
7. The power conversion device of claim 1, wherein, The power inductor also 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 that passes through the magnetic ring; 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 that passes through the magnetic ring. The other pin of the second coil passes through the magnetic ring and is connected to the circuit board.
8. The power conversion device of any one of claims 1-7, wherein, The magnetic core is U-shaped, and the first winding and the second winding are respectively wound on two opposing magnetic pillars of the magnetic core.
9. The power conversion device of any one of claims 1-8, wherein, The power inductor also includes a bracket, which is fixed to the surface of the mounting base facing the magnetic core and supports the magnetic core. The magnetic ring is located in the gap between the magnetic core and the mounting base.
10. The power conversion device of any one of claims 1-9, wherein, The power inductor also includes a first protective cover, which covers the magnetic ring and is fixed to the mounting base. The first protective cover has a guide hole, through which 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.
11. The power conversion device of claim 10, wherein, The power inductor also includes a second protective cover, which is fixed to the surface of the mounting base facing the magnetic core. The second protective cover has a groove that is recessed away from the magnetic core. The magnetic ring is installed in the groove. The first protective cover covers the magnetic ring and is connected to the second protective cover.
12. The power conversion device of any one of claims 1-11, wherein, The power conversion device further includes a DC-AC power conversion circuit, which is disposed on the circuit board. The input pins of the first winding pin and the second winding pin are both connected to the output terminal of the DC-AC power conversion circuit. The output pins of the first winding pin and the second winding pin are both used to connect to the power grid or the load. The input pins of the first winding and the second winding both pass through the magnetic ring; Alternatively, the output pins of both the first winding and the second winding pass through the magnetic ring.
13. The power conversion device of claim 12, wherein, The DC-AC power conversion circuit includes a first bridge arm and a second bridge arm disposed between the positive DC bus and the negative DC bus. The first bridge arm includes a first switch and a second switch connected in series, and the second bridge arm includes a third switch and a fourth switch 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.