Power conversion device

Abstract

A power conversion device, comprising: an enclosure used for accommodating a power board and a power module. The power board is used for bearing the power module, the power module is used for converting a direct current from a photovoltaic module into an alternating current, and the power board is fixedly arranged relative to the enclosure. An inductor comprises a housing, a coil, and a circuit board. The housing is fixedly connected to the enclosure, the housing comprises an opening, the circuit board covers the opening and is fixedly arranged relative to the housing, and a chamber defined by the housing and the circuit board is used for accommodating the coil. The coil comprises two wire outlet ends, and the wire outlet ends are electrically connected to the circuit board. One end of an electrical connector is fixed to the circuit board and electrically connected to the wire outlet ends by means of the circuit board, and the other end of the electrical connector is fixed to the power board and electrically connected thereto. Due to the flat surfaces of the circuit board and the housing, the tolerance between the circuit board and the power board on the horizontal plane perpendicular to a wire exit direction can be minimized, and is no longer constrained by the tolerances of the wire outlet ends in the wire exit direction, facilitating improvement of the installation accuracy of the wire outlet ends and the power board.

Description

Power conversion device

[0001] The present application claims priority to the Chinese patent application No. 202410819745.4, filed on June 21, 2024, and entitled "Power conversion device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of photovoltaic energy, in particular to a power conversion device. BACKGROUND

[0003] With the increase of the power level of the inverter, the volume and weight of the magnetic elements (such as inductors) used therein are also increasing. The large volume and weight of the inductor directly welded to the power board may have the risks of difficult PIN pin welding, virtual welding and PIN pin cracking. Therefore, the electrical connection between the inductor and the power board is usually achieved through electronic wires or metal bars. However, due to the error accumulation of the electronic wire and metal bar process, the installation precision between the inductor and the power board is poor. SUMMARY

[0004] The technical problem to be solved by the embodiments of the present application is to provide a power conversion device which is beneficial to improve the installation precision of the inductor and the power board.

[0005] The embodiments of the present application provide a power conversion device, which comprises a box body, a power board, a power module, an electrical connecting piece and an inductor. The box body is used to accommodate the power board and the power module. The power board is used to carry the power module. The power module is used to convert direct current from a photovoltaic module into alternating current. The power board is fixedly arranged relative to the box body. The inductor comprises a shell, a coil and a circuit board. The shell is connected and fixed with the box body, and the shell comprises an opening. The circuit board is arranged in the opening and fixed relative to the shell. The shell and the circuit board form a cavity for accommodating the coil. The coil comprises two wire outlets, and the wire outlets are electrically connected with the circuit board. One end of the electrical connecting piece is fixed with the circuit board and electrically connected with the wire outlets through the circuit board, and the other end of the electrical connecting piece is fixed with the power board and electrically connected with the power board.

[0006] With the increase of the power level of the inverter, the volume and weight of the inductor used therein are also increasing. The large volume and weight of the inductor directly welded to the power board in the inverter may have the risks of difficult PIN pin welding, virtual welding and PIN pin cracking. Therefore, the electrical connection between the inductor and the power board is usually achieved through electronic wires or metal bars. However, due to the error accumulation of the electronic wire and metal bar process, the installation precision between the inductor and the power board is poor.

[0007] In the application, the circuit board is fixed on the shell, and the two outgoing ends of the coil are directly electrically connected with the circuit board. Due to the flat surfaces of the circuit board and the shell, the tolerance between the circuit board and the power board in the horizontal plane perpendicular to the outgoing direction of the outgoing end can be controlled to be small, and is no longer restricted by the tolerance of the outgoing end in the outgoing direction, thereby avoiding the error accumulation of the conventional electronic wire and crimping terminal process, and thus the installation precision of the outgoing end and the power board is improved.

[0008] In a possible implementation, the circuit board is provided with a metal layer, and the metal layer is used for shielding the magnetic field generated by the inductor.

[0009] The metal layer is arranged in the circuit board to shield the magnetic field generated by the inductor, so as to avoid the magnetic field from interfering with the normal work of the devices in the box, and to optimize the electro magnetic compatibility (EMC) effect of the power conversion device.

[0010] In a possible implementation, the power conversion device further comprises a temperature detector, the temperature detector is arranged on the circuit board and electrically connected with the circuit board, and the temperature detector is used for monitoring the temperature of the coil.

[0011] In a possible implementation, the distance between the temperature detector and the outgoing end is less than the distance between the power board and the outgoing end.

[0012] The temperature detector can be electrically connected with the power board through the circuit board. The temperature detector arranged on the circuit board can be closer to the outgoing end, and the distance between the temperature detector and the outgoing end is shortened compared with the temperature detector arranged on the power board, so as to improve the accuracy of the temperature detector collecting the temperature of the coil.

[0013] In a possible implementation, the electrical connector comprises a metal strip, the circuit board away from the outgoing end is provided with a first terminal seat, the first terminal seat is electrically connected with the outgoing end through the circuit board, and the surface of the first terminal seat away from the circuit board is connected and fixed with one end of the metal strip and is electrically connected.

[0014] The outgoing end is sequentially connected with the circuit board, the first terminal seat and the metal strip and is electrically connected with the power board, so as to realize large current capacity while avoiding the case that the large current electronic wire connection occupies too much space in the box, and to improve the power density of the power conversion device. The installation position of the first terminal seat on the circuit board can be placed arbitrarily according to the demand, and the electrical connector connecting the first terminal seat and the power board can be unified to the same specification, thereby reducing the manufacturing cost of the electrical connector.

[0015] In a possible implementation, the distance between the first terminal seat and the power board is less than the distance between the outgoing end and the power board.

[0016] The circuit board is provided with two first terminal seats corresponding to the two outgoing terminals on the side away from the outgoing terminals. The two outgoing terminals are usually not on the same side of the coil, and the two outgoing terminals are directly electrically connected with the circuit board. The positions of the two first terminal seats can be flexibly adjusted. The distance between the first terminal seat and the power board is smaller than the distance between the outgoing terminal and the power board. In this way, the length of the plurality of metal rows can be minimized, the size design of the metal row is simplified, and the EMC effect is optimized.

[0017] In a possible implementation, the surface of the power board is provided with a second terminal seat, the second terminal seat is electrically connected with the power board, and the side away from the power board of the second terminal seat is connected and fixed with the other end of the metal row and is electrically connected.

[0018] In a possible implementation, the circuit board is accommodated in the box, and the side away from the circuit board of the first terminal seat is flush with the side away from the power board of the second terminal seat.

[0019] In this way, the metal row connected between the first terminal seat and the second terminal seat does not need to be bent, which reduces the complexity of the metal row processing and helps to reduce the manufacturing cost of the power conversion device.

[0020] In a possible implementation, the hardness of the metal row is greater than the hardness of the outgoing terminal.

[0021] The metal row is connected between the circuit board and the power board, the height tolerance of the two ends of the metal row is controllable, and the metal row with a hardness greater than the hardness of the outgoing terminal is connected, which helps to reduce the manufacturing cost of the power conversion device.

[0022] In a possible implementation, the shell is provided with a support framework, and the support fastener is connected with the coil and is used for limiting and fixing the coil.

[0023] The coil is fixed and limited by the support framework, the installation of the coil is controlled, and the reliability of the connection between the outgoing terminal of the coil and the circuit board is improved, so that the distance between the side of the circuit board facing the outgoing terminal and the side of the coil away from the circuit board is effectively controlled. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments or the background art of the present application, the drawings needed to be used in the embodiments or the background art of the present application will be described below.

[0025] Fig. 1 is a networking schematic diagram of a large ground power station or an industrial and commercial application scenario of a light storage system according to an embodiment of the present application;

[0026] Fig. 2 is a structural schematic diagram of a power conversion device according to an embodiment of the present application;

[0027] Fig. 3 is a schematic diagram of a partial structure of the power conversion device shown in Fig. 2;

[0028] Fig. 4 is a schematic diagram of an exploded structure of the power conversion device shown in Fig. 3;

[0029] Fig. 5 is a schematic diagram of a cross-sectional structure of the power conversion device shown in Fig. 2 along line V-V.

[0030] Legend: A-first direction; B-second direction; C-third direction; 10-box body; 11-through hole; 20-power board; 21-second terminal seat; 30-power module; 40-inductor; 41-housing; 411-opening; 412-cavity; 413-fixing member; 414-support framework; 415-heat dissipation part; 42-coil; 421-wire outlet end; 43-circuit board; 44-first terminal seat; 50-electric connecting member; 50a-metallic row; 60-temperature detector; 70-nut; 100-power conversion device; 100a-photovoltaic inverter; 100b-energy storage converter; 200-photovoltaic assembly; 300-box-type substation; 400-voltage boosting station; 500-power grid; 600-energy storage system. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be described in further detail below with reference to the accompanying drawings.

[0032] Please refer to Fig. 1, which is a schematic diagram of networking of a large ground power station or an industrial and commercial application scenario provided by an embodiment of the present application. In the diagram, the photovoltaic assembly 200 converts solar energy into direct current through photovoltaic effect, and the photovoltaic inverter 100a converts the direct current output by the photovoltaic assembly 200 into alternating current and further delivers the alternating current to the box-type substation 300. The box-type substation 300 converts the low-voltage alternating current output by the photovoltaic inverter 100a into medium-voltage alternating current and further delivers the alternating current to the voltage boosting station 400 (power grid 500) or the corresponding box-type substation 300 of the energy storage system 600. The energy storage system 600 is used to store unstable electric energy from the photovoltaic assembly 200 and output stable electric energy to the power grid 500 through the energy storage converter 100b and the corresponding box-type substation 300. It can be understood that the energy storage system 600 includes an energy storage battery, and the direct current of the energy storage battery is converted into alternating current through the energy storage converter.

[0033] The photovoltaic inverter 100a and the energy storage converter 100b are core devices for power conversion in the light storage system shown in FIG. 1, and they are collectively referred to as a power conversion device 100. In the following, the structure of the power conversion device 100 provided by the present application will be specifically introduced in combination with the drawings. In addition, the power conversion device 100 provided by the present application can also be applied to a household photovoltaic system. Since the networking mode of the household photovoltaic system is similar to FIG. 1, the present application will not be described again.

[0034] Referring to FIG. 2, FIG. 2 is a structural schematic diagram of a power conversion device 100 provided by an embodiment of the present application; and FIG. 3 is a partial structural schematic diagram of the power conversion device 100 shown in FIG. 2. The power conversion device 100 includes a box body 10, a power board 20, a power module 30, an inductor 40, an electrical connector 50, and a temperature detector 60. The box body 10 is used to accommodate the power board 20 and the power module 30. The power board 20 is fixedly arranged relative to the box body 10, and the power board 20 is used to carry the power module 30. The power module 30 is used to convert direct current from a photovoltaic module 200 into alternating current. The inductor 40 is fixedly connected with the box body 10. The electrical connector 50 is used to realize electrical connection between the inductor 40 and the power board 20. The temperature detector 60 is arranged on the inductor 40 and electrically connected with the power board 20.

[0035] With the increase of the power level of the inverter, the volume and weight of the inductor used are also increasing. The inductor with large volume and weight is directly welded on the power board in the inverter, which may have the risk of large PIN pin welding difficulty, virtual welding and PIN pin cracking. Therefore, the inductor and the power board are usually electrically connected through an electronic wire or a metal row. However, due to the error accumulation of the electronic wire, the installation precision between the inductor and the power board is poor.

[0036] One end of the electronic wire is welded with the enameled wire, and the other end is crimped with the OT terminal. The length error of the machine cutter, the stripping error, the terminal crimping error and the welding offset error need to be considered.

[0037] Referring to FIG. 4, FIG. 4 is an exploded structural schematic diagram of the power conversion device 100 shown in FIG. 3. The inductor 40 includes a shell 41, a coil 42, a circuit board 43 and a magnetic core. The shell 41 includes an opening 411, and the circuit board 43 is coveringly arranged in the opening 411 and fixedly arranged relative to the shell 41. A cavity 412 formed by the circuit board 43 and the shell 41 is used to accommodate the coil 42 and the magnetic core. The coil 42 is wound around the magnetic core, and the coil 42 includes two wire outlets 421. The wire outlets 421 are electrically connected with the circuit board 43. One end of the electrical connector 50 is fixed with the circuit board 43 and electrically connected with the wire outlets 421 through the circuit board 43, and the other end of the electrical connector 50 is fixed with the power board 20 and electrically connected with the power board 20.

[0038] In the present application, the circuit board 43 is fixed on the shell 41, and the two outgoing ends 421 of the coil 42 are directly electrically connected with the circuit board 43. Due to the flat surfaces of the circuit board 43 and the shell 41, the tolerance between the circuit board 43 and the power board 20 in the horizontal plane perpendicular to the outgoing direction of the outgoing ends 421 can be controlled to be small, and is no longer constrained by the tolerance of the outgoing ends in the outgoing direction, thereby avoiding the problem of error accumulation of the conventional process of using electronic wires and crimping terminals, and thus facilitating the improvement of the installation precision of the outgoing ends 421 and the power board 20.

[0039] The inductor 40 can be a three-phase inductor 40, and the inductor 40 includes three coils 42, each of which is provided with two outgoing ends 421. The plurality of outgoing ends 421 control the outgoing height through the circuit board 43.

[0040] The type of the inductor 40 can include a boost inductor and a filter inductor. The boost inductor is applied to a boost circuit of the power module 30, and is used to convert low-voltage direct current into high-voltage direct current to achieve voltage boosting. The filter inductor is applied to an LCL filter or an LC filter in an inverter, the LCL filter is used to filter the alternating current output by the DC / AC circuit in the power module 30, and the LCL filter is composed of the inductor 40, a capacitor and a resistor; the LC filter is composed of the inductor 40 and the capacitor. The shell 41 is fixedly connected with the cabinet 10, for example, the shell 41 is fixedly connected with one side of the cabinet 10 through screws.

[0041] Specifically, the shell 41 is provided with a fixing member 413, which can be located at the opening 411 of the shell 41 and used to fix the circuit board 43 on the shell 41. For example, the fixing member 413 can be a positioning pin or a threaded hole. When the circuit board 43 is installed on the shell 41, the position of the circuit board 43 can be limited by a limiting tool, the welding position of the circuit board 43 is controlled by the limiting tool, and then the circuit board 43 is fixed on the shell 41 by the fixing member 413, which is beneficial to control the height tolerance of the one end of the electrical connector 50 connected with the circuit board 43.

[0042] Further, the shell 41 is used to support and fix the coil 42. For example, the shell 41 is provided with a support framework 414, which is connected with the coil 42 and used to limit and fix the coil 42. Specifically, the position of the coil 42 in the shell 41 can be limited by a limiting tool, and the coil 42 is attached to the support framework 414 to fix the position of the coil 42 in the shell 41 by the support framework 414, so as to control the installation position of the coil 42, which is beneficial to improve the reliability of the connection between the outgoing ends 421 and the circuit board 43, and thus effectively control the distance between the one side of the circuit board 43 facing the outgoing ends 421 and the one side of the coil 42 away from the circuit board 43.

[0043] In summary, by limiting the installation position of the coil 42 and the circuit board 43, the distance between the side of the coil 42 facing away from the circuit board 43 and the side of the circuit board 43 facing the outgoing terminal 421 is controlled, which is conducive to reducing the tolerance between the outgoing terminal 421 and the power board 20 in the outgoing direction.

[0044] For example, the shell 41 is also provided with a heat dissipation portion 415 located on the side of the coil 42 facing away from the circuit board 43, which is used to assist in dissipating heat from the coil 42. Specifically, the side of the heat dissipation portion 415 facing the coil 42 is shaped like the coil 42, which helps to improve the heat dissipation effect of the coil 42 and can also serve to support and fix the coil 42.

[0045] Please refer to FIG. 5, which is a cross-sectional view of the power conversion device 100 along line V-V shown in FIG. 2. In one embodiment, part of the shell 41 and the circuit board 43 are located in the box 10, and the other part of the shell 41 and the coil 42 are located outside the box 10. The box 10 is provided with a through hole 11 for passing through the other part of the shell 41.

[0046] The opening size of the through hole 11 is smaller than the outer edge of the shell 41 where the circuit board 43 is arranged. The inductor 40 can be extended out of the box 10 through the through hole 11, and the outer edge of the shell 41 abuts against the outer edge of the through hole 11 and is fixedly connected with the box 10. The circuit board 43 is located in the box 10, and the side of the circuit board 43 facing away from the outgoing terminal 421 can be arranged flush with the surface of the power board 20, so that the electrical connection 50 connecting the circuit board 43 and the power board 20 can be arranged without bending, which reduces the complexity of the processing of the electrical connection 50 and is conducive to reducing the manufacturing cost of the power conversion device 100.

[0047] The circuit board 43 is provided with a metal layer for shielding the magnetic field generated by the inductor 40 to avoid interference with the normal operation of the devices in the box 10 and to optimize the EMC effect of the power conversion device 100. The metal layer can be a metal copper layer, a copper alloy layer, an aluminum layer, or a metal iron layer, and the specific type is not limited.

[0048] In another embodiment, the shell 41 and the circuit board 43 are both arranged outside the box 10. The box 10 is provided with a through hole 11, which is used for the power connecting member 50 to extend into the box 10 and electrically connect with the power board 20 in the box 10. The circuit board 43 and the power board 20 are not in the same plane, and the power connecting member 50 can be bent to electrically connect with the power board 20. In this embodiment, the shell 41 can be mounted on the box 10 from outside the box 10. At this time, the opening size of the through hole 11 can be made smaller, reducing the size of the channel for external moisture to enter the box 10 and reducing the possibility of external moisture entering the box 10. The bottom surface of the box 10 can also be used to shield the magnetic field generated by the inductor 40, avoiding interference with the normal operation of the devices in the box 10 and facilitating optimization of the EMC effect of the power conversion device 100. In this way, the setting of the metal layer in the circuit board 43 can also be reduced, which is conducive to cost savings.

[0049] The circuit board 43 and the outlet end 421 can be electrically connected by internal wiring. The outlet end 421 does not need to be reserved for electrical connection with the power connecting member 50, which is conducive to reducing the cumulative error of the outlet end 421 in the outlet direction when electrically connected with the power connecting member 50.

[0050] The side of the circuit board 43 away from the outlet end 421 is provided with a first terminal seat 44. The first terminal seat 44 is electrically connected with the outlet end 421 through the circuit board 43. The side of the first terminal seat 44 away from the circuit board 43 is connected and fixed with one end of the power connecting member 50 and is electrically connected with the power connecting member 50. The number of the first terminal seat 44 is consistent with the number of the outlet end 421. The installation position of the first terminal seat 44 on the circuit board 43 can be placed arbitrarily according to requirements. The power connecting member 50 connecting the first terminal seat 44 and the power board 20 can be unified to the same specification, which reduces the manufacturing cost of the power connecting member 50.

[0051] The power connecting member 50 includes a metal strip 50a, for example, a copper strip. The side of the first terminal seat 44 away from the circuit board 43 is connected and fixed with one end of the metal strip 50a and is electrically connected with the metal strip 50a. The first terminal seat 44 and one end of the metal strip 50a can be connected and fixed through a nut 70 and are electrically connected. The outlet end 421 is sequentially connected with the circuit board 43, the first terminal seat 44, and the metal strip 50a and is electrically connected with the power board 20. This realizes large current capacity while avoiding the case that the large current electronic wire connection occupies too much internal space of the box 10, which is conducive to improving the power density of the power conversion device 100.

[0052] In addition, when the circuit board 43 is located outside the box 10, under the premise of realizing large current, compared with the electronic wire connection, the metal strip 50a connecting the circuit board 43 and the power board 20 can reduce the opening size of the through hole 11, thereby reducing the size of the channel for external moisture to enter the box 10 and reducing the possibility of external moisture entering the box 10.

[0053] Specifically, the distance between the first terminal seat 44 and the power plate 20 is less than the distance between the outgoing terminal 421 and the power plate 20.

[0054] The positions of the two outgoing terminals 421 are generally not on the same side of the coil 42, and both of the outgoing terminals 421 are directly connected to the circuit board 43. The positions of the two first terminal seats 44 can be flexibly adjusted. For example, when the power plate 20 and the circuit board 43 are arranged along the first direction A, and the two outgoing terminals 421 are located on opposite sides of the coil 42 along the first direction A, the plurality of first terminal seats 44 are arranged on the side of the coil 42 close to the power plate 20 along the first direction A, and the plurality of first terminal seats 44 are arranged along the second direction B, wherein the second direction B is perpendicular to the first direction A. In this way, without the need to lead the two outgoing terminals 421 out to the same side of the circuit board 43, the distance from the first terminal seat 44 to the power plate 20 is less than the distance from the outgoing terminal 421 to the power plate 20, and the size of the metal strip 50a connected between the first terminal seat 44 and the power plate 20 can be minimized, simplifying the size design of the metal strip 50a and facilitating cost reduction.

[0055] For example, the surface of the power plate 20 is provided with a second terminal seat 21, the second terminal seat 21 is connected to the power plate 20, and the side of the second terminal seat 21 away from the power plate 20 is connected to and electrically connected to the other end of the metal strip 50a. The second terminal seat 21 can be connected to and electrically connected to the other end of the metal strip 50a through the nut 70.

[0056] The number of power plates 20 can be one, and a plurality of second terminal seats 21 are arranged on one power plate 20. At this time, all the metal strips 50a are connected to one power plate 20.

[0057] The number of power plates 20 can also be multiple, and multiple power plates 20 can be stacked along the third direction C in the box 10. For example, the plurality of power plates 20 are arranged on one side of the inductor 40 along the first direction A, and each power plate 20 is provided with a second terminal seat 21. The second terminal seat 21 on each power plate 20 is connected to one metal strip 50a. For example, the number of power plates 20 is two, and the two power plates 20 are arranged in the box 10 along the third direction C. The second terminal seat 21 on one power plate 20 is connected to a part of the metal strips 50a, and the part of the metal strips 50a connected to one power plate 20 can be a flat plate structure, so that this part of the metal strips 50a does not need to be bent and arranged, facilitating the size minimization design of this part of the metal strips 50a. The second terminal seat 21 on the other power plate 20 is connected to another part of the metal strips 50a, and this part of the metal strips 50a is connected to the other power plate 20 after being bent, optimizing the space utilization in the box 10 and minimizing the size of this part of the metal strips 50a.

[0058] The distance between the first terminal seat 44 and the second terminal seat 21 is less than the distance between the outgoing terminal 421 and the second terminal seat 21. For example, the first terminal seat 44 and the second terminal seat 21 are arranged opposite to each other along the first direction A, and the metal bar 50a is in a flat plate structure. The positions of the first terminal seat 44 and the second terminal seat 21 can be adjusted flexibly, so that the distance between the first terminal seat 44 and the second terminal seat 21 along the first direction A is less than the distance between the outgoing terminal 421 and the second terminal seat 21 along the first direction A. The size of the metal bar 50a is minimized, the space utilization in the box body 10 is optimized, and the power density of the power conversion device 100 is improved.

[0059] Further, when the circuit board 43 is accommodated in the box body 10, the side of the first terminal seat 44 away from the circuit board 43 is flush with the side of the second terminal seat 21 away from the power board 20. When the first terminal seat 44 and the second terminal seat 21 are arranged opposite to each other along the first direction A, the metal bar 50a connected between the first terminal seat 44 and the second terminal seat 21 does not need to be bent, which reduces the complexity of the processing of the metal bar 50a and reduces the manufacturing cost of the power conversion device 100.

[0060] The circuit board 43 can completely cover the opening 411 of the shell 41. At this time, an injection port can be formed on the circuit board 43 for injecting potting glue into the shell 41. Alternatively, the circuit board 43 covers part of the opening 411. At this time, the potting glue can be injected through the part of the opening 411 not covered by the circuit board 43.

[0061] The outgoing terminal 421 is connected to the power board 20 by the electronic wire. The outgoing terminal 421 has a tolerance of ±10mm in the third direction C, wherein the third direction C, the second direction B and the first direction A are perpendicular to each other, and the third direction C is the arrangement direction of the circuit board 43 and the outgoing terminal 421. The application connects the outgoing terminal 421 by the circuit board 43. The tolerance of the outgoing terminal 421 in the third direction C does not affect the height difference of the metal bar 50a in the third direction C, and the tolerance of the outgoing terminal 421 in the third direction C can be ignored. At this time, the only factors affecting the height difference of the metal bar 50a in the third direction C are the tolerance of the circuit board 43 in the third direction C, the tolerance of the power board 20 in the third direction C, and the tolerance of the first terminal seat 44 and the second terminal seat 21 in the third direction C. In summary, the height tolerance of the metal bar 50a at both ends in the third direction C can be controlled within ±1mm, which improves the installation accuracy of the outgoing terminal 421 and the power board 20.

[0062] Further, the hardness of the metal strip 50a is greater than the hardness of the outgoing terminal 421, that is, the electrical connection between the circuit board 43 and the power board 20 is achieved by the hard connection of the metal strip 50a. The metal strip 50a is connected between the circuit board 43 and the power board 20, and the height tolerance of the two ends of the metal strip 50a is controllable, which effectively reduces the height tolerance of the two ends of the metal strip 50a. And through the metal strip 50a with greater hardness than the hardness of the outgoing terminal 421, it is beneficial to reduce the manufacturing cost of the power conversion device 100.

[0063] The circuit board 43 is provided, on the one hand, to facilitate the fixation of the outgoing terminal 421 and shorten the manufacturing tolerance between the outgoing terminal 421 and the power board 20; on the other hand, to facilitate the size design of the metal strip 50a and simplify the overall size design, which is beneficial to the electromagnetic compatibility problem.

[0064] The circuit board 43 is provided with a temperature detector 60, for example, the side of the circuit board 43 away from the outgoing terminal 421 is provided with a temperature detector 60, or the side of the circuit board 43 facing the outgoing terminal 421 is provided with a temperature detector 60. Among them, the temperature detector 60 is electrically connected with the circuit board 43 and is used for monitoring the temperature of the coil 42. The temperature detector 60 is electrically connected with the power board 20 through the circuit board 43. The distance between the temperature detector 60 and the outgoing terminal 421 is less than the distance between the power board 20 and the outgoing terminal 421. Specifically, in any direction, the distance between the temperature detector 60 and the outgoing terminal 421 is less than the distance between the power board 20 and the outgoing terminal 421. The temperature detector 60 is arranged on the circuit board 43 and can be closer to the outgoing terminal 421, compared with the temperature detector 60 arranged on the power board 20, the distance between the temperature detector 60 and the outgoing terminal 421 is shortened, thereby improving the accuracy of the temperature detector 60 collecting the temperature of the coil 42.

[0065] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A power conversion device, characterized in that, The power conversion device includes a housing, a power board, a power module, electrical connectors, and an inductor, wherein: The enclosure is used to house the power board and the power module; The power board is used to carry the power module, which is used to convert the direct current from the photovoltaic module into alternating current. The power board is fixedly installed relative to the housing. The inductor includes a housing, a coil, and a circuit board. The housing is connected and fixed to the box. The housing includes an opening. The circuit board covers the opening and is fixedly disposed relative to the housing. The cavity formed by the housing and the circuit board is used to house the coil. The coil includes two output terminals. The output terminals are electrically connected to the circuit board. One end of an electrical connector is fixed to the circuit board and electrically connected to the output terminals through the circuit board. The other end of the electrical connector is fixed to the power board and electrically connected to the power board.

2. The power conversion device according to claim 1, characterized in that, The circuit board has a metal layer inside, which is used to shield the magnetic field generated by the inductor.

3. The power conversion device according to claim 1 or 2, characterized in that, The power conversion device also includes a temperature detector, which is located on the circuit board and electrically connected to the circuit board, and is used to monitor the temperature of the coil.

4. The power conversion device according to claim 3, characterized in that, The distance between the temperature detector and the output terminal is less than the distance between the power board and the output terminal.

5. The power conversion device according to any one of claims 1-4, characterized in that, The electrical connector includes a metal busbar. A first terminal block is provided on the side of the circuit board opposite to the output terminal. The first terminal block is electrically connected to the output terminal through the circuit board. The side of the first terminal block opposite to the circuit board is connected and fixed to one end of the metal busbar and electrically connected.

6. The power conversion device according to claim 5, characterized in that, The distance between the first terminal block and the power board is less than the distance between the output terminal and the power board.

7. The power conversion device according to claim 5 or 6, characterized in that, The power board has a second terminal block on its surface. The second terminal block is electrically connected to the power board. The side of the second terminal block facing away from the power board is connected and fixed to the other end of the metal busbar and electrically connected.

8. The power conversion device according to claim 7, characterized in that, The circuit board is housed within the enclosure, and the side of the first terminal block facing away from the circuit board is flush with the side of the second terminal block facing away from the power board.

9. The power conversion device according to any one of claims 5-8, characterized in that, The hardness of the metal busbar is greater than the hardness of the output end.

10. The power conversion device according to any one of claims 1-9, characterized in that, The housing is provided with a support frame, which is connected to the coil and used to limit and fix the coil.

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