Power converter, heat exchanger, radiator and photovoltaic power generation system

Abstract

A power converter (200), heat exchangers (212, 212b), radiators (215, 215b) and a photovoltaic power generation system (26) relate to the technical field of heat dissipation equipment. The power converter (200) comprises a power semiconductor device (214), a magnetic element (211), a closed cavity (210) and a heat dissipation cavity (220). The power semiconductor device (214) and the magnetic element (211) are arranged in the closed cavity (210); the power semiconductor device (214) dissipates heat through the first radiator (215), and heat dissipation fins of the first radiator (215) are located in the heat dissipation cavity (220). The magnetic element (211) dissipates heat through the second radiator (215b), and heat dissipation fins of the second radiator (215b) are located in the heat dissipation cavity (220), or the magnetic element (211) dissipates heat through the first heat exchanger (212), and the first heat exchanger (212) is located in the heat dissipation cavity (220). According to the technical scheme, the reliability and the heat dissipation effect when the power converter (200) is subjected to heat dissipation are improved.

Description

[0001] This application is a divisional application. The application number of the original application is 202080031667.1, and the original application date is December 22, 2020. The entire contents of the original application are incorporated into this application by reference. Technical Field

[0002] The present application relates to the technical field of heat dissipation equipment, and in particular to a power converter, a heat exchanger, a radiator and a photovoltaic power generation system. Background Art

[0003] Photovoltaic power generation is a technology that uses the photovoltaic effect of semiconductor interfaces to convert light energy into electrical energy. Photovoltaic power generation systems usually include photovoltaic units, power converters, AC power distribution equipment, etc.

[0004] The power converters used in photovoltaic power generation systems mainly include photovoltaic inverters, and distributed photovoltaic power generation systems also include maximum power point tracking (MPPT) boost combiner boxes. Power converters include power semiconductor devices, magnetic components, capacitors and other environmentally sensitive components, among which magnetic components are usually composed of windings and magnetic cores, mainly inductors.

[0005] The current power converter heat dissipation scheme is: exposing the magnetic components in a low protection cavity for ventilation and heat dissipation, or filling them with glue and setting them in a metal shell, and placing the metal shell outside the chassis or in a low protection cavity for ventilation and heat dissipation; exposing the power semiconductor devices in a low protection cavity for ventilation and heat dissipation; setting other devices in a high protection cavity and dissipating the heat naturally to the outside through the high protection cavity wall.

[0006] However, this solution exposes environmentally sensitive components such as power semiconductor devices and magnetic components directly in the low protection cavity, which has poor reliability and limited heat dissipation capacity. In addition, for the solution of potting the magnetic components in the metal shell, as the power of the power converter continues to increase, the heat loss of the magnetic components gradually increases, while the potting glue has low thermal conductivity and high thermal resistance, making it impossible to effectively improve the heat dissipation effect.

[0007] In summary, the current power converter heat dissipation solution has the problems of poor reliability and poor heat dissipation effect. Summary of the invention

[0008] The present application provides a power converter, a heat exchanger, a radiator and a photovoltaic power generation system, which improve the reliability and heat dissipation effect of the power converter when dissipating heat.

[0009] In a first aspect, the present application provides a power converter, which includes a power semiconductor device, a magnetic element, a closed cavity and a heat dissipation cavity. The power semiconductor device and the magnetic element are evenly arranged in the closed cavity to avoid being exposed. The closed cavity can strictly protect the power semiconductor device and the magnetic element, thereby improving reliability. The power semiconductor device dissipates heat through a first radiator, and the heat dissipation fins of the first radiator are located in the heat dissipation cavity. The magnetic element can dissipate heat using a radiator or a heat exchanger. Specifically, when the magnetic element dissipates heat through a second radiator, the heat dissipation fins of the second radiator are located in the heat dissipation cavity. When the magnetic element dissipates heat through a first heat exchanger, the first heat exchanger is located in the heat dissipation cavity.

[0010] By using the solution provided by the present application, power semiconductor devices and magnetic elements are arranged in a closed cavity for heat dissipation, thereby improving the reliability of the power converter. For power semiconductor devices with high heat dissipation density, a radiator is used for heat dissipation, thereby improving the heat dissipation efficiency. For magnetic elements, a radiator or a heat exchanger (also known as a heat exchanger) can be used for heat dissipation. The heat dissipation fins or heat exchanger of the radiator used are arranged in the heat dissipation cavity. By separately setting the heat dissipation cavity and the closed cavity, efficient heat dissipation is achieved while ensuring a high protection level for the internal devices.

[0011] In summary, by using the power converter provided in the embodiments of the present application, the reliability and heat dissipation effect of the power converter are improved.

[0012] In a possible implementation, the magnetic element dissipates heat through a first heat exchanger, the sealed cavity includes a first air duct, and the magnetic element is disposed in the first air duct. The first end of the first air duct is an air supply port, and the second end of the first air duct is an air return port. The air supply port is connected to the first end of the first heat exchanger, and the air return port is connected to the second end of the first heat exchanger; at least one first internal circulation fan is also disposed at the air supply port or the air return port, which is used to control the air flow starting from the air supply port and reaching the air return port along the inner cavity of the first air duct to achieve cooling of the magnetic element.

[0013] In a possible implementation, the sealed cavity also includes a second air duct, the first end of the second air duct is shared with the first end of the first air duct, and the second end of the second air duct is connected to the inner cavity of the first air duct and the inner cavity of the sealed cavity. The second air duct is also provided with at least one second internal circulation fan for controlling the airflow starting from the second air duct and reaching the return air outlet along the inner cavity of the first air duct. When the first internal circulation fan fails, the second internal circulation fan can continue to work, so that the first heat exchanger continues to dissipate heat for the magnetic element. The second internal circulation fan can also dissipate heat for high protection level components inside the sealed cavity.

[0014] In a possible implementation, the closed cavity is further provided with at least one second internal circulation fan. The cavity wall of the first air duct includes a plurality of groups of rebound structures, each group of rebound structures includes an air duct plate and a cavity wall opening. The force direction of the air duct plate during rebound is directed to the inside of the first air duct, the area of ​​the air duct plate is larger than the area of ​​the cavity wall opening, and the air duct plate can completely cover the cavity wall opening.

[0015] When the first internal circulation fan works normally, the pressure of the airflow on the air duct plate is greater than the elastic force, and the air duct plate is closed. When the first internal circulation fan fails, the air duct plate rebounds under the action of the elastic force, and the second internal circulation fan controls the airflow to pass through the inner cavity of the closed cavity and the inner cavity of the first air duct before reaching the return air port to cool the magnetic components.

[0016] In a possible implementation, the rebound structure further includes a stop structure, and the stop structure is used to limit the rebound position of the air duct plate when the air duct plate rebounds.

[0017] In a possible implementation, the heat dissipation fins of the first heat sink and the first heat exchanger are cooled in the heat dissipation cavity by using series air ducts, parallel air ducts or mutually independent air ducts.

[0018] In a possible implementation, the first heat exchanger includes a first air collecting chamber, a second air collecting chamber and a connecting portion. The connecting portion includes at least one tubular channel. The connecting portion is used to connect the first air collecting chamber and the second air collecting chamber. The first air collecting chamber is connected to the air supply port through a first sealing flange, and the second air collecting chamber is connected to the air return port through a second sealing flange. A partition rib is arranged inside at least one tubular channel to improve the heat dissipation effect.

[0019] In a possible implementation, the connecting portion includes at least two tubular channels, and a heat dissipation fin is embedded between the at least two tubular channels to improve the heat dissipation effect.

[0020] In a possible implementation, the first heat exchanger includes a first sealing flange, a second sealing flange and at least two bent tubular channels. The first ends of the at least two bent tubular channels are connected to the air supply port through the first sealing flange, and the second ends of the at least two bent tubular channels are connected to the air return port through the second sealing flange. Partition ribs are arranged inside the at least two bent tubular channels to improve the heat dissipation effect.

[0021] In a possible implementation manner, a heat dissipation fin is embedded between at least two bent tubular channels.

[0022] In a possible implementation, the magnetic element dissipates heat through a second heat sink, and the power converter further includes a high protection level component. The high protection level component is arranged in a closed cavity, and the high protection level component dissipates heat through a second heat exchanger, and the second heat exchanger is located in the heat dissipation cavity.

[0023] In a possible implementation, a third air duct is provided at the first end of the sealed cavity, the first end of the third air duct is an air supply port, and the second end of the third air duct is connected to the inner cavity of the sealed cavity. The second end of the sealed cavity is a return air port; the air supply port is connected to the first end of the second heat exchanger, and the return air port is connected to the second end of the second heat exchanger. At least one third internal circulation fan is also provided at the air supply port or the return air port, which is used to control the airflow starting from the air supply port and reaching the return air port along the inner cavity of the sealed cavity.

[0024] In a possible implementation, a third air duct is provided at the first end of the sealed cavity, and a fourth air duct is provided at the second end of the sealed cavity. The first end of the third air duct is an air supply port, and the second end of the third air duct is connected to the inner cavity of the sealed cavity. The first end of the fourth air duct is a return air port, and the second end of the fourth air duct is connected to the inner cavity of the sealed cavity. At least one third internal circulation fan is provided at the air supply port, and at least one fourth internal circulation fan is provided at the return air port. The third internal circulation fan and the fourth internal circulation fan are used to control the airflow starting from the air supply port and reaching the return air port along the inner cavity of the sealed cavity.

[0025] In a possible implementation, the heat dissipation fins of the first heat sink, the heat dissipation fins of the second heat sink, and the second heat exchanger are cooled in the heat dissipation cavity by using series air ducts, parallel air ducts, or independent air ducts.

[0026] In a possible implementation, the first heat sink and the second heat sink include a substrate and heat dissipation fins. The heat dissipation fins are used to perform contact heat dissipation on the substrate. The substrate includes a temperature-averaging cavity filled with a working fluid capable of gas-liquid phase change, and the lower middle portion of the substrate is used to set a device to be cooled.

[0027] In a possible implementation, heat dissipation fins are further disposed in the temperature-averaging chamber.

[0028] In a possible implementation, the first heat sink and the second heat sink include: a substrate, a temperature averaging plate and heat dissipation fins. The heat dissipation fins are used to perform contact heat dissipation on the substrate, and the inner cavity of the temperature averaging plate is filled with a working medium that can undergo a gas-liquid phase change. The temperature averaging plate is fixedly arranged on the substrate, and the lower middle portion of the temperature averaging plate is used to set the device to be dissipated, or the temperature averaging plate is fixedly arranged in the inner cavity of the substrate and the lower middle portion of the substrate is used to set the device to be dissipated.

[0029] In a possible implementation, heat dissipation fins are further disposed in the temperature homogenizing plate.

[0030] In a possible implementation, the power converter is a centralized inverter, a string inverter, or a maximum power point tracking (MPPT) boost combiner box.

[0031] In a second aspect, the present application further provides a heat exchanger, the heat exchanger comprising a first gas collecting chamber, a second gas collecting chamber and a connecting portion. The connecting portion comprises at least one tubular channel, the at least one tubular channel is used to connect the first gas collecting chamber and the second gas collecting chamber; the first gas collecting chamber is connected to the air supply port through a first sealing flange, and the second gas collecting chamber is connected to the air return port through a second sealing flange. A partition rib is arranged inside at least one tubular channel.

[0032] In a possible implementation, the connecting portion includes at least two tubular channels, and a heat dissipation fin is embedded between the at least two tubular channels.

[0033] In a third aspect, the present application also provides another heat exchanger, the heat exchanger comprising a first sealing flange, a second sealing flange and at least two bent tubular channels. The first ends of the at least two bent tubular channels are connected to the air supply port through the first sealing flange, and the second ends of the at least two bent tubular channels are connected to the air return port through the second sealing flange. Partition ribs are arranged inside the at least two bent tubular channels.

[0034] In a possible implementation manner, a heat dissipation fin is embedded between at least two bent tubular channels.

[0035] In a fourth aspect, the present application further provides a heat sink, which includes a substrate and heat dissipation fins. The heat dissipation fins are used to perform contact heat dissipation on the substrate. The substrate includes a temperature-averaging cavity, and the temperature-averaging cavity is filled with a working fluid that can undergo a gas-liquid phase change. The lower middle part of the substrate is used to set a device to be cooled.

[0036] In a possible implementation, heat dissipation fins are further disposed in the temperature-averaging chamber.

[0037] In a fifth aspect, the present application also provides another radiator, a radiator substrate, a temperature averaging plate and heat dissipation fins. The heat dissipation fins are used to perform contact heat dissipation on the substrate, and the inner cavity of the temperature averaging plate is filled with a working fluid that can undergo a gas-liquid phase change. The temperature averaging plate is fixedly arranged on the substrate, and the lower middle part of the temperature averaging plate is used to set the device to be dissipated, or the temperature averaging plate is fixedly arranged in the inner cavity of the substrate and the lower middle part of the substrate is used to set the device to be dissipated.

[0038] In a possible implementation, heat dissipation fins are further disposed in the temperature homogenizing plate.

[0039] In a sixth aspect, the present application also provides a photovoltaic power generation system, which includes the power converter provided by the above implementation method and a photovoltaic unit. The photovoltaic unit includes at least one photovoltaic group; the photovoltaic unit is used to convert light energy into direct current. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic diagram of a photovoltaic power generation system based on a centralized inverter;

[0041] Figure 2 is a schematic diagram of a photovoltaic power generation system based on a string inverter;

[0042] Figure 3 A schematic diagram of an exemplary string inverter provided in an embodiment of the present application;

[0043] Figure 4 It is a schematic diagram of a photovoltaic power generation system based on a centralized inverter and an MPPT boost combiner box;

[0044] Figure 5 A schematic diagram of an exemplary MPPT boost combiner box provided in an embodiment of the present application;

[0045] Figure 6 A schematic diagram of a photovoltaic power generation system based on a photovoltaic optimizer and a string inverter;

[0046] Figure 7 A side view of a power converter provided in an embodiment of the present application;

[0047] Figure 8 Provided in the embodiments of this application Figure 7 The front view corresponding to the power converter shown;

[0048] Fig. 9 Provided in the embodiments of this application Figure 8 A-A' section diagram in;

[0049] Fig.10 A front view of another power converter provided in an embodiment of the present application;

[0050] Fig.11 Provided in the embodiments of this application Fig.10 A-A' section diagram in;

[0051] Fig.12 A front view of the air duct plate of the power converter provided in an embodiment of the present application when closed;

[0052] Fig.13 A front view of the air duct plate of the power converter provided in an embodiment of the present application when it is opened;

[0053] Fig.14 Provided in the embodiments of this application Fig.12 A-A' section diagram in;

[0054] Fig.15 A side view of another power converter provided in an embodiment of the present application;

[0055] Fig.16 Provided in the embodiments of this application Fig.15A front view of the power converter shown;

[0056] Fig.17 Provided in the embodiments of this application Fig.16 B-B' section diagram;

[0057] Fig.18 A front view of another power converter provided in an embodiment of the present application;

[0058] Fig.19 Provided in the embodiments of this application Fig.18 B-B' section diagram;

[0059] Fig. 20 A schematic diagram of a heat exchanger provided in an embodiment of the present application;

[0060] Fig.21 A schematic diagram of another heat exchanger provided in an embodiment of the present application;

[0061] Fig. 22 A schematic diagram of the structure of a radiator provided in an embodiment of the present application;

[0062] Fig.23 Provided in the embodiments of this application Fig. 22 C-C' section diagram;

[0063] Fig.24 A schematic diagram of the structure of another radiator provided in an embodiment of the present application;

[0064] Fig.25 A cross-sectional view of a temperature homogenizing plate provided in an embodiment of the present application;

[0065] Fig.26 A schematic diagram of a photovoltaic power generation system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0066] In order to enable those skilled in the art to better understand the technical solution provided by the embodiments of the present application, the application scenarios of the technical solution provided by the present application are first introduced below.

[0067] The following first describes a photovoltaic power generation system based on a centralized inverter.

[0068] See also Figure 1 , which is a schematic diagram of a photovoltaic power generation system based on a centralized inverter.

[0069] The photovoltaic power generation system includes a photovoltaic unit 10 , a DC combiner box 11 , a centralized inverter 12 and a transformer 14 .

[0070] Each photovoltaic unit 10 includes one or more photovoltaic modules, wherein the photovoltaic module is a direct current power source composed of solar cells packaged in series or in parallel, and is used to convert light energy into electrical energy.

[0071] When the photovoltaic unit 10 includes multiple photovoltaic components, the multiple photovoltaic components can form a photovoltaic string by connecting the positive and negative poles in series end to end to form the photovoltaic unit 10; the multiple photovoltaic components can also be connected in series to form multiple photovoltaic strings, and the multiple photovoltaic strings are then connected in parallel to form the photovoltaic unit 10.

[0072] The centralized inverter 12 includes a direct current (DC)-alternating current (AC) circuit, which can also be called an inverter circuit, and is used to invert the direct current input by at least one DC combiner box 11 into alternating current. The power of the centralized inverter 12 is relatively large, so a cabinet design is adopted. The centralized inverter 12 is generally set in a machine room or a container 13. Centralized inverters with a power of more than 500kW are generally used in photovoltaic power stations.

[0073] The AC power output by the centralized inverter 12 is transformed by the transformer 14 and then fed into the AC power grid 15 .

[0074] The following describes a photovoltaic power generation system based on a string inverter.

[0075] See also Figure 2 , which is a schematic diagram of a photovoltaic power generation system based on a string inverter.

[0076] The photovoltaic power generation system includes a photovoltaic unit 10 , a string inverter 16 , an AC combiner box 17 and a transformer 14 .

[0077] The DC side of the string inverter 16 is connected to one or more photovoltaic units 10 . In actual applications, the DC side of the string inverter 11 is generally connected to multiple photovoltaic units 10 .

[0078] The following is a detailed introduction to the implementation of string inverters.

[0079] See also Figure 3 , which is a schematic diagram of a schematic string inverter provided in an embodiment of the present application.

[0080] The power of the string inverter 16 is smaller than that of the centralized inverter, and it mostly adopts an outdoor modular design, including a two-stage power conversion circuit, the first stage is a DC-DC circuit 161, a general boost circuit, and the second stage is a DC-AC circuit 121, that is, an inverter circuit.

[0081] Among them, the string inverter 16 may include multiple DC-DC circuits 161, the positive output ports of the multiple DC-DC circuits 161 are connected in parallel to the positive input ports on the DC side of the DC-AC circuit 121, and the negative output ports of the multiple DC-DC circuits 161 are connected in parallel to the negative input ports on the DC side of the DC-AC circuit 121.

[0082] The AC output terminal of the DC-AC circuit 121 is the output terminal of the string inverter 16 .

[0083] Each DC-DC circuit 161 is connected to at least one photovoltaic unit 10 , the positive input port of each DC-DC circuit 161 is connected to the positive pole of the photovoltaic unit 10 , and the negative input port of each DC-DC circuit 161 is connected to the negative pole of the photovoltaic unit 10 .

[0084] The AC power output by the multi-channel string inverter 16 is collected after passing through the AC combiner box 12 , and then transformed by the transformer 14 before being connected to the AC power grid 15 .

[0085] The following describes a photovoltaic power generation system based on a centralized inverter and a maximum power point tracking (MPPT) boost combiner box, which is also called a distributed photovoltaic power generation system.

[0086] See also Figure 4 , which is a schematic diagram of a photovoltaic power generation system based on a centralized inverter and an MPPT boost combiner box.

[0087] The photovoltaic power generation system shown in the figure includes a photovoltaic unit 10 , an MPPT boost combiner box 18 , a centralized inverter 21 and a transformer 14 .

[0088] The MPPT boost combiner box 18 is a boost converter, which will be described in detail below with reference to the accompanying drawings.

[0089] See also Figure 5 , which is a schematic diagram of a schematic MPPT boost combiner box provided in an embodiment of the present application.

[0090] The MPPT boost combiner box 20 generally includes at least two DC-DC circuits 161. Each DC-DC circuit 161 is connected to at least one photovoltaic unit 10. The positive input port of each DC-DC circuit 161 is connected to the positive pole of the photovoltaic unit 10, and the negative input port of the DC-DC circuit 161 is connected to the negative pole of the photovoltaic unit 10.

[0091] The positive output ports of the DC-DC circuits 161 are connected in parallel to the positive pole of the output DC bus, and the negative output ports of the DC-DC circuits 161 are connected in parallel to the negative pole of the output DC bus.

[0092] The positive and negative poles of the DC bus serve as the positive and negative output ports of the MPPT boost combiner box 20 , respectively, and are connected to the positive and negative input ports of the subsequent centralized inverter 12 via DC cables.

[0093] The centralized inverter 12 is used to convert a single or multiple parallel DC inputs connected to the DC side into AC outputs, generally using DC-AC single-stage power conversion. The AC power output by the centralized inverter 21 is fed into the AC grid 15 through the transformer 14 .

[0094] The centralized inverter 12 is generally electrically far away from the photovoltaic unit 10 and is often designed in an outdoor cabinet or in an outdoor modularized manner.

[0095] The following describes a photovoltaic power generation system based on a photovoltaic optimizer and a string inverter.

[0096] See also Figure 6 , which is a schematic diagram of a photovoltaic power generation system based on a photovoltaic optimizer and a string inverter.

[0097] The photovoltaic power generation system shown in the figure includes a photovoltaic unit 10 , a photovoltaic optimizer 19 , a string inverter 16 , a transformer 14 and an AC power grid 15 .

[0098] Among them, the photovoltaic optimizer 19 is a DC-DC converter, whose input side is connected to the photovoltaic unit 10, and the output side is connected to the string inverter 16 in series. In other embodiments, it can also be connected to a centralized inverter. The photovoltaic optimizer 19 is used to increase or decrease the output voltage of the photovoltaic unit 10.

[0099] The photovoltaic optimizer 19 includes a DC-DC circuit, which can be a buck circuit, a boost circuit, or a buck-boost circuit. The positive input port of the DC-DC circuit is connected to the positive electrode of the photovoltaic unit 10, and the negative input port of the DC-DC circuit is connected to the negative electrode of the photovoltaic unit 10.

[0100] The positive pole of the DC-DC circuit is connected to the positive pole of the output DC bus, serving as the positive output port of the photovoltaic optimizer 19; the negative pole of the DC-DC circuit is connected to the negative pole of the output DC bus, serving as the negative output port of the photovoltaic optimizer 19.

[0101] A photovoltaic power generation system using the photovoltaic optimizer 19 generally connects a plurality of photovoltaic optimizers 19 in series to form a substring.

[0102] For example, N photovoltaic optimizers are connected in series, that is, the positive output port of the i-th photovoltaic optimizer is connected to the negative output port of the i-1-th photovoltaic optimizer, and the negative output port of the i-th photovoltaic optimizer is connected to the positive output port of the i+1-th photovoltaic optimizer, i=2, 3, ..., N-1. The positive output port of the first photovoltaic optimizer serves as the positive output port of the photovoltaic optimizer substring, and the negative output port of the N-th photovoltaic optimizer serves as the negative output port of the photovoltaic optimizer substring. The output end of the photovoltaic optimizer substring is connected to the input end of the subsequent string inverter or the centralized inverter via a DC cable.

[0103] The AC power output by the string inverter 16 is transformed by the transformer 14 and then fed into the AC power grid 15 .

[0104] As the output power of photovoltaic power generation systems increases, the total output power of the photovoltaic unit 10 continues to increase. Therefore, it is an inevitable trend that the power density of power converters such as centralized inverters, MPPT boost junction boxes and string inverters used in the above photovoltaic power generation systems continues to increase, and the heat dissipation challenges brought about by this are also increasing.

[0105] When dissipating heat in current power converters, the magnetic components are exposed in a low protection cavity for ventilation and heat dissipation, or are glued and set in a metal shell for heat dissipation; the power semiconductor devices are exposed in a low protection cavity for ventilation and heat dissipation; other devices are set in a high protection cavity for closed protection, and the heat is naturally dissipated to the outside through the high protection cavity wall.

[0106] However, this solution exposes environmentally sensitive components such as power semiconductor devices and magnetic components directly in the low protection cavity, which has poor reliability and limited heat dissipation capacity. In addition, for the solution of potting the magnetic components in the metal shell, as the power of the power converter continues to increase, the heat loss of the magnetic components gradually increases, while the potting glue has low thermal conductivity and high thermal resistance, making it impossible to effectively improve the heat dissipation effect.

[0107] In order to solve the above technical problems, the present application provides a power converter, a heat exchanger, a radiator and a photovoltaic power generation system, in which power semiconductor devices and magnetic elements are arranged in a closed cavity for heat dissipation, thereby improving the reliability of the power converter. For power semiconductor devices with high heat consumption density, a radiator is used for heat dissipation, thereby improving the heat dissipation efficiency. For magnetic elements, a radiator or a heat exchanger can be used for heat dissipation. In addition, the heat dissipation fins or heat exchanger of the radiator used are arranged in the heat dissipation cavity. By separately setting the heat dissipation cavity and the closed cavity, efficient heat dissipation is achieved while ensuring a high protection level for the internal devices.

[0108] The technical solution of the present application is described in detail below with reference to the accompanying drawings.

[0109] The terms "first", "second", etc. in the following description of this application are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0110] In the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0111] A typical example of the magnetic element in the embodiments of the present application is an inductor.

[0112] The following first describes a solution in which the magnetic element dissipates heat through a heat exchanger.

[0113] See also Figure 7-Figure 9 .in, Figure 7 A side view of a power converter provided in an embodiment of the present application; Figure 8 Provided in the embodiments of this application Figure 7 The front view corresponding to the power converter shown; Fig. 9 Provided in the embodiments of this application Figure 8 A-A' section diagram.

[0114] The power converter 200 shown in the figure includes a magnetic element 211 , a semiconductor device 214 , a sealed cavity 210 and a heat dissipation cavity 220 .

[0115] The power semiconductor device 214 and the magnetic element 211 are disposed in the sealed cavity 210 .

[0116] The power semiconductor device 214 dissipates heat through the first heat sink 215 , and the heat dissipation fins of the first heat sink 215 are located in the heat dissipation cavity 220 .

[0117] The magnetic element 211 dissipates heat through the first heat exchanger 212 , and the first heat exchanger 212 is located in the heat dissipation cavity 220 , which will be described in detail below.

[0118] The sealed chamber 210 includes a first air duct 213, and the magnetic element 211 is disposed in the first air duct 213. The first air duct 213 is used to restrict the flow direction of the gas for dissipating heat from the magnetic element 211. In a possible implementation, the first air duct 213 is a sealed air duct.

[0119] See also Figure 8The first end of the first air duct is an air supply port 2131, which is connected to the first end of the first heat exchanger 212 and is used to receive gas from the first heat exchanger 212. The second end of the first air duct is a return air port 2132, which is connected to the second end of the first heat exchanger 212 and is used to send gas into the first heat exchanger 212.

[0120] At least one first internal circulation fan 2133 is also provided at the air supply port 2131 or the air return port 2132 for controlling the air flow starting from the air supply port 2131 and reaching the air return port 2132 along the inner cavity of the first air duct to cool the magnetic element 211 .

[0121] In some embodiments, the air supply port 2131 and the air return port 2132 may be provided with at least one first internal circulation fan 2133 to enhance the heat dissipation effect.

[0122] The flow circuit of the airflow at this time can be seen in Fig. 9 The gas starts from the air supply port 2131, flows through the magnetic element 211 along the first air duct, and becomes high-temperature gas after heat exchange with the magnetic element 211, returns to the first heat exchanger 212 through the return air port 2132, and becomes low-temperature gas after completing heat exchange with the external air (or other cooling medium), and then returns to the first air duct through the air supply port 2132, and the cycle continues.

[0123] The sealed cavity 210 also includes high protection level components 216 , such as single-board circuits, controllers and other devices with low heat dissipation density. The sealed cavity 210 ensures the safety of the high protection level components 216 .

[0124] The embodiments of the present application do not specifically limit the type of power semiconductor devices. In some embodiments, the power semiconductor devices may be insulated gate bipolar transistors (IGBT), metal oxide semiconductor field effect transistors (MOSFET, MOS tube for short), silicon carbide metal oxide semiconductors (SiC MOSFET), etc.

[0125] The power converter 200 in the embodiment of the present application may specifically be a centralized inverter, a string inverter or an MPPT boost combiner box, which is not specifically limited in the embodiment of the present application.

[0126] Among them, when the two ends of the first air duct 213 are connected to the two ends of the first heat exchanger 212, both ends can be sealed and connected; or, one end is sealed and connected, and the other end is connected through the inner cavity of the closed cavity. At this time, the port of the first air duct 213 and the port of the first heat exchanger 212 should be relatively close; or, the two ends of the first air duct 213 and the two ends of the first heat exchanger 212 are connected through the inner cavity of the closed cavity. At this time, the two side ports of the first air duct 213 and the two side ports of the first heat exchanger 212 should be relatively close.

[0127] In summary, by using the solution provided in the embodiment of the present application, the power semiconductor device and the magnetic element are arranged in a closed cavity for heat dissipation, thereby improving the reliability of the power converter. For power semiconductor devices with high heat consumption density, a radiator is used for heat dissipation, thereby improving the heat dissipation efficiency. The magnetic element is cooled by a heat exchanger. The heat dissipation fins and the heat exchanger of the radiator are arranged in the heat dissipation cavity. By separating the heat dissipation cavity and the closed cavity, efficient heat dissipation is achieved while ensuring a high protection level for the internal devices.

[0128] The power converter 200 in the above embodiment is a single-duct design. In order to ensure that when the fan in the first duct 213 fails, the first heat exchanger 212 can continue to dissipate heat for the magnetic element 211, the present application also provides another power converter that adopts a dual-duct design, which is described in detail below in conjunction with the accompanying drawings.

[0129] See also Fig.10 and Fig.11 .in, Fig.10 A front view of another power converter provided in an embodiment of the present application; Fig.11 Provided in the embodiments of this application Fig.10 A-A' section diagram.

[0130] As shown in the figure, the sealed cavity 210 further includes a second air duct 213 b , a first end of the second air duct 213 b is shared with a first end of the first air duct 213 , and a second end of the second air duct 213 b is communicated with an inner cavity of the first air duct 213 .

[0131] The first internal circulation fan 2133 controls the air flow to start from the air supply port 2131, flow through the magnetic element 211 along the first air duct 213, and become high-temperature gas after heat exchange with the magnetic element 211, and return to the first heat exchanger 212 through the return air port 2132. The gas circulation direction can be seen in Fig.11 The solid arrow in .

[0132] The second air duct 213b is further provided with at least one second internal circulation fan 2133b for controlling the air flow starting from the second air duct 213b and passing through the second air duct 213b. Fig.11The path indicated by the dashed arrow is connected to the first air duct 213 , and then reaches the return air port 2132 along the inner cavity of the first air duct 213 .

[0133] At this time, when the first internal circulation fan 2133 in the first air duct 213 partially or completely fails, the second internal circulation fan 2133b can be started so that the first heat exchanger 212 can still dissipate heat normally.

[0134] Another power converter using a rebound structure is described below with reference to the accompanying drawings.

[0135] See also Figure 12-14 .in, Fig.12 A front view of the air duct plate of the power converter provided in an embodiment of the present application when closed; Fig.13 A front view of the air duct plate of the power converter provided in an embodiment of the present application when it is opened; Fig.14 Provided in the embodiments of this application Fig.12 A-A' section diagram.

[0136] The enclosed cavity shown in the figure includes a second air duct 213b. In some embodiments, the second air duct 213b includes other enclosed areas of the enclosed cavity except the first air duct 213. In other embodiments, the second air duct 213b is a separately provided air duct.

[0137] The first end of the second air duct 213 b is shared with the first end of the first air duct 213 , and the second end of the second air duct 213 b is communicated with the inner cavity of the sealed cavity.

[0138] The cavity wall of the first air duct 213 includes a plurality of groups of rebound structures, as shown by the dotted line boxes in the figure, and each group of rebound structures includes an air duct plate 218 and cavity wall openings.

[0139] The embodiment of the present application does not specifically limit the specific number of the rebound structures, which can be determined according to the actual length of the cavity wall of the first air duct 213 .

[0140] The force direction of the air duct plate 218 when it rebounds points to the inside of the first air duct 213. The area of ​​the air duct plate 218 is larger than the area of ​​the cavity wall opening, and the air duct plate 218 can completely cover the corresponding cavity wall opening. At this time, when the air duct plate 218 is combined with the corresponding cavity wall opening, the first air duct 213 can be in a closed state.

[0141] The second air duct 213b is further provided with at least one second internal circulation fan 2133b.

[0142] When the first internal circulation fan 2133 of the first air duct 213 works normally, the air duct plate 218 overcomes its own elastic force and merges into the corresponding cavity wall opening under the action of gas pressure. The airflow starts from the air supply port 2131, flows through the magnetic element 211 along the first air duct 213, and becomes high-temperature gas after heat exchange with the magnetic element 211, and returns to the first heat exchanger 212 through the return air port 2132. At this time, the gas flow cycle can be seen Fig.14 As shown by the solid arrow in .

[0143] See also Fig.13 When the first internal circulation fan 2133 partially or completely fails, the air duct plate 218 rebounds, and an opening appears in the cavity wall of the first air duct 213. The second internal circulation fan 2133b controls the airflow to start from the second air duct 213b, pass through the inner cavity of the closed cavity and the inner cavity of the first air duct 213 in sequence, and then reach the return air port 2132 to achieve heat dissipation for the magnetic element 211.

[0144] The second internal circulation fan 2133b can also dissipate heat for the high protection level component 216 in the closed cavity.

[0145] In some embodiments, each set of rebound structures further includes a stop structure 217 , which may be a stop column or a stop nail, and is used to limit the rebound position of the air duct plate 218 when the air duct plate 218 rebounds.

[0146] In some embodiments, in order to prevent the air duct plate 218 from rebounding when the first internal circulation fan 2133 operates normally, the rebound structure is located close to the first internal circulation fan 2133 to ensure that the gas pressure on the air duct plate 218 is sufficient to overcome the rebound force.

[0147] The power converter provided in the above embodiments uses a first heat exchanger to dissipate heat from the magnetic element, and uses a first radiator to dissipate heat from the power semiconductor device. In the heat dissipation cavity, the heat dissipation fins of the first radiator and the first heat exchanger can use series air ducts, parallel air ducts or independent air ducts to dissipate heat, or use a cooling medium to dissipate heat, which is not specifically limited in the embodiments of the present application.

[0148] The following describes how to use a radiator to dissipate heat for magnetic components and a heat exchanger to dissipate heat for high protection level components.

[0149] See also Figure 15-17 .in, Fig.15 A side view of another power converter provided in an embodiment of the present application; Fig.16 Provided in the embodiments of this application Fig.15 A front view of the power converter shown; Fig.17 Provided in the embodiments of this application Fig.16 B-B' cross-section diagram.

[0150] The power semiconductor device 214 of the power converter 200 dissipates heat through a first heat sink 215 , and the heat dissipation fins of the first heat sink 215 are located in the heat dissipation cavity 220 .

[0151] The magnetic element 211 of the power converter 200 dissipates heat through the second heat sink 215 b , and the heat dissipation fins of the second heat sink 215 b are located in the heat dissipation cavity 220 .

[0152] In some embodiments, the magnetic element 211 can be disposed in a metal housing, and then the metal housing is fixed to the second heat sink 215b. In other embodiments, the magnetic element 211 can be directly fixed to the second heat sink 215b by glue filling. In still other embodiments, the magnetic element 211 can be attached to the second heat sink 215b through a thermal pad.

[0153] In order to improve the heat dissipation efficiency, the magnetic element 211 may be covered with a thermal interface material (TIM). The present application does not specifically limit the type of the thermal interface material.

[0154] The high protection grade component 216 of the power converter 200 is disposed in the sealed cavity 210 . The high protection grade component 216 dissipates heat through the second heat exchanger 212 b , and the second heat exchanger 212 b is located in the heat dissipation cavity 220 .

[0155] At this time, a third air duct 213 c is disposed at the first end of the sealed chamber 210 , a first end of the third air duct 213 c is an air outlet 2131 , and a second end of the third air duct 213 c is communicated with the inner cavity of the sealed chamber 210 .

[0156] The second end of the sealed chamber 210 is an air return port 2132 .

[0157] The air supply port 2131 is connected to a first end of the second heat exchanger 212 b , and the air return port 2132 is connected to a second end of the second heat exchanger 212 b .

[0158] At least one third internal circulation fan 2133c is also provided at the air supply port 2131 or the air return port 2132, which is used to control the air flow to start from the air supply port 2131, and to complete the heat exchange with the high protection level component 216 along the inner cavity of the closed cavity to become high-temperature gas, and then enter the second heat exchanger 212b through the air return port 2132, thereby realizing the heat dissipation of the high protection level component 216. At this time, the gas circulation path can be seen in Fig.17 The implementation arrow in is shown.

[0159] To summarize, by using the power converter provided in the embodiment of the present application, the power semiconductor devices and magnetic elements are arranged in a closed cavity for heat dissipation, and the high protection level components are cooled by a heat exchanger. By separately setting the heat dissipation cavity and the closed cavity, efficient heat dissipation is achieved while ensuring the high protection level of the internal devices.

[0160] The power converter 200 in the above embodiment is a single-duct design. In order to ensure that when the fan in the third duct 213c fails, the second heat exchanger 212b can continue to dissipate heat for high-protection-level components, the present application also provides another power converter that adopts a dual-duct design, which is described in detail below in conjunction with the accompanying drawings.

[0161] See also Fig.18 and Fig.19 .in, Fig.18 A front view of another power converter provided in an embodiment of the present application; Fig.19 Provided in the embodiments of this application Fig.18 B-B' cross-section diagram.

[0162] The power converter is shown in Figure 1. Figure 15-17 The difference is that the first end of the sealed cavity 210 is provided with a third air duct 213c, and the second end of the sealed cavity 210 is provided with a fourth air duct 213d.

[0163] A first end of the third air duct 213 c is an air outlet 2131 , and a second end of the third air duct 213 c is in communication with the inner cavity of the sealed cavity 210 .

[0164] A first end of the fourth air duct 213 d is an air return port 2132 , and a second end of the fourth air duct 213 d is in communication with the inner cavity of the sealed cavity 210 .

[0165] At least one third internal circulation fan 2133 c is disposed at the air supply port 2131 , and at least one fourth internal circulation fan 2133 d is disposed at the air return port 2132 .

[0166] The third internal circulation fan 2133c and the fourth internal circulation fan 2133d are used to control the air flow from the air supply port 2131 to the air return port 2132 along the inner cavity of the closed cavity. Fig.19 The implementation arrow in is shown.

[0167] The third inner circulation fan 2133c and the fourth inner circulation fan 2133d can be started at the same time, or one of them can be started, for example, the third inner circulation fan 2133c is started and the fourth inner circulation fan 2133d is turned off. When the started fan fails, another fan is started to ensure that the heat dissipation of the high protection level component is not affected.

[0168] In the above embodiments, the cooling fins of the first radiator 215, the cooling fins of the second radiator 215b and the second heat exchanger 212b can use series air ducts, parallel air ducts or independent air ducts to dissipate heat in the heat dissipation cavity 220, and can also use cooling media to dissipate heat, which is not specifically limited in the embodiments of the present application.

[0169] By using the heat exchanger provided in the embodiment of the present application, the heat dissipation efficiency is improved when dissipating heat for high protection level components or magnetic components.

[0170] Based on the power converter provided in the above embodiments, the embodiments of the present application also provide a heat exchanger, which can be used to dissipate heat for magnetic components or for high-protection components, that is, the first heat exchanger and the second heat exchanger in the above embodiments can adopt this heat exchanger, which is described in detail below in conjunction with the accompanying drawings.

[0171] See also Fig. 20 , which is a schematic diagram of a heat exchanger provided in an embodiment of the present application.

[0172] The heat exchanger includes a first plenum chamber 31 , a second plenum chamber 32 and a connecting portion 33 .

[0173] The connecting portion 33 includes at least one tubular channel. In practical applications, in order to improve the heat dissipation effect, it generally includes multiple tubular channels.

[0174] The tubular channel is formed by extrusion of a profile, or by rolling a plate into the tubular channel, which is not specifically limited in the embodiment of the present application. In a possible implementation, the tubular channel is a flat rectangular parallelepiped channel.

[0175] The connecting portion 33 is used to connect the first gas collecting cavity 31 and the second gas collecting cavity 32 .

[0176] The first air collecting cavity 31 is connected to the air supply port through the first sealing flange 34 , and the second air collecting cavity 32 is connected to the air return port through the second sealing flange 35 .

[0177] The side wall of the gas collecting cavity is provided with holes matching the number and size of the tubular channels, and the tubular channels are inserted into the gas collecting cavity.

[0178] A partition rib 331 may be provided inside the tubular channel to improve the heat dissipation effect.

[0179] When the connecting portion 33 includes a plurality of tubular channels, a heat dissipation fin 37 may be embedded between two adjacent tubular channels to improve the heat dissipation effect.

[0180] The tubular passage, the air collecting cavity and the external fins are formed into one piece by welding.

[0181] See also Fig.21, which is a schematic diagram of another heat exchanger provided in an embodiment of the present application.

[0182] The heat exchanger shown in the figure includes a first sealing flange 34 , a second sealing flange 35 and at least two bent tubular channels 38 .

[0183] The first ends of at least two bent tubular channels 38 are connected to the air supply port through the first sealing flange 34 , and the second ends of at least two bent tubular channels 38 are connected to the air return port through the second sealing flange 35 .

[0184] The bent tubular channel is formed by extrusion of a profile, or by rolling a plate into a tubular channel, which is not specifically limited in the present embodiment. In a possible implementation, the bent tubular channel is a flat rectangular channel, and is bent at both ends.

[0185] In some embodiments, the first sealing flange 34 and the second sealing flange 35 are provided with holes matching the number and size of the bent tubular channel, and both ends of the bent tubular channel can be inserted into the corresponding holes of the sealing flanges.

[0186] A partition rib 331 is disposed inside the bent tubular channel 38 to enhance the heat dissipation effect.

[0187] Heat dissipation fins are embedded between the bent tubular channels 38 to enhance the heat dissipation effect.

[0188] The bent tubular passage, the sealing flange and the external fins are integrated by welding.

[0189] By using the heat exchanger provided in the embodiment of the present application, the heat dissipation efficiency is improved when dissipating heat for high protection level components or magnetic components.

[0190] Based on the power converter provided in the above embodiments, the embodiments of the present application further provide a heat sink, which will be described in detail below in conjunction with the accompanying drawings.

[0191] See also Fig. 22 and Fig.23 .in, Fig. 22 A schematic diagram of the structure of a radiator provided in an embodiment of the present application; Fig.23 Provided in the embodiments of this application Fig. 22 C-C' cross-section diagram.

[0192] The heat sink 40 includes a base plate 41 and heat dissipation fins 42 .

[0193] The heat dissipation fins 42 are used to perform contact heat dissipation on the substrate 41 .

[0194] The substrate 41 includes a temperature-averaging cavity, and the temperature-averaging cavity is filled with a working medium capable of undergoing a gas-liquid phase change.

[0195] The lower middle portion of the substrate is used to place devices to be cooled, namely, devices with high heat dissipation density such as the magnetic element 211 and the power semiconductor device 214 .

[0196] In some embodiments, internal heat dissipation fins 412 are further disposed in the temperature-averaging chamber to accelerate the speed of temperature-averaging of the substrate.

[0197] The heat dissipation fins, the bottom of the substrate and the cavity cover 411 on the top of the substrate in the temperature-averaging cavity are welded together. After vacuuming, the working fluid is injected into the temperature-averaging cavity through the reserved injection port, and finally the injection port is closed.

[0198] The external heat dissipation fins 42 can be integrally formed by extrusion, shovel teeth, etc., or connected by welding. The working fluid at the bottom of the inner cavity undergoes a gas-liquid phase change when heated, and condenses and refluxes at the top to achieve uniform temperature of the entire substrate.

[0199] Another implementation of the heat sink is described below.

[0200] See also Fig.24 and Fig.25 .in, Fig.24 A schematic diagram of the structure of another radiator provided in an embodiment of the present application; Fig.23 A cross-sectional view of a temperature homogenizing plate provided in an embodiment of the present application.

[0201] The heat sink 40 includes a base plate 41 , heat dissipation fins 42 and a temperature balancing plate 43 .

[0202] The heat dissipation fins 42 are used for contact heat dissipation of the substrate 41;

[0203] The embodiment of the present application is described by taking the temperature uniformity plate 43 being disposed on the substrate 41 as an example.

[0204] The inner cavity of the temperature equalizing plate 43 is filled with a working medium capable of undergoing a gas-liquid phase change.

[0205] The lower middle part of the temperature homogenizing plate 43 is used to place devices to be cooled, namely, devices with high heat dissipation density such as the magnetic element 211 and the power semiconductor device 214 .

[0206] In some embodiments, heat dissipation fins 433 are further disposed in the temperature homogenizing plate 43 to increase the temperature homogenizing speed.

[0207] See also Fig.25 The temperature averaging plate 43 can be mounted on the substrate by screws or welding. The temperature averaging plate 43 includes an upper cover plate 431 and a lower cover plate 432 .

[0208] The upper cover plate 431, the lower cover plate 432 and the internal heat dissipation fins 433 are welded together. After vacuuming, the working fluid is injected into the cavity of the temperature equalizing plate through the reserved liquid injection port, and finally the liquid injection port is closed. The external heat dissipation fins 42 can be integrally formed by extrusion, shovel teeth, etc., or they can be connected and fixed by welding. During operation, the device to be dissipated is installed in the lower middle part of the temperature equalizing plate 43. The working fluid at the bottom of the inner cavity of the temperature equalizing plate 43 undergoes a gas-liquid phase change when heated, and condenses and refluxes at the top to achieve uniform temperature of the entire substrate.

[0209] In other implementations, the temperature homogenizing plate 43 may be installed into the inner cavity of the substrate 41 by means of screws or welding. In this case, the lower middle portion of the substrate 41 is used to arrange the device to be cooled.

[0210] By using the heat sink provided in the embodiment of the present application, the temperature equalization speed of the substrate is improved, thereby improving the heat dissipation efficiency when dissipating heat for power semiconductor devices, magnetic elements and other devices with high heat dissipation density.

[0211] Based on the power converter provided in the above embodiments, the embodiments of the present application further provide a photovoltaic power generation system, which will be described in detail below with reference to the accompanying drawings.

[0212] See also Fig.26 , which is a schematic diagram of a photovoltaic power generation system provided in an embodiment of the present application.

[0213] The photovoltaic power generation system 26 includes the power converter 200 provided in the above embodiment, and also includes a photovoltaic unit 10 .

[0214] The embodiment of the present application does not specifically limit the number of photovoltaic units.

[0215] The photovoltaic unit 10 includes at least one photovoltaic module. When the photovoltaic unit 10 includes multiple photovoltaic modules, the multiple photovoltaic modules can be connected in series with the positive and negative electrodes to form a photovoltaic string to form the photovoltaic unit 10; the multiple photovoltaic modules can also be connected in series to form multiple photovoltaic strings, and the multiple photovoltaic strings are then connected in parallel to form the photovoltaic unit 10.

[0216] The photovoltaic unit 10 is used to convert light energy into direct current.

[0217] For the specific implementation of the power converter 200, please refer to the relevant description in the above embodiments, and the embodiments of the present application will not be repeated here.

[0218] In some embodiments, the power converter 200 is a centralized inverter. In this case, the photovoltaic power generation system includes a DC combiner box or an MPPT boost combiner box, collectively referred to as a combiner box below. The photovoltaic unit first combines the DC power into the combiner box, and the centralized inverter then inverts the DC power input by at least one combiner box into AC power.

[0219] In other embodiments, the power converter 200 is a string inverter, in which case the input end of the power converter 200 can be directly connected to a photovoltaic unit, or connected to a photovoltaic optimizer string.

[0220] In some other embodiments, the power converter 200 is an MPPT boost combiner box, and in this case, the input end of the power converter 200 can be directly connected to the photovoltaic unit.

[0221] In summary, the photovoltaic power generation system utilizes the power converter provided by the embodiment of the present application, which sets the power semiconductor device and the magnetic element in a closed cavity for heat dissipation, thereby improving the reliability of the power converter. For power semiconductor devices with high heat consumption density, a radiator is used for heat dissipation, thereby improving the heat dissipation efficiency. For magnetic elements, a radiator or a heat exchanger (also known as a heat exchanger) can be used for heat dissipation. The heat dissipation fins or heat exchanger of the radiator used are set in the heat dissipation cavity. By setting the heat dissipation cavity and the closed cavity separately, efficient heat dissipation is achieved while ensuring a high protection level of the internal devices.

[0222] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0223] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A power converter, characterized in that: The power converter comprises a power semiconductor device, a magnetic element, a circuit board, a sealed cavity, a heat dissipation cavity, a first heat sink and a second heat sink; The power semiconductor device is arranged in the sealed cavity and dissipates heat in the sealed cavity through a first heat sink, the first heat sink is formed with heat dissipation fins and the heat dissipation fins are located in the heat dissipation cavity outside the sealed cavity; The magnetic element dissipates heat through a second radiator, the heat dissipation fins of the second radiator are located in the heat dissipation cavity, the magnetic element is arranged in a metal shell and then the metal shell is fixed to the second radiator or the magnetic element is glued and fixed to the second radiator; The power converter further comprises a high protection level element and a second heat exchanger, wherein the second heat exchanger comprises an air supply port and an air return port; The high protection level component and the circuit board are arranged in the closed cavity, the power semiconductor device is installed on one side of the circuit board and is located between the circuit board and the first radiator and is thermally bonded to the first radiator, the high protection level component is located on the other side of the circuit board, and at least one third internal circulation fan is also arranged at the air supply port or the return air port. The third internal circulation fan is used to control the airflow starting from the air supply port and reaching the return air port along the inner cavity of the closed cavity, so that the high protection level component located on the other side of the heat sink is cooled in the closed cavity through the second heat exchanger.

2. The power converter according to claim 1, characterized in that: The second heat exchanger includes a first gas collecting cavity, a second gas collecting cavity and a connecting portion; The connecting portion includes at least one tubular passage; The at least one tubular channel is used to connect the first gas collecting cavity and the second gas collecting cavity; The first air collecting cavity is connected to the air supply port via a first sealing flange, and the second air collecting cavity is connected to the air return port via a second sealing flange; Partition ribs are arranged inside the at least one tubular channel.

3. The power converter according to claim 2, characterized in that: The connecting portion includes at least two tubular channels, and a heat dissipation fin is embedded between the at least two tubular channels.

4. The power converter according to any one of claims 1 to 3, characterized in that: The second heat exchanger comprises a first sealing flange, a second sealing flange and at least two bent tubular channels; The first ends of the at least two bent tubular channels are connected to the air supply port through the first sealing flange, and the second ends of the at least two bent tubular channels are connected to the air return port through the second sealing flange; Partition ribs are arranged inside the at least two bent tubular channels.

5. The power converter according to claim 4, characterized in that: A heat dissipation fin is embedded between the at least two bent tubular channels.

6. The power converter according to any one of claims 1 to 5, characterized in that: The magnetic element is glue-filled and arranged in the metal shell of the second radiator, and the second radiator is located in the radiating cavity.

7. The power converter according to any one of claims 1 to 5, characterized in that: The second heat exchanger is located in the heat dissipation cavity or the closed cavity, and the second heat exchanger includes an air supply port connected to a first end of the second heat exchanger.

8. The power converter according to any one of claims 1 to 5, characterized in that: The heat dissipation fins of the first heat sink and the heat dissipation fins of the second heat sink are cooled in the heat dissipation cavity by using series air ducts, parallel air ducts or mutually independent air ducts.

9. The power converter according to any one of claims 1 to 5, characterized in that: The first heat sink comprises: a substrate and heat dissipation fins; The heat dissipation fins are used to perform contact heat dissipation on the substrate; The substrate comprises a temperature-averaging cavity, and the temperature-averaging cavity is filled with a working medium capable of undergoing a gas-liquid phase change; The lower middle portion of the substrate is used to arrange components to be cooled.

10. The power converter according to claim 9, characterized in that: The temperature-averaging chamber is also provided with heat dissipation fins.

11. The power converter according to any one of claims 1 to 5, characterized in that: The second heat sink comprises: a base plate and heat dissipation fins; The heat dissipation fins are used to perform contact heat dissipation on the substrate; The magnetic element is arranged in the metal shell formed by the substrate, and then the metal shell is fixed to the second radiator, or the magnetic element is directly glued and fixed in the metal shell of the substrate of the second radiator, and the heat dissipation fins are located in the heat dissipation cavity.

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