Power conversion device and energy storage device

Abstract

A power conversion device and an energy storage device, relating to the technical field of heat dissipation of energy storage devices. The power conversion device comprises a housing, a heat exchanger, a heat sink, inductor boxes, and a circuit board; the housing is provided with a power cavity and a heat dissipation cavity; power devices and heating electronic devices are respectively mounted on two sides of the circuit board; the heating electronic devices, the circuit board, the power devices, and the heat sink are sequentially arranged; the heat sink is partially located in the heat dissipation cavity to dissipate heat of the power devices; the heat exchanger is partially located in the power cavity to cool the heating electronic devices; the inductor boxes and the heat sink are all located in the heat dissipation cavity. The present application improves the heat dissipation efficiency of the whole power conversion device, and can satisfy the heat dissipation requirement of components having higher power and higher power density and improve the working performance of the power conversion device.

Description

Power conversion device and energy storage device

[0001] The present application claims priority to the Chinese patent application No. 202410591457.8, filed on May 14, 2024, and entitled "Power conversion device and energy storage device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of heat dissipation technology of energy storage devices, and in particular, to a power conversion device and an energy storage device. BACKGROUND

[0003] With the development of the new energy industry, the power of power conversion devices and the like is continuously increasing, and the power consumption of internal components is also continuously increasing. For example, as an important component for realizing energy conversion and transmission in a power conversion module, an insulated gate bipolar transistor (IGBT) accounts for more than two-thirds of the total heat generated by internal components in the power conversion device, and is a bottleneck component that restricts the power improvement of the module. With the increasing power and power density of inverters, the heat generated by the internal components of the inverter case, such as single-board through-flow and cables, is also increasing, and components such as electrolytic capacitors that are easily affected by heat are all inside the case. The internal temperature rise of the case directly determines the service life of these components, thereby affecting the service life and failure rate of the inverter.

[0004] In the power conversion device and the like, components with different power consumptions can be installed in different areas, and the same heat dissipation system is usually used for heat dissipation for components with different power consumptions. On the one hand, different components have different heat generation amounts and different heat resistance temperatures, and the heat dissipation system needs to meet the requirement of the lowest heat resistance temperature, and heat dissipation for components with high heat resistance will affect the heat dissipation efficiency, which cannot meet the requirement of increasing power and power density. On the other hand, components such as IGBTs, capacitors, relays, and circuit boards cannot be effectively sealed and protected, and dust and moisture may come into contact with high-precision components through the heat dissipation system, thereby affecting the service life of the components. SUMMARY

[0005] The present application provides a power conversion device and an energy storage device. A heat exchanger is arranged in the device, and the heat exchanger has an internal refrigerant circulation system. The internally circulated refrigerant can exchange heat with the wall surface of the heat exchanger and the external space of the heat exchanger (an area outside the heat exchanger), so as to cool the medium (which can be air) in the device, and then dissipate heat from high-power and high-power-density electronic components and the like installed in the device. The heat dissipation efficiency of the entire power conversion device is improved, the heat dissipation requirement of components with higher power and higher power density can be met, and the working performance of the power conversion device is improved.

[0006] In a first aspect, the present application provides a power conversion device for connecting in an energy system for converting electric power in the energy system, comprising:

[0007] a housing having a sealed and isolated power cavity, the housing having a back plate with an open and ventilated heat dissipation cavity on a side facing away from the power cavity, the back plate being provided with a first through hole;

[0008] a circuit board located in the power cavity, the circuit board being provided with a heat generating electronic device and a power device on two mounting surfaces thereof respectively;

[0009] a heat sink for dissipating heat of the power device, the heat sink comprising a heat exchange plate and first fins, the heat sink being in thermal contact with the first through hole and the power device, the heat generating electronic device, the circuit board, the power device, the heat exchange plate and the first fins being arranged in sequence, the heat exchange plate being in thermal contact with the power device to conduct heat of the power device to the first fins, the first fins being located in the heat dissipation cavity to dissipate heat, the first fins having first heat dissipation air ducts therebetween;

[0010] a heat exchanger for dissipating heat of the heat generating electronic device, at least partially located in the power cavity, the heat exchanger having a heat exchange channel inside, the heat exchange channel being parallel or perpendicular to the first heat dissipation air ducts;

[0011] an inductor box located in the heat dissipation cavity and on a side of the heat sink where air is out and / or in, the inductor box being provided with an inductor, an electric connection line of the inductor passing through the back plate to be electrically connected with the power device, the inductor box being provided with second fins on an outer wall thereof, the second fins having second heat dissipation air ducts therebetween, the first heat dissipation air ducts and the second heat dissipation air ducts being parallel.

[0012] The power conversion device provided by the embodiment of the present application has the power device and the heat generating electronic device respectively installed on the two sides of the circuit board in the power cavity, the power device can be in contact with the heat sink, the heat sink extends into the heat dissipation cavity, the heat dissipation cavity is used for cooling the heat sink, and the heat sink is used for cooling the power device; the heat exchanger is arranged in the power cavity, the heat exchanger has an internal refrigerant circulation system, the internally circulated refrigerant can exchange heat with the wall of the heat exchanger and the external space of the heat exchanger (an area outside the heat exchanger in the power cavity), so as to cool the medium (which can be air) in the power cavity, and then cool the heat generating electronic device and other devices installed in the power cavity, thereby improving the heat dissipation efficiency of the entire power conversion device, meeting the heat dissipation requirements of higher power and higher power density components, and improving the working performance of the power conversion device; in addition, the entire heat dissipation system can meet the closed state of the power cavity, prevent water or dust in the external medium from entering the power cavity, and ensure the use safety of the components in the power cavity. In addition, the inductor box is installed in the heat dissipation cavity, the inductor box is cooled at the same time of the heat dissipation and ventilation of the heat sink, and the overall heat dissipation efficiency is improved.

[0013] In a possible implementation manner, the heat exchanger is located in the power cavity, and the heat exchanger has an inflow passage and an outflow passage, the inflow passage and the outflow passage are both isolated from the power cavity, the inflow passage, the heat exchange passage and the outflow passage are sequentially communicated, and the inflow port and the outflow port of the inflow passage are both in communication with the heat dissipation cavity space outside the power cavity, so that the internal circulation passage of the heat exchanger can be connected with the outside to cool the high-temperature medium flowing in the heat exchanger, and the sealing of the power cavity is realized.

[0014] In a possible implementation manner, the cavity wall of the heat dissipation cavity is provided with an air inlet and an air outlet, the air inlet and the air outlet are both in communication with the heat dissipation cavity, the air inlet and the air outlet have a ventilation passage therebetween, the ventilation passage is parallel to the first heat dissipation air duct, and at least one of the inflow port and the outflow port is located in the heat dissipation cavity and in communication with the heat dissipation cavity. The low-temperature medium can flow in the ventilation passage, when the inflow port is located in the heat dissipation cavity, the low-temperature medium flowing in the ventilation passage can flow into the heat exchanger to cool the heat exchanger; when the outflow port is located in the heat dissipation cavity, the low-temperature medium flowing in the ventilation passage can cool the high-temperature medium discharged from the heat exchanger, and timely blow out the high-temperature medium discharged from the heat exchanger, so as to indirectly improve the flow speed of the refrigerant in the heat exchanger and improve the heat dissipation efficiency of the high-temperature medium in the heat exchanger.

[0015] In a possible implementation manner, the back plate is provided with a second through hole, the inflow channel passes through the second through hole and is in sealing connection with the inner wall of the second through hole, the inflow port is located in the heat dissipation cavity, the inflow channel and the heat dissipation cavity are in communication, the inflow port is in communication with the ventilation channel of the heat dissipation cavity through the second through hole, and the low-temperature medium flowing in the ventilation channel can flow into the heat exchanger to cool the heat exchanger.

[0016] In a possible implementation manner, the back plate is provided with a third through hole, the outflow channel passes through the third through hole and is in sealing connection with the inner wall of the third through hole, the outflow port is located in the heat dissipation cavity, the outflow channel and the heat dissipation cavity are in communication, the outflow port is in communication with the ventilation channel of the heat dissipation cavity through the third through hole, and the low-temperature medium flowing in the ventilation channel can cool the high-temperature medium discharged from the heat exchanger and blow out the high-temperature medium discharged from the heat exchanger in time, thereby indirectly increasing the flow speed of the refrigerant in the heat exchanger and improving the heat dissipation efficiency of the high-temperature medium in the heat exchanger.

[0017] In a possible implementation manner, the power conversion device further includes a first baffle, at least part of the first baffle is located on one side of the inflow port close to the air outlet, the first baffle and the inner wall of the heat dissipation cavity enclose a first inflow cavity, the first inflow cavity and the inflow port are in communication, and the opening of the first inflow cavity is located on the side of the inflow port facing the air inlet.

[0018] The first baffle is erected on the side of the inflow port facing the air outlet, and part of the air blown in by the air inlet is blocked by the first baffle, thereby reducing the air flowing to the air outlet above the inflow port, more air can be diverted to enter the inflow port on the back plate, the air amount entering the heat exchanger is increased, and the heat exchange efficiency of the heat exchanger is improved.

[0019] In a possible implementation manner, the opening of the first inflow cavity is located on the cavity wall of the heat dissipation cavity, the first baffle divides the heat dissipation cavity into the first inflow cavity and the second inflow cavity which are separated from each other, the air inlet includes a first air inlet and a second air inlet, the first air inlet is the opening of the first inflow cavity, and the second air inlet is an opening on the cavity wall of the second inflow cavity. The space where the inflow port is located and the space of the heat dissipation cavity are separated into two independent spaces, and the external low-temperature refrigerant can enter the first inflow cavity and the second inflow cavity respectively to reduce the temperature of the refrigerant entering the inflow port.

[0020] In a possible implementation manner, the power conversion device further includes a second baffle, at least part of the second baffle is located on a side of the outflow port close to the air inlet, the second baffle and the inner wall of the heat dissipation cavity form an outflow cavity, the outflow cavity is connected with the outflow port, and an opening of the outflow cavity is located on a side of the outflow port facing the air outlet. The second baffle can be located on the side of the outflow port close to the air inlet, so that the air flowing in the ventilation channel cannot directly reach the outflow port. On one hand, a negative pressure area is formed on the side of the outflow port facing the air outlet, so as to improve the rate of the high-temperature gas discharged outwards by the outflow port. On the other hand, the high-temperature medium discharged by the outflow port can be prevented from flowing back to the inflow port, so that the heat exchange efficiency of the heat exchanger is prevented from being reduced.

[0021] In a possible implementation manner, the power conversion device further includes a heat sink, the heat sink is located in the ventilation channel, the inflow port is located on a side of the heat sink close to the air inlet or on a side of the heat sink close to the air outlet, and the outflow port is located on a side of the heat sink close to the air inlet or on a side of the heat sink close to the air outlet. The heat sink can dissipate heat of part of the devices in the power cavity.

[0022] In a possible implementation manner, the power conversion device includes a circuit board, a power device and a heat-generating electronic device, the circuit board, the power device and the heat-generating electronic device are located in the power cavity, and the power device and the heat-generating electronic device are respectively mounted on opposite surfaces of the circuit board.

[0023] The heat sink partially penetrates the back plate to be connected with the power device, and the heat exchanger is used to reduce the temperature in the power cavity, so as to dissipate heat of the heat-generating electronic device in the power cavity.

[0024] The heat generated by the power device can be directly transmitted to the heat sink, and the heat is conducted out of the heat sink to be dissipated. The heat-generating electronic device is mounted on the Z-direction surface of the circuit board. The heat-generating electronic device exchanges heat with the air and other media in the power cavity on one hand, and the heat is reduced through the heat exchanger. On the other hand, the heat-generating electronic device exchanges heat with the circuit board, and the heat is transmitted to the heat sink through the power device to be dissipated.

[0025] In a possible implementation manner, the heat sink and the inner wall of the heat dissipation cavity are sealingly connected to divide the heat dissipation cavity into a first cavity and a second cavity, the first cavity is located on a side of the heat sink close to the air inlet, the second cavity is located on a side of the heat sink close to the air outlet, the first cavity and the second cavity are connected through the heat sink, and the air flowing in the ventilation channel needs to pass through the heat sink to flow between the first cavity and the second cavity, so that the heat dissipation efficiency of the heat sink by the air flowing in the ventilation channel is improved.

[0026] In a possible implementation manner, the power conversion device comprises a third baffle connected between the heat sink and an inner wall surface of the heat dissipation cavity, and the heat sink and the third baffle jointly divide the heat dissipation cavity into a first cavity and a second cavity. When the length of the heat sink is insufficient to divide the heat dissipation cavity, the third baffle can be added to divide the heat dissipation cavity, so as to improve the heat dissipation efficiency of the heat sink by the air flowing in the ventilation channel.

[0027] In a possible implementation manner, the power conversion device further comprises a first baffle, at least a part of the first baffle is located on a side of the inflow port close to the air outlet, the first baffle and the inner wall of the heat dissipation cavity jointly form a first inflow cavity, the first inflow cavity is connected to the inflow port, an opening of the first inflow cavity is located on a side of the inflow port facing the air inlet, and the first baffle is the third baffle. The first baffle and the third baffle can be an integrated structure, or the first baffle and the third baffle are the same plate body, so as to simultaneously improve the ventilation volume of the heat dissipation air entering the inflow port and the heat dissipation efficiency of the heat sink.

[0028] In a possible implementation manner, one of the inflow port and the outflow port is connected to the first cavity, and the other is connected to the second cavity.

[0029] In a possible implementation manner, at least one of the inflow port and the outflow port is located on the shell, and at least one of the inflow port and the outflow port is provided with a second fan, so that the high-temperature medium in the heat exchanger is cooled by an externally arranged heat dissipation device.

[0030] In a possible implementation manner, the power conversion device further comprises a refrigerant system, the refrigerant system is connected to the inflow port and the outflow port of the inflow channel to form a refrigerant circulation channel, and the refrigerant system is used to inject refrigerant into the heat exchanger.

[0031] In a possible implementation manner, a refrigerant heat sink is arranged in the heat dissipation cavity, the refrigerant heat sink is attached to at least part of components in the power cavity, and the refrigerant system, the refrigerant heat sink and the heat exchanger are connected in series to form a circulating refrigerant channel.

[0032] In a possible implementation, the heat exchanger is located in the heat dissipation cavity, and the heat exchanger has an inlet flow channel and an outlet flow channel, the inlet flow channel and the outlet flow channel are both isolated from the heat dissipation cavity, the inlet flow channel, the heat exchange channel, and the outlet flow channel are sequentially communicated, and the inlet flow port and the outlet flow port of the inlet flow channel are both communicated with the space of the power cavity. The high-temperature gas in the power cavity can enter the internal channel of the heat exchanger through the inlet flow port, and is cooled in the heat dissipation cavity through the heat exchange channel, and the cooled gas can flow back to the power cavity from the outlet flow port, so that the heat-emitting electronic device installed in the power cavity is cooled. In this embodiment, the internal channel of the heat exchanger is communicated with the power cavity, and the internal channel of the heat exchanger and the heat dissipation cavity are sealed and isolated, so as to ensure the sealing performance of the power cavity.

[0033] In a possible implementation, the power conversion device further includes a first fan, and the first fan is located in the power cavity to improve the heat exchange efficiency of the sealing medium (which can be air) in the power cavity and the heat exchanger.

[0034] In a second aspect, the present application provides an energy storage device, including a photovoltaic panel, an alternating current bus box, and the power conversion device as described above, the photovoltaic panel, the power conversion device, and the alternating current bus box are connected in series, and the power conversion device is used to convert the variable direct current voltage of the photovoltaic panel into a power frequency alternating current and transmit the power frequency alternating current to the alternating current bus box.

[0035] In a third aspect, the present application provides an energy storage device, including a battery and the power conversion device as described above, the battery and the power conversion device are connected, and the power conversion device is used for power conversion of electric energy to charge and discharge the battery. BRIEF DESCRIPTION OF DRAWINGS

[0036] FIG. 1 is a structural schematic diagram of a power conversion device;

[0037] FIG. 2 is a schematic diagram of a power conversion device provided by an embodiment of the present application;

[0038] FIG. 3 is a schematic diagram of a structure in a heat dissipation cavity provided by an embodiment of the present application;

[0039] FIG. 4 is a schematic diagram of a structure in a power cavity provided by an embodiment of the present application;

[0040] FIG. 5 is a schematic diagram of an A-A cross section in FIG. 2;

[0041] FIG. 6 is a schematic diagram of a structure in a heat dissipation cavity provided by an embodiment of the present application;

[0042] FIG. 7 is a schematic diagram of a structure in a power cavity provided by an embodiment of the present application;

[0043] Fig. 8 is a schematic view of the structure of the heat dissipation cavity according to an embodiment of the present application;

[0044] Fig. 9 is a schematic view of the structure of the power cavity according to an embodiment of the present application;

[0045] Fig. 10 is a schematic view of the structure of the heat dissipation cavity according to an embodiment of the present application;

[0046] Fig. 11 is a schematic view of the structure of the power cavity according to an embodiment of the present application;

[0047] Fig. 12 is a schematic view of the structure of the heat dissipation cavity according to an embodiment of the present application;

[0048] Fig. 13 is a schematic view of the inlet and outlet located on the same side of the shell according to an embodiment of the present application;

[0049] Fig. 14 is a schematic view of the inlet and outlet located on the same side of the shell according to an embodiment of the present application;

[0050] Fig. 15 is a schematic view of the inlet and outlet located on different sides of the shell according to an embodiment of the present application;

[0051] Fig. 16 is a schematic view of the inlet and outlet located on different sides of the shell according to an embodiment of the present application;

[0052] Fig. 17 is a schematic view of the inlet and outlet located on different sides of the shell according to an embodiment of the present application;

[0053] Fig. 18 is a schematic view of the outlet located on the side of the shell according to an embodiment of the present application;

[0054] Fig. 19 is a schematic view of the outlet located on the side of the shell according to an embodiment of the present application;

[0055] Fig. 20 is a schematic view of the heat exchanger and the heat sink connected in parallel according to an embodiment of the present application;

[0056] Fig. 21 is a schematic view of the heat exchanger and the heat sink connected in parallel according to an embodiment of the present application;

[0057] Fig. 22 is a schematic view of the heat exchanger and the heat sink connected in series according to an embodiment of the present application;

[0058] Fig. 23 is a schematic view of the heat exchanger and the heat sink connected in series according to an embodiment of the present application;

[0059] Fig. 24 is a schematic view of an energy storage device according to an embodiment of the present application;

[0060] Fig. 25 is a schematic view of another energy storage device according to an embodiment of the present application;

[0061] Fig. 26 is a schematic view of the structure of the heat sink according to an embodiment of the present application;

[0062] Fig. 27 is a B-B sectional view of Fig. 26;

[0063] Fig. 28 is a schematic view of a heat exchanger structure according to an embodiment of the present application;

[0064] Fig. 29 is a schematic view of an internal passage of a heat exchanger according to an embodiment of the present application;

[0065] Fig. 30 is a schematic view of an inductance box structure according to an embodiment of the present application;

[0066] Fig. 31 is a schematic view of a connection between an inductance and a power device according to an embodiment of the present application;

[0067] Fig. 32 is a schematic view of a heat exchanger located in a heat dissipation cavity according to an embodiment of the present application;

[0068] Fig. 33 is a schematic view of an inlet and outlet communicating with a power cavity according to an embodiment of the present application. DETAILED DESCRIPTION

[0069] The embodiments of the present application will be described below with reference to the accompanying drawings.

[0070] For the convenience of understanding, the English abbreviations and related technical terms involved in the embodiments of the present application will be explained and described below.

[0071] It should be noted that the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0072] The terms used in the embodiments of the present application are only for the purpose of describing the specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0073] It should be understood that the term "and / or" used herein is only to describe the same field of associated objects, which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects have an "or" relationship.

[0074] Depending on the context, the word "if" as used herein can be interpreted to mean "when" or "while" or "in response to determining" or "in response to detecting." Similarly, the phrase "if it is determined" or "if [a stated condition or event] is detected" can be interpreted to mean "upon determining" or "in response to determining" or "upon detecting [the stated condition or event]" or "in response to detecting [the stated condition or event]."

[0075] It should be understood that "first", "second", etc. used in the present application are only for the purpose of distinguishing description, and cannot be understood as indicating or implying relative importance, nor can it be understood as indicating or implying sequence.

[0076] In the description of the present application, the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0077] As used herein, "in the range of", unless otherwise indicated separately, includes both end values of the range by default, for example, in the range of 1 to 5, including both 1 and 5.

[0078] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, it can also be detachably connected, it can also be in contact or integrally connected; for those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0079] The power equipment provided by the present application can include at least one of an inverter, a power storage converter (PCS), a direct current converter (DC-DC), a charging module, a power storage cabinet and a charging pile.

[0080] Among them, the inverter is an electronic device that converts direct current (DC) power into alternating current (AC) power, which is widely used in renewable energy fields such as solar power generation and wind power generation. The power storage converter (PCS), the direct current converter (DC-DC) and the charging module can be used as independent devices, or can be integrated in the power storage cabinet and the charging pile. The power storage converter (PCS) and the direct current converter (DC-DC) can be arranged in the power storage cabinet, and the charging module can be arranged in the charging pile.

[0081] The power conversion device described in the present application takes an inverter as an example, and referring to FIG. 1, the inverter 30 can adopt a split cavity design and be divided into a high protection cavity 31 and a low protection cavity 32. In an embodiment, the high protection cavity 31 is a sealed cavity, which means that the high protection cavity 31 is not connected with the external space to prevent dust and moisture in the external space from entering the high protection cavity 31 to protect the components in the high protection cavity 31; the low protection cavity 32 can be a straight-through ventilation cavity. High-power and high-power-density electronic devices can be installed in the high protection cavity 31, and low-power and low-power-density magnetic devices can be installed in the low protection cavity 32. A fan can be arranged in the low protection cavity 32 to blow or draw air to dissipate heat. In the embodiment, the heat dissipation of the high protection cavity 31 in the inverter cabinet mainly relies on the natural heat dissipation of the wall surface of the high protection cavity 31, and the heat dissipation efficiency is low, which cannot meet the requirements of increasing power and power density. In some other ways, the low protection cavity 32 and the high protection cavity 31 are connected, and the air blown or drawn by the fan in the low protection cavity 32 can dissipate heat for the devices in the low protection cavity 32 and the high protection cavity 31 at the same time, but it will cause the high protection cavity 31 to be in an open state, and dust and moisture may contact the electronic devices in the high protection cavity 31 through the heat dissipation system, affecting the service life of the devices.

[0082] To solve the above problems and realize a power device capable of effectively dissipating heat for electronic devices and improving the service life of the electronic devices, the present application provides a power conversion device, which can be connected with a battery and used for power conversion of electric energy to charge and discharge the connected battery.

[0083] Referring to FIGS. 2, 3, 4 and 5, the power conversion device described in the embodiment of the present application can include a shell 110, a circuit board 131, a heat exchanger 140 and a first fan 151. The shell 110 can include a surrounding plate 110a, a first cover plate 110b and a second cover plate 110c. The surrounding plate 110a forms a channel (the channel through which the surrounding plate 110a is enclosed is not shown in FIG. 2) penetrating in the Z direction, and the upper and lower sides of the channel are closed by the first cover plate 110b and the second cover plate 110c to form an internal accommodating cavity. The first cover plate 110b can be sealingly connected to one side of the surrounding plate 110a in the Z direction, and the second cover plate 110c can be sealingly connected to the other side of the surrounding plate 110a in the Z direction. The surrounding plate 110a, the first cover plate 110b and the second cover plate 110c can collectively enclose an accommodating cavity.

[0084] In an embodiment, referring to FIG. 5, the housing 110 is enclosed to form a power cavity 111 inside, one side of the housing 110 is a back plate 120, the back plate 120 has an open heat dissipation cavity 112 on the side facing away from the power cavity 111, wherein the heat dissipation cavity 112 can be completely open or can have a certain accommodation space by covering the air duct cover 113 outside the back plate 120. In an embodiment, the air duct cover 113 can also be two parts independent of the housing 110, or can be a part of the housing 110. In this embodiment, the air duct cover 113 is a part of the housing 110, the housing 110 can include a body 114 and an air duct cover 113, and the back plate 120 is a side plate of the body 114, which can be understood as being laid horizontally in the housing 110. The back plate 120 can be a partition plate, which can be a flat plate, an arc-shaped plate or other regular or irregular plate-shaped structures. In an embodiment, the back plate 120 can also be other non-plate-shaped structures (for example, the back plate 120 has a large thickness in the Z direction to form a non-plate-shaped structure). In this embodiment, the partition plate is an example, the four peripheral edges of the partition plate and the inner wall surface of the housing 110 can be sealed and connected, for example, the metal plate can be sealed by welding, and the non-metal plate such as plastic can be sealed by gluing, to form relatively sealed power cavity 111 and heat dissipation cavity 112, the power cavity 111 and the heat dissipation cavity 112 are sealed and isolated, and the air in the heat dissipation cavity 112 cannot flow into the power cavity 111.

[0085] The circuit board 131 can be installed in the power cavity 111, wherein the circuit board 131 can be parallel to the partition plate, and one side of the Z direction and the Z reverse direction of the circuit board 131 can be installed with devices, in an embodiment, both sides of the Z direction and the Z reverse direction of the circuit board 131 can be installed with devices.

[0086] In an embodiment, referring to FIG. 4 and FIG. 5, the circuit board 131 can be placed in the power cavity 111 of the housing 110, and components can be mounted on both sides of the circuit board 131. One side of the circuit board 131 can be mounted with power devices 133, and the other side can be mounted with heat-generating electronic devices 134 (it should be noted that heat-generating electronic devices refer to some devices that cannot be directly attached to a heat sink substrate and have certain heat dissipation requirements. Compared with some low-protective devices, heat-generating electronic devices have lower working heat resistance, and need to be cooled to a relatively low temperature to work and maintain a certain working life). The power devices 133 and the heat-generating electronic devices 134 are respectively mounted on opposite sides of the circuit board 131. In an embodiment, the power devices 133 can include IGBT, power MOSFET, gallium nitride enhancement HEMT, power discrete components, protection switches, silicon drivers, gallium nitride drivers, IGBT modules, and intelligent power modules (IPM), etc. The heat-generating electronic devices 134 can include thin film capacitors, relays, electrolytic capacitors, optocouplers, resistors, common mode inductors, L2 inductors, Hall, lightning protection devices, and PCBs, etc. The heat-generating electronic devices generate heat directly into the high-protection cavity, which can cause the temperature in the high-protection cavity to be high, and some of these devices, such as electrolytic capacitors, need to work at a lower temperature (e.g., below 75 degrees) to ensure long-term reliability and service life.

[0087] In an embodiment, referring to FIG. 3, FIG. 5, FIG. 6, and FIG. 8, the power conversion device 10 further includes a heat sink 180 located in the heat dissipation cavity 112. The wind in the heat dissipation cavity 112 can pass through the heat sink 180 and contact heat exchange when passing through the heat sink 180 to cool the heat sink 180.

[0088] As shown in FIGS. 26 and 27, the heat sink 180 can include a heat exchange plate 183 and first fins 184. The heat exchange plate 183 can be a metal plate with high thermal conductivity, such as an aluminum plate. The heat exchange plate 183 can be a flat plate, or can be shaped to match the shape of the power device. The first fins 184 are erected on one side of the heat exchange plate 183. The number of the first fins 184 can be at least two, such as 30. The 30 first fins 184 are arranged along the length direction of the heat exchange plate 183 (the interval direction is not limited, and the length direction is taken as an example in the embodiment), so as to form first heat dissipation air channels 185 between adjacent first fins 184. The first fins 184 are parallel to each other, so that all the first heat dissipation air channels 185 in the heat sink 180 extend in the same direction. As shown in FIG. 26, the first heat dissipation air channels 185 extend in the Y direction, and air in the first heat dissipation air channels 185 flows in the Y direction, so as to take away the heat of the first fins 184 between the first fins 184, and reduce the temperature of the heat sink 180. The first fins 184 and the heat exchange plate 183 can be an integral structure, which can be an integral plastic molding, or a structure formed by turning an aluminum block to form the first heat dissipation air channels 185.

[0089] In an embodiment, as shown in FIGS. 3 and 5, the back plate 120 can be provided with a first through hole 123. Part of the heat sink 180 can pass through the first through hole 123 of the back plate 120, and contact the power device 133 in the power cavity 111. The heat sink 180 is attached to the inner wall of the first through hole 123 of the back plate 120, such as the side wall of the heat exchange plate 183 being sealed and attached to the inner wall of the first through hole 123, so as to ensure that the power cavity 111 is a sealed cavity. The first fins 184 of the heat sink 180 are arranged in the heat dissipation cavity 112. The power device 133 on the circuit board 131 in the power cavity 111 can conduct heat to the heat sink 180. The heat sink 180 conducts heat to the heat dissipation cavity 112, and the heat is dissipated by the fan arranged in the heat dissipation cavity 112.

[0090] In an embodiment, the heat sink 180 can be located entirely in the heat dissipation cavity 112. The power device 133 mounted on the circuit board 131 in the power cavity 111 can pass through the first through hole 123 and contact the heat sink 180 in the heat dissipation cavity 112, so as to achieve the heat conduction contact between the heat sink 180 and the power device 133, and the power device can transfer heat to the heat sink 180. In the embodiment, the size of the first through hole 123 can be the same as the size of the power device 133. The inner wall of the first through hole 123 is sealed and connected to the power device 133, so as to achieve the sealed connection between the power cavity 111 and the heat dissipation cavity 112.

[0091] In an embodiment, the power device 133 can be located between the circuit board 131 and the heat sink 180, the power device 133 is installed on the side opposite to the Z direction of the circuit board 131, and is in contact with the heat sink 180 passing through the back plate 120, the heat generated by the power device 133 can be directly transmitted to the heat sink 180, and the heat is conducted out through the heat sink 180 for heat dissipation. The heat-generating electronic device 134 is installed on the side of the Z direction of the circuit board 131, and the heat-generating electronic device 134 is in heat exchange with the medium such as air in the power cavity 111 on the one hand, and is cooled through the heat exchanger 140; on the other hand, the heat-generating electronic device 134 can be in heat exchange with the circuit board 131, and the heat is transmitted to the heat sink 180 through the power device 133 for heat dissipation.

[0092] At least a part of the heat exchanger 140 is located in the power cavity 111, in an embodiment, the body part of the heat exchanger 140 that plays a role in heat exchange can be located entirely in the power cavity 111. For example, the heat exchanger 140 can be a plate heat exchanger or a coil heat exchanger, the heat exchanger plate or the outer wall of the heat exchanger pipe has a heat dissipation fin structure, and the heat exchanger plate or the heat exchanger pipe with the heat dissipation fin structure is partially or entirely located in the power cavity 111.

[0093] The heat exchanger 140 has an internal refrigerant circulation channel, the internally circulated refrigerant exchanges heat with the wall surface of the heat exchanger 140 and the external space of the heat exchanger 140 (the area outside the heat exchanger 140 in the power cavity 111) to cool the medium (which can be air) in the power cavity 111. In an embodiment, the internal refrigerant circulation channel of the heat exchanger 140 is insulated from the external space to achieve the sealing of the power cavity 111.

[0094] In one embodiment, referring to FIG. 28, the embodiment provides a specific structure of the heat exchanger 140, and the two side plates of the inlet flow channel 140a and the outlet flow channel 140c are exploded to show the internal structure of the inlet flow channel 140a and the outlet flow channel 140c. The heat exchanger 140 can include the inlet flow channel 140a, the heat exchange channel 140b, and the outlet flow channel 140c, and the inlet flow channel 140a and the outlet flow channel 140c are communicated at both ends of the heat exchange channel 140b. The heat exchange channel 140b can be multiple, for example, 6 as shown in FIG. 28, and the 6 heat exchange channels 140b can be 6 heat exchange flat tubes. The 6 heat exchange channels 140b are arranged at intervals along the Z direction, and the direction of the heat exchange channel 140b can be the Y direction, and the medium can flow in the heat exchange channel 140b along the Y direction. There is a gap between the adjacent two heat exchange channels 140b, and a fin structure can be arranged in the gap to increase the heat exchange efficiency of the outer wall surface of the heat exchange channel 140b and the air in the power cavity. The shell wall of the inlet flow channel 140a is provided with a first flow hole 1401, and the number of the first flow hole 1401 is the same as the number of the heat exchange channel 140b, so that the medium in the inlet flow channel 140a can enter the multiple heat exchange channels 140b respectively. Correspondingly, the shell wall of the outlet flow channel 140c can also be provided with multiple second flow holes (not shown in the figure), and the medium flowing out of the heat exchange channel 140b can enter the outlet flow channel 140c for discharge.

[0095] The side opposite to the Z direction of the inlet flow channel 140a is provided with an inlet port 141 to connect with the external space, and the refrigerant can enter the heat exchange channel 140b through the inlet port 141. The side opposite to the Z direction of the outlet flow channel 140c is provided with an outlet port 142, and the high-temperature medium in the heat exchange channel 140b can be discharged through the outlet port 142.

[0096] Referring to FIG. 29, as shown by the direction of the arrow in FIG. 29, the refrigerant can enter the heat exchange channel 140b of the heat exchanger 140 through the inlet port 141 of the inlet flow channel 140a. The low-temperature refrigerant contacts and exchanges heat with the medium in the power cavity 111 through the wall tube of the heat exchange channel 140b, and the refrigerant after heat exchange can be discharged through the outlet port 142 of the outlet flow channel 140c and discharged out of the power cavity 111.

[0097] In an embodiment, the inflow passage 140a and the outflow passage 140c are isolated from the power cavity 111, and the refrigerant in the inflow passage 140a and the outflow passage 140c cannot flow into the power cavity 111. In an embodiment, the inflow port 141 of the inflow passage 140a is in communication with the external space of the power cavity 111, so that the low-temperature refrigerant outside the power cavity 111 is injected into the inflow port 141 and enters the inflow passage 140a through the inflow port 141. In an embodiment, the outflow port 142 of the outflow passage 140c is in communication with the external space of the power cavity 111, and the relatively high-temperature refrigerant after heat exchange is discharged to the outside of the power cavity 111 through the outflow port 142 of the outflow passage 140c, so as to prevent the high-temperature refrigerant after heat exchange from flowing back to the power cavity 111 and affecting the heat dissipation efficiency of the medium and components in the power cavity 111.

[0098] In an embodiment, the first fan 151 can be located in the power cavity 111, and the first fan 151 can blow the medium in the power cavity 111 to flow, so as to increase the contact rate of the medium in the power cavity 111 and the heat exchanger 140, and improve the heat dissipation efficiency of the heat exchanger 140 on the medium in the power cavity 111.

[0099] In an embodiment, the direction of the heat exchange passage 140b can be parallel to the first heat dissipation air duct 185, as shown in FIGS. 3, 4 and 28, the heat exchange passage 140b can flow in the Y direction, and the first heat dissipation air duct 185 can flow in the Y direction, so that the low-temperature gas flowing in the heat dissipation cavity 112 can flow into the heat exchange passage 140b in part, and the heat exchanger 140 can cool the heating electronic device 134 in the power cavity 111; and the low-temperature gas can flow into the first heat dissipation air duct 185 in part, and the heat dissipation device 180 can cool the power device in the power cavity 111.

[0100] In an embodiment, the direction of the heat exchange passage 140b can be perpendicular to the first heat dissipation air duct 185, as shown in FIGS. 8 and 9, the heat exchange passage (the flow direction is consistent with the direction of the inflow port 141 to the outflow port 142) can extend in the X direction, and the first heat dissipation air duct 185 (the flow direction is consistent with the width direction of the heat dissipation device 180) can extend in the Y direction. In this design, the length of the heat dissipation device 180 can be longer, and the inflow port 141 and the outflow port 142 do not need to be arranged in the length direction, so as to improve the heat dissipation efficiency of the power device.

[0101] In an embodiment, the power conversion device 10 further comprises an inductor box 132, as shown in FIG. 3 and FIG. 30, the inductor box 132 is internally hollow and internally provided with an inductor. The inductor box 132 can be located in the heat dissipation cavity 112, and the cavity in the inductor box 132 and the heat dissipation cavity 112 are in a sealed and isolated structure. The inductor box 132 comprises an inductor box body 1321 and a second fin 1322 located on the inductor box body 1321, the second fin 1322 is erected on the upper wall surface of the inductor box body 1321, and the second fin 1322 can increase the contact area of the outer wall surface of the inductor box 132 and the heat dissipation cavity 112, and improve the heat dissipation efficiency of the inductor box 132. The number of second fins 1322 can be at least two, and the second fins 1322 are parallel to each other, so that the second heat dissipation air ducts 1323 on the inductor box 132 can extend in the Y direction. The extension direction of the second heat dissipation air ducts 1323 is the same as the extension direction of the first heat dissipation air ducts 185, and the gas flowing in the Y direction in the heat dissipation cavity 112 can simultaneously cool the heat sink 180 and the inductor box 132. Among them, the inductor box 132 can be located on the side of the heat sink 180 close to the air outlet 1122, and the low-temperature medium in the heat dissipation cavity 112 can first cool the heat sink 180 and then cool the inductor box 132. In an embodiment, the inductor box 132 and the heat sink 180 can be arranged in the X direction, and the low-temperature medium in the heat dissipation cavity 112 can cool the heat sink 180 and the inductor box 132 respectively. In an embodiment, the inductor box 132 can be located on the side of the heat sink 180 away from the air outlet 1122, and the low-temperature medium in the heat dissipation cavity 112 can first cool the inductor box 132 and then cool the heat sink 180.

[0102] The inductor in the inductor box 132 can be electrically connected to the power device 133 in the power cavity through the electric connection wire 1324, the electric connection wire 1324 can pass through the back plate 120, one end extends into the power cavity and is electrically connected to the power device 133, and the other end extends into the interior of the inductor box 132 and is electrically connected to the inductor.

[0103] In an embodiment, as shown in FIG. 31, the back plate 120 can be provided with a pipe perforation, and the side of the inductor box 132 facing the back plate 120 is also provided with a pipe perforation penetrating through, and the internal cavity of the inductor box 132 and the power cavity are in communication. In an embodiment, the internal cavity of the inductor box 132 and the power cavity can be sealed and isolated by the back plate 120, and the electric connection wire 1324 is sealed when passing through the back plate 120 to form a sealed isolation between the internal cavity of the inductor box 132 and the power cavity.

[0104] The power conversion device provided by the embodiment of the present application has the power device and the heat generating electronic device respectively installed on both sides of the circuit board in the power cavity, the power device can be in contact with the heat sink, the heat sink extends into the heat dissipation cavity, the heat dissipation cavity is used for cooling the heat sink, and the heat sink is used for cooling the power device; the heat exchanger is arranged in the power cavity, the heat exchanger has an internal circulation system of refrigerant, the internally circulated refrigerant can exchange heat with the wall of the heat exchanger and the external space of the heat exchanger (an area outside the heat exchanger in the power cavity), so as to cool the medium (which can be air) in the power cavity, and then cool the heat generating electronic device and the like installed in the power cavity, thereby improving the heat dissipation efficiency of the entire power conversion device, meeting the heat dissipation requirement of the higher power and higher power density components, and improving the working performance of the power conversion device; and the entire heat dissipation system can meet the closed state of the power cavity, prevent water or dust in the external medium from entering the power cavity, and ensure the use safety of the components in the power cavity. In addition, the inductor box is installed in the heat dissipation cavity, the inductor box is cooled at the same time of the heat dissipation and ventilation of the heat sink, and the overall heat dissipation efficiency is improved.

[0105] In some possible embodiments, referring to FIG. 3, the second cover plate is omitted to show the structure in the heat dissipation cavity 112, and the heat dissipation cavity 112 is provided with an air inlet 1121 and an air outlet 1122. In this embodiment, the shell 110 is taken as a square, the air inlet 1121 and the air outlet 1122 are both in communication with the heat dissipation cavity 112, the air inlet 1121 can be located on the side opposite to the Y direction of the shell 110, and the air outlet 1122 can be located on the side of the Y direction of the shell 110, so as to form a ventilation channel extending along the Y direction between the air inlet 1121 and the air outlet 1122.

[0106] In one embodiment, at least one of the air inlet 141 and the air outlet 142 can be located in the heat dissipation cavity 112 and in communication with the heat dissipation cavity 112. Referring to FIG. 3, the air inlet 141 and the air outlet 142 can both be located in the heat dissipation cavity 112 and in communication with the heat dissipation cavity 112.

[0107] In one embodiment, referring to FIG. 3, the back plate 120 can be provided with a second through hole 121, and the air inlet channel 140a can pass through the second through hole 121 and be in sealing connection with the inner wall of the second through hole 121. In one embodiment, the air inlet 141 of the air inlet channel 140a and the second through hole 121 are coincident in position, and the edge of the air inlet 141 can coincide with and be in sealing connection with the edge of the second through hole 121. The air inlet 141 is located in the heat dissipation cavity 112, and the air inlet channel 140a is in communication with the heat dissipation cavity 112.

[0108] In an embodiment, referring to FIG. 3, the back plate 120 can be provided with a third through hole 122, and the outflow channel 140c can pass through the third through hole 122 and be sealingly connected to the inner wall of the third through hole 122. In an embodiment, the outflow port 142 of the outflow channel 140c coincides with the position of the third through hole 122, and the edge of the outflow port 142 can coincide with and be sealingly connected to the edge of the third through hole 122. The outflow port 142 is located in the heat dissipation cavity 112, and the outflow channel 140c is in communication with the heat dissipation cavity 112.

[0109] In an embodiment, the power conversion device further comprises a first baffle plate 160, which can be vertically arranged in the heat dissipation cavity 112 and extend in the z direction in the heat dissipation cavity 112. In an embodiment, the first baffle plate 160 can be a flat plate, or an arc-shaped plate or other irregular shape. At least part of the first baffle plate 160 is located on the side of the inflow port 141 close to the air outlet 1122. Referring to FIGS. 3 and 6, the first baffle plate 160 can comprise a first sub-baffle plate 161, and the x direction side of the first sub-baffle plate 161 is sealingly connected to the inner wall of the enclosure 110. In FIG. 6, only the enclosure 110a is shown, and the x direction side of the first sub-baffle plate 161 is sealingly connected to the inner wall of the enclosure 110a. The z direction side of the first sub-baffle plate 161 is sealingly connected to the back plate 120, and the z direction side of the first sub-baffle plate 161 can be sealingly connected to the first cover plate (not shown in FIG. 3) of the enclosure 110. The x direction side of the first sub-baffle plate 161 has a spacing distance with the x direction side of the side plate of the enclosure 110a, and the air of the ventilation channel can pass through the spacing distance (a heat sink or other structure can be arranged in the spacing distance). The first sub-baffle plate 161 is vertically arranged on the side of the inflow port 141 facing the air outlet 1122, and part of the air blown by the air inlet 1121 is blocked by the first sub-baffle plate 161, reducing the air flowing from the inflow port 141 to the air outlet 1122, and more air can be diverted to enter the inflow port 141 on the back plate 120, increasing the air volume entering the heat exchanger 140 and improving the heat exchange efficiency of the heat exchanger 140.

[0110] In an embodiment, referring to FIG. 6, the first baffle plate 160 can further comprise a second sub-baffle plate 162, which can extend in the y direction. The second sub-baffle plate 162 can be a flat plate, or an arc-shaped plate or other irregular shape. The second sub-baffle plate 162 can be sealingly connected to the first sub-baffle plate 161, and the x direction end of the second sub-baffle plate 162 can be connected to the first sub-baffle plate 161. In an embodiment, the x direction end of the first sub-baffle plate 161 can be connected to the middle part of the second sub-baffle plate 162, or can be connected to the y direction end of the second sub-baffle plate 162 as shown in FIG. 6. In an embodiment, the y direction end of the second sub-baffle plate 162 can be connected to the middle part of the first sub-baffle plate 161.

[0111] The first baffle 160 and the inner wall of the heat dissipation cavity 112 enclose the first inflow cavity 112a. Specifically, the first sub-baffle 161 is located on the y-direction side of the first inflow cavity 112a, the second sub-baffle 162 is located on the x-direction side of the first inflow cavity 112a, the shell 110 is located on the x-anti-direction and z-direction side of the first inflow cavity 112a, the back plate 120 is located on the z-anti-direction side of the first inflow cavity 112a, and the inflow port 141 on the first inflow cavity 112a and the back plate 120 are in communication. The first inflow cavity 112a has an opening on the y-anti-direction side (which can coincide with part of the air inlet 1121), and the opening of the first inflow cavity 112a can be located on the side of the inflow port 141 facing the air inlet 1121 (the y-anti-direction side in FIG. 3). The x-direction, x-anti-direction, y-direction, z-direction and z-anti-direction of the first inflow cavity 112a are all sealed and blocked, the opening on the y-anti-direction side of the first inflow cavity 112a, the first inflow cavity 112a and the inflow port 141 are in communication, and part of the cooling air entering from the air inlet 1121 can enter the inflow port 141 more, improving the heat exchange efficiency of the heat exchanger 140.

[0112] In an embodiment, referring to FIG. 6, the y-anti-direction side of the second sub-baffle 162 can extend to the cavity wall of the heat dissipation cavity 112. The air inlet 1121 can be located on the y-anti-direction side wall of the heat dissipation cavity 112, and the second fan 152 can be provided at the air inlet 1121. The second sub-baffle 162 can extend to the side wall provided with the air inlet 1121, so that the opening of the first inflow cavity 112a is located on the cavity wall of the heat dissipation cavity 112, and the opening of the first inflow cavity 112a coincides with the position of the air inlet 1121. The air inlet 1121 can have multiple air inlets 1121, the opening of the first inflow cavity 112a can coincide with the air inlet 1121 located at the x-anti-direction end of the multiple air inlets 1121, and the air entering the air inlet 1121 will only enter the first inflow cavity 112a and will not flow to the area outside the first inflow cavity 112a. One of the second fans 152 can be located in the first inflow cavity 112a.

[0113] In an embodiment, referring to FIGS. 6 and 7, the first baffle 160 divides the heat dissipation cavity 112 into a first inflow cavity 112a and a second inflow cavity 112b, and the second baffle 162 can extend to the side wall of the heat dissipation cavity 112 to divide the air inlet 1121 into a first air inlet 1121a and a second air inlet 1121b. The first air inlet 1121a can be one, and the first air inlet 1121a can be located at one end of the x direction opposite to the second air inlet 1121b. The position of the first air inlet 1121a coincides with the opening position of the first inflow cavity 112a, and the first air inlet 1121a can be the opening of the first inflow cavity 112a. The second air inlet 1121b is the opening on the cavity wall of the second inflow cavity 112b. The space where the inflow port is located and the space where the heat dissipation device is located are two independent spaces, and the external low-temperature refrigerant can enter the first inflow cavity and the second inflow cavity, respectively, to reduce the temperature of the refrigerant entering the inflow port.

[0114] In an embodiment, referring to FIGS. 3 and 6, the power conversion device 10 further includes a second baffle 170, which is similar to the first baffle 160. At least part of the second baffle 170 is located on the side of the outflow port 142 close to the air inlet 1121. The second baffle 170 and the inner wall of the heat dissipation cavity 112 form an outflow cavity 173. The outflow cavity 173 is connected to the outflow port 142, and the opening of the outflow cavity 173 is located on the side of the outflow port 142 facing the air outlet 1122.

[0115] In an embodiment, referring to FIGS. 3 and 6, the inflow port 141 and the outflow port 142 can be distributed along the y direction. The arrangement direction of the inflow port 141 and the outflow port 142 can be consistent with the ventilation direction between the air inlet 1121 and the air outlet 1122. The first baffle 160 and the second baffle 170 can be an integrated structure, or the first baffle 160 and the second baffle 170 can be the same baffle. The first baffle 160 (the second baffle 170) is spaced between the inflow port 141 and the outflow port 142 to prevent the air flowing in the ventilation channel from directly reaching the outflow port 142 without entering the inflow port 141, and to prevent the high-temperature medium discharged from the outflow port 142 from flowing back to the inflow port 141, thereby preventing the heat exchange efficiency of the heat exchanger 140 from being reduced.

[0116] In an embodiment, for example, as shown in FIG. 8, the inflow port 141 and the outflow port 142 can be distributed along the x direction. The arrangement direction of the inflow port 141 and the outflow port 142 can be perpendicular or inclined to the ventilation direction between the air inlet 1121 and the air outlet 1122. The second baffle 170 and the first baffle 160 can be two separate baffles.

[0117] In an embodiment, referring to FIG. 8, the second baffle 170 can include a third sub-baffle 171, and an x-direction side of the third sub-baffle 171 is sealingly connected to an inner wall of the shell 110. In FIG. 8, only the surrounding plate 110a is shown, and the x-direction side of the third sub-baffle 171 is sealingly connected to an inner wall of the surrounding plate 110a. A z-anti-direction side of the third sub-baffle 171 is sealingly connected to the back plate 120, a z-direction side of the third sub-baffle 171 is sealingly connected to a first cover plate (not shown in the figure) of the shell 110, and an x-anti-direction side of the third sub-baffle 171 has a spacing space between an x-anti-direction side plate of the surrounding plate 110a, and the wind of the ventilation channel can pass through the spacing space. The third sub-baffle 171 is erected on a side of the outflow port 142 close to the air inlet 1121, and the wind blown by the air inlet 1121 is partially blocked by the third sub-baffle 171 to prevent the incoming cold wind from entering the heat exchanger 140, and the hot wind blown by the outflow port 142 is blocked by the third sub-baffle 171 to prevent the hot wind blown by the outflow port 142 from flowing back to the inflow port 141, thereby increasing the amount of wind entering the heat exchanger 140 and improving the heat exchange efficiency of the heat exchanger 140. In an embodiment, the third sub-baffle 171 can be an integral structure with the fixing plate that fixes the second fan 152, and at the same time, the third sub-baffle 171 is prevented from directly entering the upper side of the outflow port 142.

[0118] In an embodiment, referring to FIG. 8, the second baffle 170 can further include a fourth sub-baffle 172, and the fourth sub-baffle 172 can extend along the y-direction. The fourth sub-baffle 172 can be a flat plate, or can be an arc-shaped or other irregular shape. The fourth sub-baffle 172 can be sealingly connected to the third sub-baffle 171, and the fourth sub-baffle 172 can be connected to an x-anti-direction end of the third sub-baffle 171. The x-anti-direction end of the third sub-baffle 171 can be connected to a middle part of the fourth sub-baffle 172, or can be connected to a y-anti-direction end of the fourth sub-baffle 172 as shown in FIG. 8. In an embodiment, the y-anti-direction end of the fourth sub-baffle 172 can be connected to a middle part of the third sub-baffle 171.

[0119] The second baffle 170 and the inner wall of the heat dissipation cavity 112 enclose the outflow cavity 173. Specifically, the third sub-baffle 171 is located on the y reverse direction side of the outflow cavity 173, the fourth sub-baffle 172 is located on the x reverse direction side of the outflow cavity 173, the x direction and the z direction side of the outflow cavity 173 are the partial shell 110, the back plate 120 is located on the z reverse direction side of the outflow cavity 173, and the outflow cavity 173 and the outflow port 142 on the back plate 120 are connected in communication. The outflow cavity 173 has an opening on the y direction side, and the opening of the outflow cavity 173 can be located on the side of the outflow port 142 facing the air outlet 1122 (the y direction side in FIG. 8). The x direction, the x reverse direction, the y reverse direction, the z direction and the z reverse direction of the outflow cavity 173 are all sealed and blocked, the opening on the y direction side of the outflow cavity 173, the outflow cavity 173 and the outflow port 142 are in communication, the hot air blown out of the outflow port 142 is blocked by the third sub-baffle 171, preventing the hot air blown out of the outflow port 142 from flowing back into the inflow port 141, improving the air volume of the cold air entering the heat exchanger 140, and improving the heat exchange efficiency of the heat exchanger 140.

[0120] In some possible embodiments, referring to FIG. 3, the inflow port 141 can be located on the side of the heat sink 180 close to the air inlet 1121. The cold air blown in by the air inlet 1121 can first partially enter the inflow port 141, and the other part can be heat dissipated through the heat sink 180. The inflow port 141 is located on the air inlet side of the heat sink 180, which can prevent the air after heat exchange of the heat sink 180 from entering the inflow port 141, and ensure the heat dissipation efficiency of the heat exchanger 140.

[0121] In an embodiment, referring to FIG. 8, the inflow port 141 and the outflow port 142 can be located on the side of the heat sink 180 close to the air inlet 1121. The heat sink 180 can be connected with the circuit board in the power cavity 111. In this structure, referring to FIG. 9, the circuit board 131 in the power cavity 111 can be located on the y reverse direction side of the heat exchanger 140, which meets the requirement of heat dissipation for the components in the power cavity 111.

[0122] In an embodiment, referring to FIG. 10, the inflow port 141 and the outflow port 142 can be located on the side of the heat sink 180 close to the air outlet 1122. The heat sink 180 can be connected with the circuit board in the power cavity 111. In this structure, referring to FIG. 11, the circuit board 131 in the power cavity 111 can be located on the y direction side of the heat exchanger 140, which meets the requirement of heat dissipation for the components in the power cavity 111.

[0123] In an embodiment, referring to FIG. 12, the inlet port 141 can be located on the side of the heat sink 180 close to the air outlet 1122, in which case the heat sink 180 can be located on the side of the inlet port 141 close to the air inlet 1121, the outlet port 142 can be located on the side of the heat sink 180 close to the air inlet 1121, and in this structure, the heat sink 180 can be located on the side of the outlet port 142 close to the air inlet 1121.

[0124] Referring to FIGS. 3, 6, and 10, the outlet port 142 can be located on the side of the heat sink 180 close to the air outlet 1122. The high-temperature medium discharged by the heat exchanger 140 through the outlet port 142 can be discharged from the air outlet 1122 on the air outlet side of the heat sink 180, which can prevent the high-temperature medium discharged by the outlet port 142 from affecting the heat sink 180 and improve the heat dissipation efficiency of the heat sink 180 and the heat exchanger 140.

[0125] In some possible embodiments, referring to FIGS. 3, 6, 8, 10, and 12, the power conversion device 10 includes an inductor box 132, the inductor box 132 can be installed in the heat dissipation cavity 112, the inductor box 132 is provided with an inductor, and the inductor box 132 can be located on the side of the heat sink 180 close to the air outlet 1122.

[0126] In some possible embodiments, referring to FIGS. 3 and 5, the heat sink 180 can be sealingly connected with the inner wall surface of the heat dissipation cavity 112 to divide the heat dissipation cavity 112 into a first cavity 1123 and a second cavity 1124. The first cavity 1123 is located on the side of the heat sink 180 close to the air inlet 1121, the second cavity 1124 is located on the side of the heat sink 180 close to the air outlet 1122, and the first cavity 1123 and the second cavity 1124 are in communication through the heat sink 180.

[0127] In an embodiment, the x direction, the x reverse direction, the z direction, and the z reverse direction of the heat sink 180 are sealingly connected with the inner wall surface of the heat dissipation cavity 112. The z direction of the heat sink 180 can be attached to the first cover plate 110b, the z reverse direction of the heat sink 180 can be attached to the back plate 120, and the x direction of the heat sink 180 can be attached to the inner wall surface of the surrounding plate 110a.

[0128] In an embodiment, the power conversion device 10 comprises a third baffle 190 connected between the heat sink 180 and the inner wall of the heat dissipation cavity 112, and the third baffle 190 is located at the x-anti-direction side of the heat sink 180. The third baffle 190 can extend along the x-direction, the z-direction side of the third baffle 190 can be sealingly connected with a first cover plate (not shown in the figure), the z-anti-direction side of the third baffle 190 can be sealingly connected with the back plate 120, the x-anti-direction side of the third baffle 190 can be sealingly connected with the inner wall of the surrounding plate 110a, and the x-direction side of the third baffle 190 can be connected with the heat sink 180. The heat sink 180 and the third baffle 190 together divide the heat dissipation cavity 112 into a first cavity 1123 and a second cavity 1124. In an embodiment, the cooling medium in the first cavity 1123 can only enter the second cavity 1124 through the ventilation gap of the heat sink 180, so as to more efficiently dissipate heat from the heat sink 180.

[0129] In an embodiment, referring to FIGS. 3 and 5, the third baffle 190 can be at least part of the first baffle 160. The first baffle 160 can divide the heat dissipation cavity 112 into the first cavity 1123 and the second cavity 1124 together with the heat sink 180, and divide the inflow port 141 at the inflow side of the heat sink 180. In an embodiment, one of the inflow port 141 and the outflow port 142 is connected with the first cavity 1123, and the other is connected with the second cavity 1124. Referring to FIGS. 3 and 5, the inflow port 141 can be connected with the first cavity 1123, and the outflow port 142 can be connected with the second cavity 1124. The cooling medium blown in by the air inlet 1121 can enter the inflow port 141 more, so as to improve the heat dissipation efficiency of the heat sink 180. And the high-temperature medium discharged from the outflow port 142 can be directly discharged from the air outlet 1122, and will not flow back to the heat sink 180 to affect the heat dissipation efficiency of the heat sink 180.

[0130] In some possible embodiments, at least one of the inflow port 141 and the outflow port 142 can be located on the shell 110. In an embodiment, the inflow port 141 can be located on at least one of the surrounding plate 110a, the first cover plate 110b and the second cover plate 110c. In an embodiment, the outflow port 142 can be located on at least one of the surrounding plate 110a, the first cover plate 110b and the second cover plate 110c.

[0131] In an embodiment, at least one of the inlet port 141 and the outlet port 142 is provided with a third fan (not shown in the figure), which can be arranged on the inlet port 141 and / or the outlet port 142, and the air passing through the inlet port 141 and / or the outlet port 142 must pass through the third fan. The third fan can blow or suck the external cooling air into the heat exchanger 140 to provide low-temperature medium to the heat exchange channel of the heat exchanger 140.

[0132] In an embodiment, the heat exchanger 140 can be entirely located in the power cavity 111, and the inlet flow channel 140a of the heat exchanger 140 is also located in the power cavity 111. The inlet port 141 of the inlet flow channel 140a can be located on the cavity wall of the power cavity 111. In an embodiment, the inlet port 141 can be located on the surrounding plate 110a or the first cover plate 110b. Referring to FIGS. 13 and 14, the embodiment is taken as an example of being located on the surrounding plate 110a. In an embodiment, the inlet port 141 is provided with a third fan 153, which can directly blow or suck the air in the environment into the heat exchanger 140 to dissipate heat for the heat exchanger 140.

[0133] In an embodiment, the inlet port 141 located on the shell 110 can be connected with a refrigerant preparation device (not shown in the figure) outside the shell 110. The refrigerant preparation device can be a liquid refrigerant preparation device composed of a compressor, a throttle valve, and a radiator, which can provide low-temperature refrigerant for the heat exchanger 140. In this embodiment, the temperature of the refrigerant can reach below 10°C, which can provide efficient heat dissipation for the heat exchanger 140.

[0134] In an embodiment, referring to FIGS. 13 and 14, the outlet flow channel of the heat exchanger 140 is located in the power cavity 111, and the outlet port 142 of the outlet flow channel can be located on the cavity wall of the power cavity 111. In an embodiment, the outlet port 142 can be located on the surrounding plate 110a or the first cover plate (not shown in the figure). The embodiment is taken as an example of being located on the surrounding plate 110a. In an embodiment, the third fan 153 can be installed on the inlet port 141, and the high-temperature air after heat exchange of the heat exchanger 140 can be directly blown out of the shell 110 through the outlet port 142, preventing the high-temperature gas after heat exchange of the heat exchanger 140 from affecting the heat dissipation of the power conversion device 10, and improving the heat dissipation efficiency of the power conversion device 10.

[0135] In an embodiment, referring to FIGS. 13 and 14, the inlet port 141 and the outlet port 142 can be located on the same side plate of the surrounding plate 110a. The inlet port 141 and the outlet port 142 can be located on the side plate on the x-anti-direction side of the shell 110. The heat exchanger 140 corresponding to the power cavity 111 can extend along the y-anti-direction, which is perpendicular to the direction in which the radiator 180 in the heat dissipation cavity 112 extends.

[0136] In one embodiment, referring to FIG. 15, FIG. 16 and FIG. 17, the inlet port 141 and the outlet port 142 can be located on different side plates of the enclosure 110a. The inlet port 141 can be located on the side plate of the x-anti-direction side of the housing 110, and the outlet port 142 can be located on the side plate of the x-direction side of the housing 110. The heat exchanger 140 in the power cavity 111 can extend along the x-anti-direction, which is consistent with the direction of the length extension of the heat sink 180 in the heat dissipation cavity 112.

[0137] The heat exchanger 140 described in the embodiments of the present application can have various arrangements in the power cavity 111 to match the power conversion device 10 with different internal structures.

[0138] In one embodiment, one of the inlet port 141 and the outlet port 142 can be located in the heat dissipation cavity 112, and the other can be located on the inner wall of the power cavity 111. Referring to FIG. 18 and FIG. 19, the inlet port 141 is located in the heat dissipation cavity 112 as an example. The inlet port 141 can be located on the back plate 120. The cold air passing through the heat dissipation cavity 112 can enter the heat exchanger 140 from the inlet port 141 and exchange heat with the heat exchanger 140. Finally, the high-temperature gas discharged from the heat exchanger 140 through the outlet port 142 is discharged from the side wall of the enclosure 110a. The high-temperature gas discharged from the heat exchanger 140 does not return to the heat dissipation cavity 112, preventing the heat dissipation of the heat sink 180 in the heat dissipation cavity 112 from being affected, and improving the heat dissipation efficiency of the heat sink 180. Moreover, the high-temperature gas in the heat exchanger 140 can be discharged faster, improving the air intake speed of the heat dissipation air in the heat exchanger 140 and improving the heat dissipation efficiency of the heat exchanger 140.

[0139] In one embodiment, the inlet port 141 in FIG. 18 can be arranged on the side of the heat sink 180 close to the air outlet 1122. In one embodiment, the inlet port 141 can also be arranged on the side of the heat sink 180 close to the air inlet 1121, improving the heat dissipation efficiency of the heat exchanger 140.

[0140] In one embodiment, referring to FIG. 20 and FIG. 21, the power conversion device 10 further comprises a refrigerant system (not shown in the figure), which can include a compressor, a throttle valve and a heat sink, etc. to form a liquid refrigerant preparation circulation system, which can provide low-temperature refrigerant for the heat exchanger 140. In this embodiment, the temperature of the refrigerant can reach below 10℃, which can provide efficient heat dissipation for the heat exchanger 140.

[0141] In an embodiment, the coolant system can be in communication with the inlet port 141 and the outlet port 142 of the inlet passage 140a respectively to form a coolant circulation passage, and the coolant system is used to inject coolant into the heat exchanger 140, wherein the inlet pipe and the outlet pipe of the heat exchanger 140 can pass through the back plate 120, so that the inlet pipe and the outlet pipe can pass through the heat dissipation cavity 112 and be transmitted from the side wall of the heat dissipation cavity 112 to the outside of the shell 110 and be connected with the coolant system.

[0142] In an embodiment, referring to FIG. 20 and FIG. 21, the heat dissipation cavity 112 is provided with a heat sink 180, which can be attached to at least part of the components on the circuit board 131 to cool the components arranged on the circuit board 131. In an embodiment, the back plate 120 can be provided with a through hole, and part of the heat sink 180 can pass through the through hole of the back plate 120 and contact the components in the power cavity 111. The outer wall surface of the heat sink 180 is attached to the inner wall of the through hole of the back plate 120 to ensure that the power cavity 111 is a sealed cavity. The main body of the heat sink 180 is arranged in the heat dissipation cavity 112, and the components on the circuit board in the power cavity 111 can conduct heat to the heat sink 180, and the heat sink 180 can conduct heat to the heat dissipation cavity 112 and be cooled by the fan arranged in the heat dissipation cavity 112.

[0143] The heat sink 180 can include a plate heat exchanger, which can have an inlet passage 181 and an outlet passage 182. The plate heat exchanger can be connected in parallel with the heat exchanger 140, and the coolant prepared by the coolant system can enter the heat sink 180 and the heat exchanger 140 respectively, and the coolant in the heat sink 180 and the coolant in the heat exchanger 140 are not communicated. In an embodiment, the system can have one, and the outlet pipe of one coolant system is divided into two to inject low-temperature coolant into the heat exchanger 140 and the heat sink 180 respectively to dissipate heat. In an embodiment, the system can have two, and the two coolant systems are connected with the heat exchanger 140 and the heat sink 180 respectively to cool the heat exchanger 140 and the heat sink 180 respectively.

[0144] In an embodiment, referring to FIG. 22 and FIG. 23, the coolant system and the coolant heat sink 180 can be connected in series with the heat exchanger 140 to form a circulating coolant passage, the outlet passage 140c (outlet port 142) of the heat exchanger 140 can be in communication with the inlet passage 181 of the heat sink 180, the inlet passage 140a (inlet port 141) can be in communication with the outlet of the coolant system, and the outlet passage 182 can be in communication with the return port of the coolant system. The low-temperature coolant prepared by the coolant system can first enter the heat exchanger 140, the coolant flowing out of the heat exchanger 140 can enter the heat sink 180, and finally be discharged from the heat sink 180 and returned to the coolant system.

[0145] In an embodiment, the flow direction of the refrigerant can also be reversed, and the low-temperature refrigerant prepared by the refrigerant system can first enter the heat sink 180 and then enter the heat exchanger 140. The cooling requirements of the heat exchanger and the heat sink can be selected as needed.

[0146] In some possible embodiments, different from the above-mentioned embodiments, the heat exchanger 140 can be located in the heat dissipation cavity 112. Referring to FIGS. 32 and 33, the inlet flow channel, the heat exchange channel and the outlet flow channel of the heat exchanger 140 can all be located in the heat dissipation cavity 112. The inlet flow port 141 of the inlet flow channel can be located on the back plate 120, and the inlet flow port 141 can be in communication with the power cavity 111. Similarly, the outlet flow port 142 of the outlet flow channel can be located on the back plate 120, and the outlet flow port 142 can be in communication with the power cavity 111.

[0147] The high-temperature gas in the power cavity 111 can enter the internal channel of the heat exchanger 140 through the inlet flow port 141, and be cooled in the heat dissipation cavity 112 through the heat exchange channel. The cooled gas can flow back to the power cavity 111 from the outlet flow port 142, so as to cool the heat-emitting electronic device 134 installed in the power cavity 111. In this embodiment, the internal channel of the heat exchanger 140 is in communication with the power cavity 111, and the internal channel of the heat exchanger 140 is sealed from the heat dissipation cavity 112, so as to ensure the sealing performance of the power cavity 111.

[0148] The application also provides an energy storage device, which comprises the power conversion device 10 provided in any of the above-mentioned embodiments. Referring to FIG. 24, the energy storage device can further comprise a photovoltaic panel 21, an alternating current bus box 22 and a string inverter 25. The string inverter 25 can be the power conversion device 10 described in any of the above-mentioned embodiments, and is connected between the photovoltaic panel 21 and the alternating current bus box 22. The string inverter can convert the variable direct-current voltage of the photovoltaic panel 21 into a commercial frequency alternating current, and transmit the alternating current to the alternating current bus box 22, and then transmit the alternating current to the power grid 24 through a transformer 23, so as to realize the conversion of light energy into usable electrical energy. In an embodiment, the converted alternating current can also be fed back to a commercial power transmission system. The string inverter 25 is one of important system balances (BOS) in a photovoltaic array system, and can be used with general alternating current power supply equipment.

[0149] In an embodiment, the string inverter, the alternating current bus box 22, the transformer 23 and the power grid 24 are connected in series, and the string inverter 25, the alternating current bus box 22 and the transformer 23 can be connected through an alternating current cable.

[0150] In some possible embodiments, referring to FIG. 25, the power conversion device 10 can also be used for power conversion of electrical energy, so as to charge and discharge a battery. The battery is taken as a battery pack 320, and the battery pack 320 is connected with the power conversion device 10.

[0151] The energy storage device can be an energy storage cabinet, the energy storage converter (PCS), the direct current converter (DC-DC) and the charging module can be independent devices or can be integrated in the energy storage cabinet and the charging pile. The energy storage cabinet can be provided with the energy storage converter (PCS) and the direct current converter (DC-DC), and the charging pile can be provided with the charging module.

[0152] The energy storage cabinet 300 includes a cabinet body 310, a battery pack 320 and an energy storage converter 330. The energy storage converter can be the power conversion device of any of the above embodiments, which is a bidirectional current controllable conversion device connecting the energy storage battery and the power grid (or load). The energy storage converter can control the charging and discharging process of the battery, convert AC and DC, accurately and quickly regulate the voltage, frequency and power between the power grid and the energy storage system, realize constant power and constant current charging and discharging, and smooth the fluctuation of the power output.

[0153] The cabinet body 310 has a containing space, and the battery pack 320 and the energy storage converter 330 are located in the cabinet body 310. The energy storage cabinet can also be provided with a direct current converter and a power distribution module, and the direct current converter and the power distribution module can also constitute the power conversion device in the energy storage cabinet.

[0154] 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 modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features. The modification or replacement does not change the essence of the corresponding technical solution, and should be included in the protection scope of the present application.

Claims

1. A power conversion device for connection in an energy system for conversion of electric energy power in the energy system, characterized in that, The power conversion device comprises: a housing having a sealed and isolated power cavity, the housing having a back plate, the back plate having an open and ventilated heat dissipation cavity on a side facing away from the power cavity, the back plate being provided with a first through hole; a circuit board located in the power cavity, the circuit board being provided with a heat generating electronic device and a power device on two mounting surfaces of the circuit board respectively; a heat sink for dissipating heat of the power device, the heat sink comprising a heat exchange plate and first fins, the heat sink being in thermal contact with the first through hole and the power device, the heat generating electronic device, the circuit board, the power device, the heat exchange plate and the first fins being arranged in sequence, the heat exchange plate being in thermal contact with the power device to conduct heat of the power device to the first fins, the first fins being located in the heat dissipation cavity to dissipate heat, the first fins having a first heat dissipation air duct therebetween; a heat exchanger for dissipating heat of the heat generating electronic device, the heat exchanger being located at least partially in the power cavity, the heat exchanger having a heat exchange channel inside, the heat exchange channel being parallel or perpendicular to the first heat dissipation air duct; an inductor box located in the heat dissipation cavity and located on a side of the heat sink where air is out and / or air is in, the inductor box being provided with an inductor, an electric connection line of the inductor penetrating through the back plate to be electrically connected with the power device, the inductor box being provided with second fins on an outer wall of the inductor box, the second fins having a second heat dissipation air duct therebetween, the first heat dissipation air duct and the second heat dissipation air duct being parallel.

2. The power conversion device of claim 1, wherein, The heat exchanger is located in the power cavity, and the heat exchanger has an inlet flow channel and an outlet flow channel, the inlet flow channel and the outlet flow channel being isolated from the power cavity, the inlet flow channel, the heat exchange channel and the outlet flow channel being communicated in sequence, inlet and outlet flow ports of the inlet flow channel being in space communication with the heat dissipation cavity outside the power cavity.

3. The power conversion device of claim 2, wherein, The heat dissipation cavity is provided with an air inlet and an air outlet on a cavity wall of the heat dissipation cavity, the air inlet and the air outlet being in communication with the heat dissipation cavity, the air inlet and the air outlet having a ventilation channel therebetween, the ventilation channel being parallel to the first heat dissipation air duct, at least one of the inlet flow port and the outlet flow port being located in the heat dissipation cavity and being in communication with the heat dissipation cavity.

4. The power conversion device of claim 3, wherein, The back plate is provided with a second through hole, the inlet flow channel penetrating through the second through hole and being sealingly connected with an inner wall of the second through hole, the inlet flow port being located in the heat dissipation cavity, the inlet flow channel being in communication with the heat dissipation cavity.

5. A power conversion device according to claim 3 or 4, characterised in that, The back plate is provided with a third through hole, the outlet flow channel penetrating through the third through hole and being sealingly connected with an inner wall of the third through hole, the outlet flow port being located in the heat dissipation cavity, the outlet flow channel being in communication with the heat dissipation cavity.

6. The power conversion device of claim 3, wherein, The power conversion device further comprises a first baffle, at least a part of the first baffle being located on a side of the inlet flow port close to the air outlet, the first baffle and an inner wall of the heat dissipation cavity enclosing a first inlet flow cavity, the first inlet flow cavity being in communication with the inlet flow port, an opening of the first inlet flow cavity being located on a side of the inlet flow port facing the air inlet.

7. The power conversion device of claim 6, wherein, The opening of the first inflow cavity is located on the cavity wall of the heat dissipation cavity, the first baffle separates the heat dissipation cavity into the first inflow cavity and the second inflow cavity, the air inlet comprises a first air inlet and a second air inlet, the first air inlet is the opening of the first inflow cavity, and the second air inlet is the opening on the cavity wall of the second inflow cavity.

8. The power conversion device according to any one of claims 3, 4, 6 and 7, characterized by, The power conversion device further comprises a second baffle, at least part of the second baffle is located on the side of the outflow port close to the air inlet, the second baffle and the inner wall of the heat dissipation cavity form an outflow cavity, the outflow cavity is in communication with the outflow port, and the opening of the outflow cavity is located on the side of the outflow port facing the air outlet.

9. The power conversion device according to any one of claims 3, 4, 6 and 7, characterized by, The inflow port is located on the side of the radiator close to the air inlet or on the side of the radiator close to the air outlet; and / or, The outflow port is located on the side of the radiator close to the air inlet or on the side of the radiator close to the air outlet.

10. The power conversion device according to any one of claims 3, 4, 6 and 7, characterized by, The radiator and the inner wall surface of the heat dissipation cavity are sealingly connected to separate the heat dissipation cavity into a first cavity and a second cavity, the first cavity is located on the side of the radiator close to the air inlet, the second cavity is located on the side of the radiator close to the air outlet, and the first cavity and the second cavity are in communication through the radiator.

11. The power conversion device of claim 10, wherein, The power conversion device comprises a third baffle connected between the radiator and the inner wall surface of the heat dissipation cavity, and the radiator and the third baffle jointly separate the heat dissipation cavity into a first cavity and a second cavity.

12. The power conversion device of claim 11, wherein, The power conversion device further comprises a first baffle, at least part of the first baffle is located on the side of the inflow port close to the air outlet, the first baffle and the inner wall of the heat dissipation cavity form a first inflow cavity, the first inflow cavity is in communication with the inflow port, the opening of the first inflow cavity is located on the side of the inflow port facing the air inlet, and the first baffle is the third baffle.

13. The power conversion device of claim 10, wherein, One of the inflow port and the outflow port is in communication with the first cavity, and the other is in communication with the second cavity.

14. A power conversion device according to any one of claims 3, 4, 6, 7, 11, 12 and 13, characterized in that, At least one of the inflow port and the outflow port is located on the shell, and at least one of the inflow port and the outflow port is provided with a second fan.

15. The power conversion device of claim 2, wherein, The power conversion device further comprises a refrigerant system in communication with the inflow port and the outflow port respectively to form a refrigerant circulation channel, and the refrigerant system is used for injecting refrigerant into the heat exchange channel.

16. The power conversion device of claim 15, wherein, The refrigerant radiator is arranged in the heat dissipation cavity, the refrigerant radiator and at least part of the components in the power cavity are attached, the refrigerant system, the refrigerant radiator and the heat exchanger are connected in series to form a circulating refrigerant channel.

17. The power conversion device of claim 1, wherein, The heat exchanger is located in the heat dissipation cavity, the heat exchanger has an inflow channel and an outflow channel, the inflow channel and the outflow channel are both isolated from the heat dissipation cavity, the inflow channel, the heat exchange channel and the outflow channel are in sequence communication, and the inflow port and the outflow port of the inflow channel are both in communication with the space of the power cavity.

18. A power conversion device according to any one of claims 3, 4, 6, 7, 11, 12, 13, 15, 16 and 17, characterized by The power conversion device further comprises a first fan, which is located in the power cavity.

19. An energy storage device, comprising: The power conversion device is connected with a battery, and is used for power conversion of electric energy to charge and discharge the battery.

20. An energy storage device, comprising: The power conversion device is connected in series with a photovoltaic panel and an alternating current combiner box, and is used for converting variable direct current voltage of the photovoltaic panel into mains frequency alternating current and transmitting to the alternating current combiner box.

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