Power main circuit unit and frequency converter

Abstract

The application relates to a power main loop unit and a frequency converter. The power main loop unit comprises a power connection plate, power modules, a heat dissipation module and an auxiliary heat dissipation unit, the power connection plate is provided with a circuit layer; the power modules are electrically connected with the power connection plate, and the power modules are electrically connected through the circuit layer; the heat dissipation module comprises a radiator and the auxiliary heat dissipation unit, the radiator is in heat conduction connection with the power modules; the auxiliary heat dissipation unit is in heat conduction connection between the power connection plate and the radiator, and is used for transmitting the heat of the power connection plate to the radiator. The power connection plate with high automation degree and mature and stable process is used to replace the traditional copper bar, the use of the copper bar and a large number of assembly fasteners is reduced, the power connection plate is in plane layout, the circuit layer is compactly arranged in the plate, and the heat dissipation module has good heat dissipation effect.

Description

Technical Field

[0001] This application relates to the field of motor drive technology, and in particular to power main circuit units and frequency converters. Background Technology

[0002] Currently, in frequency converter products, especially those in the medium and high power range, the main power layout mostly uses copper-aluminum busbars to connect various main power devices such as rectifiers, inverters, brakes, bus capacitors, and reactors.

[0003] However, using copper-aluminum busbars to connect power modules involves a large number of copper and aluminum busbar parts, resulting in a complex and time-consuming manufacturing process, which directly leads to high material costs. At the same time, the large number and variety of fasteners required for assembly not only complicate the assembly process and extend the production cycle but also increase manufacturing costs and reduce manufacturability. Furthermore, copper-aluminum busbar connections occupy a significant volume, which is seriously inconsistent with the trend towards miniaturization in frequency converters and makes it difficult to meet the needs of compact installation scenarios.

[0004] If a PCB board is used to replace the copper-aluminum busbar, the circuit layer on the PCB board will generate a lot of heat when conducting large currents due to the high current transmission requirements of medium and high power inverters. The heat will easily accumulate on the PCB board, which will not only lead to a decrease in the insulation performance of the PCB board itself and a shortened service life, but may also affect the normal operation of surrounding power devices, causing equipment operation stability problems, and even posing a risk of failure due to overheating. Utility Model Content

[0005] Based on this, a power main circuit unit and a frequency converter are provided to solve the problems of high cost, complex assembly, large space occupation and poor heat dissipation caused by using copper-aluminum busbars to connect power modules.

[0006] An embodiment of the first aspect of this application provides a power main circuit unit, comprising:

[0007] A power connection board having a circuit layer;

[0008] A power module, which is electrically connected to the power connection board, and the power modules are electrically connected to each other through the circuit layer;

[0009] The heat dissipation module includes:

[0010] A heat sink, which is thermally connected to the power module;

[0011] An auxiliary heat dissipation unit is thermally connected between the power connection plate and the heat sink, and is used to transfer the heat from the power connection plate to the heat sink.

[0012] In one embodiment, the power main circuit unit further includes:

[0013] A thermally conductive insulating layer is provided, which is thermally connected between the auxiliary heat dissipation unit and the power connection plate.

[0014] In one embodiment, the thermally conductive insulating layer is a thermally conductive insulating pad or a thermally conductive gel.

[0015] In one embodiment, the auxiliary heat dissipation unit includes:

[0016] A first heat dissipation element, one end of which is disposed between the power modules, and the other end of which passes through the power modules and is thermally connected to the heat sink.

[0017] In one embodiment, the auxiliary heat dissipation unit further includes:

[0018] The second heat dissipation element has one end disposed on the side of the power module and the other end thermally connected to the heat sink.

[0019] In one embodiment, the power main circuit unit further includes a thermally conductive insulating layer, which is thermally connected between the auxiliary heat dissipation unit and the power connection plate;

[0020] The first heat dissipation element includes a first heat sink and a second heat sink. The first heat sink is thermally connected to the thermally conductive insulating layer. One end of the second heat sink is thermally connected to the first heat sink, and the other end passes through the power module and is thermally connected to the radiator. And / or

[0021] The second heat dissipation element includes a third heat dissipation plate, a fourth heat dissipation plate, and a fifth heat dissipation plate. The third heat dissipation plate is thermally connected to the thermally conductive insulating layer. The fourth heat dissipation plate is thermally connected to the third heat dissipation plate and the fifth heat dissipation plate. The fifth heat dissipation plate is thermally connected to the radiator.

[0022] In one embodiment, the power module includes a rectifier module and an inverter module, the rectifier module and the inverter module are disposed on the same side of the power connection board, the electrical connection terminals of the rectifier module and the inverter module are located on the same connection plane, and the electrical connection terminals of the rectifier module and the inverter module are electrically connected to the power connection board by screws.

[0023] In one embodiment, the power module further includes a braking module, the braking module, the rectifier module, and the inverter module are disposed on the same side of the power connection board, and the electrical connection terminals of the braking module, the rectifier module, and the inverter module are located on the same connection plane.

[0024] In one embodiment, the heat sink has several placement slots on the side surface near the power module, and the braking module, the rectifier module, and the inverter module are respectively installed in the placement slots.

[0025] In one embodiment, each of the placement slots has a different depth.

[0026] In one embodiment, the power main circuit unit further includes:

[0027] A reactor, comprising a reactor body, a flexible conductor, and a hard connection terminal, wherein the flexible conductor electrically connects the reactor body and the hard connection terminal, and the hard connection terminal is electrically connected to the power connection plate on the connection plane.

[0028] In one embodiment, the reactor body is located on the side of the heat sink away from the power connection plate.

[0029] In one embodiment, a windbreak is provided between the reactor body and the heat sink, the windbreak comprising:

[0030] A first partition is disposed between the heat sink and the reactor body;

[0031] The second partition covers and shields the front end of the reactor body, and the second partition is provided with ventilation holes.

[0032] An embodiment of the second aspect of this application provides a frequency converter, the frequency converter comprising:

[0033] The driver board, the capacitor board, and the power main circuit unit described in any of the above embodiments.

[0034] In one embodiment, the capacitor plate and the power connection plate are electrically connected via conductive studs.

[0035] In one embodiment, the driver board, the power connection board, and the capacitor board are arranged sequentially along a first direction.

[0036] In one embodiment, the frequency converter further includes an inter-board connector, the inter-board connector comprising:

[0037] A first inter-board connector, comprising a first male terminal and a first female terminal, wherein one of the first male terminal and the first female terminal is disposed on the power connection board, and the other is disposed on the capacitor board, and the power connection board and the capacitor board are connected for signal transmission via the first inter-board connector; and / or

[0038] The second board connector includes a second male terminal and a second female terminal. One of the second male terminal and the second female terminal is disposed on the power connection board, and the other is disposed on the driver board. The power connection board and the driver board are connected by the second board connector.

[0039] In one embodiment, the projections of the power connection board and the capacitor board in the second direction have a first overlapping area, and the first inter-board connector is disposed in the first overlapping area;

[0040] The projections of the drive board and the power connection board in the second direction have a second overlapping area, and the second inter-board connector is disposed in the second overlapping area;

[0041] Wherein, the first direction and the second direction are perpendicular to each other.

[0042] In one embodiment, the frequency converter includes:

[0043] A chassis, the chassis including an air duct cavity with an opening;

[0044] A bottom shell, which covers the opening side of the chassis;

[0045] The middle shell is connected to the bottom shell on the side away from the chassis, and the middle shell and the bottom shell enclose a power cavity for housing the power connection board;

[0046] A cover is attached to the side of the middle shell away from the bottom shell. The cover and the middle shell enclose a control cavity for housing a control board.

[0047] In one embodiment, a capacitor is provided on the capacitor plate, and a capacitor hole is provided on the bottom shell at a position corresponding to the capacitor so that the capacitor can extend into the air duct cavity. There is a gap between the bottom end of the capacitor and the bottom end of the air duct cavity.

[0048] And / or, the chassis is provided with an air inlet and an air outlet, and the capacitor is located near the air inlet relative to the heat sink.

[0049] In one embodiment, the chassis is configured to be made of a first material;

[0050] The bottom shell, the middle shell, and the top cover are each configured to be made of a second material;

[0051] Wherein, the strength of the first material is higher than that of the second material; and / or, the thermal conductivity of the first material is higher than that of the second material.

[0052] In one embodiment, the power of the frequency converter is not less than 45KW.

[0053] According to the power main circuit unit and frequency converter of this application embodiment, the power modules are electrically connected to the power connection board. The power modules are electrically connected to each other through the wiring layer on the power connection board. The wiring layer on the power connection board replaces the traditional copper busbar, realizing current transmission and high-power conduction. The power main circuit unit of this application embodiment uses a power connection board with a high degree of automation and mature and stable technology to replace the traditional copper busbar, reducing the use of copper busbars and a large number of assembly fasteners, and reducing material costs. There is no need for complex positioning, alignment and multi-step fixing of copper and aluminum busbars. Only the fixing of power modules and power connection boards needs to be completed, reducing assembly steps and manual intervention. In addition, compared with the three-dimensional bending and stacking layout of copper and aluminum busbars, the power connection board has a planar layout, and the wiring layer is compactly arranged in the board. Each power module can be directly installed on the power connection board to form a flat integrated structure, which significantly compresses the overall volume and is more in line with the trend of frequency converter miniaturization. Meanwhile, the heat dissipation module includes a heat sink that is directly thermally connected to the power module, which can quickly dissipate the heat from the power module; an auxiliary heat dissipation unit is added, which is thermally connected to the power connection plate and the heat sink, and can efficiently transfer the heat generated by the power connection plate when the current is too high to the heat sink, avoiding the accumulation of heat on the connection plate and having a good heat dissipation effect. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the power main circuit unit and frequency converter according to an embodiment of this application.

[0055] Figure 2 This is an exploded view of the power main circuit unit and frequency converter according to an embodiment of this application.

[0056] Figure 3 This is a schematic diagram of the power main circuit unit and the power module in the frequency converter according to an embodiment of this application.

[0057] Figure 4 for Figure 3 An explosion diagram.

[0058] Figure 5 This is a cross-sectional view of a power main circuit unit and a frequency converter embodying a first heat dissipation element according to an embodiment of this application.

[0059] Figure 6 This is a cross-sectional view of a power main circuit unit and a frequency converter according to an embodiment of this application, showing a first heat dissipation element and a second heat dissipation element.

[0060] Figure 7 This is a schematic diagram illustrating the structure of the power main circuit unit and the inverter in an embodiment of this application, showing the first inter-board connector and the second inter-board connector.

[0061] Figure 8 This is a side view of the air duct cavity in a frequency converter according to an embodiment of this application.

[0062] Figure 9 This is a schematic diagram of the structure of the internal components of the air duct cavity in a frequency converter according to an embodiment of this application.

[0063] Figure 10 This is a schematic diagram of the structure of the windbreak baffle in a frequency converter according to an embodiment of this application.

[0064] Figure 11 This is a schematic diagram of the structure of a frequency converter according to an embodiment of this application.

[0065] Figure 12 This is an exploded view of a frequency converter according to an embodiment of this application.

[0066] Figure label:

[0067] 1000, Power Main Circuit Unit;

[0068] 100. Power connection plate; 110. Thermally conductive insulating layer; 120. Conductive connection hole;

[0069] 200 Power module; 210 Rectifier module; 211 First electrical connection terminal; 220 Inverter module; 221 Second electrical connection terminal; 230 Braking module; 231 Third electrical connection terminal;

[0070] 300. Heat dissipation module; 310. Heat sink; 320. Auxiliary heat dissipation unit; 321. First heat dissipation element; 3211. First heat dissipation plate; 3212. Second heat dissipation plate; 322. Second heat dissipation element; 3221. Third heat dissipation plate; 3222. Fourth heat dissipation plate; 3223. Fifth heat dissipation plate;

[0071] 400. Reactor; 410. Flexible conductor; 420. Hard connection terminal; 430. Reactor body;

[0072] 500. Windbreak panel; 510. First partition; 520. Second partition; 521. Ventilation hole;

[0073] 2000, driver board;

[0074] 3000, capacitor board; 3100, conductive stud; 3200, capacitor;

[0075] 4000, First inter-board connector; 4100, First male terminal; 4200, First female terminal;

[0076] 5000, Second board connector; 5100, Second male terminal; 5200, Second female terminal;

[0077] 6000, Chassis; 6100, Air duct cavity; 6110, Opening; 6200, Air inlet; 6300, Air outlet; 6400, Heat dissipation air duct; 6500, Reactor air duct;

[0078] 7000, bottom case; 7100, capacitor hole; 7200, heat sink hole;

[0079] 8000, middle shell; 8100, power cavity;

[0080] 9000, faceplate; 9100, control cavity; 9110, control panel. Detailed Implementation

[0081] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0082] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0083] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0084] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0085] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0086] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0087] See Figure 1 and Figure 2 At least one embodiment of this application provides a power main circuit unit 1000, which includes a power connection board 100, power modules 200, and a heat dissipation module 300. The power connection board 100 has a wiring layer, and the power modules 200 are electrically connected to the power connection board 100. The power modules 200 are electrically connected to each other through the wiring layer. The heat dissipation module 300 includes a heat sink 310 and an auxiliary heat dissipation unit 320. The heat sink 310 is thermally connected to the power modules 200; the auxiliary heat dissipation unit 320 is thermally connected between the power connection board 100 and the heat sink 310, and is used to transfer heat from the power connection board 100 to the heat sink 310.

[0088] According to the power main circuit unit 1000 and frequency converter of this application embodiment, the power module 200 is electrically connected to the power connection plate 100. The power modules 200 are electrically connected to each other through the wiring layer on the power connection plate 100. The wiring layer on the power connection plate 100 replaces the traditional copper busbar, realizing current transmission and high power conduction. The power main circuit unit 1000 in this application embodiment uses the highly automated and technologically mature power connection plate 100 to replace the traditional copper busbar, reducing the use of copper busbars and a large number of assembly fasteners, thus reducing material costs. There is no need for complex positioning, alignment and multi-step fixing of copper and aluminum busbars. Only the fixing of the power module 200 and the power connection plate 100 needs to be completed, reducing assembly steps and manual intervention. In addition, compared with the three-dimensional bending and stacking layout of copper and aluminum busbars, the power connection plate 100 has a planar layout, with the wiring layer compactly arranged inside the plate. Each power module 200 is directly installed on the connection plate, forming a flat integrated structure, which significantly compresses the overall volume and is more in line with the miniaturization trend of frequency converters. Meanwhile, the heat dissipation module 300 includes a heat sink 310 that is directly thermally connected to the power module 200, which can quickly dissipate the heat from the power module 200. An auxiliary heat dissipation unit 320 is added, which thermally connects the power connection plate 100 and the heat sink 310. This unit efficiently transfers the heat generated by the power connection plate 100 under high current conditions to the heat sink 310, preventing heat accumulation on the power connection plate 100 and providing excellent heat dissipation.

[0089] In some embodiments, the power module 200 can be electrically connected to the power connection plate 100 via screws. The power module 200 is fixed to the power connection plate 100 by the screws, thus achieving an electrical connection between the power module 200 and the power connection plate 100. The direct contact between the power module 200 and the power connection plate 100 establishes a current conduction path from the power module 200 to the power connection plate 100. The screws between the power module 200 and the power connection plate 100 ensure a stable transmission of current from the power module 200 to the power connection plate 100, or vice versa. The screws ensure a tight fit between the power module 200 and the surface of the power connection plate 100, increasing the conductive contact area, reducing contact resistance, and preventing overheating, losses, or open circuits caused by poor contact during high current transmission, thus ensuring efficient conduction of the main power flow.

[0090] In this embodiment, the core function of the power connection board 100 is to form a circuit layer through internal copper traces, thereby enabling the conduction of the main power flow, i.e., the transmission of electrical energy between various components. However, due to the limited thickness of the board material, the thickness of the internal copper traces cannot be increased indefinitely, resulting in an upper limit to the current carrying capacity. When transmitting a large current, the copper traces will generate a large amount of heat due to resistance loss. If the heat cannot be dissipated in time, the temperature of the power connection board 100 will exceed the allowable value, potentially causing insulation aging, decreased conductivity, or even burnout. To solve this problem, the power main circuit unit 1000 in this embodiment introduces a heat dissipation module 300.

[0091] See Figure 2 In some embodiments, the heat dissipation module 300 includes a heat sink 310 and an auxiliary heat dissipation unit 320. The heat sink 310, as the primary heat dissipation carrier, has a large heat dissipation area and good thermal conductivity, enabling it to quickly absorb and dissipate heat. The auxiliary heat dissipation unit 320 allows the heat from the power connection board 100 to be efficiently conducted to the heat sink 310. The power module 200 is the main heat source besides the power connection board 100. The heat sink 310 is directly thermally connected to the power module 200, preferentially absorbing and dissipating the heat generated by the power module 200. This allows the heat sink 310 to simultaneously cover multiple heat-generating components, improving heat dissipation efficiency. As a unified heat dissipation terminal, the heat sink 310 centrally dissipates all absorbed heat, ensuring that the power connection board 100 and each power module 200 operate stably within the allowable temperature range, thus solving the overheating problem caused by the limited overcurrent capacity of the power connection board 100.

[0092] Through the above settings, the heat dissipation module 300 is a key compensation design for the structural limitations of the power connection board 100 itself. Through the collaboration of the heat sink 310 and the auxiliary heat dissipation unit 320, efficient heat conduction and dissipation are achieved, ensuring the reliable operation of the power main circuit unit 1000 under high current scenarios.

[0093] See Figure 3 and Figure 4 In some embodiments, the power main circuit unit 1000 further includes a thermally conductive insulating layer 110, which is thermally connected between the auxiliary heat dissipation unit 320 and the power connection plate 100. The thermally conductive insulating layer 110 serves as a dual medium combining thermal conductivity and insulation. On the one hand, it transfers heat from the power connection plate 100 to the auxiliary heat dissipation unit 320 through its own thermal conductivity; on the other hand, it uses its insulating properties to isolate the power connection plate 100 from the auxiliary heat dissipation unit 320, preventing an electrical short circuit between the high-voltage network on the power connection plate 100 and the grounded heat sink 310.

[0094] In some embodiments, the thermally conductive insulating layer 110 is a thermally conductive insulating pad or a thermally conductive gel. Specifically, the thermally conductive insulating pad is a solid sheet, suitable for scenarios requiring a fixed thickness and long-term stable insulation, and is easy to install. The thermally conductive gel is semi-fluid, which can better fill the tiny gaps between the auxiliary heat dissipation unit 320 and the power connection plate 100, improving the interface thermal conductivity, and is suitable for scenarios with higher heat dissipation requirements. Both materials can simultaneously meet the core requirements of thermal conductivity and insulation, and can be flexibly selected according to the heating intensity and assembly precision of the power connection plate 100.

[0095] In this system, the heat generated by excessive current in the power connection board 100 is first transferred to the auxiliary heat dissipation unit 320 through the thermally conductive insulation layer 110, and then conducted by the auxiliary heat dissipation unit 320 to the heat sink 310, which finally dissipates the heat to the outside. This solves the heat generation problem caused by the limited copper thickness and insufficient heat dissipation capacity of the power connection board 100, ensuring that the temperature of the power connection board 100 is controlled within the allowable range.

[0096] With the above settings, the heat of the power connection board 100 can be transferred to the heat sink 310 through the auxiliary heat dissipation unit 320. At the same time, the thermally conductive insulation layer 110 is used to achieve basic insulation of the high voltage network on the power connection board 100 and the ground, ensuring the stable operation of the power main circuit unit 1000 and the frequency converter under high current conditions.

[0097] See Figure 3 and Figure 4 In some embodiments, the auxiliary heat dissipation unit 320 includes a first heat dissipation element 321. One end of the first heat dissipation element 321 is disposed between the power modules 200, and the other end passes through the power modules 200 and is thermally connected to the heat sink 310. The first heat dissipation element 321 passes through the power modules 200, utilizing the gaps or reserved channels between the power modules 200, avoiding structural interference with the power modules 200, and completing heat conduction without occupying additional space, thus adapting to the compact internal layout of the power main circuit unit 1000 and the frequency converter.

[0098] In some embodiments, the auxiliary heat dissipation unit 320 further includes a second heat dissipation element 322, one end of which is disposed on the side of the power module 200, and the other end is thermally connected to the heat sink 310.

[0099] Specifically, the heat generation of the circuit layers and various components on the power connection board 100 varies significantly. Some high-heat areas may be concentrated on the sides or edges of the board, such as the sides near the power module 200 or the edges of densely packed circuit layers. By placing the second heat dissipation element 322 on the side of the power module 200, it can directly target the high-heat areas on the side of the power connection board 100. Through thermally conductive connection with the power connection board 100, it can accurately absorb these locally concentrated heats, avoiding heat accumulation caused by the heat points being off-center from the heat dissipation element. The side-mounted layout of the second heat dissipation element 322 can accurately cover the high-heat areas on the side of the power connection board 100, achieving targeted heat dissipation of locally concentrated heat from the power connection board 100. Finally, heat dissipation is completed through connection with the heat sink 310, effectively solving the problem of poor heat dissipation caused by high current transmission in the power connection board 100.

[0100] In some embodiments, the power main circuit unit 1000 further includes a thermally conductive insulating layer 110, which is thermally connected between the auxiliary heat dissipation unit 320 and the power connection plate 100. The first heat dissipation element 321 includes a first heat dissipation plate 3211 and a second heat dissipation plate 3212. The first heat dissipation plate 3211 is thermally connected to the thermally conductive insulating layer 110. One end of the second heat dissipation plate 3212 is thermally connected to the first heat dissipation plate 3211, and the other end passes through the power module 200 and is thermally connected to the heat sink 310.

[0101] See Figure 4 and Figure 5 Specifically, the first heat sink 3211 and the second heat sink 3212 form a T-shaped structure. The first heat sink 3211, as the front end that directly absorbs heat from the power connection plate 100, is tightly attached to the thermally conductive insulation layer 110 to achieve thermal conductivity. Since the thermally conductive insulation layer 110 directly covers the surface of the power connection plate 100, the first heat sink 3211 can efficiently receive the heat transferred by the power connection plate 100 through contact with the thermally conductive insulation layer 110. The second heat sink 3212, as the output end of heat transfer, has one end directly thermally connected to the first heat sink 3211 to ensure that the heat absorbed by the first heat sink 3211 can be transferred to itself, and the other end passes through the gap between the power modules 200, such as the rectifier module 210, inverter module 220, or braking module 230, extending to the radiator 310 and thermally connected to it, so that the heat received by the first heat sink 3211 can overcome the spatial barrier of the power module 200 and finally be transferred to the radiator 310 for dissipation.

[0102] See Figure 4 and Figure 5In some embodiments, the second heat dissipation element 322 includes a third heat dissipation plate 3221, a fourth heat dissipation plate 3222, and a fifth heat dissipation plate 3223. The third heat dissipation plate 3221 is thermally connected to the thermally conductive insulating layer 110. The fourth heat dissipation plate 3222 is thermally connected to the third heat dissipation plate 3221 and the fifth heat dissipation plate 3223. The fifth heat dissipation plate 3223 is thermally connected to the heat sink 310.

[0103] Specifically, the third heat sink 3221, acting as the front end for absorbing heat from the power connection plate 100, functions similarly to the first heat sink 3211 of the first heat sink element 321. It is directly connected to the thermally conductive insulating layer 110 covering the surface of the high-heat-generating area of ​​the power connection plate 100, receiving heat transferred from the power connection plate 100 through the thermally conductive insulating layer 110, especially heat from the area of ​​the power connection plate 100 near the side of the power module 200. The fourth heat sink 3222 is thermally connected at one end to the third heat sink 3221 and at the other end to the fifth heat sink 3223, transferring the heat absorbed by the third heat sink 3221 to the fifth heat sink 3223, utilizing the side gaps to adapt to the spatial layout of the side of the power module 200. The fifth heat sink 3223, as the output end of the side heat dissipation path, is directly connected to the heat sink 310, ultimately channeling the heat transferred by the fourth heat sink 3222 into the heat sink 310 for dissipation.

[0104] See Figure 6 The first heat dissipation element 321 and the second heat dissipation element 322 complement each other. The heat generation in different areas of the power connection plate 100 may vary. The first heat dissipation element 321 mainly covers the internal area of ​​the power connection plate 100, while the second heat dissipation element 322, by being positioned on the side of the power module 200, can specifically absorb heat from high-heat areas of the power connection plate 100 near the power module 200, preventing localized heat accumulation. The power module 200, power connection plate 100, and heat sink 310 are arranged compactly. The second heat dissipation element 322 utilizes unused space on the side of the power module 200, such as the gap between the power module 200 and the inner wall of the chassis 6000, and the lateral gap of the power module 200, to construct an independent heat dissipation path. This does not interfere with the normal operation of the power module 200 and adds a new heat dissipation channel. The first heat dissipation element 321 and the second heat dissipation element 322 form a multi-path heat dissipation system, which can disperse the heat transfer pressure of the power connection plate 100, avoid conduction bottlenecks caused by heat concentration in a single heat dissipation path, and ensure that the overall temperature of the power connection plate 100 is controlled within the allowable range.

[0105] See Figure 2 and Figure 3In some embodiments, the power module 200 includes a rectifier module 210 and an inverter module 220, which are disposed on the same side of the power connection board 100. The electrical connection terminals of the rectifier module 210 and the inverter module 220 are located on the same connection plane. Specifically, the rectifier module 210 is provided with a first electrical connection terminal 211 for electrical connection with the power connection board 100; the inverter module 220 is provided with a second electrical connection terminal 221 for electrical connection with the power connection board 100. The first electrical connection terminal 211 and the second electrical connection terminal 221 are located on the same connection plane.

[0106] The rectifier module 210 rectifies external AC power into DC power, and its output DC power needs to be transmitted to the power connection board 100, and then distributed to other components through the power connection board 100. The first electrical connection terminal 211 is provided on the rectifier module 210, with one end electrically connected to the output terminal of the rectifier module 210 and the other end attached to the power connection board 100, thereby conducting the rectified DC power to the power connection board 100.

[0107] The function of inverter module 220 is to invert the DC power transmitted by power connection board 100 into AC power with adjustable frequency, and it needs to receive electrical energy from power connection board 100. The second electrical connection terminal 221 is provided on inverter module 220, one end of which is electrically connected to the input terminal of inverter module 220, and the other end is attached to power connection board 100, so as to realize the transmission of electrical energy from power connection board 100 to inverter module 220.

[0108] The rectifier module 210 and inverter module 220 are located on the same side of the power connection plate 100. This layout results in a shorter contact path with the power connection plate 100, a more compact structure, reduced losses during current transmission, and easier overall assembly and heat dissipation design. This arrangement provides a reliable structural foundation for the conduction of the entire main power circuit unit 1000 and the main power flow of the frequency converter, while simultaneously ensuring both current transmission stability and a compact layout.

[0109] In some embodiments, a first locking screw (not shown in the figure) is provided between the first electrical connection terminal 211 and the power connection plate 100; a second locking screw (not shown in the figure) is provided between the second electrical connection terminal 221 and the power connection plate 100. On the one hand, the first locking screw and the second locking screw respectively press the first electrical connection terminal 211 and the second electrical connection terminal 221 tightly onto the surface of the circuit layer of the power connection plate 100, preventing the first electrical connection terminal 211 and the second electrical connection terminal 221 from separating or loosening from the power connection plate 100 due to environmental factors such as vibration and impact, ensuring that the two always maintain a stable contact state. On the other hand, the electrical connection between the first electrical connection terminal 211, the second electrical connection terminal 221 and the power connection plate 100 depends on the tight contact between the metal contact surface and the circuit layer of the power connection plate 100. The pressure generated by the first locking screw and the second locking screw can reduce the gap between the contact surfaces, reduce the contact resistance, avoid heat generation due to poor contact, and thus ensure efficient conduction of the main power flow between the two.

[0110] Furthermore, the first electrical connection terminal 211 corresponds to the rectifier module 210, responsible for transmitting the rectified electrical energy to the power connection board 100; the second electrical connection terminal 221 corresponds to the inverter module 220, responsible for transmitting the electrical energy from the power connection board 100 to the inverter module 220. The fact that the first electrical connection terminal 211 and the second electrical connection terminal 221 are located on the same connection plane facilitates the operation of the first and second locking screws and avoids tilting of the contact surface due to local loosening, thereby reducing the imbalance of current transmission. It also facilitates the overall assembly and subsequent maintenance of the power connection board 100.

[0111] With the above settings, the first locking screw and the second locking screw strengthen the fit reliability between the first electrical connection end 211, the second electrical connection end 221 and the power connection plate 100 through mechanical locking. This ensures a stable mechanical connection between the two and reduces contact resistance through pressure, thereby ensuring efficient and stable transmission of the main power flow and achieving a reliable electrical connection.

[0112] See Figure 2 and Figure 3 In some embodiments, the power module 200 further includes a braking module 230. The braking module 230, the rectifier module 210, and the inverter module 220 are disposed on the same side of the power connection plate 100. The electrical connection terminals of the braking module 230, the rectifier module 210, and the inverter module 220 are located on the same connection plane.

[0113] The rectifier module 210, inverter module 220, and braking module 230 are the core components of the main power circuit, and all three need to be electrically connected to the power connection board 100. Concentrating them on the same side of the power connection board 100 facilitates the connection of each module to the power connection board 100 via its respective electrical connection terminal, resulting in a shorter and more direct path, reducing current loss during transmission, and improving the transmission efficiency of the main power flow. The same-side layout of the rectifier module 210, inverter module 220, and braking module 230 allows for a more compact internal structure of the main power circuit unit 1000 and the frequency converter, avoiding space waste caused by scattered module placement, and contributing to a reduction in overall size, in line with the trend of miniaturization. Simultaneously, the same-side layout facilitates unified planning of the installation position of the electrical connection terminals, the routing direction of the wiring, and the assembly path of the screws, reducing the risk of spatial interference during assembly and improving assembly efficiency.

[0114] In addition, the power module 200 is the main heat source of the power main circuit unit 1000 and the frequency converter. The rectifier module 210, inverter module 220 and braking module 230 are arranged on the same side so that they are concentrated close to the heat sink 310, which facilitates the efficient removal of heat through the same heat dissipation system and avoids the heat dissipation difficulties caused by the dispersed layout.

[0115] Specifically, the braking module 230 is provided with a third electrical connection terminal 231. One end of the third electrical connection terminal 231 is connected to the electrical interface of the braking module 230, and the other end is attached to the wiring layer of the power connection board 100 to realize the power transmission between the braking module 230 and the power connection board 100, and ensure that the braking circuit and the main power circuit form a complete path.

[0116] In some embodiments, a third locking screw (not shown in the figure) is provided between the third electrical connection terminal 231 and the power connection plate 100. The third locking screw functions similarly to the aforementioned first and second locking screws. By tightening with the third locking screw, the third electrical connection terminal 231 is tightly pressed against the surface of the circuit layer of the power connection plate 100, preventing loosening due to vibration or impact and ensuring the stability of the fit. The tightening pressure also reduces the contact resistance between the third electrical connection terminal 231 and the circuit layer of the power connection plate 100, preventing overheating due to poor contact during high-current transmission and ensuring efficient and safe power transmission in the braking circuit.

[0117] The first, second, and third locking screws are located on the same connecting plane, meaning that the pressure direction of the three screws on their respective modules is consistent and perpendicular to the surface of the power connection board 100. This ensures uniform contact between the first electrical connection terminal 211, the second electrical connection terminal 221, and the third electrical connection terminal 231 and the circuit layer of the power connection board 100, avoiding poor local contact caused by tilted contact angles. Especially during high current transmission, uniform contact reduces the risk of local overheating and ensures stable conduction of the main power flow between the three modules and the power connection board 100. Simultaneously, the power connection board 100 can be designed with a uniform screw hole layout for the same connecting plane, eliminating the need to adapt differentiated structures for modules of different heights and reducing the processing difficulty of the power connection board 100. Furthermore, during assembly, the locking depth of the three locking screws can be positioned using the same reference plane, avoiding assembly errors caused by height differences and improving the adaptability of automated assembly.

[0118] It is understandable that the rectifier module 210, inverter module 220, and braking module 230 can be configured individually or in parallel. This configuration allows for flexible adaptation to power main circuit units 1000 and frequency converters with different power requirements. The scalability of each module enhances the power level coverage of the power main circuit unit 1000 and frequency converters. There is no need to redesign the overall architecture for changes in power level; power capacity can be adjusted simply by adding or removing modules, reducing the development costs for different models of power main circuit units 1000 and frequency converters.

[0119] In some embodiments, the upper surface of the radiator 310 is smoothly disposed, and the rectifier module 210, inverter module 220, and braking module 230 are respectively mounted on the upper surface of the radiator 310 by bolts. Specifically, the rectifier module 210, inverter module 220, and braking module 230 are configured as modules of equal height. Taking advantage of the equal height of the three modules, after all three modules are fixed on the upper surface of the radiator 310, the upper surfaces of the rectifier module 210, inverter module 220, and braking module 230 are also of equal height, so that the first electrical connection terminal 211, the second electrical connection terminal 221, and the third electrical connection terminal 231 are located on the same connection plane.

[0120] Specifically, the smooth surface of the heat sink 310 provides a uniform and flat mounting reference surface for the rectifier module 210, inverter module 220, and braking module 230. This smooth surface ensures a tight fit between the bottom of each module and the heat sink 310, guaranteeing efficient heat conduction between the power module 200 and the heat sink 310, and providing a stable foundation for horizontal installation, preventing uneven stress on the modules due to tilted mounting surfaces. The rectifier module 210, inverter module 220, and braking module 230 are secured to the upper surface of the heat sink 310 with bolts. This ensures a stable connection between the modules and the heat sink 310, preventing loosening due to vibration or impact, and the tightening force of the bolts further strengthens the fit between the bottom of the modules and the heat sink 310, further improving heat dissipation efficiency.

[0121] The rectifier module 210, inverter module 220, and braking module 230 are configured as modules of equal height. When all three are bolted to the smooth upper surface of the radiator 310, their tops—namely, the first electrical connection end 211, the second electrical connection end 221, and the third electrical connection end 231—are naturally on the same connecting plane due to their identical height. This design avoids the problem of uneven tops caused by differences in module height. Furthermore, the first, second, and third locking screws used to secure the first, second, and third electrical connection ends 211, 221, and 231 to the power connection plate 100 only need to be installed perpendicular to the surface of the power connection plate 100, eliminating the need for additional height compensation structures. This simplifies the assembly process and reduces the risk of errors caused by manual adjustments.

[0122] The above settings improve assembly efficiency and ensure the stability of power transmission and heat dissipation.

[0123] In some embodiments, the rectifier module 210, inverter module 220, and braking module 230 are not at the same height. In order to make the first electrical connection terminal 211, the second electrical connection terminal 221, and the third electrical connection terminal 231 located on the same connection plane, the heat sink 310 has a plurality of placement slots on the side surface near the power module 200, and the braking module 230, rectifier module 210, and inverter module 220 are respectively installed in the placement slots.

[0124] Specifically, based on the actual height differences of the rectifier module 210, inverter module 220, and braking module 230, a placement slot of different depth is matched for each module. The taller modules correspond to deeper placement slots, and the shorter modules correspond to shallower placement slots. When each module is installed in its corresponding placement slot, the depth of the slot offsets the height difference of the modules themselves. The originally taller modules, placed in deeper slots, have their top height reduced; the originally shorter modules, placed in shallower slots, have their top height relatively increased, ultimately bringing the tops of the three modules to the same horizontal plane.

[0125] By setting up the placement slot, the height difference between the rectifier module 210, inverter module 220, and braking module 230 is compensated, so that the first electrical connection terminal 211, the second electrical connection terminal 221, and the third electrical connection terminal 231 are located on the same connection plane.

[0126] The above settings optimize the adaptability to the height differences of each module. The placement slot of the heat sink 310 achieves structural compensation, ensuring that modules of different heights can still achieve consistency in the connection plane.

[0127] See Figure 1 and Figure 2 In some embodiments, the power main circuit unit 1000 further includes a reactor 400, which includes a reactor body 430, a flexible conductor 410, and a rigid connection terminal 420. The flexible conductor 410 electrically connects the reactor body 430 and the rigid connection terminal 420, and the rigid connection terminal 420 is electrically connected to the power connection plate 100 on the connection plane. Through the above arrangement, the reactor body 430 is connected to the rigid connection terminal 420 through the flexible conductor 410, which is a connection method combining flexibility and rigidity, to achieve a reliable electrical connection between the reactor 400 and the power connection plate 100, while adapting to installation layout requirements.

[0128] Combination Figure 3 Specifically, the flexible conductor 410 connects the reactor body 430 and the rigid connection terminal 420, adapting to installation errors and layout flexibility. The flexible conductor 410 is bendable and deformable, absorbing minor deviations in the installation positions of the reactor 400 and the power connection plate 100, avoiding stress concentration caused by the forced alignment of the rigid connection terminal 420. If there are spatial angle or distance differences in the layout of the reactor 400 and the rigid connection terminal 420, the flexible conductor 410 can adjust the connection path through its own deformation, making the overall layout more flexible and eliminating the need to strictly limit the relative positions of the reactor 400 and the power connection plate 100, thus reducing the difficulty of structural design. The rigid connection terminal 420 can form a stable mechanical contact with the power connection plate 100, ensuring low resistance characteristics for current transmission.

[0129] With the above settings, the hard connection terminal 420 is electrically connected to the power connection board 100 on the connection plane, so that the path of the reactor 400 to the main power circuit is spatially coordinated with the connection paths of the rectifier module 210 and the inverter module 220, avoiding uneven local stress or disordered current transmission path of the power connection board 100 due to misalignment of the connection plane, and ensuring the uniform distribution of the main power flow on the power connection board 100.

[0130] See Figure 7In some embodiments, the reactor body 430 is located on the side of the heat sink 310 away from the power connection plate 100. That is, the heat sink 310 and the reactor body 430 are stacked, which can make full use of space and reduce volume.

[0131] See Figure 8 and Figure 9 In some embodiments, a windbreak baffle 500 is provided between the reactor body 430 and the heat sink 310. The windbreak baffle 500 includes a first baffle 510 and a second baffle 520. The first baffle 510 is disposed between the heat sink 310 and the reactor body 430. The second baffle 520 covers and shields the front end of the reactor body 430, and a ventilation hole 521 is provided on the second baffle 520.

[0132] Specifically, in some embodiments, the reactor 400 and the heat sink 310 are arranged within a duct cavity 6100, which has an air inlet 6200 and an air outlet 6300 to form an air duct within the duct cavity 6100 pointing from the air inlet 6200 to the air outlet 6300. A baffle 500 is also arranged within the duct cavity 6100, dividing it into a heat dissipation duct 6400 and a reactor duct 6500. The heat dissipation duct 6400 is used to cool the heat sink 310, and the reactor duct 6500 is used to cool the reactor 400. A second baffle 520 covers and shields the front end of the reactor body 430, that is, the end of the reactor body 430 closest to the air inlet 6200.

[0133] The baffle 500 can distribute the airflow for cooling the radiator 310 and the airflow for cooling the reactor 400. The flow fields of the heat dissipation air duct 6400 and the reactor air duct 6500 do not interfere with each other, avoiding airflow turbulence that could lead to insufficient local heat dissipation and ensuring stable flow of their respective cooling airflows.

[0134] Understandably, the size of the vents on the baffle 500 can be flexibly adjusted. By changing the flow area of ​​the vents, the proportion of airflow entering the reactor duct 6500 can be precisely controlled. The larger the vent, the more airflow enters the reactor duct 6500, and vice versa, ensuring that the limited airflow is fully and rationally distributed between the radiator 310 and the reactor 400. The vents on the second baffle 520 can guide some airflow into the reactor duct 6500 to provide cooling airflow for the reactor 400; meanwhile, the airflow that does not enter the reactor duct 6500 continues to flow through the cooling duct 6400 to cool the radiator 310. This ensures that the limited total airflow is fully and rationally distributed between the reactor 400 and the radiator 310, avoiding airflow waste and improving overall heat dissipation efficiency.

[0135] Through the above configuration, the first partition 510 and the second partition 520 achieve directional airflow distribution through structured separation, eliminating the need for excessive spacing between the radiator 310 and the reactor 400, and also eliminating the need to increase the size of the air duct cavity 6100 to expand airflow. This design allows the radiator 310 and the reactor 400 to be compactly arranged in a smaller space, thereby effectively controlling the overall height and width dimensions of the unit, meeting the requirements of compact installation, while ensuring heat dissipation efficiency through precise airflow distribution. This allows the overall height and width dimensions of the unit to be minimized, meeting compact installation requirements and ensuring heat dissipation efficiency.

[0136] See Figure 10 Specifically, the top of the second partition 520 is fixedly connected to the edge of the first partition 510, forming an L-shaped structure. A mounting plate is connected to the bottom of the second partition 520, and the second partition 520 is mounted on the bottom wall of the duct cavity 6100 via the mounting plate and screws. Screw fixing ensures that the second partition 520 remains stable under the impact of airflow in the duct cavity 6100, preventing displacement due to vibration or airflow pressure, thereby maintaining the positional accuracy of the vent and the airflow distribution ratio. The screw connection facilitates the disassembly and installation of the second partition 520 when adjustments to airflow distribution or replacement with different vent sizes are needed, improving the flexibility of later maintenance.

[0137] It is understood that in some embodiments, the baffle 500 can be configured as a cover with an inlet and an outlet. The inlet is located near the air inlet 6200, and the outlet is located near the air outlet 6300. Enclosing the reactor 400 with this cover achieves an effect similar to that of the baffle 500. Specifically, the inlet corresponds to the vent of the second baffle 520, used to introduce airflow from outside the cover into the cover; the outlet corresponds to the end of the reactor air duct 6500, used to guide the airflow passing through the reactor 400 to the outside of the cover; the cover itself forms an independent airflow channel, replacing the separating function of the first baffle 510 and the second baffle 520, avoiding airflow interference with the heat dissipation air duct 6400, and achieving directional cooling of the reactor 400.

[0138] See Figure 11 and Figure 12 At least one embodiment of this application provides a frequency converter, which includes a drive board 2000, a capacitor board 3000, and a power main circuit unit 1000 as described in any of the above embodiments.

[0139] See Figure 12In some embodiments, the driver board 2000, power connection board 100, and capacitor board 3000 are arranged sequentially along a first direction. The first direction is the X direction in the figure, which is the horizontal direction, to ensure that the driver board 2000, power connection board 100, and capacitor board 3000 are arranged in an orderly manner.

[0140] See Figure 2 In some embodiments, the capacitor board 3000 and the power connection board 100 are electrically connected via conductive studs 3100. Specifically, the power connection board 100 is provided with conductive connection holes 120, and the conductive connection holes 120 are copper-plated on both sides. The connection and locking of the conductive studs 3100 and the conductive connection holes 120 achieves the fixation of the capacitor board 3000 and the power connection board 100, as well as the conduction of the electrical network. The circuit layer, as a conductive medium, allows the main power flow of the power connection board 100 to be discharged through the holes, while simultaneously enhancing the conductivity of the holes. The locking fit between the conductive studs 3100 and the conductive connection holes 120 securely fixes the capacitor board 3000 to one side of the power connection board 100, preventing loosening of the connection due to environmental factors such as vibration and impact, and ensuring structural stability. The copper plating on both sides of the conductive connection holes 120 is conductive to the circuit layer inside the power connection board 100, and the conductive studs 3100 are made of metal, possessing good conductivity. When the conductive stud 3100 is locked with the conductive connection hole 120, the conductive stud 3100 is in close contact with the circuit layer, realizing the electrical network connection between the capacitor board 3000 and the power connection board 100, that is, the transmission of the main power flow between the two.

[0141] With the above configuration, the conductive connection hole 120 and the conductive stud 3100 integrate mechanical fixing and electrical connection functions, eliminating the need for additional wires or connectors, thus reducing material costs and assembly complexity. The connection between the conductive connection hole 120 and the conductive stud 3100 can be completed using automated equipment, improving assembly efficiency.

[0142] See Figure 2 and Figure 7 In some embodiments, the frequency converter further includes an inter-board connector, which includes a first inter-board connector 4000. The first inter-board connector 4000 includes a first male terminal 4100 and a first female terminal 4200. One of the first male terminal 4100 and the first female terminal 4200 is disposed on the power connection board 100, and the other is disposed on the capacitor board 3000. The power connection board 100 and the capacitor board 3000 are connected for signal transmission through the first inter-board connector 4000. By replacing signal lines with the first inter-board connector 4000, automated production can be achieved, the overall size of the machine can be reduced, and the overall cost of the machine can be lowered.

[0143] In some embodiments, the inter-board connector further includes a second inter-board connector 5000, which includes a second male terminal 5100 and a second female terminal 5200. One of the second male terminal 5100 and the second female terminal 5200 is disposed on the power connection board 100, and the other is disposed on the driver board 2000. The power connection board 100 and the driver board 2000 are connected by the second inter-board connector 5000. By replacing the signal line with the second inter-board connector 5000, automated production can be achieved, the overall size of the machine can be reduced, and the overall cost can be lowered.

[0144] The first inter-board connector 4000 is configured with a first male terminal 4100 and a first female terminal 4200 interlocked, and the second inter-board connector 5000 is configured with a second male terminal 5100 and a second female terminal 5200 interlocked. This interlocking design eliminates the need for additional fasteners. When the capacitor board 3000, drive board 2000, and power connection board 100 are installed in their preset positions, the male and female terminals automatically align and connect, reducing manual plugging and unplugging or wiring procedures and adapting to automated assembly. The tight interlocking of the male and female terminals ensures stable signal contact, avoiding the risks of loosening or detachment that may occur with traditional cable connections, and is particularly suitable for the vibration environment of the power main circuit unit 1000 and the frequency converter during operation.

[0145] See Figure 6 In some embodiments, the projections of the power connection board 100 and the capacitor board 3000 in the second direction have a first overlapping area, and the first inter-board connector 4000 is disposed in the first overlapping area. The projections of the drive board 2000 and the power connection board 100 in the second direction have a second overlapping area, and the second inter-board connector 5000 is disposed in the second overlapping area. The first direction and the second direction are perpendicular to each other; the second direction is the Z direction in the figure, i.e., the vertical direction.

[0146] Specifically, the first board connector 4000 and the second board connector 5000 are respectively located in the corresponding first and second overlapping areas, which simplifies the signal connection path. Within the overlapping area, the physical distance between the two boards is the shortest, and the male and female signal terminals can be directly plugged in without the need for additional cables or extension structures, reducing the path length and loss of signal transmission.

[0147] In addition, when the drive board 2000, power connection board 100 and capacitor board 3000 are fixed along the first direction, the terminals in the overlapping area can be naturally aligned and plugged in without the need for manual adjustment of position, which greatly improves assembly efficiency and is suitable for automated production.

[0148] Meanwhile, by using vertical projection overlap to set up the inter-board connectors, extra space is avoided in the first direction, making the layout of the driver board 2000, power connection board 100 and capacitor board 3000 more compact.

[0149] With the above settings, while ensuring the orderly layout of the driver board 2000, power connection board 100, and capacitor board 3000, the first and second overlapping areas are used to achieve short signal connection paths, easy insertion, and space saving. This is an optimized solution that balances structural compactness and assembly efficiency.

[0150] See Figure 11 and Figure 12 In some embodiments, the frequency converter includes a chassis 6000, a bottom shell 7000, a middle shell 8000, and a front cover 9000. The chassis 6000 includes an air duct cavity 6100 with an opening 6110. The bottom shell 7000 covers one side of the chassis 6000 with the opening 6110. The middle shell 8000 is connected to the side of the bottom shell 7000 away from the chassis 6000. The middle shell 8000 and the bottom shell 7000 together form a power cavity 8100, which is used to house a power connection plate 100. The front cover 9000 is connected to the side of the middle shell 8000 away from the bottom shell 7000. The front cover 9000 and the middle shell 8000 together form a control cavity 9100, which is used to house a control plate 9110.

[0151] With the above configuration, the air duct cavity 6100, power cavity 8100 and control cavity 9100 are designed in layers, forming an orderly stacked box structure, which allows the internal components of the frequency converter to be placed layer by layer according to functional zones. The significant advantage of this design lies in its ability to adapt to a progressive installation logic. Installation can begin with the bottom chassis 6000, first fixing the basic frame and then installing the heatsink 310 inside. Next, the bottom shell 7000 is placed on top of the chassis 6000. The bottom shell 7000 has heatsink holes 7200 at positions corresponding to the heatsink 310, which mate with the top of the heatsink 310 to seal the airflow cavity 6100. The top of the heatsink 310 can then connect to the power module 200 within the power cavity 8100 via the heatsink holes 7200. Subsequently, a power connection plate 100 is placed on the bottom shell 7000, and the middle shell 8000 is assembled to form the power cavity 8100. Finally, a control board 9110 is placed on the middle shell 8000, and a cover 9000 is installed to form the control cavity 9100. The entire process requires no flipping or significant displacement of the installed components; simply stack and secure them layer by layer in sequence. Compared to the complex process in existing technologies that requires first installing and locking the radiator 310 on the base shell 7000 before flipping the entire assembly, this solution's layered cavity design completely avoids the redundancy and operational risks associated with flipping installation. There is no need to worry about loosening or shifting of installed components during the flipping process, nor is it necessary to adjust the operating posture to adapt to the assembly angle after flipping. This layered installation method significantly simplifies the assembly steps, reduces the difficulty of manual operation, and minimizes installation errors caused by complex processes, thereby significantly improving assembly efficiency and reliability.

[0152] In some embodiments, a capacitor 3200 is provided on the capacitor plate 3000, and a capacitor 3200 hole is provided at the position corresponding to the capacitor 3200 on the bottom shell 7000 so that the capacitor 3200 can extend to the air duct cavity 6100.

[0153] Specifically, the capacitor 3200 hole provides a channel for the capacitor 3200 of the capacitor plate 3000 to extend from the power cavity 8100 to the air duct cavity 6100. The capacitor 3200 hole only provides the necessary through path for the capacitor 3200, avoiding the large-area connection between the air duct cavity 6100 and the power cavity 8100 caused by excessive opening 6110 in the bottom shell 7000. This maintains the relative independence of the two cavities to a certain extent and reduces the mutual interference between the airflow in the air duct cavity 6100 and the environment in the power cavity 8100.

[0154] In some embodiments, a gap exists between the bottom end of the capacitor 3200 and the bottom end of the air duct cavity 6100. This avoids heat dissipation obstruction caused by direct contact between the capacitor 3200 and the bottom of the air duct cavity 6100, and prevents heat conduction or airflow blockage that may be caused by contact. It ensures that cool air can flow more smoothly around the capacitor 3200, improving the cooling effect. At the same time, the gap also provides installation buffer space for the capacitor 3200, adapting to its structural layout extending into the air duct cavity 6100. The aforementioned gap is part of the air intake path, allowing cool air to supplement airflow or enhance airflow flow when flowing through the capacitor 3200, without the need to additionally enlarge the volume of the air duct cavity 6100 for a separate air intake channel.

[0155] With the above setup, the heat-sensitive capacitor 3200 is placed at the cold air end, and the gap at the bottom of the capacitor 3200 is used as an air intake channel, achieving dual utilization of one space.

[0156] In some embodiments, the chassis 6000 is provided with an air inlet 6200 and an air outlet 6300, and the capacitor 3200 is close to the air inlet 6200 relative to the heat sink 310. With the above arrangement, the temperature-sensitive capacitor 3200 can be located at the cold air end of the air duct, that is, upstream of the air duct path, so as to preferentially obtain low-temperature airflow for cooling and improve heat dissipation efficiency.

[0157] In some embodiments, the chassis 6000 is configured to be made of a first material. The bottom shell 7000, the middle shell 8000, and the front cover 9000 are each configured to be made of a second material. The first material has a higher strength than the second material. And / or, the first material has a higher thermal conductivity than the second material.

[0158] The first material can be sheet metal, and the second material can be plastic. Compared to plastic, sheet metal has higher strength and thermal conductivity. On the one hand, when the chassis 6000 serves as the basic framework of the entire machine, the overall strength is higher and the resistance to deformation is stronger, especially in compact installation or under external stress, it can maintain its overall shape. On the other hand, as the outer wall of the air duct cavity 6100, the chassis 6000 has better thermal conductivity, which is conducive to heat dissipation. Some of the heat inside the air duct cavity 6100 is conducted to the external environment through the chassis 6000 wall, enhancing the overall heat dissipation efficiency and forming a synergy with the active heat dissipation within the air duct.

[0159] The plastic base shell 7000 and middle shell 8000, once fixed together, form the power cavity 8100. The properties of the plastic material make the gaps between them easier to control. The fit of these gaps creates a seal, achieving a high level of protection and effectively preventing dust and moisture from entering, protecting core power components such as the power board and drive board 2000 from environmental interference. The plastic middle shell 8000 and the cover 9000 together form the control cavity 9100. The insulating properties and structural stability of the plastic ensure more reliable physical isolation between the control cavity 9100 and the power cavity 8100, preventing electrical interference between the control board 9110 and the high-voltage components of the power cavity 8100.

[0160] Through the above configuration, the chassis 6000 ensures structural integrity and heat dissipation with its high strength and high thermal conductivity, while the bottom shell 7000, middle shell 8000, and top cover 9000 ensure protection and maintainability with the easy sealing and processing characteristics of plastic, ultimately achieving synergistic optimization of the overall machine performance.

[0161] In some embodiments, the power of the frequency converter is not less than 45KW. Specifically, the frequency converter of this application is adapted to frequency converters of 45KW and above. For high-power frequency converters of 45KW and above, their main power circuit unit will carry a very large current during operation, and the heat generation of core components such as the power module 200 and the power connection board 100 is significantly higher than that of low-power devices. Among them, the power connection board 100, as a key component replacing the traditional copper-aluminum busbar, has a particularly prominent heat generation problem in its circuit layer when conducting large currents. If heat dissipation is not timely, it is very easy to cause performance degradation or even burnout due to overheating. The frequency converter of this application is directly thermally connected to the power module 200 through the heat sink 310, and the auxiliary heat dissipation unit 320 is specifically designed for heat conduction of the power connection board 100, accurately dissipating the concentrated heat generated by various components under high power conditions and avoiding heat accumulation. At the same time, the independent setting of the air duct cavity 6100 and the reasonable airflow planning further enhance the overall heat dissipation efficiency, ensuring that the equipment temperature remains stable within a safe range when operating at high power of 45KW and above. The frequency converter provided by this application can still operate reliably in high-power scenarios.

[0162] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0163] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A power main circuit unit, characterized in that, include: A power connection board having a circuit layer; A power module, which is electrically connected to the power connection board, and the power modules are electrically connected to each other through the circuit layer; The heat dissipation module includes: A heat sink, which is thermally connected to the power module; An auxiliary heat dissipation unit is thermally connected between the power connection plate and the heat sink, and is used to transfer the heat from the power connection plate to the heat sink.

2. The power main circuit unit according to claim 1, characterized in that, The power main circuit unit also includes: A thermally conductive insulating layer is provided, which is thermally connected between the auxiliary heat dissipation unit and the power connection plate.

3. The power main circuit unit according to claim 2, characterized in that, The thermally conductive insulating layer is a thermally conductive insulating pad or a thermally conductive gel.

4. The power main circuit unit according to claim 1, characterized in that, The auxiliary heat dissipation unit includes: A first heat dissipation element, one end of which is disposed between the power modules, and the other end of which passes through the power modules and is thermally connected to the heat sink.

5. The power main circuit unit according to claim 4, characterized in that, The auxiliary heat dissipation unit also includes: The second heat dissipation element has one end disposed on the side of the power module and the other end thermally connected to the heat sink.

6. The power main circuit unit according to claim 5, characterized in that, The power main circuit unit also includes a thermally conductive insulating layer, which is thermally connected between the auxiliary heat dissipation unit and the power connection plate. The first heat dissipation element includes a first heat dissipation plate and a second heat dissipation plate. The first heat dissipation plate is thermally connected to the thermally conductive insulating layer. One end of the second heat dissipation plate is thermally connected to the first heat dissipation plate, and the other end passes through the power module and is thermally connected to the radiator. and / or The second heat dissipation element includes a third heat dissipation plate, a fourth heat dissipation plate, and a fifth heat dissipation plate, wherein the third heat dissipation plate is thermally connected to the thermally conductive insulating layer; The fourth heat sink provides a thermally conductive connection between the third heat sink and the fifth heat sink. The fifth heat sink is thermally connected to the radiator.

7. The power main circuit unit according to claim 1, characterized in that, The power module includes a rectifier module and an inverter module. The rectifier module and the inverter module are disposed on the same side of the power connection board. The electrical connection terminals of the rectifier module and the inverter module are located on the same connection plane. The electrical connection terminals of the rectifier module and the inverter module are electrically connected to the power connection board by screws.

8. The power main circuit unit according to claim 7, characterized in that, The power module also includes a braking module. The braking module, the rectifier module, and the inverter module are disposed on the same side of the power connection board. The electrical connection terminals of the braking module, the rectifier module, and the inverter module are located on the same connection plane.

9. The power main circuit unit according to claim 8, characterized in that, The heat sink has several placement slots on the side surface near the power module, and the braking module, the rectifier module, and the inverter module are respectively installed in the placement slots.

10. The power main circuit unit according to claim 9, characterized in that, Each of the placement slots has a different depth.

11. The power main circuit unit according to claim 7, characterized in that, The power main circuit unit also includes: A reactor, comprising a reactor body, a flexible conductor, and a hard connection terminal, wherein the flexible conductor electrically connects the reactor body and the hard connection terminal, and the hard connection terminal is electrically connected to the power connection plate on the connection plane.

12. The power main circuit unit according to claim 11, characterized in that, The reactor body is located on the side of the heat sink away from the power connection plate.

13. The power main circuit unit according to claim 12, characterized in that, A windbreak is provided between the reactor body and the heat sink, the windbreak comprising: A first partition is disposed between the heat sink and the reactor body; The second partition covers and shields the front end of the reactor body, and the second partition is provided with ventilation holes.

14. A frequency converter, characterized in that, The frequency converter includes: The driver board, the capacitor board, and the power main circuit unit as described in any one of claims 1 to 13.

15. The frequency converter according to claim 14, characterized in that, The capacitor plate and the power connection plate are electrically connected by conductive studs.

16. The frequency converter according to claim 14, characterized in that, The driver board, the power connection board, and the capacitor board are arranged sequentially along the first direction.

17. The frequency converter according to claim 16, characterized in that, The frequency converter also includes an inter-board connector, which includes: A first inter-board connector, comprising a first male terminal and a first female terminal, wherein one of the first male terminal and the first female terminal is disposed on the power connection board, and the other is disposed on the capacitor board, and the power connection board and the capacitor board are connected for signal transmission via the first inter-board connector; and / or The second board connector includes a second male terminal and a second female terminal. One of the second male terminal and the second female terminal is disposed on the power connection board, and the other is disposed on the driver board. The power connection board and the driver board are connected by the second board connector.

18. The frequency converter according to claim 17, characterized in that, The projections of the power connection board and the capacitor board in the second direction have a first overlapping area, and the first inter-board connector is disposed in the first overlapping area. The projections of the drive board and the power connection board in the second direction have a second overlapping area, and the second inter-board connector is disposed in the second overlapping area; Wherein, the first direction and the second direction are perpendicular to each other.

19. The frequency converter according to claim 14, characterized in that, The frequency converter includes: A chassis, the chassis including an air duct cavity with an opening; A bottom shell, which covers the opening side of the chassis; The middle shell is connected to the bottom shell on the side away from the chassis, and the middle shell and the bottom shell enclose a power cavity for housing the power connection board; A cover is attached to the side of the middle shell away from the bottom shell. The cover and the middle shell enclose a control cavity for housing a control board.

20. The frequency converter according to claim 19, characterized in that, The capacitor plate is provided with a capacitor, and the bottom shell is provided with a capacitor hole at a position corresponding to the capacitor so that the capacitor can extend into the air duct cavity. There is a gap between the bottom end of the capacitor and the bottom end of the air duct cavity. And / or, the chassis is provided with an air inlet and an air outlet, and the capacitor is located near the air inlet relative to the heat sink.

21. The frequency converter according to claim 19, characterized in that, The chassis is configured to be made of a first material; The bottom shell, the middle shell, and the top cover are each configured to be made of a second material; Wherein, the strength of the first material is higher than that of the second material; and / or, the thermal conductivity of the first material is higher than that of the second material.

22. The frequency converter according to claim 14, characterized in that, The power of the frequency converter is not less than 45KW.

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