Power unit cabinet of doubly-fed wind power converter

Abstract

This invention provides a power unit cabinet for a doubly-fed wind power converter. The power unit cabinet includes a grid-side power cabinet and a turbine-side power cabinet arranged side by side. Both the grid-side and turbine-side power cabinets include a module cavity. Each module cavity contains at least a power module, a DC capacitor bank, a first water-air heat exchanger, and a first fan. The power module is located in the center of the module cavity, and a first heat dissipation duct is formed between the power module and the inner wall of the module cavity. The DC capacitor bank is located on one side of the power module, and a first return air duct is formed within the DC capacitor bank. The first water-air heat exchanger and the first fan are sequentially arranged below the DC capacitor bank. The advantages of this invention include: the reasonable arrangement of the DC capacitor bank and power module within the module cavity forms a circulating air duct for heat dissipation, and the effective combination of water cooling and air cooling achieves efficient heat dissipation.

Description

Technical Field

[0001] This utility model relates to the field of new energy wind power generation technology, and in particular to a power unit cabinet of a doubly fed wind power converter. Background Technology

[0002] With the continuous development of wind power generation technology and the increasing capacity of single wind turbine generator sets, the power rating of the matching doubly-fed induction generator (DFIG) wind power converters is also constantly improving, and the output current of their power unit cabinets is continuously increasing. Meanwhile, in terms of heat dissipation, traditional air cooling methods can no longer meet the heat dissipation requirements of high-power power unit cabinets. Water cooling, with its highly efficient heat dissipation capacity, is widely used in high-power wind power converters. Furthermore, compared to air cooling, water cooling does not require direct introduction of outside air into the cabinet for heat dissipation, resulting in a higher protection rating for the converter cabinet. Water-cooled products offer a significant advantage in adaptability, especially in harsh environments such as offshore areas and desert regions.

[0003] The prior art includes a Chinese utility model disclosure with publication number CN218997916 U, which discloses a marine high-protection air-cooled doubly-fed converter cabinet. This doubly-fed wind power converter is an air-cooled product, and its power unit consists of two identical unit cabinets on the right side. The power cabinet mainly includes N power modules (middle 6), a machine-side inductor (bottom 11), a grid-side inductor (bottom 12), a chopper module (middle 7), a chopper resistor (bottom 9), an inductor cooling fan (bottom 8) and a radiator (bottom 13), a top module cooling fan (top cabinet exterior 4), and a module cooling condenser (upper 5) housed inside the main body of the power cabinet. The back of the main body of the power cabinet is provided with two layers of external circulation air ducts: an inner air duct and an outer air duct. The inner air duct is the cooling air duct for the machine-side inductor and the grid-side inductor, and the outer air duct is the cooling air duct for the power modules. The inner and outer air ducts exhaust heat outside the cabinet through a unified first air outlet.

[0004] The aforementioned doubly fed wind power converter uses air cooling. To improve the protection level, the power unit does not use the conventional air cooling method of directly drawing cold air from outside the cabinet into the interior to cool the heat-generating components. Instead, it uses two layers of isolated air ducts and is equipped with condensers and evaporators to achieve heat dissipation. Its heat dissipation method is more complex, with more radiators and fans. The heat dissipation method, the types of heat dissipation components and the layout are different from the direct water cooling method. In addition, the existence of two layers of isolated air ducts leads to an increase in cabinet size. From a layout perspective, its module capacitors are not arranged in a separate capacitor pool for centralized layout and heat dissipation.

[0005] Therefore, it is necessary to study a power unit cabinet for a doubly fed wind power converter to solve the above problems or mitigate their impact. Utility Model Content

[0006] This utility model provides a power unit cabinet for a doubly fed wind power converter. By rationally arranging the DC capacitor bank and power modules in the module cavity to form a heat dissipation circulation channel, and by effectively combining water cooling and air cooling, high-efficiency heat dissipation can be achieved, thereby effectively solving the above problems or mitigating the impact of the above problems.

[0007] The power unit cabinet of the doubly fed wind power converter of this utility model may include a grid-side power cabinet and a machine-side power cabinet arranged side by side, and both the grid-side power cabinet and the machine-side power cabinet include a module cavity, wherein the module cavity is provided with at least a power module, a DC capacitor bank, a first water-wind heat exchanger and a first wind turbine.

[0008] The power module is located in the middle of the module cavity, and a first heat dissipation air duct is formed between the power module and the inner wall of the module cavity; the DC capacitor bank is located on one side of the power module, and a first return air duct is formed inside the DC capacitor bank; the first water-air heat exchanger and the first fan are arranged sequentially below the DC capacitor bank.

[0009] Cooling water circulates within the first water-air heat exchanger, and the first fan drives the gas inside the module cavity to circulate and exchange heat sequentially through the first heat dissipation duct, the first return duct, and the first water-air heat exchanger.

[0010] In one embodiment, a water-cooled radiator is also provided inside the module cavity, and cooling water circulates inside the water-cooled radiator. The corresponding power modules are evenly distributed on opposite sides of the water-cooled radiator to form a double-sided water-cooled module assembly.

[0011] In one embodiment, the module cavity of the grid-side power cabinet is provided with two chopper modules arranged side by side with the power module, and the two chopper modules are respectively arranged on both sides of a water-cooled radiator.

[0012] In one embodiment, the bottom of the module cavity is provided with an inlet and outlet water main pipe for connecting to an external water cooling system, and both the first water-air heat exchanger and the water-cooled radiator are provided with inlet and outlet water pipe interfaces connected to the inlet and outlet water main pipe.

[0013] In one embodiment, the DC capacitor bank includes a plurality of DC capacitors arranged in a matrix in a vertical plane, with gaps between two adjacent DC capacitors in the lateral direction, and the plurality of gaps in the vertical direction forming a vertical first return air duct.

[0014] In one embodiment, each power module has a DC interface at the rear, which is connected to the low-inductance busbar of the DC capacitor bank; the power module has an AC interface at the front facing downwards, which is used to connect to the inductor below the power module.

[0015] In one embodiment, the two DC capacitor banks between the grid-side power cabinet and the machine-side power cabinet are directly short-circuited via a bridging busbar.

[0016] In one embodiment, both the grid-side power cabinet and the machine-side power cabinet include an inductor cavity separated from the module cavity. The inductor cavity is located below the module cavity, and an inductor is provided in the middle of the inductor cavity. The inductor and the inner wall of the inductor cavity form a second heat dissipation channel.

[0017] In one embodiment, both the grid-side power cabinet and the machine-side power cabinet include a second water-air heat exchanger and a second fan. The second water-air heat exchanger is located on top of the inductor, and the second fan is correspondingly arranged above the second water-air heat exchanger. The second fan can drive the gas in the inductor cavity to circulate and exchange heat sequentially through the second heat dissipation duct, the inductor, and the second water-air heat exchanger.

[0018] In one embodiment, the inductor cavity of the machine-side power cabinet includes two machine-side inductors, which are arranged side by side and form a vertical second return air duct.

[0019] The power unit cabinet of the doubly-fed wind power converter provided by this utility model has at least the following advantages compared with the prior art:

[0020] This utility model's doubly-fed wind turbine converter features parallel arrangement of grid-side and turbine-side power unit cabinets. DC capacitor banks and power modules are strategically placed within their module cavities to form a circulating heat dissipation channel. Combined with an effective integration of water and air cooling, this achieves highly efficient heat dissipation for the power unit cabinets. This compact layout, employing zoned heat dissipation, ensures that each area does not interfere with the others, guaranteeing efficient heat dissipation for temperature-sensitive components and ensuring long-term reliable system operation. Furthermore, the use of a water-air heat exchanger in conjunction with a fan effectively combines water and air cooling, achieving internal circulating heat dissipation. This design reduces cabinet size while maintaining a high protection level, making it particularly suitable for harsh environments such as offshore and desert areas. Attached Figure Description

[0021] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings.

[0022] Figure 1 This is a front structural diagram of a power unit cabinet according to an embodiment of the present utility model;

[0023] Figure 2 This is another front view of the power unit cabinet according to an embodiment of the present invention;

[0024] Figure 3This is a side view of the grid-side power cabinet according to an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of a heat exchange cycle within the grid-side power cabinet according to an embodiment of this utility model;

[0026] Figure 5 This is a side view of the power cabinet of this utility model embodiment;

[0027] Figure 6 This is a schematic diagram of a heat exchange cycle within the power cabinet on the machine side according to an embodiment of this utility model;

[0028] Figure 7 This is a schematic diagram of the structure of two three-camera side inductors and output copper busbars according to an embodiment of this utility model;

[0029] Figure 8 yes Figure 7 A frontal structural diagram;

[0030] Figure 9 This is a schematic diagram of the structure of the three single-camera-side inductors and output copper busbars according to an embodiment of the present invention;

[0031] Figure 10 yes Figure 9 A frontal structural diagram.

[0032] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale.

[0033] Figure label:

[0034] 1-Grid-side power cabinet, 2-Machine-side power cabinet

[0035] 3-Module cavity; 31-Power module; 311-Grid-side power module; 312-Machine-side power module; 32-DC capacitor bank; 321-DC capacitor; 33-First water-air heat exchanger; 34-First fan; 35-First heat dissipation duct; 36-First return air duct; 37-Water-cooled radiator; 38-Chopper module; 39-Chopper resistor.

[0036] 4-Inductor cavity, 41-Inductor, 411-Grid-side inductor, 412-Machine-side inductor, 42-Second water-air heat exchanger, 43-Second fan, 44-Second heat dissipation duct, 45-Second return air duct, 46-Machine-side external rotor interface.

[0037] 5-Inlet and outlet main water pipes,

[0038] 6-Bridging busbar. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings.

[0040] like Figures 1 to 6 As shown, the power unit cabinet of the doubly-fed wind power converter of this utility model may include a grid-side power cabinet 1 and a turbine-side power cabinet 2 arranged side by side. Both the grid-side power cabinet 1 and the turbine-side power cabinet 2 include a module cavity 3. The module cavity 3 is equipped with at least a power module 31, a DC capacitor bank 32, a first water-air heat exchanger 33, and a first fan 34. The power module 31 is located in the middle of the module cavity 3, and a first heat dissipation air duct 35 is formed between the power module 31 and the inner wall of the module cavity 3. The DC capacitor bank 32 is located on one side of the power module 31, and a first return air duct 36 is formed within the DC capacitor bank 32. The first water-air heat exchanger 33 and the first fan 34 are arranged sequentially below the DC capacitor bank 32. Cooling water circulates within the first water-air heat exchanger 33, and the first fan 34 can drive the gas in the module cavity 3 to circulate and exchange heat sequentially through the first heat dissipation air duct 35, the first return air duct 36, and the first water-air heat exchanger 33.

[0041] Specifically, the grid-side power cabinet 1 and the machine-side power cabinet 2 are arranged side by side, as shown in the diagram. Figure 2 As shown, the grid-side power cabinet 1 is located on the left and the machine-side power cabinet 2 is located on the right. Alternatively, it can be as follows: Figure 1 The grid-side power cabinet 1 is located on the right, and the machine-side power cabinet 2 is located on the left. The grid-side power cabinet 1 and the machine-side power cabinet 2 have the same structural layout, meaning their module cavities 3 also have the same structural layout, simplifying the power unit cabinet structure. The power module 31 is located in the middle of the module cavity 3, and a first heat dissipation duct 35 is formed between the power module 31 and the inner wall of the module cavity 3, allowing for air cooling. The DC capacitor bank 32 is located behind the power module 31, and a first return air duct 36 is formed within the DC capacitor bank 32, allowing for air cooling. A first water-air heat exchanger 33 and a first fan 34 are positioned below the DC capacitor bank 32. When the first fan 34 is activated, it drives the gas inside the module cavity 3 to sequentially absorb heat from the power module 31 through the first heat dissipation duct 35 and the DC capacitor bank 32 through the first return air duct 36. The gas then passes through the first water-air heat exchanger 33 and its cooling water for cooling, thus achieving efficient cooling of the power module 31 and the DC capacitor bank 32.

[0042] Overall, the power unit cabinets of the doubly-fed wind turbine converter are arranged side-by-side with grid-side power cabinet 1 and turbine-side power cabinet 2. DC capacitor banks 32 and power modules 31 are strategically placed within their module cavities 3 to form a circulating heat dissipation channel. Combined with effective water cooling and air cooling, this achieves highly efficient heat dissipation for the power unit cabinets. This compact layout, employing zoned heat dissipation, ensures that each area does not interfere with the others, guaranteeing efficient heat dissipation for temperature-sensitive components and ensuring long-term reliable system operation. Furthermore, the use of a water-air heat exchanger in conjunction with a fan effectively combines water cooling and air cooling, achieving internal circulating heat dissipation. This reduces cabinet size while achieving a high protection level, making it particularly suitable for harsh environments such as offshore and desert areas.

[0043] In one example, such as Figure 1 and Figure 2 As shown, a water-cooled radiator 37 is also provided in the module cavity 3. Cooling water circulates in the water-cooled radiator 37. Corresponding power modules 31 are evenly distributed on both sides of the water-cooled radiator 37 to form a double-sided water-cooled module assembly.

[0044] Specifically, one side of the power module 31 is in close contact with the water-cooled radiator 37, allowing the power module 31 to directly exchange heat with the cooling water inside the water-cooled radiator 37, thereby improving the cooling effect of the power module 31. Furthermore, by having two power modules 31 correspondingly positioned on both sides of the water-cooled radiator 37 to form a double-sided water-cooled module assembly, this reasonable layout allows two power modules 31 to share a single water-cooled radiator 37, thus minimizing the width of the module cavity 3.

[0045] It should be noted that, due to the inherent characteristic of doubly-fed induction generator (DFIG) wind turbine converters that the grid-side current is less than the turbine-side current, to simplify the module structure, the power modules 31 of the turbine-side power cabinet 2 and the grid-side power cabinet 1 adopt the same configuration. The turbine-side power cabinet 2 can increase its current output capacity by connecting two power modules 31 in parallel. To meet the current output capacity required by the power unit cabinets of the DFIG wind turbine converter, the grid-side power cabinet 1 may include three grid-side power modules 311 arranged side by side, and the turbine-side power cabinet 2 may include six turbine-side power modules 312 arranged side by side.

[0046] In one example, such as Figure 1 and Figure 2 As shown, the module cavity 3 of the grid-side power cabinet 1 is provided with two chopper modules 38 arranged side by side with the power module 31, and the two chopper modules 38 are respectively arranged on both sides of a water-cooled radiator 37.

[0047] Specifically, since the number of power modules 31 in the grid-side power cabinet 1 is less than the number of power modules 31 in the machine-side power cabinet 2, two chopper modules 38 are placed in the module cavity 3 of the grid-side power cabinet 1 and cooperate with the water-cooled radiator 37 to form a double-sided water-cooled module assembly. This makes the layout of the chopper modules 38 consistent with the layout of the power modules 31, which can improve the overall structure of the power unit cabinet and the compactness of the structure inside the module cavity 3.

[0048] More specifically, since the six power modules 312 of the machine-side power cabinet 2 and the three water-cooled radiators 37 form three double-sided water-cooled module assemblies, and the three grid-side power modules 311 of the grid-side power cabinet 1, together with the water-cooled radiators 37, can form a complete double-sided water-cooled module assembly and a single-sided water-cooled module assembly, the chopper module 38 is designed on the side of the single-sided water-cooled module assembly where the grid-side power modules 311 are not arranged, that is, the space on this side of the single-sided water-cooled module assembly is left empty to facilitate the installation and maintenance of the chopper module 38.

[0049] It should be noted that the external interface of the chopper module 38 is similar to that of the power module 31. Its back can be directly connected to the DC capacitor bank 32. Since it is not usually working, but only works for a short time under special conditions, the water-cooled radiator 37 that the two chopper modules 38 are close to do not need to be connected to the water circuit.

[0050] Furthermore, each of the two module cavities 3 of the power unit cabinet is equipped with a chopper resistor 39 corresponding to the chopper module 38. The chopper resistor 39 is installed on the top of the module cavity 3 and can be cooled through the first heat dissipation duct 35.

[0051] In one example, such as Figures 1 to 6 As shown, the bottom of the module cavity 3 is provided with an inlet and outlet water main pipe 5 for connecting to the external water cooling system. The first water-air heat exchanger 33 and the water-cooled radiator 37 are both provided with inlet and outlet water pipe interfaces connected to the inlet and outlet water main pipe 5 (not shown in the attached figure).

[0052] Specifically, the power unit cabinet is connected to the inlet and outlet water interfaces of the first water-air heat exchanger 33 and the water-cooled radiator 37 via the main inlet and outlet water pipes 5. This allows the water cooling system to supply circulating cooling water to the first water-air heat exchanger 33 and the water-cooled radiator 37. The circulating cooling water can remove heat from the power unit cabinet, thus achieving heat dissipation. The water cooling system can be installed close to the power unit cabinet to reduce the layout of the doubly-fed wind power converter, accelerate the circulation of cooling water, and improve the heat dissipation effect.

[0053] In one example, such as Figures 1 to 6As shown, the DC capacitor bank 32 includes multiple DC capacitors 321 arranged in a matrix in a vertical plane. There is a gap between two adjacent DC capacitors 321 in the horizontal direction, and the multiple gaps in the vertical direction form a vertical first return air duct 36.

[0054] Specifically, multiple DC capacitors 321 are connected and centrally arranged through a low-inductance busbar to form a DC capacitor pool 32. The multiple DC capacitors 321 are arranged in a matrix with horizontal and vertical spacing in a vertical plane, so that the DC capacitor pool 32 forms multiple vertical first return air ducts 36 to facilitate heat dissipation. The first return air ducts 36, in conjunction with the drive of the first fan 34, can gather the heated gas and cool it down through the first water-air heat exchanger 33.

[0055] In one example, each power module 31 has a DC interface (not shown in the figure) at the rear, which is connected to the low-inductance busbar of the DC capacitor bank 32; the power module 31 has an AC interface (not shown in the figure) at the front downward, which is used to connect to the inductor 41 below the power module 31.

[0056] Specifically, the power module 31 shortens the connection paths between components through the design of DC and AC interfaces, minimizing the connection paths of copper busbars or cables between each power module 31 and the inductor 41 or DC capacitor bank 32. The copper busbars or cables only need to be connected within their respective power cabinets, eliminating the need for cross-cabinet connections. This results in a more compact component layout within the power unit cabinet, effectively reducing manufacturing costs and achieving optimal overall cost, while also effectively lowering the turn-off voltage of the power module 31.

[0057] In one example, such as Figure 1 and Figure 2 As shown, the two DC capacitor banks 32 between the grid-side power cabinet 1 and the machine-side power cabinet 2 are directly short-circuited by a bridging busbar 6. The bridging busbar 6 is a low-inductance copper busbar, which ensures the simplification of the power unit cabinet structure and low-inductance connection.

[0058] In one example, such as Figures 1 to 6 As shown, both the grid-side power cabinet 1 and the machine-side power cabinet 2 include an inductor cavity 4 separated from the module cavity 3. The inductor cavity 4 is located below the module cavity 3. An inductor 41 is provided in the middle of the inductor cavity 4. The inductor 41 and the inner wall of the inductor cavity 4 form a second heat dissipation air duct 44.

[0059] Specifically, module cavity 3 and inductor cavity 4 are arranged vertically, separating inductor 41 from power module 31. Power module 31 is connected to inductor 41 through a downward-facing AC interface. This achieves efficient zoned heat dissipation, ensuring that each area does not affect the others, thus guaranteeing efficient heat dissipation for temperature-sensitive devices and ensuring long-term reliable system operation. It also minimizes the connection path of copper busbars or cables between power module 31 and inductor 41, requiring only internal connections within their respective power cabinets without cross-cabinet connections, resulting in optimal overall cost.

[0060] It should be noted that the two adjacent inductor cavities 4 on the left and right sides of the power unit cabinet can be connected or not, and similarly, the two adjacent module cavities 3 on the left and right sides can be connected or not, which has little impact on the overall heat dissipation effect of the power unit cabinet.

[0061] In one example, such as Figures 1 to 6 As shown, both the grid-side power cabinet 1 and the machine-side power cabinet 2 include a second water-air heat exchanger 42 and a second fan 43. The second water-air heat exchanger 42 is located on top of the inductor 41, and the second fan 43 is correspondingly arranged above the second water-air heat exchanger 42. The second fan 43 can drive the gas in the inductor cavity 4 to circulate and exchange heat sequentially through the second heat dissipation duct 44, the inductor 41, and the second water-air heat exchanger 42.

[0062] Specifically, inductor 41 is disposed in the middle of inductor cavity 4, and a second heat dissipation duct 44 is formed between the inductor 41 and the inner wall of inductor cavity 4 for heat dissipation via air cooling. A second water-air heat exchanger 42 and a second fan 43 are disposed above in conjunction with the inductor 41, so that when the second fan 43 is activated, it drives the gas in inductor cavity 4 to first absorb heat from inductor 41 through the second heat dissipation duct 44, and then exchange heat with the cooling water in the second water-air heat exchanger 42 to cool down, thereby performing a circulating heat exchange to achieve efficient cooling of inductor 41.

[0063] It should be noted that, based on simplification requirements, heat dissipation power, and space dimensions, the first water-air heat exchanger 33 and the second water-air heat exchanger 42 can be of the same model, and the first fan 34 or the second fan 43 can be of the same specification. The number of fans can also be one or more depending on the requirements. Specifically, both the first and second water-air heat exchangers 42 have coils for circulating cooling water, and the outer side of the coils has channels for air flow. The air flowing in the channels exchanges heat with the cooling water flowing inside the coils through the coil walls. The second water-air heat exchanger 42 is also equipped with inlet and outlet water pipe interfaces connected to the main inlet and outlet water pipes 5.

[0064] In one example, such as Figure 2 , Figures 6 to 10As shown, the inductor cavity 4 of the power cabinet 2 includes two inductors 412, which are arranged side by side and form a vertical second return air duct 45.

[0065] Specifically, two machine-side inductors 412 are arranged side-by-side, forming a vertical second return air duct 45 between them. When the second fan 43 is activated, it drives the gas inside the inductor cavity 4 to sequentially pass through the second heat dissipation air duct 44 and the second return air duct 45 to absorb heat from the inductor 41. The gas then passes through the second water-air heat exchanger 42 to exchange heat with the cooling water inside, thus achieving efficient cooling of the inductor 41. The machine-side power cabinet 2 also has a machine-side external rotor interface 46 inside its inductor cavity 4, which serves as the output copper busbar for the inductor 41. The machine-side inductor 412 can be a three-phase machine-side inductor 412.

[0066] It needs to be explained, such as Figure 7 and Figure 8 As shown, three grid-side power modules 311 are connected to one three-phase grid-side inductor 411, and six generator-side power modules 312 are connected to two three-phase phase-side inductors 412. The two three-phase phase-side inductors 412 are combined into one for overall heat dissipation, meaning they are fixed side-by-side together, forming a unified second heat dissipation airflow 44 around their exterior. Vertical second return airflow ducts 45 are formed at intervals between them. Only one second water-air heat exchanger 42 and a second fan 43 are configured at the top. Since there is only one second water-air heat exchanger 42, only one water path needs to be drawn from the main inlet and outlet water pipes 5. This reduces the number of heat dissipation components, achieving a compact structure and optimal cost, while also improving system reliability.

[0067] Furthermore, within the limited layout space, the middle phase copper busbars of the two three-phase side inductors 412 are short-circuited at the bottom of the inductor output busbar (the left and right parts are the same), and the two side phase copper busbars are arranged in a staggered manner at the top to ensure sufficient insulation distance between them. The copper busbar components are simple and have fewer types, and the path is clear and concise, which can achieve a small amount of copper busbars, ensure sufficient insulation distance between each copper busbar, and at the same time optimize the user's wiring convenience.

[0068] In one example, such as Figure 9 and Figure 10 As shown, the inductor cavity 4 of the power cabinet 2 on the machine side can include three single-phase side inductors 412. The three single-phase side inductors 412 adopt a three-in-one overall heat dissipation and cooling method, that is, the three single-phase side inductors 412 are fixed together in parallel, forming a unified second heat dissipation air duct 44 around the outside. Adjacent single-phase side inductors 412 are spaced to form a vertical second return air duct 45. Only a second water-air heat exchanger 42 and a second fan 43 are arranged at the top. This inductor 41 connection method simplifies the copper busbar design at the external rotor interface, and adjacent copper busbars can be short-circuited for output.

[0069] In summary, the beneficial effects of this utility model compared with the prior art include at least the following:

[0070] The power unit cabinet of the doubly fed wind power converter of this utility model adopts a water-cooled radiator in combination with a water-air heat exchanger to achieve efficient internal heat dissipation and improve the protection level, making it especially suitable for harsh environments such as offshore and desert areas.

[0071] The power unit cabinet of this invention is divided into an upper module cavity and a lower inductor cavity. A water-air heat exchanger is installed on top of the inductor in the inductor cavity, and the inductor is surrounded to form a heat dissipation airflow, ensuring efficient heat dissipation of the inductor and surrounding cables and copper busbars, while preventing the heat from the inductor from affecting the heat dissipation of the upper module cavity. In the module cavity, the DC capacitors are centrally arranged to form a DC capacitor pool and a return airflow channel. The water-air heat exchanger is located below the DC capacitor pool to ensure that all heat dissipation airflow passes around the capacitors in the DC capacitor pool, effectively guaranteeing the heat dissipation of the DC capacitors. This achieves efficient zoned heat dissipation, with each area independent of the others, and ensures efficient heat dissipation of temperature-sensitive components such as DC capacitors, guaranteeing long-term reliable system operation.

[0072] This utility model features a compact power unit cabinet layout. All module DC interfaces are directly connected to the rear DC capacitor bank via low-inductance busbars, effectively reducing power module turn-off overvoltage. The copper busbar or cable connection paths between each module and inductor are minimized, requiring only internal connections within their respective power cabinets without cross-cabinet connections, resulting in optimal overall cost. No additional external heat dissipation devices are required, contributing to the small overall cabinet size. Furthermore, the DC capacitor banks of adjacent power cabinets are directly shorted via low-inductance busbars, ensuring minimal structural simplification and low-inductance connections.

[0073] The power unit cabinet of this utility model uses a multi-integrated heat dissipation method by combining two machine-side inductors into a single unit, which can reduce the number of heat dissipation devices, achieve the dual optimal effect of compact structure and cost, and improve the reliability of the system.

[0074] Although the present invention has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A power unit cabinet for a doubly-fed wind power converter, characterized in that, The power unit cabinet includes a grid-side power cabinet and a machine-side power cabinet arranged side by side, and both the grid-side power cabinet and the machine-side power cabinet include a module cavity. The module cavity is equipped with at least a power module, a DC capacitor bank, a first water-air heat exchanger, and a first fan. The power module is located in the middle of the module cavity, and a first heat dissipation air duct is formed between the power module and the inner wall of the module cavity; the DC capacitor bank is located on one side of the power module, and a first return air duct is formed inside the DC capacitor bank; the first water-air heat exchanger and the first fan are arranged sequentially below the DC capacitor bank. Cooling water circulates within the first water-air heat exchanger, and the first fan drives the gas inside the module cavity to circulate and exchange heat sequentially through the first heat dissipation duct, the first return duct, and the first water-air heat exchanger.

2. The power unit cabinet of the doubly-fed wind power converter according to claim 1, characterized in that, The module cavity is also equipped with a water-cooled radiator, in which cooling water circulates. The corresponding power modules are evenly distributed on both sides of the water-cooled radiator to form a double-sided water-cooled module assembly.

3. The power unit cabinet of the doubly-fed wind power converter according to claim 2, characterized in that, The power cabinet on the grid side has two chopper modules arranged side by side with the power module in the module cavity, and the two chopper modules are respectively arranged on both sides of the water-cooled heat sink.

4. The power unit cabinet of the doubly-fed wind power converter according to claim 2, characterized in that, The bottom of the module cavity is provided with an inlet and outlet water main pipe for connecting to the external water cooling system. The first water-air heat exchanger and the water-cooled radiator are both provided with inlet and outlet water pipe interfaces that are connected to the inlet and outlet water main pipes.

5. The power unit cabinet of the doubly-fed wind power converter according to claim 1, characterized in that, The DC capacitor bank includes multiple DC capacitors arranged in a matrix in a vertical plane, with gaps between two adjacent DC capacitors in the horizontal direction, and the multiple gaps in the vertical direction forming the first vertical return air duct.

6. The power unit cabinet of the doubly-fed wind power converter according to claim 1, characterized in that, Each power module has a DC interface at the rear, which is connected to the low-inductance busbar of the DC capacitor bank; the front of each power module has an AC interface facing downwards, which is used to connect to the inductor below the power module.

7. The power unit cabinet of the doubly-fed wind power converter according to claim 1, characterized in that, The two DC capacitor banks between the grid-side power cabinet and the machine-side power cabinet are directly short-circuited by a bridging busbar.

8. The power unit cabinet of the doubly-fed wind power converter according to any one of claims 1 to 7, characterized in that, Both the grid-side power cabinet and the machine-side power cabinet include an inductor cavity separated from the module cavity. The inductor cavity is located below the module cavity, and an inductor is provided in the middle of the inductor cavity. The inductor and the inner wall of the inductor cavity form a second heat dissipation air duct.

9. The power unit cabinet of the doubly-fed wind power converter according to claim 8, characterized in that, Both the grid-side power cabinet and the machine-side power cabinet include a second water-air heat exchanger and a second fan. The second water-air heat exchanger is located on top of the inductor, and the second fan is correspondingly arranged above the second water-air heat exchanger. The second fan can drive the gas in the inductor cavity to circulate and exchange heat sequentially through the second heat dissipation duct, the inductor, and the second water-air heat exchanger.

10. The power unit cabinet of the doubly-fed wind power converter according to claim 9, characterized in that, The inductor cavity of the power cabinet includes two machine-side inductors, which are arranged side by side and form a vertical second return air duct.

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