A modular centralized photovoltaic inverter

Abstract

This utility model discloses a modular centralized photovoltaic inverter, comprising a fixed cavity, a maintenance cavity, and a dynamic expansion cavity arranged sequentially from bottom to top and interconnected. The fixed cavity houses copper busbars and switching devices on the DC input and AC output sides. The maintenance cavity contains terminal blocks and connecting copper busbars. The dynamic expansion cavity houses power modules and capacitors. The fixed cavity and maintenance cavity are fixedly connected. The top of the dynamic expansion cavity is equipped with a hoisting assembly to allow the dynamic expansion cavity to be hoisted onto the top of the maintenance cavity. A heat exchange module is located on the side of the dynamic expansion cavity to achieve internal heat dissipation for the photovoltaic inverter. This utility model, through its modular assembly structure, allows for faster response to customer-specific needs, lower expansion costs, and lower maintenance costs.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic inverter technology, specifically to a modular centralized photovoltaic inverter. Background Technology

[0002] As the core equipment of a photovoltaic power generation system, the photovoltaic inverter undertakes the core function of converting the direct current generated by photovoltaic modules into alternating current that meets the requirements of the power grid. Its performance, reliability and cost directly affect the power generation, revenue and life cycle value of the photovoltaic power station.

[0003] Currently, the modularity of mainstream centralized photovoltaic inverters on the market remains very limited. Existing inverters typically have a fixed power rating of 1.1MW, and some "modular" centralized inverter products mainly involve simple rack-level parallel connections. To meet the needs of different power plant sizes or customers' future expansion requirements, it is often necessary to replace the entire inverter unit or use more inverters in parallel, leading to increased costs, installation complexity, and space utilization issues. Furthermore, the high coupling of key components results in high replacement costs; when a component experiences a serious failure, it often requires shutdown to replace the entire unit, leading to long maintenance times and reduced power plant revenue. In addition, with increasing power density, the heat dissipation of centralized photovoltaic inverters also presents challenges in design complexity and reduced efficiency during modular expansion. For large-scale ground-mounted power plants, reducing the levelized cost of electricity (LCOE) over the entire lifecycle is a core requirement, rapid fault recovery and ease of maintenance are important competitive advantages, and power density scalability is a continuously pursued direction. Therefore, there is an urgent need for a modular centralized photovoltaic inverter that can respond more quickly to customers' personalized needs, with lower expansion costs and lower maintenance costs. Utility Model Content

[0004] The technical problem to be solved by this utility model is that the existing centralized photovoltaic inverters have very limited modularity, high coupling of key components leading to high replacement costs, and complex design and reduced efficiency of the heat dissipation system when it is expanded in a modular way. The present invention provides a modular centralized photovoltaic inverter with a compact structure, convenient disassembly and assembly, and low operation and maintenance costs.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A modular centralized photovoltaic inverter includes a fixed cavity, a maintenance cavity, and a dynamic expansion cavity arranged sequentially from bottom to top and interconnected. The fixed cavity contains copper busbars and switching devices on the DC input and AC output sides. The maintenance cavity contains terminal blocks, reactor input copper busbars, and connecting copper busbars. The dynamic expansion cavity contains power modules and capacitors. The fixed cavity and the maintenance cavity are connected and fixed. The top of the dynamic expansion cavity is equipped with a hoisting assembly to hoist the dynamic expansion cavity onto the top of the maintenance cavity. A heat exchange module is provided on the side of the dynamic expansion cavity to achieve internal heat dissipation of the photovoltaic inverter.

[0006] As a further improvement of this utility model, the top of the maintenance cavity is provided with a front cavity door and a rear cavity door; a wire passage hole is provided below the front cavity door, and the reactor input copper busbar and the connecting copper busbar are both located below the rear cavity door; when the dynamic expansion cavity is hoisted to the top of the maintenance cavity, the front cavity door and the rear cavity door are removed, and the power module output side is connected to the reactor input copper busbar through the connecting copper busbar. The cables of the secondary devices in the dynamic expansion cavity are connected to the terminal block in the maintenance cavity through the wire passage hole.

[0007] As a further improvement of this utility model, a first fan is provided on the top of the inner side of the dynamic expansion cavity, and a second fan is provided on the top of the maintenance cavity; the heat exchange module, the first fan, and the second fan work together to achieve heat dissipation inside the photovoltaic inverter.

[0008] As a further improvement of this utility model, a first fan is provided on the top of the inner side of the dynamic expansion cavity, and heat exchange modules are symmetrically provided on both sides of the dynamic expansion cavity. The heat exchange modules and the first fan work together to achieve heat dissipation inside the photovoltaic inverter.

[0009] As a further improvement of this utility model, a first fan is provided on the top of the inner side of the dynamic expansion cavity, a second fan is provided on the top of the maintenance cavity, and heat exchange modules are symmetrically provided on both sides of the dynamic expansion cavity. The heat exchange modules, the first fan, and the second fan work together to achieve heat dissipation inside the photovoltaic inverter.

[0010] As a further improvement of this utility model, the top of the inner side of the dynamic expansion cavity is provided with a main air duct in the horizontal direction, and the first fan is located in the main air duct.

[0011] As a further improvement of this utility model, the first fan is a centrifugal fan.

[0012] As a further improvement of this utility model, the dynamic expansion cavity is provided with a first auxiliary air duct, and the second fan is located inside the first auxiliary air duct.

[0013] As a further improvement of this utility model, the heat exchange module is provided with a third fan, a fourth fan and an external circulation duct, wherein the third fan and the fourth fan are located at both ends of the external circulation duct.

[0014] As a further improvement of this utility model, the heat exchange core of the heat exchange module adopts an air heat exchanger.

[0015] Compared with the prior art, the advantages of this utility model are: 1. The modular centralized photovoltaic inverter of this utility model divides the modular centralized inverter into a bottom fixed cavity, a middle maintenance cavity, and a top dynamic expansion cavity. The inverter is assembled in the factory like building blocks to achieve modular and platform-based assembly, which can flexibly meet the actual needs of customers or the expansion needs of power plants. Moreover, the heat dissipation system on the side of the dynamic expansion cavity can also be quickly and efficiently modularized, resulting in lower expansion and maintenance costs.

[0016] 2. The modular centralized photovoltaic inverter of this utility model decouples and classifies the key internal components of the modular centralized inverter. The components that do not require maintenance or have a low failure rate are placed in the fixed cavity at the bottom, while the components that require frequent maintenance or have a high failure rate are placed in the maintenance cavity in the middle or the dynamic expansion cavity at the top. In the event of a failure, the operation and maintenance personnel can choose to quickly replace the spare parts or quickly replace the dynamic expansion cavity at the top according to the severity of the failure, thereby improving the operation and maintenance efficiency and reducing the power generation loss of the photovoltaic power station.

[0017] 3. The modular centralized photovoltaic inverter of this utility model can quickly expand the number of heat dissipation systems by unifying the installation interfaces of the internal axial flow fan and the internal fan of the heat exchange module, thereby improving the overall heat dissipation capacity of the modular centralized inverter. The single unit power can be increased from 1.1MW to 1.2MW without replacing the whole unit, effectively reducing the expansion cost of photovoltaic power plants. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural principle diagram of the modular centralized photovoltaic inverter in a specific embodiment of this utility model; Figure 2 Figure (a) is a schematic diagram of the partial structure of the modular centralized photovoltaic inverter in a specific embodiment of this utility model, and Figure (b) is a schematic diagram of the structure of the top dynamic expansion cavity and the bottom fixed cavity. Figure 3 This is a schematic diagram of the copper busbar connection within the maintenance cavity in a specific embodiment of this utility model; Figure 4 This is a schematic diagram of the heat dissipation airflow of the modular centralized photovoltaic inverter in a specific embodiment of this utility model. Figure 1 ; Figure 5 This is a schematic diagram illustrating the structural principle of the newly added heat exchange module in the dynamic expansion cavity of the inverter in a specific embodiment of this utility model; Figure 6 This is a schematic diagram of the heat dissipation airflow of the modular centralized photovoltaic inverter in a specific embodiment of this utility model. Figure 2 ; Figure 7 This is a schematic diagram of the heat dissipation airflow of the modular centralized photovoltaic inverter in a specific embodiment of this utility model. Figure 3 ; Legend: 1. Fixed cavity; 2. Maintenance cavity; 21. Front cavity door; 22. Rear cavity door; 3. Heat exchange module; 4. Dynamic expansion cavity; 5. Lifting lug; 6. Reactor input copper busbar; 7. Connecting copper busbar; 8. First fan; 9. Cable hole; 10. Second fan; 11. Third fan; 12. Fourth fan; 13. Main air duct; 14. First auxiliary air duct; 15. External circulation air duct; 16. Second auxiliary air duct. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0020] In the description of this utility model, it should be understood that the terms "side", "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model 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 utility model.

[0021] Furthermore, the terms "first" and "second" are used 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 as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified.

[0022] Example 1 like Figure 1 , Figure 2 and Figure 3As shown, the modular centralized photovoltaic inverter of this utility model includes a fixed cavity 1, a maintenance cavity 2, and a dynamic expansion cavity 4, arranged sequentially from bottom to top and internally interconnected. The fixed cavity 1 houses copper busbars and switching devices on the DC input and AC output sides. The maintenance cavity 2 houses terminal blocks, reactor input copper busbars 6, and connecting copper busbars 7. The dynamic expansion cavity 4 houses power modules and capacitors. The fixed cavity 1 and maintenance cavity 2 are connected and fixedly mounted. Figure 5 As shown, the dynamic expansion cavity 4 is equipped with lifting lugs 5 at its top to allow it to be hoisted onto the top of the maintenance cavity 2. A heat exchange module 3 is located on the side of the dynamic expansion cavity 4 to dissipate heat inside the photovoltaic inverter. In this embodiment, the heat exchange core of the heat exchange module 3 is an air heat exchanger.

[0023] In this embodiment, during inverter assembly at the factory, the base frame, the bottom fixed cavity 1, and the middle maintenance cavity 2 are assembled first. Simultaneously, the components within the dynamic expansion cavity 4 are assembled, and the heat exchange module 3 is mounted on the cabinet door of the dynamic expansion cavity 4. Finally, the dynamic expansion cavity 4 is hoisted onto the maintenance cavity 2 using stainless steel lifting lugs 5, thus completing the overall inverter assembly. By dividing the modular centralized inverter into a bottom fixed cavity, a middle maintenance cavity, and a top dynamic expansion cavity, the inverter can be assembled at the factory in a modular and platform-based manner, much like building with blocks. This allows for flexible fulfillment of actual customer needs or power plant expansion requirements. Furthermore, the cooling system on the side of the dynamic expansion cavity can be quickly and efficiently modularized, resulting in lower expansion and maintenance costs.

[0024] like Figure 2 and Figure 3 As shown, the maintenance chamber 2 has a front door 21 and a rear door 22 at its top; a cable passage hole 9 is located below the front door 21, and the reactor input copper busbar 6 and the connecting copper busbar 7 are both located below the rear door 22. After the dynamic expansion chamber 4 is hoisted to the top of the maintenance chamber 2, the front door 21 and the rear door 22 are removed. The power module output side is connected to the reactor input copper busbar 6 through the connecting copper busbar 7, and the AC power generated by the power module can be transmitted to the reactor side. The cables of the secondary devices in the dynamic expansion chamber 4 are connected to the terminal blocks in the maintenance chamber 2 through the cable passage hole 9, completing all electrical connections inside the inverter.

[0025] like Figure 4As shown, a main air duct 13 is horizontally arranged on the top inner side of the dynamic expansion cavity 4, and the first fan 8 is located inside the main air duct 13; a second fan 10 is arranged on the top of the maintenance cavity 2, and a first auxiliary air duct 14 is arranged inside the dynamic expansion cavity 4, with the second fan 10 located inside the first auxiliary air duct 14; a third fan 11, a fourth fan 12, and an external circulation air duct 15 are arranged inside the heat exchange module 3, with the third fan 11 and the fourth fan 12 located at opposite ends of the external circulation air duct 15. Through the coordinated action of the heat exchange module 3, the first fan 8, and the second fan 10, heat dissipation inside the photovoltaic inverter is achieved. Furthermore, the first fan 8 is a centrifugal fan, while the second fan 10, the third fan 11, and the fourth fan 12 are all axial flow fans, resulting in a relatively simple structure, small size, easy installation and arrangement, and the ability to provide a large air volume, increasing the airflow speed.

[0026] The main air duct 13 adopts a direct-ventilation forced-air cooling method with an IP55 protection rating. Cool air from the outside environment enters the cabinet through the air inlet at the top, and is driven by a centrifugal fan to cool the power module heatsinks and reactors, among other high-power components, from top to bottom. Finally, hot air exits from the bottom of the inverter. The first auxiliary air duct 14 has an IP65 protection rating and primarily cools the copper busbars, frame circuit breakers, power supplies, and other components within the inverter cabinet. A heat exchange module 3 is installed on the front door of the dynamic expansion cavity 4. Driven by an axial fan, cool air flows out from the upper opening inside the heat exchanger, circulates within the inverter cabinet to remove heat generated by the components, and then returns to the heat exchanger through the lower inlet inside the heat exchanger cabinet, where it exchanges heat with the external circulation air duct 15 at the core of the heat exchanger.

[0027] In this embodiment, by decoupling and classifying the key internal components of the modular centralized inverter, devices that require no maintenance or have a low failure rate are placed in the fixed cavity at the bottom, while devices that require frequent maintenance or have a high failure rate are placed in the maintenance cavity in the middle or the dynamic expansion cavity at the top. In the event of a failure, maintenance personnel can choose to quickly replace spare parts or quickly replace the dynamic expansion cavity at the top, depending on the severity of the failure, thereby improving maintenance efficiency and reducing power generation losses in the photovoltaic power plant.

[0028] Example 2 like Figure 6 As shown, the modular centralized photovoltaic inverter in this embodiment has a similar structural setup and working principle to the inverter in embodiment 1. The main difference is that: a first fan 8 is provided on the top of the inner side of the dynamic expansion cavity 4, and heat exchange modules 3 are symmetrically provided on both sides of the dynamic expansion cavity 4. The heat exchange modules 3 and the first fan 8 work together to achieve heat dissipation inside the photovoltaic inverter.

[0029] If the inverter's single-unit power is expanded from 1.1MW to 1.2MW according to customer needs, the heat dissipation duct inside the inverter cabinet in Example 1 will no longer meet the heat dissipation requirements. In this case, the rear cabinet door of the dynamic expansion cavity 4 can be replaced with a cabinet door equipped with the heat exchange module 3, as follows. Figure 6 As shown, the number of heat exchangers in the dynamic expansion cavity 4 increases from one to two. This adds two cooling air ducts to the inverter while saving one axial fan, meeting the requirements for a single unit power of 1.2MW. Specifically, in Embodiment 1, after the cold air from the first auxiliary air duct 14 cools the capacitors and power supply components in the dynamic expansion cavity 4, it enters the interior of the newly added heat exchange module 3 through the second auxiliary air duct 16. After heat exchange through the heat exchanger core, the cold air is blown out from the bottom opening and continues to participate in the cabinet circulation, thereby meeting the overall heat dissipation requirements of the unit.

[0030] In this embodiment, by unifying the installation interfaces of the axial flow fan inside the inverter and the fan inside the heat exchange module 3, the number of heat dissipation systems can be rapidly expanded, improving the overall heat dissipation capacity of the modular centralized inverter. The single unit power can be increased from 1.1MW to 1.2MW without replacing the entire unit, effectively reducing the expansion cost of photovoltaic power plants.

[0031] Example 3 like Figure 7 As shown, the modular centralized photovoltaic inverter in this embodiment has a similar structural setup and working principle to the inverter in embodiment 2. The main difference is that: a first fan 8 is provided on the top of the inner side of the dynamic expansion cavity 4, a second fan 10 is provided on the top of the maintenance cavity 2, and heat exchange modules 3 are symmetrically provided on both sides of the dynamic expansion cavity 4. Through the coordinated action of the heat exchange modules 3, the first fan 8 and the second fan 10, heat dissipation inside the photovoltaic inverter can be achieved.

[0032] If the inverter's single-unit power is expanded to a level greater than 1.2MW, an additional heat exchange module will be added to the side of the dynamic expansion cavity 4, and an axial flow fan will be installed at the top of the maintenance cavity 2. The axial flow fan at the top of the maintenance cavity 2 will enhance airflow within the cabinet and improve the heat exchange effect.

[0033] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A modular centralized photovoltaic inverter, characterized in that, The system includes a fixed cavity (1), a maintenance cavity (2), and a dynamic expansion cavity (4) arranged sequentially from bottom to top and interconnected with each other. The fixed cavity (1) is provided with copper busbars and switching devices on the DC input side and AC output side. The maintenance cavity (2) is provided with terminal blocks, reactor input copper busbars (6), and connecting copper busbars (7). The dynamic expansion cavity (4) is provided with power modules and capacitors. The fixed cavity (1) is connected and fixed to the maintenance cavity (2). The top of the dynamic expansion cavity (4) is provided with a hoisting assembly to hoist the dynamic expansion cavity (4) to the top of the maintenance cavity (2). The side of the dynamic expansion cavity (4) is provided with a heat exchange module (3) to achieve heat dissipation inside the photovoltaic inverter.

2. The modular centralized photovoltaic inverter according to claim 1, characterized in that, The maintenance cavity (2) is provided with a front cavity door (21) and a rear cavity door (22) at the top; a wire hole (9) is provided below the front cavity door (21), and the reactor input copper busbar (6) and the connecting copper busbar (7) are both located below the rear cavity door (22); after the dynamic expansion cavity (4) is hoisted to the top of the maintenance cavity (2), the front cavity door (21) and the rear cavity door (22) are removed, and the power module output side is connected to the reactor input copper busbar (6) through the connecting copper busbar (7), and the cables of the secondary devices in the dynamic expansion cavity (4) are connected to the terminal block in the maintenance cavity (2) through the wire hole (9).

3. The modular centralized photovoltaic inverter according to claim 2, characterized in that, The top of the inner side of the dynamic expansion cavity (4) is provided with a first fan (8), and the top of the maintenance cavity (2) is provided with a second fan (10); the heat exchange module (3), the first fan (8) and the second fan (10) work together to achieve heat dissipation inside the photovoltaic inverter.

4. The modular centralized photovoltaic inverter according to claim 2, characterized in that, The top of the inner side of the dynamic expansion cavity (4) is provided with a first fan (8), and heat exchange modules (3) are symmetrically provided on both sides of the dynamic expansion cavity (4). The heat exchange modules (3) and the first fan (8) work together to achieve heat dissipation inside the photovoltaic inverter.

5. The modular centralized photovoltaic inverter according to claim 2, characterized in that, The top of the inner side of the dynamic expansion cavity (4) is provided with a first fan (8), and the top of the maintenance cavity (2) is provided with a second fan (10). The two sides of the dynamic expansion cavity (4) are symmetrically provided with heat exchange modules (3). The heat exchange modules (3), the first fan (8) and the second fan (10) work together to achieve heat dissipation inside the photovoltaic inverter.

6. The modular centralized photovoltaic inverter according to any of claims 3 to 5, characterized in that, The top of the inner side of the dynamic expansion cavity (4) is provided with a main air duct (13) in the horizontal direction, and the first fan (8) is located in the main air duct (13).

7. The modular centralized photovoltaic inverter according to claim 6, characterized in that, The first fan (8) is a centrifugal fan.

8. The modular centralized photovoltaic inverter according to claim 3 or 5, characterized in that, The dynamic expansion cavity (4) is provided with a first auxiliary air duct (14), and the second fan (10) is located inside the first auxiliary air duct (14).

9. The modular centralized photovoltaic inverter according to any of claims 3 to 5, characterized in that, The heat exchange module (3) is equipped with a third fan (11), a fourth fan (12) and an external circulation duct (15), with the third fan (11) and the fourth fan (12) located at both ends of the external circulation duct (15).

10. The modular centralized photovoltaic inverter according to any of claims 1 to 5, characterized in that, The heat exchange core of the heat exchange module (3) is an air heat exchanger.

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