A grid-forming cascaded energy storage device energy storage converter structure

Abstract

This invention relates to the field of energy storage converter technology, and discloses a grid-type cascaded energy storage device energy storage converter structure. In this structure, the converter frame includes a first assembly area, a second assembly area, and a third assembly area. The first assembly area, located near the rear panel, houses the DC power module. The second assembly area, located near the lower part of the front panel, houses the LC filter module. The third assembly area, located near the upper part of the front panel, houses the AC / DC conversion and temperature control module. The DC power module is electrically connected to both the AC / DC conversion and temperature control module and the LC filter module. The interaction terminal and temperature control terminal of the AC / DC conversion and temperature control module are interconnected with external devices through the front panel. This invention effectively integrates the design of the energy storage converter.

Description

Technical Field

[0001] This invention relates to the field of energy storage converter technology, specifically to an energy storage converter structure for a grid-type cascaded energy storage device. Background Technology

[0002] In the process of power systems increasingly integrating with high-proportion renewable energy sources, grid-connected cascaded energy storage devices have become a core product for meeting grid stability requirements and adapting to technological advancements. Through the deep integration of high-voltage cascaded topology and grid-connected control algorithms, this device effectively addresses the critical issue of insufficient grid stability caused by high-proportion renewable energy grid integration, and is gradually becoming the main equipment in the future energy storage field, especially in large-scale grid support scenarios.

[0003] As a core component of the power electronic system of grid-connected energy storage devices, the structural design of energy storage converters directly determines the overall operating performance, reliability, and ease of maintenance of the entire device. With the continuous iteration of power electronics technology, the structural design of energy storage converters is increasingly focusing on improving compactness, modularity, and ease of maintenance to adapt to the application requirements of different scenarios.

[0004] Currently, several technical solutions exist in the industry for the structural design of energy storage converters, but all have varying degrees of defects and are difficult to fully meet the needs of practical applications. For example, the invention patent with publication number CN119834324A discloses a high-voltage direct-connected cascaded energy storage integrated converter device and its application. To ensure the compatibility of the energy storage converter in the battery cluster of the cascaded energy storage device, this solution integrates the battery high-voltage box function, which directly increases the total weight of the device and significantly increases the difficulty of installation, transportation, and subsequent maintenance. At the same time, the DC support capacitor in this solution adopts a vertical placement installation method, which requires tightening nuts from below the energy storage converter. The device needs to be raised during the installation process, and special lifting tools are required to complete the disassembly and replacement when replacing the capacitor on site, further increasing the complexity of on-site maintenance. In addition, its DC support capacitor terminals adopt a three-layer superimposed connection structure of copper busbar, insulating sheet, and copper busbar, which not only makes the assembly process cumbersome but also results in high stray inductance, affecting the performance of the device.

[0005] The invention patent with publication number CN119253980A discloses a novel energy storage converter structure. This solution uses a fan as a heat dissipation component. Dust and grime from the external environment can easily enter the device with the heat dissipation airflow. After long-term operation, this will increase the risk of damage to precision components such as internal circuit boards and reduce the insulation performance of internal components. On the other hand, the energy storage converter adopts a thin-shell structure with limited structural strength. When it is necessary to increase the capacity of the device, the original structure must be completely overhauled and redesigned, which seriously restricts the expansion flexibility of the device.

[0006] The invention patent with publication number CN118611390A discloses a liquid-cooled high-voltage cascaded energy storage converter power unit. In this scheme, the inductor and IGBT module adopt independent water cooling modes, which requires the device to be equipped with two independent water cooling pipelines to meet the cooling requirements. Moreover, all pipeline interfaces are located inside the device and far away from the casing. This not only makes the water cooling pipelines occupy too much internal space of the equipment, but also poses significant safety hazards. When water leaks or seeps into the water pipes and device interfaces, it is very easy to cause contamination of internal components, thereby affecting the operational stability of the equipment.

[0007] In summary, the existing energy storage converter structural design still has many shortcomings in terms of ease of maintenance, operational reliability, structural compactness, and expansion flexibility, and a better technical solution is urgently needed to address these issues. Summary of the Invention

[0008] In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a storage converter structure for a grid-type cascaded energy storage device, so as to solve the technical problem of how to integrate the design of the energy storage converter.

[0009] This invention is achieved through the following technical solution: In a first aspect, the present invention provides an energy storage converter structure for a grid-type cascaded energy storage device, including a converter housing, a DC power module, an AC-DC conversion and temperature control module, and an LC filter module; The converter housing includes a converter frame, two sets of heat dissipation plates, a top plate, a front plate, and a rear plate; the two sets of heat dissipation plates are respectively located on both sides of the converter frame, the top plate is located on the top of the converter frame, the front plate is located on the front side of the converter frame, and the rear plate is located on the rear side of the converter frame. The converter frame is provided with a first assembly area, a second assembly area and a third assembly area; the first assembly area is close to the rear panel area, and the DC power module is located in the first assembly area; the second assembly area is close to the lower area of ​​the front panel, and the LC filter module is located in the second assembly area; the third assembly area is close to the upper area of ​​the front panel, and the AC-DC conversion and temperature control module is located in the third assembly area. The DC power module is electrically connected to the AC / DC conversion and temperature control module and the LC filter module, respectively. The interactive terminal and the temperature control terminal of the AC / DC conversion and temperature control module are both connected to external devices through the front panel.

[0010] Preferably, the converter frame is provided with a support frame and several vertical beams in the first assembly area; the main body of the DC power module is mounted on the support frame, and the tail end of the DC power module is fixed to several vertical beams by a rear plate.

[0011] Furthermore, the DC power module includes several sets of DC support capacitors and a first composite stacked busbar; Several sets of DC support capacitor arrays are arranged and mounted on a support frame. The first composite stacked busbar is located on the front side of the support frame. The front ends of several sets of DC support capacitors are connected to the first composite stacked busbar and are electrically connected to the AC / DC conversion and temperature control module and the LC filter module respectively through the first composite stacked busbar. The rear ends of several sets of DC support capacitors are fixed to several vertical beams through the mounting holes provided on the rear plate.

[0012] Preferably, the bottom of the converter frame is provided with several support plates arranged side by side in the second assembly area; the LC filter module is mounted on several support plates.

[0013] Furthermore, the LC filter module includes a first filter inductor, a second filter inductor, and a filter capacitor; The first filter inductor, the second filter inductor, and the filter capacitor are electrically connected in sequence, and the interaction terminals of the first filter inductor, the second filter inductor, and the filter capacitor are all electrically connected to the DC power module.

[0014] Preferably, the top of the converter frame is provided with a crossbeam in the third assembly area; one end of the AC / DC conversion and temperature control module assembly end is fixedly mounted on the crossbeam, and the other end is fixed on the frame above the front panel.

[0015] Furthermore, the AC / DC conversion and temperature control module includes a water-cooling component, an IGBT component, a control component, and a second composite stacked busbar; One end of the water-cooling component is fixed on the crossbeam, and the other end is fixed on the frame above the front panel. The temperature control end of the water-cooling component is connected to external equipment through the front panel. The IGBT assembly includes an IGBT module and an IGBT driver module, which are mounted on a water-cooling assembly. The second composite stacked busbar is mounted above the IGBT module and the IGBT driver module. The interaction terminal of the IGBT module is connected to external devices via a front panel. The IGBT module and the IGBT driver module are electrically connected. One branch of the information transmission end of the IGBT driver module is connected to the control component, and the other branch is electrically connected to the DC power module after passing through the second composite stacked busbar. The control components include a control board and a control board support frame; The control board support frame is fixedly installed on the side of the water-cooling assembly, the control board is fixed on the control board support frame, and the control board is electrically connected to the IGBT drive module.

[0016] Furthermore, the water-cooling assembly includes two sets of water-cooled plate support beams, a water-cooled plate base, and water-cooled plates; One end of each of the two sets of water-cooled plate support beams is fixed to a crossbeam, and the other end is fixed to the frame above the front panel. The two ends of the water-cooled plate base are respectively fixed on two sets of water-cooled plate support beams. The water-cooled plate is placed on the water-cooled plate base. The water-cooled plate is provided with a water inlet port and a water outlet port. Water pipes are provided on the water inlet port and the water outlet port. The water pipes are connected to external equipment through the front plate. The IGBT module and IGBT driver module are mounted on a water-cooled plate; The control panel support frame is fixedly installed on the side of the water-cooled plate support beam.

[0017] Furthermore, the front panel is equipped with two sets of handles, two sets of AC series copper bus terminals, and through holes; The IGBT module's interactive terminal is connected to external devices via two sets of AC series copper busbar terminals, and the water pipes of the inlet and outlet ports are connected to external devices via through holes.

[0018] Preferably, a mounting plate is provided on the side of the converter frame, and an energy harvesting power module is fixedly mounted on the mounting plate. The energy harvesting power module is electrically connected to the control board. The heat sink is located outside the energy harvesting power module and fixed to the side of the converter frame, wherein the heat sink has several heat dissipation holes.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects: This invention provides a grid-type cascaded energy storage converter structure. By clearly dividing the converter frame into a first assembly area, a second assembly area, and a third assembly area in a three-dimensional partitioned layout, the DC power module, LC filter module, AC / DC conversion module, and temperature control module are respectively arranged in the first assembly area near the rear panel, the second assembly area below the front panel, and the third assembly area above the front panel. Each functional module occupies its own dedicated assembly space according to usage requirements and structural characteristics. This avoids spatial interference between different modules and achieves compact arrangement and modular integration of components, maximizing the utilization of the internal space of the converter housing and significantly improving the power density of the energy storage system. Simultaneously, heavy components such as the filter inductor in the LC filter module and the DC capacitor in the DC power module are rationally distributed in different areas of the frame through the aforementioned partitioned layout. This allows the center of gravity of the entire unit to be concentrated in the middle of the converter frame, effectively avoiding problems such as inconvenience in handling or operational instability caused by center of gravity shift. This reduces the operational difficulty during equipment handling and ensures the structural stability of the equipment during operation. Furthermore, the DC support capacitors are arranged horizontally and equipped with a dedicated support structure designed for them within the converter frame, as well as a pre-installed mounting structure for the filter inductors in the LC filter module. This ensures that these core components are securely connected to the frame through targeted installation design. When a core component fails and needs to be replaced, there is no need to lift and disassemble the entire converter equipment. Replacement can be completed by operating the target component in the corresponding assembly area individually. This greatly simplifies the maintenance process, reduces the technical difficulty and workload of maintenance work, and thus significantly improves the operation and maintenance efficiency of the equipment.

[0020] Furthermore, by setting up a support frame and several vertical beams in the first assembly area, a dual fixing structure for the DC power module is constructed: the main body is mounted on the support frame to achieve bottom support, and the tail end is fixed to the vertical beam through the rear plate to form a tail limit, which greatly improves the structural stability of the DC power module installation and effectively avoids module displacement or poor contact caused by vibration during equipment operation; at the same time, the clear support and fixing structure provides a precise installation positioning benchmark for the DC power module, simplifies the installation process, and the module can be completely disassembled by simply removing the tail fixing during subsequent disassembly and maintenance, thus improving the convenience of operation and maintenance.

[0021] Furthermore, several groups of DC support capacitors are arranged in an array on the support frame, achieving a compact layout of the capacitors, making full use of the space in the first assembly area, and ensuring uniform stress on the capacitors through regular arrangement. This, combined with the support frame, enhances the overall structural stability. The front end is centrally connected to other modules via the first composite stacked busbar, reducing line loss and parasitic parameters compared to the traditional distributed wiring method, improving power transmission efficiency, and simplifying the wiring process. The rear end is fixed to the vertical beam through mounting holes on the rear plate, which works in conjunction with the arrayed capacitors to make the capacitor group more secure. When replacing capacitors, only the composite stacked busbar needs to be disconnected and the rear fixation released, without disassembling the entire module, reducing maintenance difficulty.

[0022] Furthermore, the LC filter module in the second assembly area is designed with several side-by-side support plates. These support plates provide a stable bottom support foundation for the LC filter module, adapting to the weight characteristics of heavy components such as filter inductors in the LC filter module, effectively avoiding deformation of the installation structure due to the weight of the components during long-term use. At the same time, the side-by-side support plates form a regular installation and positioning structure, facilitating the rapid installation and positioning of the LC filter module. Moreover, the integrated design of the support plates and the converter frame improves the overall structural load-bearing reliability.

[0023] Furthermore, the first filter inductor, the second filter inductor, and the filter capacitor are sequentially connected to form a complete filter circuit, which is adapted to the power quality regulation requirements of the grid-type energy storage converter. The filtering effect is improved by reasonable LC parameter matching, ensuring the stability of the output power. The interaction terminals of each component are centrally connected to the DC power module, which shortens the power transmission path and reduces line interference. At the same time, the orderly connection method facilitates component testing and maintenance during fault diagnosis.

[0024] Furthermore, the AC / DC conversion and temperature control module in the third assembly area is designed with a top crossbeam. One end of the module is fixed to the crossbeam, and the other end is fixed to the upper frame of the front panel, forming a dual fixing structure of top suspension and front limiting. This adapts to the weight distribution requirements of the integrated water-cooling components, IGBT components, and other components in the module, and avoids the module's sagging deformation caused by its own weight. At the same time, this fixing method makes full use of the space between the upper part of the front panel and the top crossbeam, realizing a layered layout with the LC filter module below, improving the utilization rate of the internal space of the cabinet, and the front fixing structure facilitates the interaction and connection between the module and external devices on the front panel.

[0025] Furthermore, the IGBT module is directly mounted on the water-cooling assembly, achieving a close fit between the heat-generating core component and the heat dissipation component, significantly improving heat dissipation efficiency and ensuring stable operation of the IGBT module at rated power. The second composite stacked busbar is located above the IGBT module, simplifying the wiring between the IGBT drive module and the DC power module, reducing parasitic inductance, and improving the stability of power conversion. The control component is fixed to the side of the water-cooling assembly via a control board support frame, achieving a reasonable partitioning of the control and power sections, reducing interference from the power circuit to the control signal, improving control accuracy, and the side mounting method makes full use of the gap space, avoiding spatial interference with other components.

[0026] Furthermore, two sets of water-cooled plate support beams are fixed to the crossbeam and the upper frame of the front panel, respectively, forming a stable installation structure for the water-cooled plate in conjunction with the water-cooled plate base, ensuring a tight fit between the water-cooled plate and the IGBT assembly. The water inlet and outlet ports of the water-cooled plate interact with the outside world through water pipes passing through the front panel, realizing a closed design of the heat dissipation circuit and improving the reliability of the heat dissipation system. The control board support frame is fixed to the side of the water-cooled plate support beam, making the control component and the water-cooling component form an integrated layout, which not only improves space utilization but also facilitates the signal connection between the control component and the IGBT drive module.

[0027] Furthermore, the front panel features a handle, AC series copper busbar terminals, and through holes. The handle is designed to fit the centrally located structure of the device, providing a convenient point of leverage for handling and improving safety and convenience during transport. The AC series copper busbar terminals serve as external interfaces for the IGBT modules, employing a copper busbar structure to enhance conductivity and meet the demands of high-power power transmission. The terminals' placement on the front panel facilitates quick connection with external devices. The through holes provide a neat channel for the water pipes of the water-cooling components, preventing entanglement and interference between the pipes and other external interfaces, thus improving the neatness of the external piping layout.

[0028] Furthermore, a mounting plate is installed on the side of the converter frame to fix the power harvesting module, realizing a partitioned layout of the power harvesting module and the main circuit module. This avoids the power module occupying the installation space of the internal main circuit components and improves space utilization. The power harvesting module is directly electrically connected to the control board, shortening the power supply path and ensuring the stability of the power supply to the control components. The heat sink is located on the outside of the power harvesting module and has ventilation holes, forming a dedicated heat dissipation channel for the power harvesting module, improving the heat dissipation efficiency of the power module. At the same time, the heat sink is fixed to the side of the frame, realizing the integrated design of the heat dissipation structure and the frame, improving the integration of the overall structure. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of an explosion of an energy storage converter according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of the energy storage converter according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the AC power heat dissipation control module structure according to an embodiment of the present invention; Figure 4 This is a top view of the energy storage converter according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the energy storage converter frame according to an embodiment of the present invention; Figure 6 This is a rear view of the energy storage converter according to an embodiment of the present invention; In the diagram: 1. Converter housing; 2. DC power module; 3. AC / DC conversion and temperature control module; 4. LC filter module; 5. Power supply module; 11. Converter frame; 12. Heat sink; 13. Top plate; 14. Front plate; 15. Support frame; 16. Mounting plate; 17. Rear plate; 18. Crossbeam; 19. Vertical beam; 110. Support plate; 171. Mounting hole; 21. DC support capacitor; 22. First composite stacked busbar; 31. Water-cooled assembly; 32. IGBT assembly; 33. Control assembly; 34. Second composite laminated busbar; 41. First filter inductor; 42. Second filter inductor; 43. Filter capacitor; 141. Handle; 142. AC series copper busbar terminal; 311. Water-cooled plate support beam; 312. Water-cooled plate base; 313. Water-cooled plate; 314. Water pipe; 321. IGBT module; 322. IGBT driver module; 331. Control board; 332. Control board support frame; A. First assembly area; B. Second assembly area; C. Third assembly area. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0032] The purpose of this invention is to provide a storage converter structure for a grid-type cascaded energy storage device, so as to solve the technical problem of how to integrate the design of the energy storage converter.

[0033] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 6 As shown, in one embodiment of the present invention, a grid-type cascaded energy storage device is provided, comprising an energy storage converter structure, including a converter housing 1, a DC power module 2, an AC / DC conversion and temperature control module 3, and an LC filter module 4; the converter housing 1 includes a converter frame 11, two sets of heat dissipation plates 12, a top plate 13, a front plate 14, and a rear plate 17; the two sets of heat dissipation plates 12 are respectively disposed on both sides of the converter frame 11, the top plate 13 is disposed on the top of the converter frame 11, the front plate 14 is disposed on the front side of the converter frame 11, and the rear plate 17 is disposed on the rear side of the converter frame 11; a first assembly is provided inside the converter frame 11. The assembly consists of three areas: a first assembly area (A), a second assembly area (B), and a third assembly area (C). The first assembly area (A) is located near the rear panel 17, and the DC power module 2 is installed within it. The second assembly area (B) is located near the lower part of the front panel 14, and the LC filter module 4 is installed within it. The third assembly area (C) is located near the upper part of the front panel 14, and the AC / DC conversion and temperature control module 3 is installed within it. The DC power module 2 is electrically connected to both the AC / DC conversion and temperature control module 3 and the LC filter module 4. The interaction terminal and temperature control terminal of the AC / DC conversion and temperature control module 3 are both connected to external devices via the front panel 14.

[0034] Specifically, the converter frame 11 is provided with a support frame 15 and several vertical beams 19 in the first assembly area A; the main body of the DC power module 2 is mounted on the support frame 15, and the tail end of the DC power module 2 is fixed to several vertical beams 19 through the rear plate 17.

[0035] The DC power module 2 includes several sets of DC support capacitors 21 and a first composite stacked busbar 22. The several sets of DC support capacitors 21 are arranged in an array and mounted on a support frame 15. The first composite stacked busbar 22 is located on the front side of the support frame 15. The front ends of the several sets of DC support capacitors 21 are connected to the first composite stacked busbar 22 and are electrically connected to the AC / DC conversion and temperature control module 3 and the LC filter module 4 respectively through the first composite stacked busbar 22. The rear ends of the several sets of DC support capacitors 21 are fixed to several vertical beams 19 through the mounting holes 171 provided on the rear plate 17.

[0036] In this embodiment, the converter frame 11 is a metal frame integrally formed by riveting and welding, which has high structural strength. The rear end of the frame is designed with a layered support frame 15 to support the horizontally arranged DC support capacitor 21. The support frame 15 is cut with a passivated circular notch to protect the capacitor shell. The nut column at the tail of the DC support capacitor 21 is fixed to several vertical beams 19 through the mounting holes 171 provided on the rear plate 17. The device can be replaced without lifting the energy storage converter during disassembly. Specifically, the bottom of the converter frame 11 is provided with several support plates 110 arranged side by side in the second assembly area B; the LC filter module 4 is mounted on several support plates 110.

[0037] The LC filter module 4 includes a first filter inductor 41, a second filter inductor 42, and a filter capacitor 44. The first filter inductor 41, the second filter inductor 42, and the filter capacitor 44 are electrically connected in sequence, and the interaction terminals of the first filter inductor 41, the second filter inductor 42, and the filter capacitor 44 are all electrically connected to the DC power module 2.

[0038] In this embodiment, the support plate 110 of the front half of the frame is an L-shaped angle steel, and a nut for installing the filter inductor is welded below the angle steel.

[0039] Specifically, a crossbeam 18 is provided on the top of the converter frame 11 in the third assembly area C; one end of the AC / DC conversion and temperature control module 3 is fixed on the crossbeam 18, and the other end is fixed on the frame above the front plate 14.

[0040] Among them, according to Figure 3As shown, the AC / DC conversion and temperature control module 3 includes a water-cooling assembly 31, an IGBT assembly 32, a control assembly 33, and a second composite stacked busbar 34. One end of the water-cooling assembly 31 is fixed to the crossbeam 18, and the other end is fixed to the frame above the front panel 14. The temperature control end of the water-cooling assembly 31 is connected to external equipment via the front panel 14. The IGBT assembly 32 includes an IGBT module 321 and an IGBT drive module 322, which are mounted on the water-cooling assembly 31. The second composite stacked busbar 34 is mounted on the IGBT module 321 and the IGBT drive module 322. Above, the interaction terminal of the IGBT module 321 is connected to external devices via the front panel 14; the IGBT module 321 is electrically connected to the IGBT driver module 322, one branch of the information transmission terminal of the IGBT driver module 322 is connected to the control component 33, and the other branch is electrically connected to the DC power module 2 via the second composite stacked busbar 34; the control component 33 includes a control board 331 and a control board support frame 332; the control board support frame 332 is fixedly installed on the side of the water-cooling component 31, the control board 331 is fixed on the control board support frame 332, and the control board 331 is electrically connected to the IGBT driver module 322.

[0041] In this embodiment, the control board support frame 332 is physically isolated and electromagnetically shielded from the first filter inductor 41, the second filter inductor 42, and the filter capacitor 44; the left side of the control board 331 is adjacent to the IGBT driver 322 to minimize the length of the drive line and reduce interference.

[0042] The water-cooling assembly 31 includes two sets of water-cooled plate support beams 311, a water-cooled plate base 312, and a water-cooled plate 313. One end of each of the two sets of water-cooled plate support beams 311 is fixed to a crossbeam 18, and the other end is fixed to the upper frame of the front panel 14. Both ends of the water-cooled plate base 312 are fixed to the two sets of water-cooled plate support beams 311. The water-cooled plate 313 is placed on the water-cooled plate base 312. The water-cooled plate 313 is provided with a water inlet port and a water outlet port. Water pipes 314 are provided on the water inlet port and the water outlet port. The water pipes 314 are connected to external equipment through the front panel 14. The IGBT module 321 and the IGBT drive module 322 are mounted on the water-cooled plate 313. The control board support frame 332 is fixedly mounted on the side of the water-cooled plate support beams 311.

[0043] The front panel 14 is provided with two sets of handles 141, two sets of AC series copper busbar terminals 142 and through holes; the interactive terminal of the IGBT module 321 is connected to the external device through the two sets of AC series copper busbar terminals 142, and the water pipes 314 of the water inlet and outlet ports are connected to the external device through the through holes.

[0044] In this embodiment, all human-machine interaction interfaces are integrated on the panel 14, including: AC series copper busbar terminals 142 arranged symmetrically on the left and right, control communication interface, low-voltage test terminal arranged in the upper right corner of the panel, high-voltage test terminal arranged in the lower right corner of the panel, and metal handles 141 arranged symmetrically on the left and right and firmly connected to the internal frame.

[0045] The converter frame 11 has a mounting plate 16 on its side, and a power extraction module 5 is fixedly mounted on the mounting plate 16. The power extraction module 5 is electrically connected to the control board 331. The heat sink 12 is located outside the power extraction module 5 and fixed to the side of the converter frame 11. The heat sink 12 has several heat dissipation holes.

[0046] In this embodiment, the energy storage converter is roughly divided into three areas: the lower part of the front half, the upper part of the front half, and the rear half. The zoning is clear and compact, making the assembly more modular and significantly improving the installation efficiency. The functional areas are structurally integrated and electrically isolated through the converter frame (1), resulting in a compact layout and balanced weight distribution. In this embodiment, the top plate 13 is a single piece of metal plate, used to protect against dust and water droplets from above; the side plate 12 is designed with ventilation and heat dissipation holes for natural heat dissipation of the device.

[0047] The AC / DC conversion and temperature control module 3 consists of an IGBT module 321, an IGBT drive module 322, and a water-cooled plate 313 for heat dissipation by equalizing resistors. It also requires a first composite stacked busbar 22 to connect the terminals of the IGBT module 321, the water-cooled plate 313 for heat dissipation by equalizing resistors, and several sets of DC support capacitors 21 in parallel.

[0048] The LC filter module 4 includes a first filter inductor 41, a second filter inductor 42, and a filter capacitor 44; when the cascaded energy storage battery is charged and discharged, it is used to suppress the battery ripple current, which can effectively protect the battery and extend its life.

[0049] In this embodiment, the water-cooled plate 313 is made of aluminum. The heat is carried away by the external liquid cooling pipes after heat conduction. The filter inductor of the LC filter module dissipates heat naturally. Ventilation louvers are designed on the outer shell, and ventilation holes are also designed on the bottom plate of the device frame.

[0050] In this embodiment, in order to ensure that the center of gravity of the energy storage converter is as central as possible after completion, so as to facilitate balance during transportation, the filter inductors are concentrated at the front end of the energy storage converter, and the 12 DC support capacitors in the single-phase bridge circuit are arranged in the rear half of the energy storage converter, and the front and rear counterweights are kept as close as possible.

[0051] In this embodiment, considering the frequency of device replacement and maintenance, the DC support capacitor and filter inductor are less prone to damage than the IGBT module and its driver and auxiliary control system. Therefore, they are arranged in the lower layer of the energy storage converter, while the upper layer is used to arrange the IGBT module and its driver, control board and its auxiliary system, such as the heat dissipation system. This layered arrangement is more conducive to reducing the workload of maintenance when the energy storage converter needs to be repaired and replaced.

[0052] In this embodiment, considering the human-computer interaction requirements, the communication interface of the control board, the water cooling interface of the heat dissipation system, the AC / DC series and parallel terminals between multiple energy storage converters, and the test interface terminals of the energy storage converter all need to be arranged on the panel. This design arranges the above parts on the energy storage converter panel, and maintains the left and right symmetry of the AC copper bus terminals and the left and right symmetry of the water cooling pipe interfaces, and labels the names of each interface. In this way, in the series assembly of multiple energy storage converters in cascaded energy storage, the functions of each water pipe interface and terminal are clearer, the specifications of the copper bus parts required for series connection are uniform, and the specifications of the water pipes for water inlet and outlet are uniform.

[0053] In this embodiment, the terminals of the DC support capacitor 21 are connected in parallel and structurally supported by the first composite stacked busbar 22 and the second composite stacked busbar 34; the water-cooled plate (7) and the IGBT module (8) on it are centrally arranged in the third assembly area C through the support structure formed by the water-cooled plate support beam (17) and the water-cooled plate base (18).

[0054] In this embodiment, the IGBT module 321, IGBT driver module 322, and control component 33 are centrally arranged via a support structure to ensure symmetry between the AC terminals and the water-cooling interface. The control component 33 is located on the upper right of the third assembly area C and is electromagnetically isolated from the strong interference source below via the control board support frame 332, ensuring the reliability of the control system. In this embodiment, the handles 141 on the front panel 14 are firmly connected to the internal frame, with one handle on each side symmetrically. They do not deform under stress and facilitate the removal of the entire converter from the mounting frame, greatly simplifying on-site maintenance operations.

[0055] In summary, the energy storage converter structure of the grid-type cascaded energy storage device provided in this embodiment achieves compact and modular installation of components through a three-dimensional partitioned layout of zones A, B, and C, significantly improving the power density of the energy storage system. Simultaneously, the rational distribution of heavy components (filter inductors and DC capacitors) keeps the overall center of gravity central, facilitating handling and maintaining stability. The lateral arrangement of the DC support capacitors and the dedicated support design of the frame, along with the pre-installed structure of the filter inductors, eliminates the need to hoist the entire device for replacing core components, greatly reducing maintenance difficulty and workload, and improving operation and maintenance efficiency. The use of composite stacked busbars to connect capacitors reduces stray inductance in the power circuit, improving electrical performance, while also allowing the composite stacked busbars to provide structural support, enhancing overall stability. The control board is electromagnetically shielded by a semi-enclosed support plate, providing an excellent anti-interference environment. Combined with the proximity of the drive board, this effectively improves the reliability and stability of system control. The symmetrical design of the power components and interfaces ensures that the connectors are of uniform specifications and the piping layout is neat and aesthetically pleasing when multiple devices are connected in series, thus improving the standardization and economy of system-level integration. The symmetrical design of the handles makes it more balanced and stable to push the energy storage converter into or pull it out of the battery cluster frame guide rail slot of the cascaded energy storage device.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A structure of an energy storage converter for a grid-forming cascaded energy storage device, characterized by, It includes a converter housing (1), a DC power module (2), an AC / DC conversion and temperature control module (3), and an LC filter module (4). The converter housing (1) includes a converter frame (11), two sets of heat dissipation plates (12), a top plate (13), a front plate (14), and a rear plate (17); the two sets of heat dissipation plates (12) are respectively located on both sides of the converter frame (11), the top plate (13) is located on the top of the converter frame (11), the front plate (14) is located on the front side of the converter frame (11), and the rear plate (17) is located on the rear side of the converter frame (11); The converter frame (11) is provided with a first assembly area (A), a second assembly area (B) and a third assembly area (C); the first assembly area (A) is close to the rear plate (17) and the DC power module (2) is located in the first assembly area (A); the second assembly area (B) is close to the lower area of ​​the front plate (14) and the LC filter module (4) is located in the second assembly area (B); the third assembly area (C) is close to the upper area of ​​the front plate (14) and the AC / DC conversion and temperature control module (3) is located in the third assembly area (C). The DC power module (2) is electrically connected to the AC / DC conversion and temperature control module (3) and the LC filter module (4) respectively. The interactive terminal and temperature control terminal of the AC / DC conversion and temperature control module (3) are connected to external devices through the front panel (14).

2. The energy storage converter structure of claim 1, wherein, The converter frame (11) is provided with a support frame (15) and several vertical beams (19) in the first assembly area (A); the main body of the DC power module (2) is mounted on the support frame (15), and the tail end of the DC power module (2) is fixed to several vertical beams (19) by the rear plate (17).

3. The energy storage converter structure of a network-forming cascaded energy storage device according to claim 2, characterized in that, The DC power module (2) includes several sets of DC support capacitors (21) and a first composite stacked busbar (22). Several sets of DC support capacitors (21) are arranged in an array and mounted on a support frame (15). The first composite stacked busbar (22) is located on the front side of the support frame (15). The front ends of several sets of DC support capacitors (21) are connected to the first composite stacked busbar (22) and are electrically connected to the AC / DC conversion and temperature control module (3) and the LC filter module (4) respectively through the first composite stacked busbar (22). The tail ends of several sets of DC support capacitors (21) are fixed to several vertical beams (19) through the mounting holes (171) provided on the rear plate (17).

4. The energy storage converter structure of claim 1, wherein, The bottom of the converter frame (11) is provided with several support plates (110) arranged side by side in the second assembly area (B); the LC filter module (4) is mounted on several support plates (110).

5. The energy storage converter structure of a grid-type cascaded energy storage device according to claim 4, characterized in that, The LC filter module (4) includes a first filter inductor (41), a second filter inductor (42), and a filter capacitor (44). The first filter inductor (41), the second filter inductor (42), and the filter capacitor (44) are electrically connected in sequence, and the interaction terminals of the first filter inductor (41), the second filter inductor (42), and the filter capacitor (44) are all electrically connected to the DC power module (2).

6. The energy storage converter structure of a grid-type cascaded energy storage device according to claim 1, characterized in that, The top of the converter frame (11) is provided with a crossbeam (18) in the third assembly area (C); one end of the AC / DC conversion and temperature control module (3) is fixed on the crossbeam (18), and the other end is fixed on the frame above the front plate (14).

7. The energy storage converter structure of a grid-type cascaded energy storage device according to claim 6, characterized in that, The AC / DC conversion and temperature control module (3) includes a water-cooling component (31), an IGBT component (32), a control component (33), and a second composite stacked busbar (34). One end of the assembly end of the water-cooled component (31) is fixed on the crossbeam (18), and the other end is fixed on the frame above the front plate (14). The temperature control end of the water-cooled component (31) is connected to the external equipment through the front plate (14). The IGBT assembly (32) includes an IGBT module (321) and an IGBT driver module (322). The IGBT module (321) and the IGBT driver module (322) are mounted on the water-cooling assembly (31). The second composite stacked busbar (34) is mounted above the IGBT module (321) and the IGBT driver module (322). The interaction terminal of the IGBT module (321) is connected to external devices through the front panel (14). The IGBT module (321) is electrically connected to the IGBT drive module (322). One branch of the information transmission end of the IGBT drive module (322) is connected to the control component (33), and the other branch is electrically connected to the DC power module (2) after passing through the second composite stacked busbar (34). The control component (33) includes a control board (331) and a control board support frame (332); The control board support frame (332) is fixedly installed on the side of the water cooling assembly (31), the control board card (331) is fixed on the control board support frame (332), and the control board card (331) is electrically connected to the IGBT drive module (322).

8. The energy storage converter structure of a grid-type cascaded energy storage device according to claim 7, characterized in that, The water-cooled assembly (31) includes two sets of water-cooled plate support beams (311), a water-cooled plate base (312), and a water-cooled plate (313). One end of each of the two sets of water-cooled plate support beams (311) is fixed to the crossbeam (18), and the other end is fixed to the frame above the front plate (14); The two ends of the water-cooled plate base (312) are respectively fixed on two sets of water-cooled plate support beams (311). The water-cooled plate (313) is placed on the water-cooled plate base (312). The water-cooled plate (313) is provided with a water inlet port and a water outlet port. Water pipes (314) are provided on the water inlet port and the water outlet port. The water pipes (314) are connected to external equipment through the front plate (14). The IGBT module (321) and the IGBT driver module (322) are mounted on the water-cooled plate (313); The control panel support frame (332) is fixedly installed on the side of the water-cooled plate support beam (311).

9. The energy storage converter structure of a grid-type cascaded energy storage device according to claim 8, characterized in that, The front plate (14) is provided with two sets of handles (141), two sets of AC series copper bus terminals (142) and through holes; The IGBT module (321) is connected to external devices via two sets of AC series copper busbar terminals (142), and the water pipes (314) of the inlet and outlet ports are connected to external devices via through holes.

10. The energy storage converter structure of a grid-type cascaded energy storage device according to claim 7, characterized in that, The converter frame (11) has a mounting plate (16) on its side. The mounting plate (16) is fixedly provided with an energy harvesting power module (5). The energy harvesting power module (5) is electrically connected to the control board (331). The heat sink (12) is located outside the energy harvesting power module (5) and fixed to the side of the converter frame (11). The heat sink (12) has several heat dissipation holes.

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