Cascade frequency converter power cabinet

Abstract

The utility model discloses a cascade frequency converter power cabinet, which comprises a cabinet and a plurality of groups of power units, relates to the technical field of power electronic conversion equipment, and is characterized in that the cabinet is correspondingly divided into a plurality of layers, a group of power units is arranged in each layer of cabinet, and the plurality of power units are cascaded up and down and output from the uppermost or lowermost power unit of the cabinet. Each group of power units is divided into three modules to be installed in a power cabinet, a fuse, a rectifier bridge, an IGBT and an air-cooled radiator are integrated into a power module to be placed in the middle, and a plurality of bus capacitors are equally divided into two bus capacitor modules which are symmetrically distributed on the left side and the right side of the power module. The power cabinet has the advantages of being compact in structural layout, high in power density, stable and safe in work, convenient to install and maintain and good in heat dissipation effect, and the power cabinet has good adaptability to voltage requirements of different cascade systems and multi-phase output requirements of cascade frequency converters.

Description

Technical Field

[0001] This utility model relates to the field of power electronic conversion equipment technology, and more specifically, to a cascaded frequency converter power cabinet. Background Technology

[0002] In today's world, where energy issues are increasingly prominent, cascaded frequency converters are playing an increasingly important role in energy conservation, contributing to a green and low-carbon society. The power cabinet, composed of modular power units, is a core component of high-power cascaded frequency converters, and its operational stability and reliability are paramount, determining many factors such as the overall performance and size of the cascaded frequency converter. Therefore, the structural design of the power cabinet must fully consider factors such as compact layout, high power density, operational stability, safety, ease of installation and maintenance, and good heat dissipation. It is also necessary to consider the adaptability of the power cabinet design to the voltage requirements of different cascaded systems and the multi-phase output requirements of the cascaded frequency converter. Utility Model Content

[0003] In order to overcome the above-mentioned defects of the prior art, this utility model provides a cascaded frequency converter power cabinet with a compact structure, high power density, stable and safe operation, convenient installation and maintenance, and good heat dissipation. Moreover, this power cabinet has good adaptability to the voltage requirements of different cascaded systems and the multi-phase output requirements of cascaded frequency converters.

[0004] A cascaded frequency converter power cabinet includes a cabinet and multiple power units, characterized in that: the cabinet is divided into multiple layers, each layer of the cabinet is equipped with a set of power units, and multiple power units are cascaded vertically, with output from the power unit at the top or bottom of the cabinet.

[0005] In a preferred embodiment, each power unit in the cabinet is supported by a U-shaped sheet metal beam. The U-shaped sheet metal beam is supported by insulated angle steel on both sides of the cabinet frame to ensure sufficient electrical insulation distance between the power unit and the cabinet frame, and to ensure that the cabinet frame is not energized when the power cabinet is running.

[0006] In a preferred embodiment, the power unit is a multi-level power unit. Depending on the voltage requirements of the cascaded system, the number of power units can be increased or decreased while keeping the width and depth of the power cabinet and the assembly method of the power units unchanged. The height of the power cabinet can be changed accordingly to assemble power units with different numbers of layers, thereby adapting to different voltage requirements of the cascaded system.

[0007] In the preferred technical solution, the power cabinet is used as a single-phase output, and three power cabinets are connected in parallel with a phase-shifting transformer to form a three-phase output system. For the requirement of cascaded frequency converters with multi-phase output, the number of phase-shifting transformers and power cabinets is increased accordingly.

[0008] In the preferred technical solution, each power unit is divided into 3 modules and installed in the power cabinet: the fuse, rectifier bridge, IGBT and air-cooled heat sink are integrated into a power module and placed in the middle, and multiple bus capacitors are divided into 2 bus capacitor modules and symmetrically distributed on the left and right sides of the power module.

[0009] In the preferred embodiment, the power module in the power unit uses a three-phase uncontrolled rectifier and an IGBT inverter output H-bridge. The rectifier input and inverter output of the power module are both located after the power module, adopting a rear-in, rear-out configuration. Fuses are installed on phases A and C of the rectifier input terminal of the power module.

[0010] In the preferred embodiment, the power module mounts the rectifier bridge and IGBT on a heat sink, and lays positive and negative stacked busbars and H-bridge output busbars on the rectifier bridge and IGBTs; the bus capacitor arrays on the two bus capacitor modules are arranged; positive and negative stacked busbars are laid on the bus capacitor modules, and the positive and negative stacked busbars of the bus capacitors and the positive and negative stacked busbars of the power module are connected by short busbars.

[0011] In a preferred embodiment, the power cabinet employs air cooling. Air enters through holes in the front panel of the single-layer cabinet, cooling the power modules. The hot air is then exhausted from the cabinet via multiple fans on the rear panel. The power modules and capacitor modules are sealed off with plates, with air intake holes only in the power module sealing plate in front of the power module's heatsink. This forces cool air to pass only through the power module's heatsink, effectively cooling the power modules. Ventilation holes are also created in the capacitor module sealing plates in front of the capacitor modules on both sides, allowing for effective cooling of the bus capacitor modules.

[0012] In a preferred embodiment, the cabinet has a U-shaped sheet metal beam equipped with a power module guide rail tray and a capacitor module guide rail tray, which respectively assist in pushing the power module and capacitor module into the cabinet. The small guide ears on both sides of the capacitor module guide rail tray guide the capacitor module as it is pushed in, and the folded edges on both sides of the capacitor module guide rail tray limit the capacitor module in the left and right directions. The rear of the capacitor module guide rail tray is folded into a U-shaped slot, which can also limit the capacitor module in the front-back and up-down directions.

[0013] In a preferred embodiment, the power module guide rail tray and the capacitor module guide rail tray have the same structural form.

[0014] The technical effects and advantages of this utility model are as follows:

[0015] Enhanced safety: The use of Z-shaped sheet metal beams and insulated angle steel supports ensures electrical insulation between the power unit and the cabinet frame, preventing the cabinet frame from becoming energized and improving the safety of the power cabinet.

[0016] High adaptability: The power units are multi-stage designed, allowing for flexible increases or decreases in the number of power units and adjustments to the power cabinet height to meet different voltage requirements, based on the voltage demands of the cascaded system. Furthermore, the power cabinets can be used in parallel to satisfy multi-phase output needs.

[0017] Compact structure: The power unit is divided into multiple modules, making full use of the power cabinet space. The compact structure layout improves power density.

[0018] High stability: The use of a multilayer busbar design reduces stray inductance in the power unit and improves operational stability.

[0019] Excellent heat dissipation: It adopts an air-cooled heat dissipation method, and achieves excellent heat dissipation through the design of air intake in the front door panel and air exhaust in the rear door panel, as well as specific heat dissipation channels for the power module and capacitor module.

[0020] Easy to install and maintain: The design of the guide rail tray facilitates the pushing and pulling of power modules and capacitor modules, simplifying the installation and maintenance process. Attached Figure Description

[0021] Figure 1 This is a front view of the power unit structure layout in the power cabinet of this utility model;

[0022] Figure 2 This is a schematic diagram of the power unit of this utility model;

[0023] Figure 3 This is a structural schematic diagram of the power unit of this utility model supported in the power cabinet;

[0024] Figure 4 This is a structural schematic diagram of the guide rail tray design scheme in the power cabinet of this utility model;

[0025] Figure 5 This is a schematic diagram of the heat dissipation scheme of the power cabinet of this utility model;

[0026] Figure 6 This is a schematic diagram of the structure of the front sealing plate of the power module and capacitor module in the power cabinet of this utility model;

[0027] Figure 7 This is a schematic diagram of the power cabinet of this utility model forming a three-phase output system;

[0028] Figure 8 This is a utility model Figure 4 A magnified structural diagram of part A;

[0029] The attached figures are labeled as follows:

[0030] 1. Cabinet; 2. Power Unit; 11. Z-shaped Sheet Metal Beam; 12. Capacitor Module Rail Tray; 13. Power Module Rail Tray; 14. Insulating Angle Steel; 15. Cabinet Frame; 16. Front Door Panel; 17. Rear Door Panel; 18. Power Module Sealing Plate; 19. Capacitor Module Sealing Plate; 21. Power Module; 22. Capacitor Module; 121. Guide Ear; 122. Folded Edge; 123. U-shaped Slot; 211. Fuse; 212. Rectifier Bridge; 213. IGBT; 214. Air-cooled Heatsink; 215. Power Module Positive and Negative Stacked Busbar Conductor; 216. H-bridge Output Conductor; 217. Short Conductor; 221. Bus Capacitor; 222. Bus Capacitor Positive and Negative Stacked Conductor. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] like Figure 1 As shown, a cascaded frequency converter power cabinet includes a cabinet 1 and multiple power units 2. The cabinet 1 is divided into multiple layers. Each layer of the cabinet 1 is equipped with a power unit 2. Multiple power units 2 are cascaded vertically and output from the power unit 2 at the top or bottom of the cabinet 1.

[0033] like Figure 3 As shown, each layer of power unit 2 in the cabinet 1 is supported by a Z-shaped sheet metal beam 11. The Z-shaped sheet metal beam 11 is supported by insulated angle steel 14 on both sides of the frame 15 of the cabinet 1 to ensure that there is sufficient electrical insulation distance between the power unit 2 and the cabinet frame 15, to ensure that the cabinet frame is not energized when the power cabinet is running, and to increase the safety of the power cabinet when it is working.

[0034] like Figure 1 As shown, power unit 2 is a multi-level power unit. It can be configured to accommodate different cascaded system voltage requirements by increasing or decreasing the number of power units 2 and adjusting the height of the power cabinet accordingly, while maintaining the same width and depth of the power cabinet and the same assembly method. This allows for the installation of power units 2 with different numbers of layers, thus adapting to different cascaded system voltage requirements. This power cabinet design is highly adaptable to the voltage requirements of different cascaded systems.

[0035] like Figure 7As shown, the power cabinet serves as a single-phase output, and three power cabinets are connected in parallel with a phase-shifting transformer to form a three-phase output system. For cascaded frequency converters requiring multi-phase output, the number of phase-shifting transformers and power cabinets is increased accordingly. This solution's power cabinet is highly adaptable to the multi-phase output requirements of cascaded frequency converters.

[0036] like Figure 1 and Figure 2 As shown, considering the large size of the rectifier bridge 212 and IGBT 213 configured in a power unit 2, and the large number of bus capacitors 221, if all of them were integrated together in the traditional way, the power unit 2 would be very large and heavy, making it difficult to assemble and maintain in the cabinet 1. This invention provides a power unit for a cascaded frequency converter power cabinet, where each power unit 2 is divided into three modules installed in the power cabinet: the fuse 211, rectifier bridge 212, IGBT 213, and air-cooled heat sink 214 are integrated into a power module 21 placed in the middle; and the multiple bus capacitors 221 are evenly divided into two bus capacitor modules 22, symmetrically distributed on the left and right sides of the power module 21. This fully utilizes the space of the power cabinet, resulting in a compact structure and high power density.

[0037] like Figure 2 As shown, in power unit 2, power module 21 uses three-phase uncontrolled rectification, IGBT213 inverter output H-bridge. The rectifier input and inverter output of power module 21 are both located after power module 21, adopting a rear-in, rear-out configuration. The A and C phases of the rectifier input terminal of power module 21 are equipped with fuses 211 to provide short-circuit protection.

[0038] like Figure 2 As shown, the power module 21 mounts the rectifier bridge 212 and IGBT 213 on the heat sink 214. Power module positive and negative stacked busbars 215 and H-bridge output busbars 216 are laid on the rectifier bridge 212 and IGBT 213. The capacitors 221 on the two bus capacitor modules 22 are arranged in an array to make full use of space. Bus capacitor positive and negative stacked busbars 222 are laid on the bus capacitor modules 22. The bus capacitor positive and negative stacked busbars 222 and the power module positive and negative stacked busbars 215 are connected by short busbars 217. The stacked busbar scheme can reduce the stray inductance of the power unit and improve the stability of operation.

[0039] like Figure 5 As shown, the power cabinet uses air cooling. The single-layer cabinet 1 receives air through dense perforations on the front door panel 16, which cools the power modules 21. The hot air is then exhausted from the cabinet 1 by multiple fans 3 on the rear door panel 17. Figure 6As shown, the front of power module 21 and capacitor module 22 are sealed with a sealing plate, with air intake holes only on the power module sealing plate 18 in front of the heat sink 214 of power module 21. This forces cold air to pass only through the heat sink 214 of power module 21, effectively dissipating heat from power module 21. Several small ventilation holes are made on the capacitor module sealing plates 19 in front of the capacitor modules 22 on both sides, effectively dissipating heat from the bus capacitor modules 22. This solution provides good heat dissipation.

[0040] like Figure 4 and Figure 8 As shown, the cabinet 1 has a U-shaped sheet metal beam 11 with power module guide rail tray 13 and capacitor module guide rail tray 12, which respectively assist in pushing the power module 21 and capacitor module 22 into the cabinet 1. The small guide ears 121 on both sides of the capacitor module guide rail tray 12 guide the capacitor module 22 as it is pushed in. The folded edges 122 on both sides of the capacitor module guide rail tray 12 limit the left and right directions of the capacitor module 22. The rear of the capacitor module guide rail tray 12 is folded into a U-shaped slot 123, which also limits the front-back and vertical directions of the capacitor module 22. The design of the guide rail trays facilitates the pushing and pulling of modules into and out of the cabinet 1, and is beneficial for module installation and maintenance. The power module guide rail tray 13 and the capacitor module guide rail tray 12 have the same structure.

[0041] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A cascaded frequency converter power cabinet, comprising a cabinet (1) and multiple power units (2), characterized in that: The cabinet (1) is divided into multiple layers. Each layer of cabinet (1) is equipped with a set of power units (2). Multiple power units (2) are cascaded vertically and output from the power unit (2) at the top or bottom of the cabinet (1). Each power unit (2) in the cabinet (1) is supported by a Z-shaped sheet metal beam (11), and the Z-shaped sheet metal beam (11) is supported by insulated angle steel (14) on both sides of the frame (15) of the cabinet (1).

2. The cascaded frequency converter power cabinet according to claim 1, characterized in that: The power unit (2) is a multi-level power unit. The number of power units (2) can be increased or decreased, while the width and depth of the power cabinet remain unchanged. The height of the power cabinet can be changed accordingly to assemble power units (2) with different numbers of layers.

3. The cascaded frequency converter power cabinet according to claim 1, characterized in that: The power cabinet is used as a single-phase output. Three power cabinets are connected together and a phase-shifting transformer is added to form a three-phase output system. For the requirement of cascaded frequency converters with multi-phase output, the number of phase-shifting transformers and power cabinets are increased accordingly.

4. A cascaded frequency converter power cabinet according to any one of claims 1-3, characterized in that: Each power unit (2) is divided into 3 modules: fuse (211), rectifier bridge (212), IGBT (213) and air cooler (214) are integrated into a power module (21) placed in the middle, and multiple bus capacitors (221) are divided into 2 bus capacitor modules (22) and symmetrically distributed on the left and right sides of the power module (21).

5. A cascaded frequency converter power cabinet according to claim 4, characterized in that: The power module (21) uses a three-phase uncontrolled rectifier, the IGBT (213) inverter outputs an H-bridge, and the rectifier input and inverter output of the power module (21) are located behind the power module (21); the A-phase and C-phase rectifier input terminals of the power module (21) are equipped with fuses (211).

6. A cascaded frequency converter power cabinet according to claim 4, characterized in that: The rectifier bridge (212) and IGBT (213) are mounted on the heat sink (214). Power module positive and negative stacked busbars (215) and H-bridge output busbars (216) are laid on the rectifier bridge (212) and IGBT (213). The bus capacitors (221) are arranged in an array. Bus capacitor positive and negative stacked busbars (222) are laid on the bus capacitor module (22). The bus capacitor positive and negative stacked busbars (222) and the power module positive and negative stacked busbars (215) are connected by short busbars (217).

7. A cascaded frequency converter power cabinet according to claim 4, characterized in that: The front door panel (16) of the single-layer cabinet (1) is provided with holes, and the rear door panel (17) of the cabinet (1) is provided with multiple fans (3); the front of the power module (21) and the capacitor module (22) is sealed with a sealing plate, and the power module sealing plate (18) in front of the heat sink (214) is provided with holes; the capacitor module sealing plate (19) in front of the capacitor module (22) is provided with ventilation holes.

8. A cascaded frequency converter power cabinet according to claim 4, characterized in that: The U-shaped sheet metal beam (11) is equipped with a power module guide rail tray (13) and a capacitor module guide rail tray (12) respectively, which are used to push the power module (21) and capacitor module (22) into the cabinet (1); the capacitor module guide rail tray (12) has outwardly opening guide ears (121) on both sides, and folded edges (122) on both sides, and the capacitor module guide rail tray (12) is folded into a U-shaped slot (123) at the back.

9. A cascaded frequency converter power cabinet according to claim 8, characterized in that: The power module guide rail tray (13) and the capacitor module guide rail tray (12) have the same structure.

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