Low-voltage cabinet of high-capacity photovoltaic box-type substation

Abstract

The utility model relates to the field of power grid switch cabinets, in particular to a low-voltage cabinet of a high-capacity photovoltaic box-type substation. A low-voltage cabinet of a large-capacity photovoltaic box-type substation comprises a cabinet body and a low-voltage distribution box connected with the cabinet body, the cabinet body is divided into an upper layer and a lower layer through a lower busbar, the cabinet body comprises a main cabinet and an auxiliary cabinet which are movably connected, a frame circuit breaker is installed on the upper layer of the main cabinet, and a plurality of lower-row molded case circuit breakers are arranged on the lower layer of the main cabinet. The plurality of lower-row molded case circuit breakers extend to the lower layer of the auxiliary cabinet and are sequentially arranged at intervals, the upper layer of the auxiliary cabinet is provided with a plurality of upper-row molded case circuit breakers and an upper busbar, and the upper layer of the auxiliary cabinet is also provided with a UPS (Uninterrupted Power Supply) system; according to the utility model, by designing the installation cross arms and the installation plates, various components are reasonably arranged in a limited space, and the molded case circuit breakers are divided into an upper row and a lower row for installation according to a multi-outgoing-line loop layout, so that the overall dimension of the whole low-voltage cabinet is reduced.

Description

Technical Field

[0001] The utility model relates to the field of power grid switch cabinets, in particular to a low-voltage cabinet of a large-capacity photovoltaic box-type substation. Background Art

[0002] With the global emphasis on sustainable energy and the introduction of relevant policies, photovoltaic power generation has achieved unprecedented development. The advancement of photovoltaic power generation technology has improved the efficiency of solar power generation, while large-scale production has reduced equipment costs, making large-scale photovoltaic power station construction possible. As a key electrical equipment in photovoltaic power generation systems, the market demand for new energy box transformers has expanded rapidly with the growth of new energy power generation projects.

[0003] The new energy photovoltaic box-type substation mainly includes a high-voltage room, a transformer room and a low-voltage room in terms of structure; the low-voltage cabinet in the low-voltage room is mainly equipped with main circuit breakers and branch circuit breakers, as well as matching control and protection components. The branch circuit breaker is connected to the string inverter used for photovoltaic grid connection. As the power of this type of inverter increases, its rated voltage is also increased from the original AC315V to the current AC800V. With the increase in the rated voltage and power of the string inverter, the selection and number of the molded case circuit breakers connected to it also change accordingly.

[0004] In recent years, the design capacity of box-type substations in distributed photovoltaic projects has become larger and larger, and the number of such AC800V rated voltage string inverters equipped in the projects has also increased accordingly, resulting in the number of molded case circuit breakers installed in the switch cabinet on the low-voltage side of the box-type substation to reach up to a dozen. However, users also require that the floor space of the box-type substation be as small as possible. Therefore, when designing the structure of such low-voltage cabinets, it is necessary to consider the electrical safety clearance of the corresponding voltage level and the overall heat dissipation performance of the low-voltage cabinet, as well as the reasonable arrangement of various components in the cabinet to make the size of the low-voltage cabinet as small as possible, thereby reducing the overall floor space of the box-type substation and meeting the user's use requirements. At the same time, when the low-voltage cabinet in the box-type substation is in use, it is necessary to upload various electrical and non-electrical quantity data and realize remote control functions. Utility Model Content

[0005] In view of the problems mentioned in the prior art, the utility model proposes a low-voltage cabinet for a large-capacity photovoltaic box-type substation, which can reasonably arrange various electrical components, reduce the overall size of the box-type substation, and realize remote monitoring of the box-type substation.

[0006] The utility model discloses a low-voltage cabinet for a large-capacity photovoltaic box-type substation, comprising a cabinet body and a low-voltage distribution box connected to the cabinet body, wherein the cabinet body is divided into an upper and lower layer by a lower bus bar, wherein the cabinet body comprises a main cabinet and an auxiliary cabinet which are movably connected, wherein a frame circuit breaker is installed on the upper layer of the main cabinet, and a plurality of lower-row molded case circuit breakers are arranged on the lower layer of the main cabinet, and the plurality of lower-row molded case circuit breakers are extended to the lower layer of the auxiliary cabinet and arranged in sequence at intervals, wherein a plurality of upper-row molded case circuit breakers and an upper bus bar are arranged on the upper layer of the auxiliary cabinet, wherein a UPS system is also arranged on the upper layer of the auxiliary cabinet; the upper ports of the upper-row molded case circuit breakers are connected to the upper bus bar by a branch bar, and the lower ports are connected to user cables, wherein the upper ports of the lower-row molded case circuit breakers are connected to the bus bar by a branch bar, and the lower ports are connected to user cables, wherein the frame circuit breaker is connected to the lower bus bar by a branch bar; and a measurement and control device connected to the cabinet body is also included.

[0007] Preferably, the UPS system is placed on the upper layer of the auxiliary cabinet through a first mounting plate, and the UPS system includes a connected UPS host and a UPS battery.

[0008] Preferably, it also includes a surge protector and a low-voltage fuse installed on the upper layer of the main cabinet.

[0009] Preferably, it also includes a knife-fuse switch arranged on the upper layer of the auxiliary cabinet, and the knife-fuse switch is connected to a control transformer arranged outside the cabinet.

[0010] Preferably, the upper busbar is placed on an upper busbar frame, and the lower busbar is placed on a lower busbar frame, wherein insulating pads are provided at the bottom of both the upper busbar frame and the lower busbar frame.

[0011] Preferably, the incoming and outgoing wires of the upper row of molded case circuit breakers and the lower row of molded case circuit breakers are connected by copper bars, wherein the upper row of molded case circuit breakers and the lower row of molded case circuit breakers are installed in the cabinet by installing cross braces.

[0012] Preferably, the lower openings of the upper row molded case circuit breakers are hung on a fixed support through an insulator, and the lower openings of the lower row molded case circuit breakers are hung on a fixed support through an insulator.

[0013] Preferably, a plurality of universal mold holes are provided in the cabinet body.

[0014] Preferably, it also includes an optical fiber box connected to the measurement and control device.

[0015] Preferably, it also includes an ammeter, a voltmeter and a temperature and humidity monitor connected to the measurement and control device.

[0016] Compared with the prior art, the utility model has achieved the following technical effects:

[0017] The utility model reasonably arranges various components in a limited space by designing and installing cross braces and mounting plates. At the same time, for the layout of multiple outgoing line loops, the molded case circuit breakers are installed in upper and lower rows. This arrangement can save internal space and reduce the overall size of the low-voltage cabinet.

[0018] The insulating pads, insulators and other materials are used to ensure the safe distance between the exposed live parts and the ground and between phases under AC800V voltage, meeting the requirements for safe and reliable operation. The measurement and control devices can realize functions such as remote control and remote monitoring, saving manpower for on-site inspection. The device has a compact structure and a reasonable layout. It has certain market value in the field of new energy, especially in distributed photovoltaic power generation, and is suitable for wide promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0020] Figure 2 It is a side view of the utility model;

[0021] Figure 3 This is a side view of the utility model from another angle;

[0022] Figure 4 It is a schematic diagram of the measurement and control device of the utility model.

[0023] Figure numerals: 1. frame circuit breaker; 2. lower row of molded case circuit breakers; 3. lower busbar; 4. upper busbar; 5. lower busbar frame; 6. upper row of molded case circuit breakers; 7. upper busbar frame; 8. knife fuse switch; 9. UPS battery; 10. UPS host; 11. low-voltage distribution box; 12. low-voltage fuse; 13. surge protector; 14. optical fiber box; 15. control transformer; 16. first mounting plate; 17. second mounting plate; 18. mounting cross brace; 19. side cross brace; 20. insulator; 21. cabinet; 22. measurement and control device; 23. ammeter; 24. voltmeter; 25. temperature and humidity monitor. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0025] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0027] like Figure 1 As shown, the utility model is a low-voltage cabinet for a large-capacity photovoltaic box-type substation, including a cabinet 21 and a low-voltage distribution box 11 connected to the cabinet 21, wherein the cabinet 21 is divided into an upper and lower layer by a lower bus 3, wherein the cabinet 21 includes a main cabinet and an auxiliary cabinet that are movably connected, wherein a frame circuit breaker 1 is installed on the upper layer of the main cabinet, and a plurality of lower-row molded case circuit breakers 2 are arranged on the lower layer of the main cabinet, and a plurality of lower-row molded case circuit breakers 2 are extended to the lower layer of the auxiliary cabinet and arranged in sequence, wherein a plurality of upper-row molded case circuit breakers 6 and an upper bus 4 are arranged on the upper layer of the auxiliary cabinet, wherein a UPS system is also arranged on the upper layer of the auxiliary cabinet; the upper port of the upper-row molded case circuit breaker 6 is connected to the upper bus 4 through a branch row, and the lower port is connected to the user cable, the upper port of the lower-row molded case circuit breaker 2 is connected to the bus through a branch row, and the lower port is connected to the user cable, wherein the frame circuit breaker 1 is connected to the lower bus 3 through a branch row; and also includes a measurement and control device 22 connected to the cabinet 21. The dimensions of a single cabinet 21 of the device are: 800 mm in width, 650 mm in depth, and 2200 mm in height. Only two cabinets are required to arrange the device, which saves at least one cabinet's space compared to conventional structures.

[0028] The UPS system is placed on the upper layer of the auxiliary cabinet through the first mounting plate 16. The UPS system includes a connected UPS host 10 and a UPS battery 9. Figure 1 As shown, the UPS system of this embodiment can provide a stable uninterrupted control power supply for the low-voltage cabinet. The UPS system is placed on a first mounting plate 16. The first mounting plate 16 is formed by bending a galvanized steel plate with a thickness of 1.5 mm to 2.5 mm and is provided with fixing holes that are connected to the low-voltage cabinet for placing the UPS system.

[0029] It also includes a surge protector 13 and a low-voltage fuse 12 installed on the upper layer of the main cabinet. The surge protector 13 and the low-voltage fuse 12 can provide overvoltage protection and induction lightning protection for the device. In this embodiment, the surge protector 13 and the low-voltage fuse 12 are installed on the upper layer of the main cabinet, and can also be installed on the upper layer of the auxiliary cabinet according to actual needs, and the installation method is switched according to different scenarios.

[0030] The auxiliary cabinet further comprises a knife-fuse switch 8 arranged on the upper layer of the auxiliary cabinet, and the knife-fuse switch 8 is connected to a control transformer 15 arranged outside the cabinet body 21 .

[0031] The upper busbar 4 is placed on the upper busbar frame 7, and the lower busbar 3 is placed on the lower busbar frame 5, wherein the upper busbar frame 7 and the lower busbar frame 5 are both provided with insulating pads at the bottom. Figure 1 As shown, the frame circuit breaker 1 is arranged on the second mounting plate 17, and the second mounting plate 17 is connected to the main cabinet. In this embodiment, the lower bus 3 is supported by three lower bus frames 5, and the upper bus 4 is supported by three upper bus frames 7, but it is not limited to this. The number of lower bus frames 5 or upper bus frames 7 can be increased or decreased as needed; the insulating pad is preferably 10 mm, made of SMC material, which is a high-performance composite material and can improve the electrical safety distance.

[0032] The inlet and outlet wires of the upper row molded case circuit breakers 6 and the lower row molded case circuit breakers 2 are connected by copper bars, wherein the upper row molded case circuit breakers 6 and the lower row molded case circuit breakers 2 are installed in the cabinet 21 by installing cross braces 18. Figure 1 , Figure 2 As shown, the mounting cross brace 18 of this embodiment is formed by bending a galvanized steel plate with a thickness of 1.5 mm to 3 mm, and a plurality of universal round holes or waist holes are provided on the surface of the mounting cross brace 18, which can fix components such as the upper row of molded case circuit breakers 6, the lower row of molded case circuit breakers 2, the insulators 20, the surge protector 13, etc. in the low-voltage cabinet.

[0033] The lower end of the upper molded case circuit breaker 6 is hung and fixedly supported by an insulator 20, and the lower end of the lower molded case circuit breaker 2 is hung and fixedly supported by an insulator 20. The insulator 20 can provide fixed support for the outgoing cables at the lower ends of the upper molded case circuit breakers 6 and the lower molded case circuit breakers 2, thereby ensuring that the lower molded case circuit breakers 2 and the upper molded case circuit breakers 6 will not shake as a whole.

[0034] The cabinet 21 is provided with a plurality of universal mold holes. The cabinet 21 of this embodiment is made of cold-rolled steel plate material, and includes a top plate, a bottom plate, a cabinet door, and a frame arranged between the top plate and the bottom plate. The entire cabinet 21 is provided with a plurality of universal mold holes with a spacing of 20 mm and 100 mm, and the universal mold holes can be used to facilitate the installation of various cross braces, mounting plates and other components of the device; a plurality of side cross braces 19 are arranged between the frames for reinforcement to improve the shell strength.

[0035] It also includes an optical fiber box 14 connected to the measurement and control device 22. It also includes an ammeter 23, a voltmeter 24 and a temperature and humidity monitor connected to the measurement and control device 22, such as Figure 4 As shown, the measurement and control device 22 of the present embodiment is a controller. The controller is a commonly used technology in the prior art and will not be elaborated here. The controller can be remotely connected to the background monitoring system. The measurement and control device 22 is arranged on the surface of the cabinet 21. The optical fiber box 14 provides remote communication for the measurement and control device 22. The measurement and control device 22 can monitor the current, current, voltage, active and reactive power, electricity, and ambient temperature and humidity of the low-voltage cabinet in real time through the set ammeter 23, voltmeter 24, and temperature and humidity monitor, and upload the data to the remote background monitoring system to realize remote monitoring.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A low-voltage cabinet for a large-capacity photovoltaic box-type substation, comprising a cabinet body and a low-voltage distribution box connected to the cabinet body, characterized in that: The cabinet is divided into two layers, upper and lower, by a lower busbar, wherein the cabinet comprises a main cabinet and an auxiliary cabinet that are movably connected, the upper layer of the main cabinet is equipped with a frame circuit breaker, the lower layer of the main cabinet is provided with a plurality of lower row molded case circuit breakers, the plurality of lower row molded case circuit breakers extend to the lower layer of the auxiliary cabinet and are arranged in sequence at intervals, the upper layer of the auxiliary cabinet is provided with a plurality of upper row molded case circuit breakers and an upper busbar, wherein the upper layer of the auxiliary cabinet is also provided with a UPS system; The upper port of the upper row molded case circuit breaker is connected to the upper busbar through a branch row, and the lower port is connected to the user cable. The upper port of the lower row molded case circuit breaker is connected to the busbar through a branch row, and the lower port is connected to the user cable, wherein the frame circuit breaker is connected to the lower busbar through a branch row; It also includes a measurement and control device connected to the cabinet.

2. According to the low-voltage cabinet of a large-capacity photovoltaic box-type substation according to claim 1, it is characterized in that: The UPS system is placed on the upper layer of the auxiliary cabinet through a first mounting plate, and the UPS system includes a connected UPS host and a UPS battery.

3. According to the low-voltage cabinet of a large-capacity photovoltaic box-type substation as described in claim 1, it is characterized in that: It also includes a surge protector and a low-voltage fuse installed on the upper layer of the main cabinet.

4. According to the low-voltage cabinet of a large-capacity photovoltaic box-type substation according to claim 1, it is characterized in that: It also includes a knife-fuse switch arranged on the upper layer of the auxiliary cabinet, and the knife-fuse switch is connected to a control transformer arranged outside the cabinet.

5. According to the low-voltage cabinet of a large-capacity photovoltaic box-type substation according to claim 1, it is characterized in that: The upper busbar is placed on the upper busbar frame, and the lower busbar is placed on the lower busbar frame, wherein insulating pads are provided at the bottom of the upper busbar frame and the bottom of the lower busbar frame.

6. According to the low-voltage cabinet of a large-capacity photovoltaic box-type substation according to claim 1, it is characterized in that: The inlet and outlet wires of the upper row molded case circuit breakers and the lower row molded case circuit breakers are connected by copper bars, wherein the upper row molded case circuit breakers and the lower row molded case circuit breakers are installed in the cabinet by installing cross braces.

7. According to the low-voltage cabinet of a large-capacity photovoltaic box-type substation according to claim 6, it is characterized in that: The lower openings of the upper row molded case circuit breakers are hung and fixedly supported by insulators, and the lower openings of the lower row molded case circuit breakers are hung and fixedly supported by insulators.

8. According to the low-voltage cabinet of a large-capacity photovoltaic box-type substation according to claim 1, it is characterized in that: The cabinet body is provided with a plurality of universal mold holes.

9. According to the low-voltage cabinet of a large-capacity photovoltaic box-type substation of claim 1, it is characterized in that: It also includes an optical fiber box connected to the measurement and control device.

10. A low voltage cabinet for a large-capacity photovoltaic box-type substation according to claim 9, characterized in that: It also includes an ammeter, a voltmeter and a temperature and humidity monitor connected to the measurement and control device.

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