Low-voltage cabinet and box-type substation

Abstract

The utility model discloses a low -voltage cabinet and box -type substation. This low -voltage cabinet includes the cabinet body, and the inside of cabinet body is equipped with: the universal circuit breaker, and is installed in the intermediate position of cabinet body upper portion, the output busbar is connected with the outgoing line end of universal circuit breaker through busbar row electricity, and extends to both sides, first switch and second switch, and the universal circuit breaker is arranged in the left and right sides, and incoming line end all are connected with output busbar electricity, and first group and second group outgoing line switch are installed in the lower part of cabinet body, and are arranged along the width direction and are respectively connected with corresponding switch upper and lower corresponding and electricity. The layout makes output busbar outgoing line, and the shunt, reduces the section of busbar, and increases the outgoing line loop number. The lower part of cabinet body is equipped with the retracted section, and forms the stepped shape appearance of big down small, is used for avoiding transformer base and forms the bottom air inlet channel. Still disclosed the box -type substation containing this low -voltage cabinet.

Description

Technical Field

[0001] This utility model relates to the field of low-voltage power distribution equipment technology, specifically to a low-voltage switchgear and a prefabricated substation containing the low-voltage switchgear. Background Technology

[0002] A prefabricated substation (referred to as "prefabricated substation") is a compact power distribution device that integrates high-voltage switchgear, distribution transformer and low-voltage power distribution equipment according to a certain wiring scheme. It is widely used in residential communities, industrial and mining enterprises, public facilities and new energy charging stations.

[0003] With the rapid development of high-power electricity consumption scenarios such as supercharging stations, the market has put forward a contradictory demand for prefabricated substations: "maximum capacity and minimum size." The layout of traditional low-voltage switchgear has the following shortcomings: First, the busbar connection path between the universal circuit breaker and the knife switch and outgoing switch is long, and the current of multiple outgoing circuits is superimposed on the common busbar section, which means that the busbar cross-section must be designed according to the total current, increasing material costs and power loss; Second, the layout of various functional components in the cabinet is loose, resulting in low space utilization, and the cabinet volume is large in order to accommodate more outgoing circuits.

[0004] Therefore, how to optimize the internal layout and external structure of low-voltage switchgear, and reduce the overall size of the switchgear and transformer while ensuring electrical performance, has become a technical problem that urgently needs to be solved in this field. Utility Model Content

[0005] The purpose of this utility model is to provide a low-voltage switchgear that optimizes the spatial layout of the universal circuit breaker, knife switch and outgoing switch and the busbar connection structure, shortens the main circuit conductive circuit length, reduces the busbar cross-section, and improves the space utilization rate inside the cabinet, thereby achieving more outgoing circuits within a limited cabinet width.

[0006] Another objective of this utility model is to provide a prefabricated substation that includes the aforementioned low-voltage switchgear. By improving the external structure of the low-voltage switchgear, it achieves a compact side-by-side arrangement with the transformer, shortens the overall length of the prefabricated substation, and improves the heat dissipation conditions of the transformer.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] Firstly, a low-voltage switchgear is provided, comprising a cabinet, the cabinet containing: a universal circuit breaker installed in the upper middle position of the cabinet; an output busbar electrically connected to the outgoing terminals of the universal circuit breaker via a busbar, extending from the universal circuit breaker to both sides; a first disconnect switch and a second disconnect switch respectively installed on the left and right sides of the universal circuit breaker, the incoming terminals of the first disconnect switch and the second disconnect switch being electrically connected to the output busbar; the lower front width of the cabinet is used to install a first set of outgoing switches and a second set of outgoing switches; the outgoing switches of the first set of outgoing switches are arranged sequentially along the width direction of the cabinet, their arrangement area corresponding to the position of the first disconnect switch in the vertical direction, and the input terminals of the first set of outgoing switches are electrically connected to the output terminals of the first disconnect switch; the outgoing switches of the second set of outgoing switches are arranged sequentially along the width direction of the cabinet, their arrangement area corresponding to the position of the second disconnect switch in the vertical direction, and the input terminals of the second set of outgoing switches are electrically connected to the output terminals of the second disconnect switch.

[0009] Furthermore, a reactive power compensation switch is installed on the right side of the universal circuit breaker, and the incoming terminal of the reactive power compensation switch is electrically connected to the middle of the busbar.

[0010] Furthermore, the output terminal of the reactive power compensation switch is connected to the first reactive power compensation unit and the second reactive power compensation unit. The first reactive power compensation unit and the second reactive power compensation unit are respectively installed above the first disconnect switch and the second disconnect switch. The rear side of the housing of the first reactive power compensation unit and the second reactive power compensation unit are provided with heat dissipation ducts that exhaust air towards the upper rear of the cabinet. An air outlet corresponding to the heat dissipation duct is opened on the rear side of the top plate of the cabinet.

[0011] Furthermore, an isolation baffle is provided inside the cabinet between the first set of outgoing switches and the second set of outgoing switches.

[0012] Furthermore, a rear installation space is formed behind the first set of outgoing switches and the second set of outgoing switches inside the cabinet, and a reactive power compensation unit group is installed in the rear installation space; a side door is opened on one side of the cabinet, and the side door corresponds to the position of the rear installation space, which is used for the installation and / or maintenance of the reactive power compensation unit group.

[0013] Furthermore, it also includes a load management unit, which is fixed to the inner wall of the cabinet by a mounting bracket.

[0014] Furthermore, it also includes a third set of outgoing switches, which are fixed to the inner wall of the cabinet by a mounting bracket.

[0015] Furthermore, the lower rear side of the cabinet is provided with a recessed section that extends inward toward the interior of the cabinet, so that the cabinet forms a stepped outline with a greater depth at the top and a smaller depth at the bottom in the depth direction.

[0016] Furthermore, the recessed section is located at the rear lower part of the cabinet, which is used to provide clearance space for the protruding base of the transformer when it is installed in the same enclosure as the transformer, and to form an air intake channel at the bottom of the transformer to increase the heat dissipation efficiency of the transformer from the bottom.

[0017] Secondly, a prefabricated substation is provided, comprising a transformer and a low-voltage switchgear as described in any of the above claims, wherein the transformer and the low-voltage switchgear are arranged side by side inside the prefabricated substation enclosure, and the low-voltage output terminal of the transformer is electrically connected to the input terminal of the universal circuit breaker.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The main circuit conductive loop is shortened, and the busbar cross-section is reduced. The output busbar extends from the outgoing terminal of the universal circuit breaker to both sides via a busbar, connecting to the incoming terminals of the first and second disconnect switches on the left and right sides respectively, realizing a current path topology of "first splitting the current, then supplying power accordingly". The load current of the two sets of outgoing switches will not flow through the same section of busbar at the same time. Each side of the busbar only needs to carry the maximum operating current of the corresponding side, eliminating the need to design the busbar cross-section according to the total current of the two sets, thereby reducing the total cross-sectional area of ​​the busbar, reducing the amount of busbar used, and lowering material costs and power loss.

[0020] The cabinet has high width utilization and a large number of outgoing circuits. Two sets of outgoing switches are arranged sequentially along the width of the cabinet, and their arrangement areas correspond to the positions of the first and second disconnect switches in the vertical direction, respectively. This makes the connection path from the disconnect switch to the outgoing switch more direct in the vertical direction, and the two sets of outgoing switches can jointly occupy most of the width space in the lower front part of the cabinet, making full use of the cabinet width to arrange more outgoing circuits.

[0021] The reactive power compensation architecture is reasonable and has good heat dissipation. The reactive power compensation switch draws power from the middle of the busbar, and the outgoing lines are connected to two reactive power compensation units, which are installed above the two knife switches respectively. This balances the space utilization on the left and right sides of the cabinet and directs the heat dissipation air ducts of the reactive power compensation units toward the upper rear of the cabinet. Utilizing the principle of natural upward movement of hot air, the air is smoothly discharged through the air outlet on the rear side of the top plate of the cabinet, improving heat dissipation efficiency.

[0022] The space is partitioned for convenient utilization and maintenance. A rear installation space is formed behind the outgoing switch, which can be used to install equipment such as reactive power compensation units, realizing a front-to-back partitioned layout in the depth direction of the cabinet; a side door is opened on the side of the cabinet, allowing operators to directly install and maintain the rear equipment from the side without disassembling the front outgoing switch.

[0023] The cabinet's shape has been optimized, resulting in a more compact overall design. A recessed section is located at the lower rear of the cabinet, creating a stepped shape that tapers from bottom to top in the depth direction. When installed side-by-side with the transformer, this recessed section provides clearance for the transformer's protruding base, allowing the low-voltage cabinet and transformer to be installed compactly side-by-side in the depth direction, thus shortening the overall length of the transformer. At the same time, the recessed section increases the air intake channel between the bottom of the transformer and the bottom of the transformer, allowing cool air to enter the transformer more smoothly and improving the efficiency of natural ventilation and heat dissipation. Attached Figure Description

[0024] Figure 1 This is a front view schematic diagram of the internal component layout of the low-voltage cabinet of this utility model.

[0025] Figure 2 This is a rear view schematic diagram of the internal component layout of the low-voltage cabinet of this utility model.

[0026] Figure 3 This is a side sectional view of the low-voltage switchgear of this utility model in the depth direction, showing the relative positional relationship of the front outgoing switch, the rear mounting space and the rear lower recessed section.

[0027] Figure 4 This is a top view of the prefabricated substation of this utility model, showing the side-by-side arrangement of the low-voltage switchgear and the transformer.

[0028] Reference numerals: 1-Cabinet; 2-Universal circuit breaker; 3-Bus busbar; 4-Output busbar; 5-First disconnect switch; 6-Second disconnect switch; 7-First set of outgoing switches; 8-Second set of outgoing switches; 9-Reactive power compensation switch; 10-First reactive power compensation unit; 11-Second reactive power compensation unit; 12-Heat dissipation duct; 13-Air outlet; 14-Isolation baffle; 15-Rear installation space; 16-Reactive power compensation unit group; 17-Side door; 18-Load management unit; 19-Recessed section; 20-Transformer; 21-Substation enclosure. Detailed Implementation

[0029] The technical solution of this utility model will now be described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of this utility model.

[0030] It should be noted that in the description of this utility model, the terms "upper," "lower," "left," "right," "front," and "rear" indicate the relative positional relationship as determined by the operator facing the front door of the low-voltage switchgear under normal operating conditions of the prefabricated substation. The term "electrical connection" should be interpreted broadly, including direct connection and indirect connection through intermediate components such as switching devices and busbars.

[0031] Example 1: Low-voltage switchgear

[0032] See Figures 1 to 3 This embodiment provides a low-voltage cabinet, including a cabinet body 1. The cabinet body 1 is made of metal sheet and has a front door (not shown in the figure), a rear side panel, left and right side panels and a top panel. The interior is divided into multiple functional areas by partitions or beams.

[0033] A universal circuit breaker 2 is installed inside the cabinet 1, located in the upper middle position of the cabinet 1. The universal circuit breaker 2 is a common component in this field, with an input terminal and an output terminal, used to connect, carry, and disconnect current under normal circuit conditions, and to connect, carry, and disconnect current under abnormal circuit conditions under specified conditions.

[0034] The outgoing terminals of the universal circuit breaker 2 are electrically connected to the output busbar 4 via the busbar 3. The busbar 3 is a three-phase copper busbar that extends backward from the outgoing terminals of the universal circuit breaker 2 to connect to the output busbar 4. Specifically, the output busbar 4 extends to the left and right sides from the universal circuit breaker 2, forming a left-side output busbar and a right-side output busbar.

[0035] The first disconnect switch 5 and the second disconnect switch 6 are respectively installed on the left and right sides of the universal circuit breaker 2. The incoming terminal of the first disconnect switch 5 is electrically connected to the left output busbar, and the incoming terminal of the second disconnect switch 6 is electrically connected to the right output busbar. The first disconnect switch 5 and the second disconnect switch 6 are common disconnect switches in this field, used to establish a reliable insulation gap after the circuit breaker is opened, isolating the equipment or line requiring maintenance from the power supply and ensuring the safety of maintenance personnel.

[0036] The lower front width of cabinet 1 is used to install the first set of outgoing switches 7 and the second set of outgoing switches 8. The outgoing switches of the first set of outgoing switches 7 are arranged sequentially along the width of the cabinet (i.e., left-right direction), and their arrangement area corresponds to the installation position of the first disconnect switch 5 in the vertical direction. Similarly, the outgoing switches of the second set of outgoing switches 8 are arranged sequentially along the width of the cabinet, and their arrangement area corresponds to the installation position of the second disconnect switch 6 in the vertical direction. The outgoing switches can be molded case circuit breakers or other commonly used outgoing protection switching devices in the art. In this embodiment, the first set of outgoing switches 7 and the second set of outgoing switches 8 each have four outgoing switches.

[0037] The input terminal of the first set of outgoing switches 7 is electrically connected to the output terminal of the first disconnect switch 5 via a connecting busbar, and the input terminal of the second set of outgoing switches 8 is electrically connected to the output terminal of the second disconnect switch 6 via a connecting busbar. Since the output terminal of the first disconnect switch 5 is directly opposite the arrangement area of ​​the first set of outgoing switches 7 in the vertical direction, the connecting busbar can extend directly downwards in the vertical direction, resulting in a short path and few bends. Similarly, the connecting busbar between the second disconnect switch 6 and the second set of outgoing switches 8 is also relatively direct.

[0038] With the above layout, the current output from the universal circuit breaker 2 is split via the main busbar 3 and the output busbar 4, and enters the first disconnect switch 5 and the second disconnect switch 6 respectively, thereby supplying power to the first set of outgoing switches 7 and the second set of outgoing switches 8 respectively. The load current of the two sets of outgoing switches will not flow through the same section of the busbar at the same time. Each side of the busbar only needs to carry the maximum operating current of that side, and the cross-sectional area of ​​the busbar can be designed according to the maximum current on one side, effectively reducing the total cross-sectional area of ​​the busbar.

[0039] A reactive power compensation switch 9 is installed on the right side of the universal circuit breaker 2. The incoming terminal of the reactive power compensation switch 9 is electrically connected to the middle of the busbar 3 and draws power directly from the busbar 3. The outgoing terminals of the reactive power compensation switch 9 are connected to the first reactive power compensation unit 10 and the second reactive power compensation unit 11, respectively. The first reactive power compensation unit 10 is installed above the first disconnect switch 5, and the second reactive power compensation unit 11 is installed above the second disconnect switch 6. The reactive power compensation unit can be an SVG (Static Var Generator), a capacitor bank, or other reactive power compensation devices commonly used in the art.

[0040] Both the first reactive power compensation unit 10 and the second reactive power compensation unit 11 have heat dissipation ducts 12 on their rear sides, facing the upper rear of the cabinet 1. An air outlet 13, corresponding to the position of the heat dissipation duct 12, is located on the rear side of the top plate of the cabinet 1. The heat generated by the reactive power compensation units during operation is discharged from the upper rear of the cabinet through the heat dissipation ducts 12 and the air outlet 13. Due to the natural upward movement of hot air, this heat dissipation path utilizes the principle of natural convection, resulting in high heat dissipation efficiency.

[0041] An isolation baffle 14 is installed inside the cabinet 1 between the first set of outgoing switches 7 and the second set of outgoing switches 8. The isolation baffle 14 is installed vertically between the two sets of outgoing switches to prevent accidental contact with the live parts of the other set of outgoing switches when one set of outgoing switches is de-energized, thereby improving electrical safety.

[0042] A rear installation space 15 is formed behind the first set of outgoing switches 7 and the second set of outgoing switches 8 inside the cabinet 1. Since the two sets of outgoing switches are installed at the lower front of the cabinet, the depth space behind them (i.e., near the rear side panel of the cabinet) can still be utilized. The reactive power compensation unit group 16 or other auxiliary equipment can be installed in the rear installation space 15. A side door 17 is opened on the right (or left) side of the cabinet 1, and the position of the side door 17 corresponds to the rear installation space 15. Operators can open the side door 17 to install, wire, and perform routine maintenance on the equipment in the rear installation space 15 from the side of the cabinet without having to open the front door to remove the outgoing switches, making operation convenient.

[0043] A load management unit 18 is also fixed to the inner wall of the cabinet 1 by a mounting bracket. The load management unit 18 can be installed on the inner wall of the right or left side panel of the cabinet 1, located to the side of the installation area of ​​the universal circuit breaker 2, which facilitates data acquisition and communication wiring.

[0044] Example 2: Improvement of Cabinet Shape

[0045] See also Figure 3 Based on the above embodiment 1, this embodiment further improves the outer contour of the cabinet.

[0046] The lower rear side of the cabinet 1 is provided with a recessed section 19 that extends inward toward the interior of the cabinet. This recessed section 19 gives the cabinet 1 a stepped profile with a greater depth at the top and a smaller depth at the bottom in the depth direction (i.e., the front-to-back direction). The recessed depth and height of the recessed section 19 can be designed according to the size of the transformer base it is used with, and are generally 50mm to 300mm.

[0047] Example 3: Prefabricated Substation

[0048] See Figure 4 This embodiment provides a prefabricated substation, including a transformer 20 and a low-voltage switchgear as described in Embodiment 1 or Embodiment 2 above. The transformer 20 and the low-voltage switchgear are arranged side by side inside the substation housing 21. The high-voltage side of the transformer 20 is connected to the high-voltage incoming line equipment (not shown in the figure), and the low-voltage outgoing line of the transformer 20 is electrically connected to the incoming line of the universal circuit breaker 2 inside the low-voltage switchgear via a busbar or cable.

[0049] The transformer 20 has a protruding transformer base (not shown) at its lower part for supporting and fixing the transformer body. Since the low-voltage switchgear cabinet 1 has a recessed section 19 at its rear bottom, the recessed section 19 provides clearance for the transformer base, allowing the low-voltage switchgear and transformer 20 to be arranged more compactly side by side in the depth direction, thus shortening the overall length of the transformer enclosure 21.

[0050] Because the recessed section 19 at the lower rear of cabinet 1 is recessed towards the interior of the cabinet, a larger air intake channel is formed between the bottom of transformer 20 and the bottom of transformer housing 21. External cold air can smoothly enter the bottom of transformer 20 through this air intake channel, flow upward through the internal air duct of the transformer, and carry away the heat generated by the transformer operation, thereby improving the natural ventilation and heat dissipation efficiency of the transformer.

[0051] The prefabricated substation of this embodiment is particularly suitable for scenarios such as supercharging stations that require large-capacity, small-volume prefabricated substations. Through its compact internal layout and recessed external design, the low-voltage switchgear effectively reduces the overall footprint of the prefabricated substation while ensuring the number of outgoing circuits and electrical performance, and improves transformer heat dissipation efficiency, thus meeting the supercharging station's requirement for "increased capacity and reduced size" in prefabricated substations.

[0052] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A low-voltage switchgear, comprising a cabinet body, characterized in that, The cabinet interior is equipped with: A universal circuit breaker is installed in the middle of the upper part of the cabinet. The output busbar is electrically connected to the output terminal of the universal circuit breaker via a busbar, and extends to both sides from the universal circuit breaker. The first disconnect switch and the second disconnect switch are respectively installed on the left and right sides of the universal circuit breaker. The incoming terminals of the first disconnect switch and the second disconnect switch are electrically connected to the output busbar. The lower front width of the cabinet is used to install the first set of outgoing switches and the second set of outgoing switches. Each of the outgoing switches in the first group is arranged sequentially along the width of the cabinet, and the arrangement area corresponds to the position of the first knife switch in the vertical direction. The input terminal of the first group of outgoing switches is electrically connected to the output terminal of the first knife switch. The outgoing switches of the second group are arranged sequentially along the width of the cabinet, and their arrangement area corresponds to the position of the second knife switch in the vertical direction. The input terminal of the second group of outgoing switches is electrically connected to the output terminal of the second knife switch.

2. The low-voltage switchgear according to claim 1, characterized in that, A reactive power compensation switch is installed on the right side of the universal circuit breaker, and the incoming terminal of the reactive power compensation switch is electrically connected to the middle of the busbar.

3. The low-voltage switchgear according to claim 2, characterized in that, The output terminal of the reactive power compensation switch is connected to the first reactive power compensation unit and the second reactive power compensation unit. The first reactive power compensation unit and the second reactive power compensation unit are respectively installed above the first disconnect switch and the second disconnect switch. The rear side of the housing of the first reactive power compensation unit and the second reactive power compensation unit are provided with heat dissipation ducts that exhaust air towards the upper rear of the cabinet. An air outlet corresponding to the heat dissipation duct is opened on the rear side of the top plate of the cabinet.

4. The low-voltage switchgear according to claim 1, characterized in that, An isolation baffle is provided inside the cabinet between the first set of outgoing switches and the second set of outgoing switches.

5. The low-voltage switchgear according to claim 1, characterized in that, The cabinet has a rear installation space behind the first set of outgoing switches and the second set of outgoing switches, and a reactive power compensation unit group is installed in the rear installation space; a side door is opened on one side of the cabinet, and the side door corresponds to the position of the rear installation space, which is used for the installation and / or maintenance of the reactive power compensation unit group.

6. The low-voltage switchgear according to claim 1, characterized in that, It also includes a load management unit, which is fixed to the inner wall of the cabinet by a mounting bracket.

7. The low-voltage switchgear according to claim 1, characterized in that, It also includes a third set of outgoing switches, which are fixed to the inner wall of the cabinet by a mounting bracket.

8. The low-voltage switchgear according to claim 1, characterized in that, The lower rear side of the cabinet has a recessed section that extends inwards, giving the cabinet a stepped profile with a greater depth at the top and a smaller depth at the bottom.

9. The low-voltage switchgear according to claim 8, characterized in that, The recessed section is located at the rear lower part of the cabinet. It is used to provide clearance for the protruding base of the transformer when it is installed in the same enclosure as the transformer, and to form an air intake channel at the bottom of the transformer to increase the heat dissipation efficiency of the transformer from the bottom.

10. A prefabricated substation, characterized in that, The device includes a transformer and a low-voltage switchgear as described in any one of claims 1 to 9, wherein the transformer and the low-voltage switchgear are arranged side by side inside the transformer housing, and the low-voltage output terminal of the transformer is electrically connected to the input terminal of the universal circuit breaker.

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