A compact environmentally-friendly gas ring main-tie-point switch based on a front-mounted voltage transformer

Abstract

The application relates to the technical field of power distribution cabinets, in particular to a compact environment-friendly gas ring network cabinet based on a front-mounted voltage transformer, which comprises a fully-closed stainless steel box body, an operation panel, a cable chamber and a gas chamber filled with environment-friendly insulation gas, and further comprises a voltage transformer arranged in an independent front-mounted gas chamber below the operation panel, the front-mounted gas chamber is physically isolated from the cable chamber through an insulation partition plate, the high-voltage end of the voltage transformer is directly connected with a main bus through a sealing sleeve, and the low-voltage terminal of the voltage transformer extends to a secondary interface area of the operation panel. According to the application, the voltage transformer is front-mounted and integrated in the independent gas chamber below the operation panel, the independent front-mounted gas chamber completely releases the longitudinal space of the cable chamber, and the position conflicts of the voltage transformer with elbow cable joints and lightning arresters and other components in the fully-closed stainless steel box body are avoided; in combination with the ultra-short path of the high-voltage lead directly connected with the main bus and the modularized gas chamber, the cabinet size is still deeply compressed under the environment-friendly gas insulation condition, and the installation requirement of an extremely compact scene is met.

Description

Technical Field

[0001] This application relates to the field of distribution cabinet technology, specifically a compact environmentally friendly gas ring main unit based on a front-mounted voltage transformer. Background Technology

[0002] With the expansion of urban power grids and the upgrading of environmental protection requirements, medium-voltage ring main units are developing towards miniaturization, environmental friendliness, and high reliability. Traditional SF6 gas-insulated ring main units are being gradually phased out due to the strong greenhouse effect, while environmentally friendly gas insulation technologies such as dry air and nitrogen are becoming the new trend in the industry. However, the insulation strength of environmentally friendly gases is lower than that of SF6, forcing equipment to increase insulation spacing, which contradicts the goal of compact design.

[0003] To save space, existing compact environmentally friendly gas ring main units often place voltage transformers behind the cable compartment. This layout has significant drawbacks: maintenance or replacement requires disconnecting the cables and removing the rear cover, which is time-consuming and affects power supply continuity; it also competes with elbow cable joints, surge arresters, and other components for limited space, restricting the depth of the cabinet; and the high-voltage leads of the voltage transformers passing through the cable compartment are prone to partial discharge in the compact space. Therefore, there is an urgent need for a voltage transformer integration solution that can accommodate flexible layouts and overcome space limitations. Utility Model Content

[0004] This application provides a compact, environmentally friendly gas ring main unit based on a front-mounted voltage transformer, which can effectively solve the problems in the background technology.

[0005] To achieve the above objectives, this application provides the following technical solution: a compact environmentally friendly gas ring main unit based on a front-mounted voltage transformer, comprising a fully enclosed stainless steel enclosure, an operation panel, a cable compartment, and a gas chamber filled with environmentally friendly insulating gas.

[0006] It also includes a voltage transformer, which is located in an independent pre-air chamber below the operation panel. This pre-air chamber is physically isolated from the cable chamber by an insulating partition. The high-voltage end of the voltage transformer is directly connected to the main busbar through a sealed bushing, and its low-voltage terminal extends to the secondary interface area of ​​the operation panel.

[0007] Preferably, the pre-air chamber is located at the front end of the cable chamber.

[0008] Preferably, the insulating partition is an epoxy resin casting with a voltage equalization shielding layer on its surface. The shielding layer is connected to the grounding terminal of the fully enclosed stainless steel enclosure via a grounding lead.

[0009] Preferably, the pre-gas chamber is independently filled with dry air or nitrogen, and its gas pressure is 0.01-0.03 MPa higher than that of the cable chamber.

[0010] Preferably, the bottom of the pre-air chamber is provided with a pressure relief channel, and the pressure relief direction avoids the control panel and cable joint area.

[0011] Preferably, the high-voltage lead of the voltage transformer is ≤200mm in length, and the lead is wrapped with a solid insulation layer throughout.

[0012] Preferably, the operation panel integrates a live display, a pressure gauge, and a low-voltage terminal slot for a voltage transformer, and the slot adopts a blind-fit self-sealing interface.

[0013] Preferably, the front air chamber is a standardized module that is connected to the air chamber of the adjacent expansion unit via a flange, and the expansion units share the same secondary interface area of ​​the same operation panel.

[0014] Preferably, a pressure relief valve is installed at the end of the pressure relief channel, and the pressure relief valve is a solenoid valve.

[0015] Preferably, the interior of the fully enclosed stainless steel enclosure is further provided with a main switch chamber and an isolation structure. The main switch chamber is located near the operation panel, and the isolation structure is located inside the main switch chamber.

[0016] Compared with the prior art, the beneficial effects of this application are:

[0017] 1. This application integrates the voltage transformer into an independent air chamber below the operation panel. The independent front air chamber design completely frees up the longitudinal space of the cable compartment, avoiding positional conflicts between the voltage transformer and components such as elbow cable joints and surge arresters inside the fully enclosed stainless steel enclosure. Combined with the ultra-short path of the high-voltage lead directly connecting to the main busbar and the modular air chamber structure, a deeply compressed cabinet size is still achieved under environmentally friendly gas insulation conditions, meeting the installation requirements of extremely compact scenarios.

[0018] 2. The physically isolated independent gas chamber, combined with the epoxy resin insulating partition and the pressure equalization shielding layer design, blocks the risk of partial discharge; the front gas chamber is independently filled with higher pressure environmentally friendly gas to compensate for the insulation strength; the pressure relief device releases pressure in a directional manner to avoid the operating area, and together with the fully enclosed stainless steel box, a multi-protection system is formed to ensure long-term maintenance-free operation under high-density layout. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this application;

[0020] Figure 2 This is a schematic diagram of the internal structure of a fully enclosed stainless steel enclosure.

[0021] In the diagram: 1. Live indicator, 2. Control panel, 3. Pressure gauge, 4. Cable compartment, 5. Voltage transformer, 6. Main busbar, 7. Main switch compartment, 8. Isolation structure, 9. Fully enclosed stainless steel enclosure, 10. Pressure relief channel, 11. Environmentally friendly insulating gas chamber. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] In the description of this application, when a feature is referred to as "setting", "fixing", or "connecting" to another feature, it can be set, fixed, or connected to the other feature directly, or it can be set, fixed, or connected to the other feature indirectly.

[0024] Please see Figure 1-2 This application provides the following technical solution: a compact environmentally friendly gas ring main unit based on a front-mounted voltage transformer, including a fully enclosed stainless steel enclosure 9, an operation panel 2, a cable compartment 4, and a gas chamber 11 filled with environmentally friendly insulating gas.

[0025] It also includes a voltage transformer 5, which is located in an independent front air chamber below the operation panel 2. This front air chamber is physically isolated from the cable chamber 4 by an insulating partition. The high-voltage end of the voltage transformer 5 is directly connected to the main busbar 6 through a sealing sleeve, and its low-voltage terminal extends to the secondary interface area of ​​the operation panel 2.

[0026] Specifically, the voltage transformer 5 is encapsulated in an independent airtight cavity below the operation panel 2, and is completely separated from the cable compartment 4 by an epoxy resin insulating partition. The high-voltage end is directly connected to the main busbar 6 through a sealed bushing, eliminating the redundant leads that pass through the cable compartment in the traditional layout; the low-voltage terminal extends to the secondary interface of the operation panel 2 through a shielded cable to realize direct signal acquisition.

[0027] More specifically, voltage transformer maintenance can be completed in the operating area in front of the cabinet without disconnecting the cable or removing the back cover; the space compression ratio is improved, further releasing the longitudinal space of the cable compartment and avoiding interference with elbow joints and surge arresters; the high-voltage path is shortened to the shortest possible length, eliminating surface discharge in the compact space.

[0028] Furthermore, the pre-air chamber is located at the front end of the cable chamber 4.

[0029] Specifically, the front air chamber is embedded in the transition area between the operation panel 2 and the cable chamber 4, and its maintenance window is coaxially aligned with the removable cover of the operation panel 2, forming an integrated "panel-air chamber" maintenance channel.

[0030] More specifically, the voltage transformer 5 can be accessed simply by opening the control panel cover, thus shortening the operation time.

[0031] Furthermore, the insulating partition is an epoxy resin casting with a voltage equalization shielding layer on its surface. The shielding layer is connected to the grounding terminal of the fully enclosed stainless steel enclosure 9 via a grounding lead.

[0032] Specifically, epoxy resin partitions are cast and molded to wrap a metal grounding grid, forming an equipotential shielding layer; the grounding leads force the surface potential of the partitions to the ground potential of the enclosure 9, eliminating the electric field distortion between the gas chambers.

[0033] Furthermore, the pre-gas chamber is independently filled with dry air or nitrogen, and its gas pressure is 0.01-0.03 MPa higher than that of the cable chamber 4.

[0034] Specifically, the independent inflation system of the pre-filled air chamber maintains a positive pressure difference of 0.01-0.03 MPa and dynamically compensates for leaks through a differential pressure sensor; dry air and nitrogen are physically isolated from the gas in the cable chamber.

[0035] Furthermore, the bottom of the pre-air chamber is provided with a pressure relief channel 10, and the pressure relief direction avoids the operation panel 2 and the cable connector area.

[0036] Specifically, the outlet of the pressure relief channel 10 faces the lower side of the housing 9; in the event of an arc fault, the high-temperature gas is directionally discharged along a preset path.

[0037] Furthermore, the high-voltage lead of the voltage transformer 5 is ≤200mm in length, and the lead is wrapped with a solid insulation layer throughout.

[0038] Specifically, the high-voltage lead is integrally injection molded from silicone rubber and laid in a straight line from the high-voltage end of the voltage transformer 5 to the bus bushing 6, with a forced path constraint of ≤200mm.

[0039] Furthermore, the operation panel 2 integrates the low-voltage terminal slots of the live display 1, pressure gauge 3, and voltage transformer 5, and the slots adopt blind-plug self-sealing interfaces.

[0040] Specifically, the low-voltage terminal slot has a built-in O-ring seal and a spring pin. When inserted, the pin pierces the seal to make the circuit open. After insertion or removal, the seal automatically springs back to seal.

[0041] Furthermore, the front air chamber is a standardized module that is connected to the air chamber of the adjacent expansion unit via a flange, and the expansion units share the same secondary interface area of ​​the operation panel 2.

[0042] Specifically, the prefabricated flange with sealing groove on the side wall of the front air chamber allows the expansion unit to pass through the air chamber and share the secondary interface bus of the operation panel 2 when docking.

[0043] Furthermore, a pressure relief valve is installed at the end of the pressure relief channel 10, and the pressure relief valve is a solenoid valve.

[0044] Specifically, the solenoid valve is triggered by the microcomputer protection device inside the cabinet. After receiving a pressure change signal, it opens to release pressure within 5ms and automatically locks after the pressure returns to normal.

[0045] Furthermore, the interior of the fully enclosed stainless steel enclosure 9 is also provided with a main switch chamber 7 and an isolation structure 8. The main switch chamber 7 is located near the operation panel 2, and the isolation structure 8 is located inside the main switch chamber 7.

[0046] Specifically, the main switch chamber 7 is located adjacent to the rear of the operating panel 2 and is directly driven by a mechanical interlocking shaft; the isolation structure 8 is embedded in the main switch chamber 7 to form a "chamber within a chamber" double isolation barrier.

[0047] When using:

[0048] 1. Routine monitoring and operation

[0049] Live monitoring: The live status of the cabinet can be observed in real time through the live display 1 integrated in the operation panel 2;

[0050] Pressure check: Check pressure gauge 3 to confirm the pressure values ​​of the pre-air chamber and cable chamber 4 (dry air / nitrogen should be maintained at a pressure difference of 0.01-0.03 MPa);

[0051] Voltage sampling: The low-voltage terminal of voltage transformer 5 is directly connected to the secondary equipment via a blind-plug interface to transmit the bus voltage signal in real time.

[0052] 2. Voltage transformer maintenance

[0053] Power-off operation: Disconnect the isolation structure 8 of the main switch chamber 7 and confirm the tripping via the mechanical interlock shaft;

[0054] Quick inspection:

[0055] Open the inspection window for voltage transformer 5;

[0056] The plug-in blind-plug self-sealing interface allows for terminal replacement without touching the internal components of the cable compartment 4;

[0057] Resumption of operation: Close the maintenance window and shut down the isolation structure 8.

[0058] 3. Main switch operation

[0059] Closing: Energy is stored in the energy storage mechanism 5 of the operation panel 2, triggering the action of the main switch chamber 7 mechanism;

[0060] Trip: Operate the trip button to achieve visual separation of the isolation structure with 8 double breaks.

[0061] 4. Emergency troubleshooting

[0062] Arc pressure relief: When a fault inside the cabinet causes a sudden increase in gas pressure, the solenoid valve opens within 5ms, and high-temperature gas is sprayed down along the directional side of the pressure relief channel 10.

[0063] Intelligent interlock: The solenoid valve automatically closes after the pressure returns to normal, and the microcomputer protection device records the action event.

[0064] 5. Modular expansion installation

[0065] Splicing unit: The standardized pre-air chamber is extended by connecting the unit through the flange, and the air chamber is connected and sealed tightly;

[0066] Interface integration: The low-voltage terminal of the voltage transformer 5 of the expansion unit is connected to the secondary interface bus of the original operation panel 2;

[0067] Pressure balance: Activate the independent inflation system to maintain a positive pressure difference of 0.01-0.03 MPa in the expansion unit's air chamber.

[0068] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A compact environmentally friendly gas ring main unit based on a pre-loaded voltage transformer, comprising a fully enclosed stainless steel enclosure (9), an operation panel (2), a cable compartment (4), and a gas chamber (11) filled with environmentally friendly insulating gas, characterized in that: It also includes a voltage transformer (5), which is located in an independent pre-air chamber below the operation panel (2). This pre-air chamber is physically isolated from the cable chamber (4) by an insulating partition. The high-voltage end of the voltage transformer (5) is directly connected to the main busbar (6) through a sealing sleeve, and its low-voltage terminal extends to the secondary interface area of ​​the operation panel (2).

2. The ring main unit according to claim 1, characterized in that: The pre-air chamber is located at the front end of the cable chamber (4).

3. The ring main unit according to claim 1, characterized in that: The insulating partition is an epoxy resin casting with a voltage equalization shielding layer on its surface. The shielding layer is connected to the grounding terminal of the fully enclosed stainless steel box (9) through a grounding lead.

4. The ring main unit according to claim 1, characterized in that: The pre-filled air chamber is independently filled with dry air or nitrogen, and its gas pressure is 0.01-0.03 MPa higher than that of the cable chamber (4).

5. The ring main unit as described in claim 1, characterized in that: The bottom of the pre-air chamber is provided with a pressure relief channel (10), and the pressure relief direction avoids the operation panel (2) and the cable joint area.

6. The ring main unit as described in claim 1, characterized in that: The voltage transformer (5) has a high voltage lead length of ≤200mm, and the lead is wrapped with a solid insulation layer throughout.

7. The ring main unit as described in claim 1, characterized in that: The operation panel (2) integrates the low-voltage terminal slots of the live display (1), pressure gauge (3) and voltage transformer (5), and the slots adopt blind-insertion self-sealing interfaces.

8. The ring main unit as described in any one of claims 1-7, characterized in that: The pre-air chamber is a standardized module that is connected to the air chamber of the adjacent expansion unit through a flange, and the expansion units share the same secondary interface area of ​​the same operation panel (2).

9. The ring main unit as described in claim 5, characterized in that: A pressure relief valve is installed at the end of the pressure relief channel (10), and the pressure relief valve is a solenoid valve.

10. The ring main unit as described in claim 5, characterized in that: The fully enclosed stainless steel enclosure (9) also includes a main switch chamber (7) and an isolation structure (8). The main switch chamber (7) is located near the operating panel (2), and the isolation structure (8) is located inside the main switch chamber (7).

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