35kV insulated cable line transition power supply device and application method

Abstract

The invention discloses a 35kV insulated cable line transition power supply device which comprises a shell, an insulated gas box, a single-side sleeve, a conducting rod and a cable plugging device. An insulating gas box is arranged in an inner cavity of the shell, and two single-side sleeves are arranged on the insulating gas box; two cable plugging devices are arranged on the shell; the two conducting rods are used for respectively connecting one group of corresponding single-side sleeves and the cable plugging device, and meanwhile, the conducting rods extend into the insulating gas tank and are communicated through the conducting connecting pieces. According to the assembly type transition cable device for the 35kV high-voltage distribution line, the SF6 gas box is adopted for insulation, the safety and reliability of a 35kV assembly type transition product are ensured, meanwhile, line loss is reduced, and the power transmission efficiency is improved; and gas insulation is adopted, so that the weight of the device is greatly reduced, and field power failure transition construction is facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-voltage electrical equipment, and specifically relates to a 35kV insulated cable line transition power supply device and an application method thereof. Background Art

[0002] With the comprehensive construction of the UHV power grid and the construction of supporting power grids, the overall architecture of the power system has been gradually upgraded. At this stage, the construction of the power grid faces many challenges, including the difficulty of power construction, safety risks and the continuous reliability of distribution network power supply. These problems directly affect the quality of life of the people and the stable operation of the power system.

[0003] In order to avoid power interruptions caused by construction or maintenance and ensure the stability and continuity of power supply, when carrying out equipment maintenance or line reconstruction in the power system, special technologies and equipment are used to ensure that power lines continue to be powered during construction. This process is called non-stop crossing.

[0004] The original non-stop crossing is mostly used for 10kV lines, but with the increase of voltage level, the proportion of non-stop crossing for 35kV lines is increasing. In 35kV distribution lines, the increase of insulation distance (from 0.7m for 10kV to 1m for 35kV) brings new challenges to the design and construction of transition cables.

[0005] The existing 10kV transition cable is epoxy resin solid insulation. The insulation of the solid material itself can meet the requirements of the 10kV voltage level after testing. However, under the action of the 35kV voltage level, the original resin insulation docking method cannot meet the insulation test requirements, and neither the withstand voltage value nor the partial discharge index can meet the test requirements. Simply increasing the thickness of the insulation layer cannot meet the safety and reliability requirements of the 35kV distribution line crossing, and cannot meet the safety and reliability requirements of the 35kV distribution network field power outage transition construction. Summary of the invention

[0006] The object of the present invention is to provide a 35kV insulated cable line transition power supply device and an application method which can meet the safety and reliability requirements of 35kV distribution network field power outage transition construction.

[0007] The 35kV insulated cable line transition power supply device provided by the present invention comprises a shell, an insulating gas box, a single-sided bushing, a conductive rod and a cable plugger; an insulating gas box is provided in the inner cavity of the shell, and two single-sided bushings are provided on the insulating gas box; two cable pluggers are provided on the shell; two conductive rods respectively connect a group of corresponding single-sided bushings and cable pluggers, and at the same time, the conductive rods extend into the insulating gas box and are connected through conductive connectors.

[0008] In one embodiment of the above device, the shell is divided into an upper shell and a lower shell that are joined together; installation grooves for the cable plug are respectively arranged on both sides of the lower edge of the upper shell and the upper edge of the lower shell, that is, the joining surfaces of the upper shell and the lower shell are located at the axial center plane of the cable plug.

[0009] In one embodiment of the above device, the insulating gas box is a rectangular hollow box, and the box body is made of stainless steel; the box is filled with SF6 gas as an insulating medium.

[0010] In one embodiment of the above device, the upper surface of the insulating gas box is provided with a pressing plate that can be connected and positioned with two single-sided bushings; the single-sided bushings are horizontally placed T-shaped pieces, and the two single-sided bushings are symmetrically fixed on the pressing plate of the insulating gas box.

[0011] In one embodiment of the above device, a conductive rod is arranged in the single-sided casing, and the conductive rod passes through the insulating gas box and extends into the insulating gas box; the bottom ends of the two conductive rods are connected by a special-shaped copper rod.

[0012] In one embodiment of the above device, a barometer is provided at a corner of the upper surface of the insulating gas box.

[0013] In one embodiment of the above device, the outer ends of both sides of the insulating gas box are connected to grounding copper bars, wherein the end of the grounding copper bar on one side is connected to the shell and is provided with an external connection stud; the grounding copper bars are tin-plated.

[0014] In one implementation manner of the above device, a line display is provided on the conductive rod.

[0015] In one embodiment of the above device, baffles extending out of the side walls are provided on the mating surfaces of the two side walls of the upper shell and the lower shell.

[0016] A method for applying the above 35kV insulated cable line transition power supply device, the steps of which are as follows:

[0017] 1. Confirm that all components are intact and there are no external interference factors;

[0018] 2. Place the insulating gas box accurately at the center of the lower shell, align the upper and lower shells, and fix them together; ensure that the two single-sided casings are accurately fixed on the top of the insulating gas box, and correctly connect the conductive rods to the inside of the single-sided casings, and connect the two conductive rods through the special-shaped copper rods; the external cables are connected to the conductive rods through the cable plugger to ensure good sealing;

[0019] 3. Ensure that the grounding copper busbar is correctly connected to the housing and external grounding studs to achieve good grounding protection;

[0020] 4. After the installation is completed, check the pressure of SF6 gas through the barometer to ensure that the pressure is within the normal range; check the line display to determine the charged condition of the conductive rod to ensure that the device is well insulated;

[0021] 5. Gradually pressurize the insulating gas box to check if there is any gas leakage; gradually power on the device and during the power supply process, monitor the readings of the voltmeter and the live display in real time to ensure that the equipment operates stably at the rated voltage;

[0022] 6. During the operation of the equipment, regularly check the air pressure reading to ensure that the insulating gas box is kept within the appropriate pressure range; regularly check the sealing condition to ensure that there is no air or water leakage; if any abnormality is found during operation, such as unstable voltage, reduced pressure in the insulating gas box, or abnormal live display, stop the operation immediately and check for faults;

[0023] 7. When disassembling the equipment, first cut off the power supply to ensure that the equipment is in a power-free state; gradually release the SF6 gas in the insulating gas box, and use special tools to disassemble components such as conductive rods and cable plugs; the disassembled equipment should be properly stored in a dry, well-ventilated environment to avoid corrosion or damage.

[0024] The beneficial effects of the present invention are as follows:

[0025] 1. Provides assembled transition cable devices for 35kV high-voltage distribution lines, using SF6 gas tanks for insulation, ensuring the safety and reliability of 35kV assembled transition products, while reducing line losses and improving power transmission efficiency;

[0026] 2. The use of gas insulation greatly reduces the weight of the device, making it easier to use in field power outage transition construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the axonometric structure of an embodiment of the present invention.

[0028] Figure 2 for Figure 1 Schematic diagram of the front view structure.

[0029] Figure 3 for Figure 1 Schematic diagram of the cross-sectional structure of the central insulating gas box and the single-sided bushing.

[0030] Figure 4 for Figure 3 Schematic diagram of the front view structure. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the relevant technical solutions. Obviously, the described embodiments are only part of the embodiments, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Combination Figure 1 and Figure 2 It can be seen that the 35kV insulated cable line transition power supply device disclosed in this embodiment includes a shell 1, an insulating gas box 2, a single-side bushing 3, a conductive rod 4 and a cable plugger 5.

[0033] An insulating gas box 2 is arranged at the bottom center of the inner cavity of the shell 1, and two single-sided sleeves 3 are symmetrically arranged on the top surface of the insulating gas box. The interiors of the two single-sided sleeves are connected to the conductive rod 4; two cable pluggers 5 are respectively arranged on the two side walls of the shell, and each conductive rod is connected to the external cable through the cable plugger.

[0034] The housing 1 is divided into an upper housing 11 and a lower housing 12. The lower edge of the upper housing 11 and the upper edge of the lower housing 12 are respectively provided with mounting grooves for the cable plug 5, that is, the facing surfaces of the upper housing 11 and the lower housing 12 are located at the axial center plane of the cable plug 5.

[0035] The butting surfaces of the two side walls of the upper shell 11 and the lower shell 12 are provided with baffles 13 extending out of the side walls for limiting the end faces of external cables.

[0036] like Figure 3 and Figure 4 As shown, the insulating gas box 2 is a rectangular hollow box, and the box body is made of 3mm304 stainless steel material through a stainless steel stamping air chamber forming process; the box is filled with SF6 gas as an insulating medium.

[0037] The insulation method of this embodiment is SF6 insulation. The insulation strength of SF6 gas is three times that of air, which ensures the safety and reliability of the gas box under high pressure conditions. The electric field distribution of this embodiment has passed various test data, including partial discharge test, voltage resistance test, and dynamic thermal stability test. It has the characteristics of full insulation, full enclosure, full protection, corrosion resistance, anti-fouling, anti-condensation, and anti-frost. The shell protection level can reach IP65.

[0038] At the same time, under the condition of meeting the gas pressure sealing, the weight of the box is reduced to less than 60kg, thus meeting the requirements of field manual construction.

[0039] The upper surface of the insulating gas box 2 is provided with a pressing plate 21 which can be connected and positioned with two single-sided bushings.

[0040] The single-sided bushing 3 is a horizontally placed T-shaped piece, and the two single-sided bushings are symmetrically fixed on the pressure plate 21 of the insulating gas box 2. A conductive rod 4 is arranged in the single-sided bushing, and the conductive rod passes through the insulating gas box and extends into the insulating gas box; the special-shaped copper rod 22 connects the bottom ends of the two conductive rods.

[0041] An externally purchased barometer 23 is provided at the corner of the upper surface of the insulating gas box 2. The air pressure in the insulating gas box can be observed through the barometer, and the insulation condition can be judged based on this.

[0042] The outer ends of both sides of the insulating gas box 2 are connected to grounding copper bars 24, and the end of the grounding copper bar on one side is connected to the housing 1 and is provided with an external stud for easy grounding operation. The grounding copper bars are all tinned.

[0043] One end of each of the two conductive rods 4 passes through the insulating gas box 2 from the side arm of the corresponding single-sided bushing 3, and the other end extends out of the housing 1 from the end of the single-sided bushing. A purchased line display 41 is provided on one of the conductive rods, which can be used to judge the charged condition of the conductive rod.

[0044] The other ends of the two conductive rods 4 are plugged into the cable plug 5 on the side wall of the housing 1, and are connected to external cables through the cable plug. A rubber sealing component is provided at the connection to enhance the waterproof performance.

[0045] The upper shell 11 is provided with observation windows for the charge display 41 and the voltmeter 23, and explosion-proof glass and a sealing ring are arranged in the observation window.

[0046] The components of this embodiment are connected by a thermal welding process to prevent gas leakage.

[0047] The method when using this power supply device is as follows:

[0048] 1. Make sure all components are intact, clean the work area, and ensure there are no external interference factors.

[0049] 2. Place the insulating gas box accurately at the center of the lower shell, align the upper and lower shells, and fix them together; ensure that the two single-sided casings are accurately fixed on the top of the insulating gas box, and correctly connect the conductive rods to the inside of the single-sided casing, and connect the two conductive rods through special-shaped copper rods; connect the external cables to the conductive rods through the cable plugger to ensure good sealing.

[0050] 3. Ensure that the grounding copper busbar is correctly connected to the shell and external grounding studs to achieve good grounding protection.

[0051] 4. After the installation is completed, check the pressure of SF6 gas through the pressure gauge installed on the insulating gas box to ensure that the gas pressure is within the normal range to ensure the insulation performance of the gas box; check the line display to determine the live condition of the conductive rod to ensure that the device is in a good insulation state to prevent safety risks in live operations.

[0052] 5. After ensuring that all connections are correct and well sealed, gradually pressurize and check each part of the device to ensure that there is no gas leakage; after confirming that all inspections of the device are normal, gradually power on and start the 35kV insulated cable line transition power supply device; during the power supply process, monitor the readings of the voltmeter and the live display in real time to ensure that the equipment operates safely and stably at the rated voltage.

[0053] 6. During the operation of the equipment, regularly check the air pressure reading on the barometer to ensure that the SF6 gas remains within the appropriate pressure range; regularly check the sealing of the cable plug to ensure that there is no air or water leakage; during operation, if any abnormality is found, such as unstable voltage, reduced pressure in the insulating gas box, or abnormal live display, the operation should be stopped immediately and the fault should be checked.

[0054] 7. When it is necessary to dismantle the equipment, first cut off the power supply to ensure that the equipment is in a power-free state; gradually release the SF6 gas in the insulating gas box, and use special tools to dismantle components such as conductive rods and cable plugs; the disassembled equipment should be properly stored in a dry, well-ventilated environment to avoid corrosion or damage.

[0055] The advantages of using this device are:

[0056] 1. Provides assembled transition cable devices for 35kV high-voltage distribution lines, using SF6 gas tanks for insulation, ensuring the safety and reliability of 35kV assembled transition products, while reducing line losses and improving power transmission efficiency;

[0057] 2. The use of gas insulation greatly reduces the weight of the device, making it easier to use in field power outage transition construction;

[0058] 3. The cables and docking box are plug-and-play, requiring no complicated installation steps and tools, making them quick and easy to use.

[0059] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although detailed descriptions have been made with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A 35kV insulated cable line transition power supply device, characterized in that: It includes a shell, an insulating gas box, a single-side casing, a conductive rod and a cable plugger; An insulating gas box is provided in the inner cavity of the shell, and two single-sided bushings are provided on the insulating gas box; two cable pluggers are provided on the shell; two conductive rods respectively connect a group of corresponding single-sided bushings and cable pluggers, and at the same time, the conductive rods extend into the insulating gas box and are connected through conductive connectors.

2. The 35kV insulated cable line transition power supply device according to claim 1, characterized in that: The shell is divided into an upper shell and a lower shell which are joined together; installation grooves for the cable plug are respectively arranged on both sides of the lower edge of the upper shell and the upper edge of the lower shell, that is, the joining surfaces of the upper shell and the lower shell are located at the axial center plane of the cable plug.

3. The 35kV insulated cable line transition power supply device according to claim 1, characterized in that: The insulating gas box is a rectangular hollow box, and the box body is made of stainless steel; the box is filled with SF6 gas as an insulating medium.

4. The 35kV insulated cable line transition power supply device according to claim 1, characterized in that: The upper surface of the insulating gas box is provided with a pressing plate which can be connected and positioned with two single-sided bushings; the single-sided bushings are horizontally placed T-shaped pieces, and the two single-sided bushings are symmetrically fixed on the pressing plate of the insulating gas box.

5. The 35kV insulated cable line transition power supply device according to claim 4, characterized in that: A conductive rod is arranged in the single-sided casing, and the conductive rod passes through the insulating gas box and extends into the insulating gas box; the bottom ends of the two conductive rods are connected by a special-shaped copper rod.

6. The 35kV insulated cable line transition power supply device according to claim 1, characterized in that: A barometer is provided at a corner of the upper surface of the insulating gas box.

7. The 35kV insulated cable line transition power supply device according to claim 1, characterized in that: The outer ends of both sides of the insulating gas box are connected to grounding copper bars, wherein the end of the grounding copper bar on one side is connected to the shell and is provided with an external connection stud; the grounding copper bars are tin-plated.

8. The 35kV insulated cable line transition power supply device according to claim 1, characterized in that: The conductive rod is provided with a line display.

9. The 35kV insulated cable line transition power supply device according to claim 2, characterized in that: The butting surfaces of the two side walls of the upper shell and the lower shell are provided with baffles extending out of the side walls.

10. A method for applying the 35kV insulated cable line transition power supply device according to any one of claims 1 to 9, wherein the steps are as follows:

1. Confirm that all components are intact and there are no external interference factors; 2. Place the insulating gas box accurately at the center of the lower shell, align the upper and lower shells, and fix them together; ensure that the two single-sided casings are accurately fixed on the top of the insulating gas box, and correctly connect the conductive rods to the inside of the single-sided casings, and connect the two conductive rods through the special-shaped copper rods; the external cables are connected to the conductive rods through the cable plugger to ensure good sealing; 3. Ensure that the grounding copper busbar is correctly connected to the housing and external grounding studs to achieve good grounding protection; 4. After the installation is completed, check the pressure of SF6 gas through the barometer to ensure that the pressure is within the normal range; check the line display to determine the charged condition of the conductive rod to ensure that the device is well insulated; 5. Gradually pressurize the insulating gas box to check if there is any gas leakage; gradually power on the device and during the power supply process, monitor the readings of the voltmeter and the live display in real time to ensure that the equipment operates stably at the rated voltage; 6. During the operation of the equipment, regularly check the air pressure reading to ensure that the insulating gas box is kept within the appropriate pressure range; regularly check the sealing condition to ensure that there is no air or water leakage; if any abnormality is found during operation, such as unstable voltage, reduced pressure in the insulating gas box, or abnormal live display, stop the operation immediately and check for faults; 7. When disassembling the equipment, first cut off the power supply to ensure that the equipment is in a power-free state; gradually release the SF6 gas in the insulating gas box, and use special tools to disassemble components such as conductive rods and cable plugs; The disassembled equipment should be properly stored in a dry and well-ventilated environment to avoid corrosion or damage.

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