An apparatus and method for modifying cellulose insulating paper using low-temperature plasma.

Abstract

This invention provides an apparatus and method for modifying cellulose insulating paper using low-temperature plasma. The treatment zone utilizes four sets of discharge components for double-sided treatment of the insulating paper. Each set of discharge components is introduced with different gases and media. The treatment sequence is as follows: Ar is introduced into the surface activation group, Ar / HMDSO into the hydrophobic film deposition group, Ar / OMCTS into the insulation performance enhancement group, and Ar / APTES into the mechanical reinforcement group. The flow rate of the media is constrained, and a method for matching the treatment speed and spacing is proposed to ensure treatment efficiency and effectiveness. This invention treats insulating paper under atmospheric pressure, resulting in simple operation and high efficiency. This invention improves the dielectric matching degree of the paper, enhances its insulation performance, and provides waterproofing and fiber shedding prevention functions, extending the service life of the insulating paper without damaging its mechanical properties. This invention produces no byproducts during the treatment process, truly achieving environmentally friendly treatment.

Description

Technical Field

[0001] This invention belongs to the field of modified cellulose insulating paper, and relates to an apparatus and method for modifying cellulose insulating paper based on low-temperature plasma. Background Art

[0002] Converter transformers are the core equipment of high-voltage direct current transmission systems, and oil-paper insulation, as the main insulation form in converter transformers, directly affects the operational reliability of the transformers.

[0003] In oil-paper insulation structures, insulating paper has a higher resistivity and lower dielectric constant compared to insulating oil. Under complex working conditions such as AC / DC combined electric fields and polarity reversal, the surface charge of insulating paper accumulates severely, accelerating insulation aging and even causing partial discharge or surface flashover.

[0004] Currently, the main approach is to optimize the oil-paper insulation structure to reduce the electric field strength on the insulating paper, thereby improving insulation strength. However, this method fails to fundamentally solve the aging problem caused by the mismatch of dielectric parameters at the oil-paper insulation interface. Therefore, it is urgent to overcome the bottleneck problems of controlling the charge transport path at the oil-paper insulation interface and addressing the dielectric performance mismatch, and to develop a new method to improve the dielectric and insulation properties of the insulating paper while ensuring that its overall performance meets the requirements for the safe and reliable operation of converter transformers.

[0005] Cellulose insulating paper is widely used in oil-immersed transformers due to its low production cost and excellent insulation performance. Cellulose is a chain-like high-polymer hydrocarbon compound composed of glucose groups, and the hydroxyl groups in the molecule are the key groups affecting its insulation performance. Hydroxyl groups are polar groups, resulting in the dielectric constant of cellulose insulating paper being approximately twice that of commonly used insulating oil. This dielectric constant mismatch leads to charge accumulation at the interface, causing localized electric field distortion. Under the influence of the electric field, the fiber molecular chains are pulled and peeled off from the surface of the insulating paper, forming impurity bridges, which can then trigger partial discharge or surface flashover, resulting in a decrease in insulation performance. Furthermore, due to external intrusion and internal aging, moisture is widely present in the oil-paper insulation. Since most insulating paper is made of natural cellulose, it has significant hydrophilicity and easily absorbs moisture from the insulating oil, undergoing hydrolytic aging. This not only leads to a decrease in the insulation performance of the insulating paper but also causes the cellulose impurities to detach and enter the insulating oil, further degrading its insulation performance. Therefore, the performance of the insulating paper is a crucial factor determining the operational reliability of oil-immersed transformers.

[0006] Researchers have started by altering the structure and chemical composition of insulating paper, using physicochemical methods such as process optimization, chemical modification, and nano-doping to improve its overall insulation performance. However, limited by the maturity of relevant theories and technologies, it is currently difficult to achieve a coordinated improvement in waterproofing, anti-aging properties, dielectric matching, and insulation performance while ensuring no negative impact on the paper's mechanical strength or other properties. In contrast, starting from the surface physical structure and chemical composition of insulating paper, surface treatment can modify its properties, suppressing insulation failure at the oil-paper insulation interface while preserving the excellent properties of the insulating paper itself, providing a new approach to solving the aging problem of oil-paper insulation. Therefore, starting from the surface characteristics of insulating paper, how to regulate its physicochemical properties to achieve a synergistic improvement in waterproofing, anti-aging properties, dielectric properties, and insulation performance is fundamental and crucial to improving the insulation performance of oil-paper. Summary of the Invention

[0007] 1. The technical problem to be solved:

[0008] How to overcome the problems of controlling the moisture transport path at the interface of oil-paper insulation and the mismatch of dielectric properties? Existing methods for treating insulating paper cannot simultaneously achieve dielectric property matching, insulation performance improvement, and waterproof performance improvement without damaging the original mechanical properties of the insulating paper.

[0009] 2. Technical Solution:

[0010] To address the above problems, this invention provides a device for modifying cellulose insulating paper using low-temperature plasma. The device utilizes discharge components for processing, and the processing zone includes four sets of discharge components. Each set is introduced with different gases and media. The processing sequence is as follows: the surface activation set is introduced with Ar for surface activation; the hydrophobic film deposition set is introduced with Ar / HMDSO to deposit a hydrophobic film, improving the waterproof performance of the insulating paper; the insulation performance enhancement set is introduced with Ar / OMCTS to reduce the dielectric constant and improve the surface and bulk insulation performance of the insulating paper; and the mechanical reinforcement set is introduced with Ar / APTES to improve the mechanical properties of the film and the insulating paper, and to prevent the insulating paper fibers from falling into the insulating oil. The gases and media in each set are not interconnected with those in the other sets.

[0011] Furthermore, the surface activation group was made of pure argon; the hydrophobic film deposition group had an Ar content of 98.5%-99.5%; the insulation performance enhancement group had an Ar content of 77.5%-82.5%; and the mechanical reinforcement group had an Ar content of 45%-55%.

[0012] Furthermore, in the surface activation group, the discharge component is introduced with a gas flow rate of Ar of 9-11 L / min; in the hydrophobic film deposition group, the discharge component is introduced with a HMDSO flow rate of 0.05-0.15 L / min; in the insulation performance improvement group, the discharge component is introduced with an OMCTS flow rate of 1.75-2.25 L / min; and in the mechanical reinforcement group, the discharge component is introduced with an APTES flow rate of 4.5-5.5 L / min.

[0013] Furthermore, the surface activation group used pure argon gas; the hydrophobic film deposition group had an Ar content of 98.5%; the insulation performance enhancement group had an Ar content of 77.5%; and the mechanical reinforcement group had an Ar content of 55%. In the surface activation group, the discharge component was introduced with an Ar gas flow rate of 10 L / min; in the hydrophobic film deposition group, the discharge component was introduced with an HMDSO flow rate of 0.15 L / min; in the insulation performance enhancement group, the discharge component was introduced with an OMCTS flow rate of 2.25 L / min; and in the mechanical reinforcement group, the discharge component was introduced with an APTES flow rate of 4.5 L / min.

[0014] Furthermore, each set of discharge components includes two rod-tube type DBD electrodes. Each rod-tube type DBD electrode includes a high-voltage electrode and a ground electrode 4. Each ground electrode 4 is coupled with a high-voltage electrode 5. The high-voltage electrode 5 is located below the insulating shell, directly opposite the ground electrode 4. The ground electrode 4 is located on the outer layer of a roller. The insulating shell is provided with a gas port and a medium inlet. The outer surface of the insulating shell has gaps. The gap distance is slightly larger than the thickness of the insulating paper. The insulating paper passes through the gaps on the outer surface of each insulating shell in sequence.

[0015] Furthermore, four sets of discharge components are provided, with a gap of 0.5-2mm. The processing spacing is adjustable within the range of 0.5-2mm to form a mixed discharge mode. The outermost layer of the high-voltage electrode is an alumina ceramic barrier medium, the middle layer is a conductive aluminum powder electrode, and the innermost layer is a water cooling channel. All discharge components are adjusted by a lifting platform to adapt to the processing of insulating paper or insulating cardboard of different thicknesses. The electrode ventilation method is that each external air path is divided into 1 part and 5 parts, and then connected to 5 air path inlets.

[0016] Furthermore, the feeding area, guiding area, processing area, and take-up area are connected sequentially. The guiding area consists of a pair of first guide rollers, respectively placed on both sides of the processing area. The feeding area includes an unwinding shaft, and the take-up area includes a winding shaft. A support roller is placed below the winding shaft, and the rotation of one of the support rollers is controlled. Friction drives the winding shaft to achieve winding. This achieves continuous online processing at a speed of:

[0017] ,

[0018] Where: d is the radius of the guide roller where the ground electrode 4 is located, and c is the processing spacing. The units of d and c are both mm.

[0019] Furthermore, friction seats are added to both ends of the winding shaft in the unloading area. The friction seats are cylindrical metal blocks that are connected by a friction belt, pass around the winding shaft, and are fixed on the bracket.

[0020] Furthermore, it also includes a human-machine interface touch screen to control the gas flow rate of each group. The insulating shell is equipped with a fixed temperature measuring unit 3, a display screen of the human-machine interface system, and operation buttons.

[0021] The present invention also provides a method of using the aforementioned device based on low-temperature plasma-modified cellulose insulating paper, comprising the following steps:

[0022] Step S01: Set the rotation speed of the rotating shaft motor through the control interface of the device. After successful setting, start the power supply of the rotating shaft motor. The guide rollers of the unwinding area, the material guiding area and the winding area start to rotate. The insulating paper to be processed enters the processing area and is then collected in the winding area after processing.

[0023] Step S:2: Start the human-machine interface, input the gas and medium flow rates required for the discharge of the four sets of discharge components, and start introducing gas.

[0024] Step S03: Start the nanosecond pulse power supply, input the power supply operating parameters such as voltage and frequency, and start the power supply to discharge.

[0025] Step S04: Activate the temperature sensor of the device through the temperature monitoring panel to monitor the processing temperature of the processing area of ​​the device. When the temperature exceeds 85°C, the water cooling circulation cooling system will be automatically activated to control the temperature between 70-85°C.

[0026] Step S05: After all the insulating paper has been processed, first stop the discharge, then stop the air supply, and finally stop the rotation of the device's shaft motor.

[0027] Step S07: Power status indicator: Input power status indicator, green: normal; red: abnormal.

[0028] Step S07: Emergency Stop Button: Press the emergency stop button to cut off the power supply to the equipment's power circuit; rotate the reset emergency stop button to restore the power supply to the equipment's power circuit.

[0029] 3. Beneficial effects:

[0030] This invention enables direct processing of insulating paper under atmospheric pressure, and is simple and efficient.

[0031] This invention improves the dielectric matching degree and insulation performance of the insulating paper without damaging its mechanical properties. It also provides waterproofing and fiber shedding prevention, extending the service life of the insulating paper without harming its mechanical properties.

[0032] This invention uses argon as the working gas and a non-toxic, non-flammable, and non-explosive environmentally friendly silicon-containing medium. No by-products are generated during the process, truly achieving environmentally friendly treatment. Attached Figure Description

[0033] Figure 1 This is an overall diagram of the device of the present invention.

[0034] Figure 2 This is a schematic diagram of the human-computer interaction interface of the device.

[0035] Figure 3 This is a schematic diagram of the device.

[0036] Figure 4 This is a schematic diagram of the gas and precursors used to process the insulating paper by generating plasma through the discharge of four pairs of discharge components.

[0037] Figure 5 These are SEM images of the surface and cross-section of the insulating paper before and after the device treatment.

[0038] Figure 6 This is an example of an air intake method.

[0039] Figure 7 This is a schematic diagram of the high-voltage electrode.

[0040] Explanation of reference numerals in the attached diagram: 1. Unwinding shaft; 2. First guide roller; 3. Fixed temperature measuring unit; 4. Ground electrode; 5. High voltage electrode; 6. Second guide roller; 7. Rewinding shaft; 8. Support roller; 9. Human-machine interface touch screen; 10. First roller - cylindrical DBD electrode; 11. Second roller - cylindrical DBD electrode; 12. Third roller - cylindrical DBD electrode; 13. Fourth roller - cylindrical DBD electrode; 14. Fifth roller - cylindrical DBD electrode; 15. Sixth roller - cylindrical DBD electrode; 16. Seventh roller - cylindrical DBD electrode; 17. Eighth roller - cylindrical DBD electrode; 18. Display screen of the human-machine interface system; 19. Operation button; 20. Air inlet; 21. Lifting platform; 22. Lifting rod; 23. Air distribution plate; 24. Alumina ceramic barrier medium; 25. Conductive aluminum powder electrode; 26. Cooling channel. Detailed Implementation

[0041] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0042] like Figure 4 As shown, an apparatus for modifying cellulose insulating paper based on low-temperature plasma is used for processing. The processing zone includes four sets of discharge components, each of which is introduced with different gases and media. The processing order is as follows: the surface activation group is introduced with Ar for surface activation; the hydrophobic film deposition group is introduced with Ar / HMDSO to deposit a hydrophobic film and improve the waterproof performance of the insulating paper; the multi-performance enhancement group is introduced with Ar / OMCTS to reduce the dielectric constant and improve the surface and bulk insulation performance of the insulating paper; and the mechanical reinforcement group is introduced with Ar / APTES to improve the mechanical properties of the film and the insulating paper and to prevent the insulating paper fibers from falling into the insulating oil. The gases and media of each group are not connected to those of the other groups.

[0043] Each medium formulation has a different flow rate and plays a different role in the final effect. First, the surface activation group (Ar) uses Ar plasma, which contains a large number of high-energy active particles. Ar plasma activates the insulating paper, thus better enabling subsequent thin film deposition and improving the paper's performance. Next, the hydrophobic film deposition group is Ar / HMDSO. HMDSO is a common silicon-containing hydrophobic medium. This group can deposit hydrophobic films on the insulating paper surface, improving its hydrophobicity. Finally, the multi-performance enhancement group is Ar / OMCTS. OMCTS is the main medium used in the insulating paper treatment process and plays the most important role. OMCTS is a cyclic silicon-containing medium. Through plasma fragmentation of OMCTS… The resulting high-energy active particles and silicon-containing medium fragments are introduced into the surface and interior of the insulating paper through thin films deposited by Ar / OMCTS plasma. This improves the surface and interior insulation properties of the insulating paper, reduces the dielectric constant of the insulating paper, and achieves dielectric matching in subsequent oil-paper insulation systems. The mechanical reinforcement group is Ar / APTES. APTES, as a silicon-containing medium, contains amino groups in its molecular structure. The introduction of amino groups can enhance the mechanical properties of the material. Through the ionization of plasma, amino groups are introduced into the interior of the insulating paper, which can further improve the mechanical properties and other properties of the insulating paper.

[0044] In one embodiment, the surface activation group is pure argon gas; the proportion of Ar in the hydrophobic film deposition group is 77.5%-82.5%, preferably 77.5%; the proportion of Ar in the insulation performance improvement group is 95%-92.5%, preferably 95%; and the proportion of Ar in the mechanical reinforcement group is 45%-55%, preferably 55%.

[0045] In one embodiment, in the surface activation group, the flow rate of Ar gas introduced into the discharge electrode 5 is 9-11 L / min, preferably 10 L / min; in the hydrophobic film deposition group, the flow rate of OMCTS introduced into the discharge electrode 5 is 1.75-2.25 L / min, preferably 2.25 L / min; in the insulation performance enhancement group, the flow rate of Ar / O2 mixed gas introduced into the discharge electrode 5 is 9-11 L / min, preferably 10 L / min; and in the mechanical enhancement group, the flow rate of APTES introduced into the discharge electrode 5 is 4.5-5.5 L / min, preferably 4.5 L / min.

[0046] In one embodiment, each of the discharge components in each group includes two rod-tube DBD electrodes, each rod-tube DBD electrode including a high-voltage electrode 5 and a ground electrode 4, each ground electrode 4 cooperating with a high-voltage electrode 5, the high-voltage electrode 5 being disposed below the insulating shell, directly opposite the ground electrode 4, the ground electrode 4 being disposed on the outer layer of a roller, the insulating shell having a gas port and a medium inlet, and gaps left on the outer surface of the insulating shell, the gap distance being slightly larger than the thickness of the insulating paper, the insulating paper sequentially passing through the gaps on the outer surface of each insulating shell.

[0047] In one embodiment, four sets of discharge components are provided, and the processing area includes eight structural rod-cylinder DBD electrodes, namely a first rod-cylinder DBD electrode 10, a second rod-cylinder DBD electrode 11, a third rod-cylinder DBD electrode 12, a fourth rod-cylinder DBD electrode 13, a fifth rod-cylinder DBD electrode 14, a sixth rod-cylinder DBD electrode 15, a seventh rod-cylinder DBD electrode 16, and an eighth rod-cylinder DBD electrode 17, as shown below. Figure 1 As shown.

[0048] In one embodiment, the gap is 0.5-2mm, and the processing spacing is adjusted within the range of 0.5~2mm to form a hybrid discharge mode. The outermost layer of the high-voltage electrode 5 is an alumina ceramic barrier medium 24, the middle layer is a conductive aluminum powder electrode 25, and the innermost water cooling channel 26, as shown. Figure 7 As shown.

[0049] In one embodiment, such as Figure 1 As shown, all discharge components adjust their processing spacing via the lifting rod 22 in the lifting platform 21 to accommodate insulating paper or insulating paperboard of different thicknesses; the electrode ventilation method is that each external air path is divided into 1 / 5 sections, which are then evenly distributed by the air equalization plate 23 before being connected to an air path inlet 20, as shown. Figure 6 As shown.

[0050] The guide roller where the ground electrode 4 is located is the rotating shaft that transports the raw materials to be processed in the processing area. The high-voltage electrode 5, as the part that generates plasma, processes the insulating paper transported by the guide roller where the ground electrode 4 is located. The device has four pairs of eight roller-cylinder DBD electrodes. The two high-voltage electrodes 5 in each pair process the front and back sides of the insulating paper, respectively.

[0051] By combining two roller-cylinder DBD electrodes in each group, the conveying speed of each side in the double-sided processing of insulating paper is fixed and related to the processing time of the insulating paper. That is, the double-sided processing of insulating paper in each group is controlled by setting the conveying speed of the conveying system.

[0052] Assuming the radius of the guide roller where ground electrode 4 is located is d mm, the processing spacing is c mm, and the processing speed is v mm / s, then the processing speed... .

[0053] In one embodiment, the discharge electrode is a rod-and-cylinder DBD discharge electrode. The power supply is a nanosecond pulse power supply with operating parameters of 12kV voltage and 5kHz repetition frequency.

[0054] Plasma is generated using a rod-and-cylinder DBD electrode discharge. Dielectric barrier discharge (DBD) is currently the most common form of atmospheric pressure low-temperature plasma in industrial applications of material surface modification, especially suitable for processing wide-area planar materials. There are many ways to improve DBD discharge uniformity, enhance plasma chemical activity, and control material surface temperature, such as using pulsed excitation power supplies and optimizing operating parameters, and employing DBD discharge electrodes with different structures. This device uses a nanosecond pulse power supply to excite the rod-and-cylinder DBD electrode discharge, which can generate more uniform plasma. Secondly, by experimentally determining the gas flow rate and the type and concentration of added medium, the discharge uniformity can be further improved, and the activity and quantity of active particles generated by the discharge can be greatly increased. By controlling the discharge processing time, power supply operating parameters, and electrode structure, the material surface temperature during the discharge process can be controlled. Supplemented by a water-cooled circulating cooling system for temperature control, non-destructive plasma can be generated, thus ensuring that the mechanical properties of the insulating paper are not damaged or destroyed. Based on the above description, by controlling the electrode structure, excitation power supply type and operating parameters, discharge gas flow rate, type and concentration of added medium, and discharge treatment time, a large-area, highly active, uniform, and non-destructive DBD plasma can be obtained.

[0055] In one embodiment, such as Figure 1 and Figure 3 As shown, the feeding area, guiding area, processing area, and receiving area are connected in sequence. The feeding area includes an unwinding shaft 1, and the guiding area consists of a pair of guide rollers, namely the first guide roller 2 and the second guide roller 6, which are respectively placed on both sides of the processing area.

[0056] In one embodiment, to prevent loosening during conveying, friction seats are added to both ends of the winding shaft 7 in the unloading area of ​​the device. The friction seats are cylindrical metal blocks that are connected to the winding shaft 7 via a friction belt and then fixed to the device support. A roller control method is also employed, where two rollers 8 are placed below the winding roller, and the rotation of one of the rollers 8 is controlled to drive the winding roller through friction, thus achieving continuous online processing and efficient single-pass processing.

[0057] Cellulose insulating paper is placed in the unwinding area, passes through the unwinding shaft 1, and enters the processing area via the second guide roller 2. It is then conveyed by eight third rollers 4. The discharge electrode 5 processes the cellulose insulating paper on both sides. After passing through four sets of gas and medium treatments, it enters the unwinding area via the second roller 6.

[0058] The processed parameters are shown in Tables 1, 2, 3, and 4 below: (Effect comparison example) Figure 5 As shown.

[0059] Table 1: Test results after treatment by the first discharge assembly 10 and the second discharge assembly 11:

[0060]

[0061] Table 2: Test results after treatment by the third discharge assembly 12 and the fourth discharge assembly 13:

[0062]

[0063] Table 3 shows the test results after treatment by the fifth discharge assembly 14 and the sixth discharge assembly 15:

[0064]

[0065] Table 4 shows the test results after treatment by the seventh discharge assembly 16 and the eighth discharge assembly 17:

[0066]

[0067] The insulating paper treated with four sets of discharge components not only achieved the treatment effects shown in the table above, but also reduced its water absorption by 37.2% compared to the untreated paper, improving its resistance to hydrolytic aging and significantly extending its service life. Furthermore, to verify the effectiveness of this method in inhibiting the shedding of cellulose particles from the insulating paper, the breakdown strength of the insulating oil before and after soaking the treated paper was tested. The breakdown strength of the crude oil was 24.8 kV / mm. The test revealed that the breakdown strength of the insulating oil soaked in the untreated insulating paper was 18.6 kV / mm, while the breakdown strength of the insulating oil after treatment was 24.2 kV / mm. This demonstrates that the method effectively inhibited the shedding of cellulose particles from the insulating paper and improved the overall insulation performance of the oil-paper insulation system.

[0068] In one embodiment, a fixed temperature measuring unit is also included to regulate the temperature of the processing environment so that the medium is processed at a suitable temperature, and the insulating paper is processed at a suitable temperature.

[0069] In one embodiment, it also includes a human-machine interface touchscreen 9 for controlling the gas flow rate of different groups, such as... Figure 2 As shown.

[0070] In one embodiment, the insulating housing is provided with a display screen 18 and operation buttons 19 for a human-machine interface system. The human-machine interface display screen 18 is used to set the shaft speed, gas flow rate, medium concentration and power supply operating parameters, and simultaneously monitor the temperature of the processing area.

[0071] Operation buttons 19 include the main power switch, shaft motor start / stop button, power start / stop button, emergency stop button, water-cooled circulating cooling system manual start / stop button, and equipment operating status indicator lights. The water-cooled circulating cooling system can typically start / stop automatically or manually.

[0072] The workflow of this invention is as follows: The rotation speed of the rotating shaft motor is set through the control interface of the device. After the setting is successful, the power supply of the rotating shaft motor is turned on, and the guide rollers of the unwinding area, the guiding area and the winding area start to rotate. The insulating paper to be processed then enters the processing area and is collected in the winding area after processing.

[0073] Start the human-machine interface, input the gas and medium flow rates required for the discharge of the four sets of discharge components, and start introducing gas.

[0074] Start the nanosecond pulse power supply by inputting the power supply operating parameters such as voltage and frequency, and the power supply will begin discharging.

[0075] The temperature sensor of the device is activated by the temperature monitoring panel to monitor the processing temperature of the processing area. When the temperature exceeds 70°C, the water cooling circulation cooling system is automatically activated to control the temperature between 60-70°C.

[0076] Once all the insulating paper has been processed, first stop the discharge, then stop the ventilation, and finally stop the rotation of the device's shaft motor.

[0077] Power status indicator: Indicates the input power status. Green: Normal; Red: Abnormal.

[0078] Emergency Stop Button: Pressing the emergency stop button cuts off the power supply to the equipment's power circuit; unscrewing the reset emergency stop button restores power to the equipment's power circuit.

Claims

1. A device for modifying cellulose insulating paper using low-temperature plasma, comprising processing with a discharge assembly, characterized in that: The processing area includes four sets of discharge components. Each set of discharge components is introduced with different gases and media. The processing order is as follows: the surface activation set is introduced with Ar to activate the surface; the hydrophobic film deposition set is introduced with Ar / HMDSO to deposit a hydrophobic film and improve the waterproof performance of the insulating paper; the insulation performance enhancement set is introduced with Ar / OMCTS to reduce the dielectric constant and improve the surface and bulk insulation performance of the insulating paper; and the mechanical reinforcement set is introduced with Ar / APTES to improve the mechanical properties of the film and the insulating paper and prevent the insulating paper fibers from falling into the insulating oil. The gases and media of each set are not connected to those of the other sets.

2. The device based on low-temperature plasma-modified cellulose insulating paper as described in claim 1, characterized in that: The surface activation group uses pure argon gas; the hydrophobic film deposition group contains 98.5%-99.5% Ar; the insulation performance enhancement group contains 77.5%-82.5% Ar; and the mechanical reinforcement group contains 45%-55% Ar.

3. The device based on low-temperature plasma-modified cellulose insulating paper as described in claim 2, characterized in that: In the surface activation group, the discharge module was introduced with a gas flow rate of Ar of 9-11 L / min; in the hydrophobic film deposition group, the discharge module was introduced with a HMDSO flow rate of 0.05-0.15 L / min; in the insulation performance improvement group, the discharge module was introduced with an OMCTS flow rate of 1.75-2.25 L / min; and in the mechanical reinforcement group, the discharge module was introduced with an APTES flow rate of 4.5-5.5 L / min.

4. The device based on low-temperature plasma-modified cellulose insulating paper as described in claim 3, characterized in that: The surface activation group used pure argon gas; the hydrophobic film deposition group had an Ar content of 98.5%; the insulation performance improvement group had an Ar content of 77.5%; and the mechanical reinforcement group had an Ar content of 55%. In the surface activation group, the discharge component was introduced with an Ar gas flow rate of 10 L / min; in the hydrophobic film deposition group, the discharge component was introduced with an HMDSO flow rate of 0.15 L / min; in the insulation performance improvement group, the discharge component was introduced with an OMCTS flow rate of 2.25 L / min; and in the mechanical reinforcement group, the discharge component was introduced with an APTES flow rate of 4.5 L / min.

5. The apparatus based on low-temperature plasma-modified cellulose insulating paper as described in any one of claims 1-4, characterized in that: Each set of discharge components includes two rod-tube type DBD electrodes. Each rod-tube type DBD electrode includes a high-voltage electrode (5) and a ground electrode (4). Each ground electrode (4) is paired with a high-voltage electrode (5). The high-voltage electrode (5) is located below the insulating shell and directly opposite the ground electrode (4). The ground electrode (4) is located on the outer layer of a roller. The insulating shell is provided with a gas port and a medium inlet. The outer surface of the insulating shell has gaps. The gap distance is slightly larger than the thickness of the insulating paper. The insulating paper passes through the gaps on the outer surface of each insulating shell in sequence.

6. The device based on low-temperature plasma-modified cellulose insulating paper as described in claim 5, characterized in that: Four sets of discharge components are provided, the gap is 0.5-2mm, the processing spacing is adjustable in the range of 0.5~2mm to form a mixed discharge mode. The outermost layer of the high voltage electrode (5) is an alumina ceramic barrier medium (24), the middle layer is a conductive aluminum powder electrode (25), and the innermost water cooling channel (26). All discharge components are adjusted by lifting platform (21) to adapt to the processing of insulating paper or insulating paperboard of different thicknesses. The electrode ventilation method is that each external air path is divided into 1 part and 5 parts, and then connected to one air path inlet (20).

7. The device based on low-temperature plasma-modified cellulose insulating paper as described in claim 5, characterized in that: The feeding area, guiding area, processing area, and receiving area are connected in sequence. The guiding area consists of a pair of first guide rollers (2) placed on both sides of the processing area. The feeding area includes an unwinding shaft (1), and the receiving area includes a winding shaft (7). A support roller (8) is placed below the winding shaft (7). The rotation of one of the support rollers is controlled, and the winding shaft (7) is driven by friction to achieve winding. Achieve online continuous processing with a processing speed of: ， Where: d is the radius of the guide roller where the ground electrode (4) is located, c is the processing distance, and the units of d and c are both mm.

8. The device based on low-temperature plasma-modified cellulose insulating paper as described in claim 7, characterized in that: Friction seats are added to both ends of the winding shaft (7) in the feeding area. The friction seats are cylindrical metal blocks that are connected by a friction belt, pass around the winding shaft (7), and are fixed on the bracket.

9. The apparatus based on low-temperature plasma-modified cellulose insulating paper as described in any one of claims 1-4 and 6-8, characterized in that: It also includes a human-machine interaction touch screen (9) to control the gas flow rate of each group. The insulating shell is equipped with a fixed temperature measuring unit (3), a display screen (18) of the human-machine interaction system and operation buttons (19).

10. A method of using the apparatus based on low-temperature plasma-modified cellulose insulating paper as described in any one of claims 1-9, characterized in that: Includes the following steps: Step S01: Set the rotation speed of the shaft motor through the device's control interface. After successful setting, start the shaft motor power supply. The guide rollers in the unwinding area, guiding area, and winding area begin to rotate, and the insulating paper to be processed enters the processing area. After processing, it enters the winding area for collection. Step S02: Start the human-machine interface, input the thickness of the material to be processed, adjust the appropriate processing distance through the lifting platform, input and set the gas and medium flow rates required for the discharge of the four sets of discharge components, and start the gas flow. Step S03: Start the nanosecond pulse power supply, input the voltage and frequency power supply operating parameters, and start the power supply to begin discharging; Step S04: Activate the temperature sensor of the device through the temperature monitoring panel to monitor the processing temperature of the processing area of ​​the device. When the temperature exceeds 70°C, the water cooling circulation cooling system will be automatically activated to control the temperature between 60-70°C. Step S05: After all the insulating paper has been processed, first stop the discharge, then stop the ventilation, and finally stop the rotation of the device's shaft motor; Step S06: Power status indicator: Input power status indicator, green: normal; Red: Abnormal; Step S07: Emergency Stop Button: Press the emergency stop button to cut off the power supply to the equipment's power circuit; rotate the reset emergency stop button to restore the power supply to the equipment's power circuit.

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