Portable power cable electric tree targeted suppression device and use method

Abstract

The invention discloses a portable power cable electric tree targeted suppression device and a use method, and belongs to the technical field of electric power engineering, the device comprises a box body, an electric field applying mechanism and a repair liquid applying mechanism which are arranged in the box body, a control panel arranged on the outer surface of the box body, and a residual liquid collecting mechanism; a first adapter and a second adapter are installed at the two ends of the to-be-repaired cable respectively. The electric field applying mechanism is used for applying voltage to the to-be-repaired cable; the repairing liquid applying mechanism is used for injecting repairing liquid into the to-be-repaired cable; and the residual liquid collecting mechanism is used for collecting residual liquid in the repaired cable. The device is compact in structure, convenient to carry and operate, and suitable for power cable repair in various field environments and improvement of the electrical tree suppression capability.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric power engineering, relates to cable repair technology, and specifically relates to a portable power cable electric tree targeted suppression device and a use method thereof. Background Art

[0002] With the continuous growth of electricity demand and the increasing complexity of power grid systems, the problem of cable aging has become one of the main hidden dangers affecting the safe and stable operation of power systems. The insulation performance of aging cables gradually decreases, making them more prone to failure during operation, especially under load fluctuations and power system shocks. Cable insulation aging may not only cause cable insulation breakdown, but also lead to serious problems such as power outages and equipment damage, posing a great threat to the reliability of power supply.

[0003] The main manifestations of cable aging include chemical degradation of insulation materials, physical damage and electrical performance degradation. Common cable aging defects include water trees, holes and air gaps, which can lead to the formation and expansion of electrical trees. Electrical trees are insulation aging phenomena caused by insulation defects under the action of electric fields. Over time, these electrical trees gradually expand and may eventually lead to insulation breakdown. Electrical tree breakdown is one of the direct causes of cable failures, and the failures caused in power systems are extremely destructive. Therefore, how to effectively inhibit the development of electrical trees and improve the insulation performance of cables has become a key issue that needs to be urgently addressed in the field of cable maintenance and repair.

[0004] Traditional cable repair technology mainly focuses on the repair of water tree defects, while the suppression of electrical tree defects is often just an additional function. After the traditional repair fluid diffuses into the insulation layer, it may be difficult to distribute evenly due to its own characteristics, resulting in insufficient concentration of repair fluid at local defects, thus affecting the repair effect. In addition, the distortion effect of the electric field will cause uneven diffusion of the repair fluid in the insulation layer, further reducing the repair effect. Although some improved repair fluid formulas and injection methods have emerged, these technologies still have certain limitations in practical applications.

[0005] In recent years, the emergence of targeted repair technology has provided new ideas for cable repair. Targeted repair technology uses electric fields to induce the repair liquid to diffuse into the cable insulation defects at high concentrations, thereby achieving precise suppression of electrical trees. Compared with traditional repair technologies, this method has higher repair effects and longer service life. By optimizing the formula of the repair liquid and combining it with electric field induction technology, effective repair of cable insulation defects can be achieved. However, there are still few targeted repair devices on the market, and most of the existing devices are large-scale equipment with complex on-site operations, which affects the promotion and application of the technology.

[0006] In this context, it is particularly important to develop a portable device for targeted suppression of power cable trees. The device should have convenient operation performance and efficient repair effect to meet the actual needs under field conditions. The portable device can simplify the operation process, reduce maintenance time, and improve the efficiency of field repair. In addition, the design of the device should take into account the special requirements of cable repair, such as the ability to adapt to different cable specifications and operational safety. By further optimizing the formula of the repair fluid and improving the design of the equipment, the repair efficiency and operational convenience can be improved, thereby promoting the widespread application of targeted repair technology. Summary of the invention

[0007] The purpose of the present invention is to provide a new portable power cable electric tree targeted suppression device and a method of use in view of the deficiencies of the prior art. The device integrates various equipment required for online repair, has a compact structure, is easy to carry and operate, has good air tightness, can withstand a large external air pressure, realizes efficient repair of power cables and improves the ability of aging cables to resist electric trees. The device is particularly suitable for power cable repair work in a field environment, and has the characteristics of advanced technology, safe and stable equipment, and flexible and easy to use.

[0008] In view of the above-mentioned purpose of the present invention, the present invention provides the following technical solutions to achieve the above-mentioned purpose.

[0009] The present invention provides a portable power cable electric tree targeted suppression device, which comprises a box, an electric field applying mechanism and a repair liquid applying mechanism arranged in the box, a control panel arranged on the outer surface of the box, and a residual liquid collecting mechanism; a first adapter and a second adapter are respectively installed at both ends of the cable to be repaired;

[0010] The electric field applying mechanism comprises a DC power supply, the input end of which is electrically connected to a mobile power supply; the output end of the DC power supply is connected to a cable core to be repaired via a wire and a first adapter;

[0011] The repair liquid applying mechanism includes a liquid storage tank, which is connected to the air compressor and the first adapter through a first pneumatic hose and a second pneumatic hose respectively; the air compressor is also electrically connected to a mobile power source;

[0012] The control panel is connected to a DC power supply and an air compressor respectively;

[0013] The residual liquid collecting mechanism comprises a residual liquid tank; the second adapter is connected to the residual liquid tank via a third pneumatic hose.

[0014] In the portable power cable electric tree targeted suppression device, the first pneumatic hose, the second pneumatic hose and the third pneumatic hose are respectively equipped with a first valve, a second valve and a third valve. Furthermore, the first valve, the second valve and the third valve are all solenoid valves and are electrically connected to the control panel.

[0015] The portable power cable electric tree targeted suppression device is provided with an MCU control unit installed on the control panel, and the MCU control unit is connected to the switch of the air compressor for controlling the start and stop of the air compressor. The MCU control unit is connected to the barometer of the air compressor for real-time monitoring of the output pressure of the air compressor. The MCU control unit is respectively connected to the first valve, the second valve and the third valve for controlling the opening or closing of each valve. The MCU control unit is connected to a DC power supply for controlling the output voltage of the DC power supply.

[0016] The portable power cable electric tree targeted suppression device has multiple protection mechanisms for the DC power supply, including overload protection, short circuit protection and overheat protection, to ensure the safety of the device operation. These can be achieved by conventional means disclosed in the art.

[0017] In the portable power cable tree targeted suppression device, the first adapter is connected to the liquid storage tank through the second pneumatic hose, which is convenient for quick connection and removal, and can be adjusted at the site of use. Universal wheels are also provided at the bottom of the box, and a handle and a connection hole are provided on one side of the box. The second pneumatic hose passes through the connection hole and is connected to the first adapter.

[0018] The above-mentioned portable power cable electric tree targeted suppression device adopts a modular design for the box body, and each internal component can be disassembled and maintained independently, thereby improving the maintenance efficiency of the equipment.

[0019] The above-mentioned portable power cable electric tree targeted suppression device, the liquid storage tank is equipped with a liquid level sensor, the liquid level sensor is connected to the MCU control unit of the control panel, and is used to monitor the liquid level of the repair fluid and send out an alarm signal when the liquid level is lower than a preset value.

[0020] The above-mentioned portable power cable electric tree targeted suppression device, the liquid storage tank stores the repair liquid, the main component of the repair liquid is methylphenyldimethoxysilane, added with 1% of isopropyl titanate catalyst by mass (that is, the percentage of isopropyl titanate catalyst relative to methylphenyldimethoxysilane) and 0.1% of antioxidant 300 by mass (that is, the percentage of antioxidant 300 relative to methylphenyldimethoxysilane).

[0021] The present invention also provides a method for using a portable power cable electric tree targeted suppression device, comprising the following steps:

[0022] Step 1: Connect two ends of the cable to be repaired to the first adapter and the second adapter respectively;

[0023] Step 2: Start the air compressor and inject the repair liquid into the cable to be repaired according to the set pressure. When the repair liquid overflows from the outlet of the second adapter, stop injecting the repair liquid and maintain the pressure; turn on the DC power supply, apply DC voltage to the cable core, and maintain it for a set time period to perform targeted repair on the cable to be repaired;

[0024] Step 3: After the repair is completed, turn off the power and drain the remaining liquid in the cable. The repair is complete.

[0025] In step 2, when the repair liquid overflows from the outlet of the second adapter, the second valve and the third valve are closed, the injection of the repair liquid is stopped and the pressure is maintained;

[0026] In step 3, after the repair is completed, the power is turned off, and then the second valve and the third valve are opened to drain the remaining liquid in the cable.

[0027] The specific implementation method of step 2 is: under the power supply of a mobile power source, the air compressor generates an air pressure of 0.1-0.4MPa, drives the repair liquid in the liquid storage tank to enter the cable core through the first adapter, and realizes the injection of the repair liquid in the cable core under the action of the air pressure, and is discharged from the second adapter; at this time, stop injecting the repair liquid and maintain the pressure; start the DC power supply, apply a DC voltage of 1-4kV to the cable core, and maintain it for at least 4h.

[0028] The portable power cable electric tree targeted suppression device provided by the present invention is used to repair the aged power cable, which has the following outstanding advantages:

[0029] (1) Portability and high integration: The device integrates a mobile power supply, DC power supply, air compressor, liquid storage tank and operation panel in a compact box. With universal wheels and portable design, the device can be easily moved and deployed, and is suitable for cable repair work in various field environments, significantly improving the convenience of operation and work efficiency.

[0030] (2) Significant repair effect: During the repair liquid injection process, a DC voltage is applied to the cable core, and the repair liquid is induced to efficiently penetrate and accumulate at the insulation defects through the electric field; this not only increases the concentration of the repair liquid at the defect, but also enhances the repair effect, effectively inhibits the growth and expansion of the electrical tree, and significantly extends the service life of the power cable;

[0031] (3) High efficiency and good safety: The control panel integrates pressure regulation and monitoring functions to ensure stability and safety during the repair process, avoid leakage and uneven injection problems in traditional methods, and improve overall repair efficiency and reliability.

[0032] The promotion of this portable power cable tree targeted suppression device will provide a strong guarantee for the safe and stable operation of the power system. It can not only effectively suppress the formation and development of tree branches, but also reduce failures and accidents caused by cable aging, thereby reducing maintenance costs and improving the reliability and stability of power supply. This is crucial for the long-term healthy operation of the power system and has broad market prospects and application potential.

[0033] The present invention also applies the existing common injection repair technology and the above-mentioned portable power cable electric tree targeted suppression device to carry out cable repair tests. The test object is an aged power cable, and PDC test and electric tree induction voltage test are carried out before and after the repair. The comparative experimental test results show that the portable power cable electric tree targeted suppression device provided by the present invention can realize the live repair of power cables, and the repair effect is better than that of traditional injection repair.

[0034] The portable power cable electric tree targeted suppression device provided by the present invention is used to repair aged power cables, which has the characteristics of simple operation, safety and stability, better repair effect, low cost, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of a portable power cable electric tree targeted suppression device provided by the present invention;

[0036] Figure 2 for Figure 1 Schematic diagram of the internal structure of the middle box;

[0037] Figure 3 A schematic diagram of a residual liquid collection mechanism in a portable power cable electric tree targeted suppression device provided by the present invention;

[0038] Figure 4 This is a schematic diagram of a common injection-type power cable repair device;

[0039] Figure 5 The test results of the electric tree induction voltage of the sample after repair by using the portable power cable electric tree targeted suppression device provided by the present invention;

[0040] Figure 6 This is the test result of the electric tree induction voltage of the sample after repair using the common injection repair technology;

[0041] In the figure, 1-box, 2-control panel, 3-first adapter, 3′-second adapter, 4-DC power supply, 5-mobile power supply, 6-liquid storage tank, 7a-first pneumatic hose, 7b-second pneumatic hose, 7c-third pneumatic hose, 8-air compressor, 9-residual liquid tank, 10a-first valve, 10b-second valve, 10c-third valve, 11-universal wheel, 12-handle, 13-connecting hole, 14-cable to be repaired, 15-front end ordinary adapter, 15′-terminal ordinary adapter, 16a-valve No. 1, 16b-valve No. 2, 16c-valve No. 3. DETAILED DESCRIPTION

[0042] The present invention is described in detail below by embodiments and application examples. It is necessary to point out that the present embodiments are only used to further illustrate the present invention and cannot be construed as limiting the scope of the present invention. Those skilled in the art in this field can make some non-essential improvements and adjustments according to the above-mentioned content of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0043] Example 1

[0044] The portable power cable electric tree targeted suppression device provided in this embodiment has a structure as follows: Figure 1-Figure 3 As shown, it includes a box body 1, an electric field applying mechanism and a repair liquid applying mechanism arranged in the box body 1, a control panel 2 arranged on the outer surface of the box body, and a residual liquid collecting mechanism. A first adapter 3 and a second adapter 3' are respectively installed at both ends of the cable to be repaired, and are connected to the electric field applying mechanism, the repair liquid applying mechanism and the residual liquid collecting mechanism through the first adapter 3 and the second adapter 3'.

[0045] The electric field applying mechanism includes a DC power supply 4; the input end of the DC power supply 4 is electrically connected to a mobile power supply 5 and powered by the mobile power supply 5; the output end of the DC power supply 4 is connected to the cable core to be repaired through a wire and a first adapter 3. The DC power supply can also be provided with multiple protection mechanisms, including overload protection, short circuit protection and overheating protection, to ensure the safety of the equipment operation. These can be achieved by conventional means disclosed in the art.

[0046] The repair liquid applying mechanism includes a liquid storage tank 6, which is connected to an air compressor 8 and a first adapter 3 through a first pneumatic hose 7a and a second pneumatic hose 7b respectively; the air compressor 8 is also electrically connected to a mobile power supply 5 and powered by the mobile power supply. The liquid storage tank 6 is equipped with a liquid level sensor 6-1 connected to the control panel 2. The repair liquid is stored in the liquid storage tank 6, and the main component of the repair liquid is methylphenyldimethoxysilane, and a mass fraction of 1% isopropyl titanate catalyst and a mass fraction of 0.1% antioxidant 300 are also added.

[0047] The residual liquid collecting mechanism comprises a residual liquid tank 9; the second adapter 3' is connected to the residual liquid tank 9 via a third pneumatic hose 7c.

[0048] The first pneumatic hose 7a, the second pneumatic hose 7b and the third pneumatic hose 7c are respectively provided with a first valve 10a, a second valve 10b and a third valve 10c. The first valve 10a, the second valve 10b and the third valve 10c are all solenoid valves and are electrically connected to the control panel 2.

[0049] The control panel 2 is connected to the DC power supply 4 and the air compressor 8, respectively, and is used to monitor and adjust the output pressure of the air compressor 8 and the output voltage of the DC power supply 4. The control panel 2 is equipped with an MCU control unit, which is connected to the switch of the air compressor 8 to control the start and stop of the air compressor 8. The MCU control unit is connected to the barometer of the air compressor 8 to monitor the output pressure of the air compressor 8 in real time. The MCU control unit is connected to the first valve 10a, the second valve 10b and the third valve 10c, respectively, to control the opening or closing of each valve. The MCU control unit is connected to the DC power supply 4 to control the output voltage of the DC power supply 4. In an implementable manner, the control panel can also be provided with a pressure gauge display unit and a knob connected to the MCU control unit; the pressure gauge display unit is used to display the output pressure of the air compressor 8. Each knob corresponds to the first valve 10a, the second valve 10b, the third valve 10c and the DC power supply 4, and is used to realize the regulation of the first valve 10a, the second valve 10b, and the third valve 10c, thereby realizing the regulation of the output pressure of the air compressor 8, or realizing the control of the output voltage of the DC power supply 4; the knob can also be replaced by a key panel. Furthermore, the liquid level sensor 6 - 1 is connected to the MCU control unit of the control panel 2 , and is used to monitor the liquid level of the repair liquid and send out an alarm signal when the liquid level is lower than a preset value.

[0050] In addition, the box adopts a modular design, and each internal component can be disassembled and maintained independently, thereby improving the maintenance efficiency of the equipment. A universal wheel 11 is also provided at the bottom of the box, and a handle 12 and a connecting hole 13 are provided on one side of the box. The second pneumatic hose 7b passes through the connecting hole 13 and is connected to the first adapter 3.

[0051] Application Examples

[0052] This application example uses the portable power cable electric tree targeted suppression device provided in Example 1 to perform live repair on an aged power cable, and verifies the authenticity and effectiveness of the repair by this device.

[0053] Acquisition of experimental objects: Two new YJLV22-8.7 / 10 cross-linked polyethylene insulated power cables with a length of 50 cm were cut and named #1 and #2 respectively. 7.5 kV and 400 Hz AC were applied to conduct accelerated water tree aging test for 40 days to obtain aged power cable samples. The ordinary injection repair and portable power cable electric tree targeted suppression devices were used to repair the cables and test the insulation performance.

[0054] 1. Preparation of Repair Solution

[0055] The repair fluid used in the repair test is siloxane repair fluid (the main component is methylphenyldimethoxysilane, with 1% by mass isopropyl titanate catalyst and 0.1% by mass antioxidant 300 added). The power cable repair fluid can be obtained by stirring at room temperature for about 20 minutes using a magnetic stirrer.

[0056] 2. Repair test of power cables

[0057] For the repair test of #1 power cable, proceed as follows:

[0058] Step 0: Before repair, evaluate the insulation status of the power cable to be repaired, check the function and grounding protection of related equipment, and ensure the safety of the entire repair process;

[0059] Step 1: Install the first adapter 3 to one end of the cable 14 to be repaired, install the second adapter 3' to the other end of the cable 14 to be repaired, and connect the residual liquid tank 9 with the third pneumatic hose 7c. A third valve 10c is provided between the second adapter 3' and the residual liquid tank 9. After the connection is completed, perform an airtightness check;

[0060] Step 2: After the air tightness check is completed, start the air compressor 8, inject the power cable repair liquid into the cable to be repaired 14 at a pressure of 0.2MPa, and after the repair liquid overflows from the outlet of the second adapter 3', close the second valve 10b and the third valve 10c; turn on the DC power supply 4 according to the regulations, apply a DC voltage of 2kV to the cable core, maintain the pressure for 4 hours, and apply the voltage for 4 hours, so that the repair liquid can fully penetrate into the cable insulation layer for reaction;

[0061] Step 3: After the repair is completed, turn off the power, open the second valve 10b and the third valve 10c, and discharge the remaining repair liquid and the waste liquid (collectively referred to as the residual liquid) in the cable from the outlet of the second adapter 3', and the repair is completed.

[0062] For the #2 aged power cable, a normal injection repair test is carried out according to the following steps:

[0063] Step 1: Follow the instructions Figure 4The air compressor 8, the liquid storage tank 6, the residual liquid tank 9, the cable to be repaired 14, the start-end common adapter 15, and the end-end common adapter 15' are connected through a hose, and valve No. 1 16a, valve No. 2 16b, and valve No. 3 16c are installed on the hose, and an air tightness check is performed;

[0064] Step 2: After the air tightness check is completed, start the air compressor 8, and inject the power cable repair liquid into the cable core of the cable 14 to be repaired through the common adapter 15 at the starting end at a pressure of 0.2MPa. After the repair liquid flows out from the outlet of the common adapter 15' at the terminal, close the valve 1 16a, valve 2 16b, and valve 3 16c, and maintain the pressure for 4 hours;

[0065] Step 3: After 4 hours, open valve No. 2 16b and valve No. 3 16c to discharge the remaining repair liquid and waste liquid, and the repair is completed.

[0066] 3. PDC test before and after power cable repair

[0067] For sample #1, continuous PDC tests were performed before and after repair, with a polarization voltage of 1 kV and a polarization time of 90 s. The test results showed that the dielectric loss factors measured by PDC before and after repair were 2.6589% and 0.301%, respectively.

[0068] Using the same method and conditions as above, continuous PDC testing was performed on sample #2. The test results showed that the loss factor before repair and the dielectric loss factor measured by PDC after repair were 2.4936% and 0.599%, respectively.

[0069] 4. Test of voltage caused by electric tree before and after power cable repair

[0070] For samples #1 and #2, the electrical tree induction voltage test was performed before and after repair. The test steps are as follows:

[0071] (1) Cut a 5±0.1mm thick semicircular ring sample from the insulating layer, remove the outer semiconductive layer, and retain and polish the inner semiconductive layer. Cover the inner semiconductive layer with a 5±0.1mm wide copper strip and fix it with an insulating tie to ensure reliable contact. Finally, insert a steel needle with a diameter of 0.5mm and a curvature radius of 10±1μm into the insulation to a depth of 3±0.1mm. The AC voltage is introduced from the needle electrode, and the copper strip electrode is grounded;

[0072] (2) The sample was immersed in No. 25 transformer oil, and an AC voltage was applied to the sample through a protective resistor using a power frequency boost circuit by a uniform speed boost method. The initiation process of electrical tree formation in the sample was observed by a CCD digital imaging device.

[0073] (3) The voltage is gradually increased from 0 at a rate of 500 V / s. When electrical tree formation occurs at the needle tip, the voltage is immediately stopped and the current voltage is recorded. This voltage is recorded as the electrical tree initiation voltage of the experimental sample.

[0074] The electrical treeing voltages of samples #1 and #2 before and after repair are shown in Figure 2. Figure 5 and Figure 6 The Weibull distribution parameters of the electric tree induction voltage of the two samples are shown in Table 1:

[0075] Table 1 Weibull distribution parameters of cable tree-induced voltage

[0076]

[0077] Analysis: By comparing the PDC test results of the two groups of repaired cable samples through experimental test data, it is proved that both the ordinary injection-type repair and the portable power cable electric tree targeted suppression device provided by the present invention improve the insulation performance of the cable and achieve the repair effect; at the same time, it can be proved that the dielectric loss factor of the cable samples repaired by the portable power cable electric tree targeted suppression device provided by the present invention is lower than that of the ordinary injection-type repair, and the electric tree inducing voltage after repair is also higher than the increase before repair, which proves that the repair fluid undergoes targeted migration, increases the effective concentration of the repair fluid in the water tree area, promotes the forward progress of the hydrolysis condensation reaction, improves the water tree repair effect, and improves the ability of aging power cables to inhibit the growth of electric trees.

Claims

1. A portable power cable tree targeting suppression device, characterized in that: It comprises a box (1), an electric field applying mechanism and a repair liquid applying mechanism arranged in the box (1), a control panel (2) arranged on the outer surface of the box, and a residual liquid collecting mechanism; a first adapter (3) and a second adapter (3′) are respectively installed at both ends of the cable to be repaired; The electric field applying mechanism comprises a direct current power source (4), the input end of the direct current power source (4) being electrically connected to a mobile power source (5); the output end of the direct current power source (4) being connected to a cable core of a cable to be repaired via a wire and a first adapter (3); The repair liquid application mechanism comprises a liquid storage tank (6), and the liquid storage tank (6) is connected to an air compressor (8) and a first adapter (3) through a first pneumatic hose (7a) and a second pneumatic hose (7b) respectively; the air compressor (8) is also electrically connected to a mobile power source (5); The control panel (2) is connected to a DC power supply (4) and an air compressor (8) respectively; The residual liquid collecting mechanism comprises a residual liquid tank (9); the second adapter (3') is connected to the residual liquid tank (9) via a third pneumatic hose (7c).

2. The portable power cable tree targeting suppression device according to claim 1 is characterized in that: A first valve (10a), a second valve (10b) and a third valve (10c) are respectively installed on the first pneumatic hose (7a), the second pneumatic hose (7b) and the third pneumatic hose (7c).

3. The portable power cable tree targeting suppression device according to claim 1 is characterized in that: The first valve (10a), the second valve (10b) and the third valve (10c) are all solenoid valves and are electrically connected to the control panel (2).

4. The portable power cable tree targeting suppression device according to claim 1, characterized in that: The bottom of the box body (1) is provided with a universal wheel (11), and one side of the box body is provided with a handle (12) and a connecting hole (13), and the second pneumatic hose (7b) passes through the connecting hole (13) and is connected to the first adapter (3).

5. The portable power cable electric tree targeted suppression device according to claim 1 is characterized in that: The liquid storage tank (6) is equipped with a liquid level sensor (6-1) connected to the control panel (2).

6. The portable power cable tree targeting suppression device according to claim 1, characterized in that: The liquid storage tank (6) stores a repair liquid, the main component of which is methylphenyldimethoxysilane, to which is added 1% by mass of an isopropyl titanate catalyst and 0.1% by mass of an antioxidant 300.

7. The method for using the portable power cable electric tree targeted suppression device according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: Connecting two ends of the cable to be repaired to the first adapter (3) and the second adapter (3') respectively; Step 2: Start the air compressor (8) and inject the repair liquid into the cable to be repaired according to the set pressure. When the repair liquid overflows from the outlet of the second adapter (3′), stop injecting the repair liquid and maintain the pressure; turn on the DC power supply (4) to apply a DC voltage to the cable core and maintain it for a set time period to perform targeted repair on the cable to be repaired; Step 3: After the repair is completed, turn off the power and drain the remaining liquid in the cable. The repair is complete.

8. The method for using the portable power cable electric tree targeted suppression device according to claim 7 is characterized by: In step 2, when the repair liquid overflows from the outlet of the second adapter (3'), the second valve (10b) and the third valve (10c) are closed, the injection of the repair liquid is stopped and the pressure is maintained; In step 3, after the repair is completed, the power is turned off, and then the second valve (10b) and the third valve (10c) are opened to discharge the remaining liquid in the cable.

9. The method for using the portable power cable electric tree targeted suppression device according to claim 7 or 8, characterized in that: The specific implementation method of step 2 is as follows: under the power supply of the mobile power source (5), the air compressor (8) generates an air pressure of 0.1-0.4MPa, drives the repair liquid in the liquid storage tank (6) to enter the cable core through the first adapter (3), and realizes the injection of the repair liquid in the cable core under the action of the air pressure, and is discharged from the second adapter (3'); at this time, stop injecting the repair liquid and maintain the pressure; start the DC power source (4), apply a DC voltage of 1-4kV to the cable core, and maintain it for at least 4h.

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