Method and system for testing compatibility of defective cables with conductive repair fluids

Abstract

To provide a method for testing compatibility between a defective cable and a conductive repair liquid in order to overcome disadvantages and defects of a conventional technology.SOLUTION: A method comprises the following steps: manufacturing an artificial defective cable; measuring a local discharge signal; installing adapters for injecting repairing liquid on both sides of the cable; injecting the repairing liquid; measuring signal the local discharge signal; and determining compatibility between the injected repairing liquid and a cable main body by comparing the local discharge signals under each voltage level. The invention can determine compatibility between a repair liquid material and a cable buffer water-blocking tape, can control a flowing direction of the repair liquid in a long cable, prevents the repair liquid from overflowing from a weak point in an injection process, and problems of an orientation, sealing, and efficiency of cable repair are effectively solved. In addition, the invention can also verify electrical recovery performance of the repair liquid to the buffer water-blocking tape.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention is in the field of cable repair, and specifically relates to a method for testing the compatibility of a defective cable with a conductive repair fluid. [Background technology]

[0002] As the utilization rate of high-voltage cables in China is becoming higher and higher, high-voltage XLPE insulated cables are widely applied in the central business districts of first-tier cities, and the voltage level of urban power grids is becoming higher, which presents more serious problems in the operation and inspection of cable circuits. In recent years, high-voltage XLPE cables in many regions of the country have suffered main body failures, the main example of which is the large-area discharge ablation between the metal sheath and the outer semiconductive layer, which generates non-conductive white spots at the contact points between the buffer layer and the aluminum sheath, which prevents the electrical connection between the buffer layer and the aluminum sheath. Although it has been proposed to restore the electrical connection between the buffer layer and the aluminum sheath by injecting conductive repair fluid into the cable air gap layer, there is still no verification method for the compatibility between the conductive repair fluid and the high-voltage cable. The present invention relates to a method for testing the compatibility of a defective cable with a conductive repair fluid. A defective cable is manually manufactured by wrapping a non-conductive polyester fiber winding tape around the outside of the buffer layer so as to completely cover it. Then, the compatibility of the repair fluid with the defective cable is judged by measuring the local discharge signals of the defective cable before and after the repair fluid is injected.

[0003] At present, there is a related research technology for a high-pressure XLPE cable buffer layer repair device and its repair method. This technology has four devices, namely, a conductive repair fluid pressure injection system, an auxiliary vacuum extraction and collection system, and two repair fluid adapters, and the two repair fluid adapters are sandwiched between a high-pressure cross-linked polyethylene cable. The conductive repair fluid pressure injection system is connected to the first repair fluid adapter to inject conductive repair fluid into the high-pressure XLPE cable, and the auxiliary vacuum extraction and collection system is connected to the second repair fluid adapter to collect the excess conductive repair fluid in the high-pressure XLPE cable. Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE PRESENT EMBODIMENT The main objective of the present invention is to provide a method for testing the compatibility of a defective cable with a conductive repair fluid, in order to overcome the shortcomings and drawbacks of the prior art. [Means for solving the problem]

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: According to one aspect of the present invention, there is provided a method for testing compatibility of a defective cable with a conductive repair fluid, comprising: manufacturing an artificially defective cable; measuring a local discharge signal; Attaching adapters to both sides of the cable for injecting repair fluid; injecting a repair fluid; measuring the local discharge signal again; and determining compatibility of the injected repair fluid with the cable body by comparing the local discharge signals at each voltage level.

[0006] In a preferred technical solution, the step of manufacturing the artificially defective cable is specifically: Wrap the outside of the cable insulation shield with shock-absorbing waterproof tape. A layer of non-conductive wrapping tape is wrapped around the outside of the buffer waterproof tape; A spiral corrugated aluminum sheath is argon arc welded to the outside of the non-conductive winding tape, with a thread pitch of 25 mm. The aluminum tape used for the corrugated aluminum sheath meets the requirements of GB / T3880.1-2012, and its elongation is more than 16%.

[0007] As a preferred technical solution, the above-mentioned shock-absorbing waterproof tape includes three layers, the first layer being semiconductive expanded cotton, the third layer being semiconductive nonwoven fabric, and a layer of sodium polyacrylate expanded powder is applied between the two layers.

[0008] In a preferred technical solution, the step of measuring the local discharge signal specifically includes: Cut out the artificially defective cable to a length of 15 meters or more, and wrap the non-conductive wrapping tape exposed on both sides of the cable with insulating tape to ensure that the buffer waterproof tape and the non-conductive wrapping tape do not loosen during the experiment; According to GB / T 11017.1-2014 local discharge test standard, the local discharge test is performed to determine the starting discharge voltage U 1 , the corresponding local discharge signal and 1.0U 0 , 1.5U 0 , 1.75U 0 The corresponding local discharge signals in voltage are recorded respectively.

[0009] As a preferred technical solution, the adapter includes a front gasket, a back gasket and a center sleeve, all of which are vertically fitted together; The front gasket is an annular structure having an L-shaped cross section, and is divided into two parts along the cross section. The front gasket is arranged side by side at one end of the center sleeve and is in close contact with the aluminum sheath of the high voltage cable. The back gasket is a generally hollow cylinder, which is divided into two parts along the perpendicular bisecting plane of the cylinder, which are joined together at the outside of the non-conductive winding tape, which is fitted into the inside of one end of the center sleeve, which is then clamped into the center sleeve, and which is tightly attached to the non-conductive winding tape; and a retaining space for elastic deformation is further provided on the top and bottom surfaces of the cylinder of the back gasket; The center sleeve as a whole is a cylindrical structure, and three layers of annular partition plates are provided inside the center sleeve, and four bolt holes and two duct structures are provided outside the center sleeve. The annular partition plates inside the center sleeve divide the inner space of the adapter into three parts, namely the front, middle and rear parts, which respectively function as the front gasket connection part, the repair fluid injection part and the back gasket connection part. The duct structure introduces the repair fluid into the adapter and then injects it into the high-voltage cable that needs to be treated. The bolt holes rivet the entire adapter structure and the cable. An adapter structure is provided symmetrically at the other end of the high voltage cable segment that needs to be treated to guide away excess repair fluid.

[0010] In a preferred technical solution, the step of injecting the repair liquid is specifically: Adapters are attached to both sides of the artificially defective cable, and the gas bottle, the repair fluid can and the adapter are connected in sequence. A short inlet and long outlet pipe is installed in the repair fluid can. The gas bottle injects the repair fluid into the cable air gap layer through the adapter, and the injection flow is as follows: Close the two-way joint of the repair fluid collection port and open the two-way joint of the repair fluid injection port to check the tightness of the injection passage; After the airtightness test is completed, open the two-way joint of the repair fluid collection port, set the injection pressure to 0.3-0.4MPa, open the gas bottle switch, and inject the repair fluid into the cable air gap layer; After the repair fluid flows out of the collection port, stop applying pressure. The two-way joint of the cable is closed and the injection device is removed to complete the injection procedure.

[0011] In a preferred technical solution, the step of determining the compatibility of the injected repair fluid with the cable body by comparing the local discharge signals at each voltage level is specifically as follows: If, before the repair fluid is injected, a detectable discharge signal exceeding the standard sensitivity at each voltage level appears in the cable, and, after the repair fluid is injected, no detectable discharge signal exceeding the standard sensitivity at each voltage level appears in the cable, it is determined that the repair fluid is compatible with the cable; If, before the injection of the repair fluid, a detectable discharge signal exceeding the reference sensitivity appears in the cable at each voltage level, and, after the injection of the repair fluid, a detectable discharge signal exceeding the reference sensitivity appears at least once in the cable at said voltage level, it is determined that the compatibility between the repair fluid and the cable is poor; Starting discharge voltage U after repair fluid injection 2 is the starting discharge voltage U before the repair fluid is injected 1 If it is smaller than the value, it is determined that the compatibility of the repair fluid with the cable is poor.

[0012] According to another aspect of the present invention, there is provided a system for testing compatibility between a defective cable and a conductive repair fluid, the system being adapted to a method for testing compatibility between the defective cable and the conductive repair fluid, comprising: a cable processing module for producing artificially defective cables; a local discharge signal measurement module for measuring a local discharge signal of the cable before and after the repair fluid is injected; An adapter module for mounting an adapter for injecting repair fluid on both sides of the cable; an injection module for injecting a repair fluid; and an analysis module for determining compatibility of the injected repair fluid with the cable body by comparing the local discharge signals at each voltage level. Effect of the Invention

[0013] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) The present invention can judge the compatibility between the repair fluid material and the cable buffer waterproof tape. The non-conductive wrapping tape is wrapped around the outside of the buffer waterproof tape, and the coverage rate is more than 50%, so that the electrical connection between the cable buffer waterproof tape and the corrugated aluminum sheath can be completely cut off. After the repair fluid is injected into the cable air gap layer, the non-conductive wrapping tape and the buffer waterproof tape are made of the same material (both are polyester fiber). Therefore, if the compatibility between the repair fluid and the cable buffer waterproof tape is good, the repair fluid can infiltrate the non-conductive wrapping tape, restore the electrical connection between the insulating shielding layer and the aluminum sheath, and greatly reduce the amount of local discharge. If the compatibility is poor (the repair fluid material and the cable buffer waterproof tape are mutually exclusive), the repair fluid cannot electrically connect with the insulating shielding layer through the non-conductive wrapping tape. In this case, the conductive repair fluid cannot restore the electrical performance of the buffer layer, and the local discharge signal will also be large. (2) The present invention can control the flow direction of the repair fluid in a long cable, and prevent the repair fluid from overflowing from weak points during the injection process. The adapter injection method provided by the invention effectively realizes the problems of directionality, sealing and efficiency of cable repair. The two forward-inclined tube structures on the adapter center sleeve provide initial direction guidance for the injection of repair fluid, the sealing structure of the back gasket further ensures the flow direction of the repair fluid and prevents the repair fluid from flowing into the cable joint and causing other accidents, and the front gasket structure effectively bonds the aluminum sheath and the cable, so that the repair fluid will not overflow when entering the inside of the cable. (3) The present invention can verify the electrical recovery performance of the repair fluid on the buffer waterproof tape. According to the method for determining the magnitude of the local discharge signal of the present invention, it can be determined whether the repair fluid completely infiltrates the buffer waterproof tape after being injected into the cable air gap layer. If the repair fluid does not completely infiltrate, the phenomenon of electric field intensity concentration will appear at the interface between the non-conductive winding tape and the aluminum sheath, and there will be a local discharge signal. If the repair fluid completely infiltrates, the conductive performance of the repair fluid itself will greatly reduce the resistivity of the non-conductive winding tape and the buffer waterproof tape, and restore the electrical connection between the cable insulation layer and the corrugated aluminum sheath. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram of a conventional conductive repair fluid injection technique. [Diagram 2] 4 is a flow chart of a method for testing compatibility of a defective cable with a conductive repair fluid according to an embodiment of the present invention. [Diagram 3] 1 is a schematic diagram of a shock-absorbing waterproof tape structure according to an embodiment of the present invention; [Figure 4] FIG. 2 is a structural schematic diagram of a non-conductive winding tape according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a schematic cross-sectional view of a cable having an artificial defect according to an embodiment of the present invention. [Figure 6] FIG. 2 is a schematic diagram showing how insulating tape is wrapped around both ends of a cable having an artificial defect according to an embodiment of the present invention. [Figure 7]FIG. 2 is a schematic diagram of wiring and layout for a local discharge experiment in an embodiment of the present invention. [Figure 8] 1 is a schematic diagram of an entire adapter structure according to an embodiment of the present invention; [Figure 9] FIG. 2 is an internal plan view of an adapter according to an embodiment of the present invention. [Figure 10] 1 is a schematic diagram of a front gasket and a back gasket structure according to an embodiment of the present invention. FIG. [Figure 11] FIG. 2 is a schematic diagram of a center sleeve structure according to an embodiment of the present invention. [Figure 12] 2 is a schematic diagram of the lower half of a center sleeve according to an embodiment of the present invention. FIG. [Figure 13] FIG. 2 is a schematic diagram of a repair fluid injection circuit according to an embodiment of the present invention. [Figure 14] FIG. 2 is a structural schematic diagram of a system for testing the compatibility of a defective cable with a conductive repair fluid according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In order to make those skilled in the art better understand the solution of the present application, the technical solutions of the embodiments of the present application are described below clearly and completely in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are not all the embodiments, but only some of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art on the premise that they do not make any inventive efforts are within the scope of protection of the present application.

[0016] Working Example FIG. 1 is a device diagram of a conventional conductive repair fluid injection technology, in which the repair fluid injection end includes a high-pressure air pump, a pressure control valve, a pressure gauge, a repair fluid can intake pipe, a repair fluid can, a repair fluid can liquid discharge pipe, a pressure control valve, a first air tube sub-joint, a first connection device, a cross-linked polyethylene cable buffer layer, and a first repair fluid adapter, which are connected in sequence, and the repair fluid collection end includes a vacuum pump, a pressure control valve, a pressure gauge, a repair fluid collection can exhaust pipe, a repair fluid collection can, a repair fluid collection can liquid supply pipe, a pressure control valve, a second air tube sub-joint, a second connection device, and a second repair fluid adapter, which are connected in sequence. In practical construction applications, the defective cable to be repaired is generally a long cable, and the required injection pressure is correspondingly large, so the requirements for the repair fluid injection cable adapter are high, otherwise the situation of repair fluid overflow is likely to occur. In addition, the compatibility between the repair fluid and the cable is difficult to judge based on the divided voltage detection of the defective cable or the normal cable in the past. The measurement of the divided voltage reflects the result of good local electrical contact. If there is one point of good contact between the buffer layer and the aluminum sheath, even if the compatibility of the repair fluid with the cable is poor, the measured divided voltage at the cable end will be reduced. Based on this, the overall compatibility cannot be judged after the repair fluid is injected into the cable.

[0017] As shown in FIG. 2, this embodiment provides a method for testing the compatibility of a defective cable with a conductive repair fluid, which includes the following steps: (1) Manufacturing cables with artificial defects. First, after the 3-layer co-extrusion molding process of the 110kV high voltage cable is completed, a buffer waterproof tape is wound around the outside of the cable insulation shielding layer, and the buffer waterproof tape is composed of three layers, as shown in Figure 3, the first layer is semiconductive polyester fiber (made of polyester fiber), the third layer is semiconductive nonwoven fabric (made of polyester fiber), and one layer of sodium polyacrylate expanded powder is applied between the two layers. The thickness of the buffer waterproof tape is 2mm or less, the width is 80mm or less, and it is wound around the outside of the insulation shielding layer with a coverage rate of 50%. The resistivity test result of the buffer waterproof tape using a BDD-2 type cable semiconductive resistance measuring device should be between 1000 and 1500 Ω·m.

[0018] Then, one layer of non-conductive polyester fiber wrapping tape (hereinafter referred to as non-conductive wrapping tape) is wrapped around the outside of the buffer waterproof tape, and the wrapping tape is composed of two layers, the first layer being non-conductive expanded cotton (made of polyester fiber) and the second layer being non-conductive nonwoven fabric (made of polyester fiber). The thickness of the non-conductive wrapping tape is 1 mm or more and 2.5 mm or less, the width is 80 mm or less, and it is wrapped around the outside of the buffer waterproof tape with a coverage rate of more than 50%.

[0019] In particular, as shown in Figure 4, the coverage, thickness and width of the non-conductive winding tape structure in the above technical means are set to 50%, 2mm and 80mm respectively, the above parameters may be set to other values, but it must be ensured that the non-conductive winding tape structure can completely cut off the electrical connection between the insulating shielding layer and the aluminum sheath. In addition, in order to reflect the compatibility performance of the repair fluid and the buffer waterproof tape from the local discharge results, the main material of the non-conductive winding tape must be the same as that of the buffer waterproof tape.

[0020] Finally, a spiral corrugated aluminum sheath is argon arc welded to the outside of the non-conductive winding tape, with a thread pitch of 25 mm. The aluminum tape used for the corrugated aluminum sheath meets the requirements of GB / T3880.1-2012, and its elongation is more than 16%.

[0021] Please refer to FIG. 5 for a schematic cross-sectional view of an artificially defective cable structure.

[0022] (2) Measure the local discharge signal. Cut the artificially defective cable to a length of at least 15 meters (preferably 17 meters), and wrap the non-conductive wrapping tape exposed on both sides of the cable with insulating tape (see FIG. 6) to ensure that the buffer waterproof tape and the non-conductive wrapping tape do not loosen during the experiment. Then, connect the artificially defective cable to the local discharge test circuit (see FIG. 7), and perform a local discharge signal test according to the GB / T11017.1-2014 local discharge experiment standard to measure the starting discharge voltage U 1 , the corresponding local discharge signal and 1.0U 0 , 1.5U 0 , 1.75U 0 The corresponding local discharge signal in voltage (U 0 = 64 kV).

[0023] (3) Attach adapters to both sides of the cable for injecting repair fluid. According to the artificially defective cable manufactured as described above, the adapter described in this step is composed of a front gasket, a back gasket, and a center sleeve, and each of the three parts is composed of two parts, an upper part and a lower part, which can be fitted together. For the structure, refer to Figures 8 and 9, respectively.

[0024] The front gasket has an annular structure with an L-shaped cross section (see Figure 10) that is divided into two parts, upper and lower, along the cross section and is installed side by side at one end of the center sleeve. It comes into close contact with the aluminum sheath of the high-voltage cable, ensuring the tightness of the contact between the adapter and the high-voltage cable.

[0025] The entire back gasket is a roughly hollow cylinder, with a retaining space for elastic deformation at the top and bottom of the cylinder. The back gasket is also divided into two parts, upper and lower, along the vertical bisecting plane of the cylinder, which are joined together on the outside of the non-conductive winding tape, fitted inside one end of the center sleeve, and clamped within the center sleeve and tightly attached to the non-conductive winding tape, preventing the injected repair liquid from leaking out from that direction.

[0026] The entire center sleeve is a cylindrical structure (see Figures 11 and 12), with three layers of annular partition plates inside and four bolt holes and two duct structures on the outside. The inner annular partition plates divide the internal space of the adapter into three parts, the front, middle and rear, which respectively function as the front gasket connection point, the repair fluid injection point and the back gasket connection point. The repair fluid is injected into the adapter through the two duct structures and then into the high-voltage cable that needs to be treated. The four bolt holes use bolts to rivet the entire adapter structure to the cable. An adapter structure is also symmetrically arranged at the other end of the high-voltage cable segment that needs to be treated to guide away excess repair fluid.

[0027] (4) Inject repair fluid. As shown in Figure 13, adapters are attached to both sides of the cable with the artificial defect, and the gas bottle, repair fluid can and adapter are connected in that order. A short inlet / outlet pipe is installed inside the can, and the repair fluid is injected into the cable air gap layer through the adapter by the pressure of the gas bottle. The injection flow is as follows: 1) First, close the two-way joint of the repair fluid collection port, open the two-way joint of the repair fluid injection port, and check the tightness of the injection passage; 2) After the airtightness test is completed, open the two-way joint of the repair fluid collection port, set the injection pressure at 0.3-0.4MPa, open the gas bottle switch, and inject the repair fluid into the cable air gap layer; 3) After the repair fluid flows out of the collection port, the pressure is stopped. Since both two-way joints are connected above the cable, in this case, the cable air gap layer is completely filled with repair fluid; 4) Close the two-way joint of the cable and remove the injection device to complete the injection operation.

[0028] (5) Measure the local discharge signal again. The initial discharge voltage U 2 , the corresponding local discharge signal, and 1.0U 0 , 1.5U 0 , 1.75U 0 The corresponding local discharge signal in voltage (U 0 = 64kV) are recorded. By comparing the local discharge signals at each voltage level, the compatibility of the injected repair fluid with the cable body can be judged. The judgment method is as follows: 1) Before the repair fluid is injected, detectable discharge signals exceeding the standard sensitivity at each voltage level appear on the cable, and after the repair fluid is injected, no detectable discharge signals exceeding the standard sensitivity at each voltage level appear on the cable; this indicates that the repair fluid is compatible with the cable; 2) If, before the repair fluid is injected, the cable shows detectable discharge signals that exceed the standard sensitivity at each voltage level, and after the repair fluid is injected, the cable shows at least one detectable discharge signal that exceeds the standard sensitivity at the same voltage level, then the compatibility of the repair fluid with the cable is poor; 3) Initial discharge voltage U 2 U 1 If it is smaller, the compatibility of the repair fluid with the cable is poor.

[0029] As shown in FIG. 14, in another embodiment of the present application, a system for testing compatibility between a defective cable and a conductive repair fluid is provided, the system comprising: a cable processing module for producing the artificially defective cable; a local discharge signal measurement module for measuring a local discharge signal of the cable before and after the repair fluid is injected; An adapter module for mounting an adapter for injecting repair fluid on both sides of the cable; an injection module for injecting a repair fluid; and an analysis module for determining compatibility of the injected repair fluid with the cable body by comparing the local discharge signals at each voltage level.

[0030] Here, the system provided in the above embodiment is described by way of example based on the division of each of the above functional modules. In practical application, the above functions may be allocated to be completed by different functional modules according to needs, that is, the internal structure may be divided into different modules to complete all or part of the functions described above, and the system is applied to the method for testing the compatibility of a defective cable with a conductive repair fluid in the above embodiment.

[0031] Here, each part of the present application may be realized by hardware, software, firmware, or a combination thereof. In the above embodiment, a plurality of steps or methods may be realized by software or firmware stored in a memory and executed by a suitable command execution system. For example, when realized by hardware, as in another embodiment, the present invention may be realized by any one of the following known techniques in the art or a combination thereof, namely, a discrete logic circuit having logic gate circuits that realize a logic function for a data signal, an application specific integrated circuit having an appropriate combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0032] The above examples are preferred embodiments of the present invention, and the embodiments of the present invention are not limited to the above examples. Any completed changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit, substance, and principle of the present invention are equivalent replacement methods and fall within the protection scope of the present invention.

Claims

1. 1. A method for testing compatibility of a defective cable with a conductive repair fluid, comprising the steps of: manufacturing an artificially defective cable; measuring a local discharge signal; Attaching adapters to both sides of the cable for injecting repair fluid; injecting a repair fluid; measuring the local discharge signal again; and determining compatibility of the injected repair fluid with the cable body by comparing the local discharge signals at each voltage level; The step of manufacturing the artificially defective cable is specifically described as follows: Wrap the outside of the cable insulation shield with shock-absorbing waterproof tape. A layer of non-conductive wrapping tape is wrapped around the outside of the buffer waterproof tape so as to completely cover the outside of the buffer waterproof tape; A spiral corrugated aluminum sheath is argon-arc welded to the outside of the non-conductive winding tape, and the thread pitch is 25 mm. The aluminum tape used for the corrugated aluminum sheath meets the requirements of GB / T3880.1-2012, and its elongation is 16% or more. The main material of the non-conductive wrapping tape is the same as the main material of the buffer waterproof tape.

13. A method for testing the compatibility of a defective cable with a conductive repair fluid, comprising:

2. The method for testing the compatibility of defective cables with conductive repair fluid as claimed in claim 1, characterized in that the buffer waterproof tape comprises three layers, the first layer being semiconductive expanded cotton, the third layer being semiconductive nonwoven fabric, and a layer of sodium polyacrylate expanded powder being applied between the two layers.

3. The step of measuring the local discharge signal specifically includes: Cut out at least 15 meters of the artificially defective cable and wrap the non-conductive wrapping tape exposed on both sides of the cable with insulating tape to ensure that the buffer waterproof tape and the non-conductive wrapping tape do not loosen during the experiment; According to GB / T 11017.1-2014 local discharge test standard, local discharge test was performed, and the starting discharge voltage U １ , the corresponding local discharge signal and 1.0U ０ , 1.5U ０ , 1.75U ０ Record the corresponding local discharge signals in voltage, respectively. U ０ The method for testing the compatibility of a defective cable with a conductive repair fluid according to claim 1, characterized in that: is the effective value of the rated voltage at the power frequency between the conductor of the cable with the artificial defect and the spiral corrugated aluminum sheath.

4. The adapter includes a front gasket, a back gasket, and a center sleeve, all of which have a vertical fitting structure; The front gasket is an annular structure having an L-shaped cross section, and is divided into two parts along the cross section. The front gasket is arranged side by side at one end of the center sleeve and is in close contact with the aluminum sheath of the high voltage cable. The back gasket is a generally hollow cylinder, which is divided into two parts along a perpendicular bisecting plane of the cylinder, which are joined together at the outside of the non-conductive winding tape, which is fitted into one end of the center sleeve, which is clamped in the center sleeve, and which is tightly attached to the non-conductive winding tape. The cylinder of the back gasket is further provided with a retaining space for elastic deformation at its top and bottom. The center sleeve as a whole is a cylindrical structure, and three layers of annular partition plates are provided inside the center sleeve, and four bolt holes and two duct structures are provided outside the center sleeve. The annular partition plates inside the center sleeve divide the inner space of the adapter into three parts, i.e., the front, middle and rear parts, which respectively function as the front gasket connection part, the repair fluid injection part and the back gasket connection part. The duct structure introduces the repair fluid into the adapter and then injects it into the high-voltage cable that needs to be treated. The bolt holes rivet the entire adapter structure and the cable. The method for testing the compatibility of a defective cable with a conductive repair fluid as described in claim 1, characterized in that an adapter structure is symmetrically provided at the other end of the high-voltage cable segment that needs to be treated to guide away excess repair fluid.

5. The step of injecting the repair fluid is specifically described as follows: an adapter is attached to both sides of the artificially defective cable; a gas bottle, a repair fluid can and an adapter are connected in sequence; a short inlet / outlet pipe is installed in the repair fluid can; the gas bottle injects the repair fluid into the cable air gap layer through the adapter; the injection flow is as follows: Close the two-way joint of the repair fluid collection port and open the two-way joint of the repair fluid injection port to check the tightness of the injection passage; After the airtightness test is completed, open the two-way joint of the repair fluid collection port, set the injection pressure to 0.3-0.4MPa, open the gas bottle switch, and inject the repair fluid into the cable air gap layer; After the repair fluid flows out of the collection port, stop applying pressure.

2. The method for testing the compatibility of a defective cable with a conductive repair fluid as claimed in claim 1, further comprising the steps of: closing the two-way joint of the cable, removing the injection device, and completing the injection operation.

6. The step of determining the compatibility of the injected repair liquid with the cable body by comparing the local discharge signals at each voltage level is specifically: If, before the repair fluid is injected, a detectable discharge signal exceeding the standard sensitivity at each voltage level appears in the cable, and, after the repair fluid is injected, no detectable discharge signal exceeding the standard sensitivity at each voltage level appears in the cable, it is determined that the repair fluid is compatible with the cable; If, before the injection of the repair fluid, a detectable discharge signal exceeding the reference sensitivity appears in the cable at each voltage level, and, after the injection of the repair fluid, a detectable discharge signal exceeding the reference sensitivity appears at least once in the cable at the voltage level, it is determined that the compatibility between the repair fluid and the cable is poor; The method for testing the compatibility of a defective cable with a conductive repair fluid as described in claim 1, characterized in that if the initial discharge voltage U2 after the repair fluid is injected is smaller than the initial discharge voltage U1 before the repair fluid is injected, it is determined that the compatibility of the repair fluid with the cable is poor.

7. A test system for compatibility between a defective cable and a conductive repair liquid, the test system being applied to the method for testing compatibility between a defective cable and a conductive repair liquid according to any one of claims 1 to 6, a cable processing module for producing artificially defective cables; a local discharge signal measurement module for measuring a local discharge signal of the cable before and after the repair fluid is injected; An adapter module for mounting an adapter for injecting repair fluid on both sides of the cable; an injection module for injecting a repair fluid; and an analysis module that determines the compatibility of the injected repair fluid with the cable body by comparing the local discharge signals at each voltage level.

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