Method of installing a high voltage power cable termination

Abstract

This invention relates to the field of cable installation technology, and more particularly to an installation method for high-voltage power cable terminals, comprising the following steps: S100, pre-processing of the pre-installed module in the factory: assembling the various components constituting the pre-installed module, completing a sealing test, and sealing and storing the qualified pre-installed module. S200, cable pre-processing: pre-processing the cable end, applying fluorescent positioning marks, and then verifying the marks. S300, installation of the pre-installed module and cable: unpacking the pre-installed module, then fitting the corresponding processed cable end into the pre-installed module to complete the overall fixation. S400, final assembly: completing the installation of the cable terminal body according to process requirements, and conducting an overall test after installation. This invention avoids unstable quality problems caused by manual on-site operation by pre-constructing pre-installed modules.

Description

Technical Field

[0001] This invention relates to the field of cable installation technology, and more particularly to a method for installing high-voltage power cable terminals. Background Technology

[0002] In high-voltage power transmission and distribution systems, cables are crucial for connecting power generation equipment, transformers, and switchyards. The typical steps in cable termination installation include cable pretreatment, component pre-assembly, and on-site installation of the termination or T-joint. The installation quality of high-voltage cable terminations directly determines the overall operational performance of the cable. However, existing high-voltage cable termination installations clearly have deficiencies:

[0003] The final assembly quality of high-voltage cable assemblies relies excessively on the uncontrollable quality of on-site manual operation, resulting in the inability to achieve a complete transfer of product reliability from the manufacturing end to the application end.

[0004] The main reason for this problem is that cable handling relies on manual operation by construction personnel, and the construction site lacks high-precision positioning and measurement methods. Most of the work depends on experience and visual inspection. If excessive stripping or damage to the main insulation is done, the entire cable will be scrapped or need to be cut and reworked. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides the following technical solution:

[0006] The installation method for high-voltage power cable terminals includes the following steps:

[0007] S100, pre-assembled modules are pre-processed at the factory:

[0008] The various components that make up the pre-assembled module are assembled, and then a sealing test is performed. The pre-assembled module that passes the test is then sealed and stored.

[0009] S200, Cable Pretreatment:

[0010] The cable ends are pre-treated and fluorescent positioning marks are applied before the marking is verified.

[0011] S300, pre-installed modules and cable installation:

[0012] Unpack the pre-installed module, then insert the corresponding processed cable end into the pre-installed module to complete the overall fixation.

[0013] S400, final assembly complete:

[0014] Complete the installation of the cable terminal body according to the process requirements, and conduct an overall test after installation.

[0015] As an improvement to the above technical solution, in step S100, the preprocessing includes the following steps:

[0016] S110, Component Pre-processing:

[0017] Under clean conditions, each component is cleaned and defective products are removed through quality inspection.

[0018] S120, component assembly:

[0019] Based on positioning fixtures, the various components are assembled sequentially to form a pre-assembled module;

[0020] S130, Pre-detection:

[0021] The assembled pre-assembled modules are inspected for quality. Defective pre-assembled modules are disassembled and sent to step S110 for reassembly.

[0022] S140, markings and packaging:

[0023] Products that pass quality inspection are marked with traceability tags and sealed tightly before being placed in protective packaging.

[0024] As an improvement to the above technical solution, the quality inspection requirements in step S130 are as follows:

[0025] Send the pre-installed module into the airtightness testing equipment, introduce dry compressed air into the pre-installed module to 0.02MPa, and start the pressure holding timer after turning off the air source;

[0026] If the pressure holding time is 30 seconds and the pressure drop is ≤5%, the sealing performance is considered qualified.

[0027] As an improvement to the above technical solution, in step S140, the marking includes at least:

[0028] The label and traceability QR code are affixed to the pre-installed module and printed on the pre-installed module. The label and traceability QR code contain at least the model specification, testing date, testing result, warranty period, and production date.

[0029] As an improvement to the above technical solution, in step S200, the cable pretreatment includes the following steps:

[0030] S210, Cable termination treatment:

[0031] The cable ends are stripped and chamfered using prefabricated cutting tools;

[0032] S220, fluorescent localization marker:

[0033] The installation location is determined based on the cable and the corresponding design standards, and then a ring-shaped marking strip is formed at the installation location using fluorescent material.

[0034] S230, Mark Verification:

[0035] Use ultraviolet light to illuminate the marked locations to confirm that the fluorescent marks are clearly visible and accurately positioned.

[0036] If the markings are unclear, remark them.

[0037] As an improvement to the above technical solution, in step S300, the installation steps of the pre-installed module and cable are as follows:

[0038] S310, Pre-installed Module Unpacking and Inspection:

[0039] Remove the pre-installed module that is compatible with the cable, remove the protective packaging, and inspect the appearance and sealing of the pre-installed module, and then inspect the fluorescent positioning mark;

[0040] S320, assembly and fixing:

[0041] Clean and lubricate the cable end and the pre-assembly module. Then push the cable end into the pre-assembly module along the cable axis until it fits in place. Finally, fix the cable to the pre-assembly module with fasteners.

[0042] S330, Fastening check;

[0043] The tightening force of fasteners is tested using a torque meter to ensure that the tightening force reaches the design torque.

[0044] As an improvement to the above technical solution, in step S320, a multi-stage guide cone sleeve is detachably installed at the open end of the pre-installed module, and the end of the cable is fed into the pre-installed module through a pushing device.

[0045] During the advancement process, the acoustic emission signal of the contact surface between the seal and the cable outer sheath is collected by the sensor to monitor the sealing status in real time. If an abnormality is detected during monitoring, the advancement is stopped and the seal is replaced.

[0046] When the cable end is pushed to the predetermined position within the pre-installed module, the mechanical structure on the pre-installed module determines whether the cable end has been pushed into place.

[0047] As an improvement to the above technical solution, in step S330, the fastening inspection method is as follows:

[0048] Detection and warning:

[0049] Apply torque along the tightening direction using a torque wrench until the set detection torque value is reached, and record the peak torque and cumulative rotation angle;

[0050] If rotation occurs before the test torque is reached, the initial rotation torque is recorded; if rotation does not occur when the test torque is reached, the locking force is recorded as qualified.

[0051] Loosening test:

[0052] Apply torque in the loosening direction using a torque wrench, and record the breaking torque at the start of rotation;

[0053] If the ratio of the breaking torque to the detection torque is not less than the set value, it is recorded as qualified; if the ratio of the breaking torque to the detection torque is less than the set value, it is recorded as having a risk of pre-locking attenuation.

[0054] Re-tightening verification:

[0055] Apply torque along the tightening direction using a torque wrench, tighten to the detected torque value, and record the torque-angle curve during the re-tightening process;

[0056] If the curve shape is basically consistent with the standard curve, the thread condition is normal; if the curve is abnormal, the thread is abnormal.

[0057] As an improvement to the above technical solution, the data during the inspection process is uploaded to the cloud, and data association and archiving are performed to finally generate an installation test report;

[0058] For those that fail the inspection and warning, the final torque is redesigned and the inspection is repeated.

[0059] For those that fail the loosening test, loosen the fasteners, check and clean the fit, and then tighten them again.

[0060] For fasteners that fail the re-tightening verification, repair or replace the fasteners, then re-tighten and test.

[0061] As an improvement to the above technical solution, in step S400, the overall test includes at least:

[0062] Insulation resistance retest; sealing verification; simplified withstand voltage test; grounding resistance measurement;

[0063] After passing the test, an intelligent detection device for continuous monitoring of the operating status is installed.

[0064] The beneficial effects of this invention are:

[0065] By pre-assembling pre-assembled modules in a clean factory environment and conducting pre-quality testing, unstable quality issues caused by manual on-site operations are avoided. Furthermore, after quality testing, the pre-assembled modules are sealed during storage and transportation, ensuring they maintain good sealing performance upon arrival at the construction site, significantly reducing the unreliability of sealing during on-site assembly.

[0066] All testing operations during construction are quantified through data. Whether it is the assembly of pre-installed modules, the installation of pre-installed modules and cables, the final assembly, or real-time monitoring by sensors, the quality defects can be reduced throughout the entire process. The data of the entire process is automatically linked and archived, realizing complete traceability of the cable assembly from manufacturing, installation to commissioning. Detailed Implementation

[0067] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0068] The final assembly quality of high-voltage cable assemblies relies excessively on the uncontrollable quality of on-site manual operation, resulting in the inability to achieve a complete transfer of product reliability from the manufacturing end to the application end.

[0069] To solve the above-mentioned technical problems, the installation method for high-voltage power cable terminals includes the following steps:

[0070] Step S100: The pre-assembled module undergoes pre-processing at the factory.

[0071] The various components that make up the pre-assembled module are assembled, and then a sealing test is performed. The pre-assembled module that passes the test is then sealed and stored.

[0072] This step is the starting point of the high-voltage cable assembly process and the core of prefabrication in this solution. This step is usually completed in a clean manufacturing environment and implemented by the cable accessory manufacturer. Components such as sealing components, terminal bodies, and T-joints, which would otherwise need to be installed one by one on the construction site, are pre-assembled into standardized modules that have undergone comprehensive testing. Based on the corresponding cable specifications, these finished products can be supplied to the implementation site immediately.

[0073] Furthermore, to facilitate understanding of the preprocessing steps, the following explanation is provided.

[0074] In step S100, the preprocessing includes the following steps:

[0075] S110, Component Pre-processing:

[0076] Under clean conditions, each component is cleaned and defective products are removed through quality inspection.

[0077] Assembly is carried out under clean conditions, with controlled relative temperature and humidity. Environmental data is recorded in real time, and any deviations are immediately adjusted and the affected batches are traced back to their source.

[0078] For cleaning metal parts such as C-shaped protective shells, flanges, fasteners, equalizing rings, and grounding terminals, the following method is used: first, ultrasonic cleaning is performed using anhydrous ethanol or a special cleaning agent. After cleaning, pure deionized water is used for rinsing to remove residual cleaning agent.

[0079] After rinsing, the parts are dried. Before drying, compressed air is used to blow the surface of the parts to remove residual moisture. Then the parts are placed in a clean drying oven for drying.

[0080] After cleaning, random checks are performed on each batch, for example, 2 pieces out of every 50 pieces per batch, to verify cleanliness and product quality. If any sample fails the check, the entire batch is reworked and cleaned again.

[0081] For cleaning of sealing components, such as main sealing rings, auxiliary sealing rings, and interface sealing rings, the cleaning method is as follows: use a special cleaning agent to wipe manually. Do not soak to prevent swelling or deterioration of material properties. Allow to air dry naturally after cleaning.

[0082] Visual inspection ensures that the surface of the parts is free of bubbles, cracks, scratches, particles, and distortion. Products with these defects are immediately scrapped and must not be downgraded for use. Precise dimensional measurements are also performed; any parts that do not meet dimensional standards are immediately scrapped.

[0083] S120, component assembly:

[0084] Based on the positioning fixture, the various components are assembled sequentially to form a pre-assembled module.

[0085] Before assembly, inventory all components to ensure they are complete, and complete cleaning and quality inspection. Use a dedicated assembly positioning fixture for installation, which can calibrate the fixture's reference surface to ensure installation accuracy, and perform periodic calibration. Then assemble the sealing module, terminal module, and T-head module.

[0086] S130, Pre-detection:

[0087] The assembled pre-assembled modules are inspected for quality. Any unqualified pre-assembled modules are disassembled and sent to step S110 for reassembly.

[0088] In this solution, pre-inspection applies to all types of pre-assembled modules, and the inspection steps include: visual inspection, re-inspection of critical dimensions, and sealing inspection. Sealing inspection is the core component, and all pre-assembled modules are inspected.

[0089] In step S130, the sealing performance test requirements are as follows:

[0090] Send the pre-installed module into the airtightness testing equipment, introduce dry compressed air into the pre-installed module to 0.02MPa, and start the pressure holding timer after turning off the air source;

[0091] If the pressure holding time is 30 seconds and the pressure drop is ≤5%, the sealing performance is considered qualified.

[0092] The qualified pre-installed modules are associated with the test data to create a serial number for each module, enabling later traceability. The specific testing method is as follows:

[0093] Connect the pre-installed module and the pre-test nozzle to the air tightness tester via a quick connector. Start the air tightness tester and fill the test chamber inside the module with dry compressed air. According to the air tightness test requirements, perform inflation and pressure holding, and record the pressure-time curve.

[0094] Judgments and records are made based on the sealing performance testing requirements. In practice, engineers will also investigate the causes of non-conforming modules, such as: non-conforming sealing, non-conforming electrical performance, non-conforming dimensions, etc., and analyze and summarize the findings.

[0095] Some defective products that can be reworked are disassembled and then processed sequentially through step S110. All reworked modules must be re-inspected to prevent defective parts from entering during the rework process.

[0096] S140, markings and packaging:

[0097] Products that pass quality inspection are marked with traceability tags and sealed tightly before being placed in protective packaging.

[0098] In step S140, the marking includes at least:

[0099] The label and traceability QR code are affixed to the pre-installed module and printed on the pre-installed module. The label and traceability QR code contain at least the model specification, testing date, testing result, warranty period, and production date.

[0100] A unique traceable QR code is printed onto the surface of the pre-installed module using a laser marking machine. A label recording routine data is also affixed for easy viewing. After labeling, the QR code is scanned to verify that the information matches the label. If the information does not match, corrections are made.

[0101] After all quality inspections are passed, the modules are sealed with specialized sealing plugs. To prevent them from being undetected after being pulled out, the sealing plugs are designed with a self-locking reverse tooth structure, ensuring they cannot be pulled out without damage once inserted. After sealing, the pre-assembled module is kept under positive pressure to prevent external moisture and contaminants from entering during transportation and storage. The protective packaging uses an aluminum foil composite film dust bag with an internal desiccant packet. The outer casing is a box, and the aluminum foil composite film dust bag is vacuum-sealed and placed inside the box.

[0102] Furthermore, to facilitate understanding of the cable pretreatment steps, the following explanation is provided.

[0103] S200, Cable Pretreatment:

[0104] The cable ends are pre-treated and fluorescent positioning marks are applied before the marking is verified.

[0105] The cable pretreatment step is completed on-site. This step involves stripping, chamfering, marking, and positioning the cable to ensure precise alignment with the pre-installed modules.

[0106] Specifically, in step S200, the cable pretreatment includes the following steps:

[0107] S210, Cable termination treatment:

[0108] The cable ends are stripped and chamfered using prefabricated cutting tools.

[0109] First, the cable ends are cleaned and straightened. After straightening, they are fixed in place. Then, a prefabricated stripping and chamfering combination tool, compatible with the cable, is used. The tool is a manually operated cutting device, with a prefabricated stripping mechanism based on the cable stripping and chamfering design requirements. The original manual operation is precisely controlled by the stripping mechanism, simplifying the stripping process and eliminating quality fluctuations caused by manual operation on site.

[0110] For example, the stripping mechanism can achieve fixed-length stripping of the cable outer sheath, circumferential cutting of the outer sheath, longitudinal cutting and stripping of the outer sheath, etc.

[0111] S220, fluorescent localization marker:

[0112] The installation location is determined based on the cable and the corresponding design standards, and then a ring-shaped marking strip is formed at the installation location using fluorescent material.

[0113] In this step, the purpose of setting the fluorescent positioning marker is to determine the installation location. During operation, the complete design parameters can be obtained by scanning the traceable QR code on-site, and then the installation location can be determined based on the design parameters.

[0114] After measuring from the cable end to determine the marking location, make a temporary mark, and then apply UV fluorescent marking material. If necessary, different colors of fluorescent material can be used for different requirements and cable specifications to facilitate differentiation and identification.

[0115] After coating, a curing process is performed by irradiating the fluorescent mark with a curing lamp for no less than 60 seconds. During irradiation, the light moves evenly around the mark, so that the cured fluorescent material adheres firmly to the surface of the cable.

[0116] S230, Mark Verification:

[0117] Use ultraviolet light to illuminate the marked locations to confirm that the fluorescent marks are clearly visible and accurately positioned.

[0118] If the marking is not clear, perform re-marking.

[0119] This step is used to visually verify the cured fluorescent mark, and the verification method is:

[0120] Under ultraviolet light irradiation, the fluorescent mark presents a clear, uniform and continuous fluorescent signal. The ultraviolet light can be emitted by a handheld ultraviolet lamp.

[0121] In addition, the fluorescence intensity of the fluorescent mark is detected. A mark is deemed clear when it reaches the standard value, and re-marking is performed if it is not clear. The standard value is a design parameter. Meanwhile, the position accuracy of the fluorescent mark is also measured to ensure that the position meets the design requirements.

[0122] If necessary, it is also required to test the adhesion of the fluorescent mark, and the specific test method is as follows:

[0123] A practical 3M tape is adhered to the surface of the marking tape, pressed firmly and then quickly torn off, and the surface of the tape is observed;

[0124] If no fluorescent material is transferred to the surface of the tape, it is judged as qualified.

[0125] If the transferred fluorescent material accounts for more than 5% of the area of the fluorescent mark, it is judged as unqualified. If unqualified, re-marking and curing shall be carried out.

[0126] Further, for the convenience of understanding the steps of installing the preassembled module and the cable, the following description is provided.

[0127] S300, Installation of preassembled module and cable:

[0128] Unpack the preassembled module, then fit the corresponding processed cable end into the preassembled module as a whole, and complete the overall fixation.

[0129] This step is also completed at the construction site, and is a key step for butt joint and reliable fixation between the preassembled module and the cable end.

[0130] Specifically, in step S300, the steps for installing the preassembled module and the cable are as follows:

[0131] S310, Unpacking and inspection of the preassembled module:

[0132] Take out the preassembled module matching the cable, remove the protective package, inspect the appearance and the sealing performance of the preassembled module, and then inspect the fluorescent positioning mark.

[0133] During on-site construction, information matching verification shall be performed first to ensure that the cable, the preassembled module and the engineering project are uniformly matched. If any item is found to be inconsistent, stop the installation, replace and correct the mismatched parts, and contact the manufacturer for confirmation if necessary. In addition, the specifications of the preassembled module and the cable shall also match.

[0134] Before unpacking, ensure the packaging, sealing plugs, and module appearance are free of abnormalities, and verify the fluorescent markings. Once confirmed to be free of abnormalities, prepare for assembly.

[0135] S320, assembly and fixing:

[0136] Clean and lubricate the cable end and the pre-assembly module. Then push the cable end into the pre-assembly module along the cable axis until it fits properly. Finally, fix the cable to the pre-assembly module with fasteners.

[0137] Before inserting the cable end into the pre-assembled module, clean the area to be mated to ensure a clean interface. Then, apply lubricant to reduce resistance during assembly and improve the installation efficiency of the cable end and pre-assembled module. Connect with fasteners after installation.

[0138] Specifically, in step S320, a multi-stage guide cone sleeve is detachably installed at the open end of the pre-installed module, and the end of the cable is fed into the pre-installed module through a pushing device.

[0139] During the advancement process, the acoustic emission signal of the contact surface between the seal and the cable outer sheath is collected by the sensor to monitor the sealing status in real time. If an abnormality is detected during monitoring, the advancement is stopped and the seal is replaced.

[0140] When the cable end is pushed to the predetermined position within the pre-installed module, the mechanical structure on the pre-installed module determines whether the cable end has been pushed into place.

[0141] The multi-stage guide cone sleeve is matched with the corresponding pre-installed module. In this solution, the multi-stage guide cone sleeve is connected to the pre-installed module through quick-release parts so that the multi-stage guide cone sleeve can be removed and reused after the cable is connected to the pre-installed module.

[0142] During the advancement process, manual advancement is initially employed, with auxiliary mechanisms used when resistance is encountered. Acoustic emission sensors continuously collect acoustic emission signals from the cable's outer sheath contact surface throughout the advancement process.

[0143] For example, a uniform, continuous low-amplitude acoustic emission signal indicates normal propulsion; a sudden high-amplitude spike in the acoustic emission signal indicates scratches on the seal; and periodic fluctuations in the acoustic emission signal indicate curling or twisting of the seal ring. When an abnormal signal is detected, an alarm is triggered and the operator is alerted.

[0144] In this solution, in addition to using sensors to determine the propulsion status, an additional mechanical mechanism can be used for positioning to determine whether the propulsion is in place. Furthermore, the position of the fluorescent marker relative to the pre-installed module can also determine whether the cable and the pre-installed module are properly aligned. By using multiple methods to determine proper propulsion, the solution avoids the instability in quality that can result from relying on visual judgment and experience.

[0145] S330, Fastening check;

[0146] The tightening force of fasteners is tested using a torque meter to ensure that the tightening force reaches the design torque.

[0147] The tightening force still needs to be checked using a torque wrench. Before using the torque wrench, it must be calibrated to ensure that the tightening force meets the set requirements. Through multi-dimensional quality verification, it is ensured that the tightening force, the ability to maintain the tightened state, and the condition of the connecting parts all meet the design requirements.

[0148] In step S330, the fastening check is performed as follows:

[0149] Detection and warning:

[0150] Apply torque along the tightening direction using a torque wrench until the set detection torque value is reached, and record the peak torque and cumulative rotation angle.

[0151] If rotation occurs before the test torque is reached, the initial rotation torque is recorded; if rotation does not occur when the test torque is reached, the locking force is recorded as qualified.

[0152] The detection and early warning step is mainly used to detect locking force problems, determine whether the locking force meets the requirements, and provide real-time feedback on the detection results.

[0153] Loosening test:

[0154] Apply torque in the loosening direction using a torque wrench and record the breaking torque at the start of rotation.

[0155] If the ratio of the breaking torque to the detection torque is not less than the set value, it is recorded as qualified; if the ratio of the breaking torque to the detection torque is less than the set value, it is recorded as having a risk of pre-locking attenuation.

[0156] After the detection and warning steps are completed, without changing the wrench position, immediately apply torque slowly and evenly along the loosened section until the bolt begins to rotate. In this solution, the ratio of the loosening torque to the detection torque is set to 0.8. However, the requirements for different cables and pre-installed modules vary, and the ratio setting will differ accordingly.

[0157] Re-tightening verification:

[0158] Apply torque along the tightening direction using a torque wrench, tighten to the detected torque value, and record the torque-angle curve during the re-tightening process;

[0159] If the curve shape is basically consistent with the standard curve, the thread condition is normal; if the curve is abnormal, the thread is abnormal.

[0160] Data from the inspection process is uploaded to the cloud, linked, and archived, ultimately generating an installation inspection report.

[0161] After the loosening test is completed, the operator applies torque again along the tightening direction with a torque wrench to tighten the fastener to the tested torque value. In addition to recording the torque-angle curve, the final torque value and cumulative angle also need to be recorded. The collected measured torque-angle curve is compared and analyzed with the preloaded standard torque-angle curve to determine whether the thread is abnormal.

[0162] Data is uploaded during on-site installation. If the construction site lacks the capability to upload data, it can be stored locally first and then uploaded when conditions permit. The on-site installation management terminal associates the received data with the previously stored data, creating an independent full lifecycle digital file for each pre-installed module and its corresponding cable installation process.

[0163] For those failing the detection warning, the final torque is redesigned and the test is repeated.

[0164] If the inspection warning fails, loosen the fasteners, check and clean the fit, and then retighten them. Alternatively, repair or replace the fasteners and then tighten them again until the reset final torque is achieved.

[0165] For items that fail the loosening test, loosen the fasteners, check and clean the fit, and then tighten them again.

[0166] For fasteners that fail the loosening test, completely loosen them, disassemble and inspect them, remove any foreign objects, and then re-tighten them.

[0167] For fasteners that fail the re-tightening verification, repair or replace the fasteners, then re-tighten and test.

[0168] This step is mainly used to inspect the thread condition. For thread defects that cannot be repaired, the fasteners are replaced directly. For repairable fasteners, the construction personnel will repair them and then tighten them again.

[0169] If the re-inspection still fails, quality traceability will be initiated to find the root cause of the failure. The components will be replaced simultaneously.

[0170] Furthermore, to facilitate understanding of the final assembly steps, the following explanation is provided.

[0171] S400, final assembly complete:

[0172] Complete the installation of the cable terminal body according to the process requirements, and conduct an overall test after installation.

[0173] This step is the final assembly process, usually completed on-site. It is carried out after the pre-assembled modules and cables are installed and secured. Electrical performance tests are conducted to verify the final installation quality. If necessary, intelligent monitoring devices are installed to monitor the operational status of the assembly.

[0174] Specifically, in step S400, the overall test includes:

[0175] Insulation resistance retest:

[0176] Use an insulation resistance tester for measurement, calibrating it beforehand to ensure accuracy. For example, apply a 5kV DC voltage, maintain the voltage for 1 minute, record and calculate the absorption ratio. After completing the test, charge and discharge the cable using the insulation resistance tester. Ensure the cable meets the test requirements; if it does not, replace the component.

[0177] Sealing verification:

[0178] Use an airtightness testing device to verify the sealing performance and make a judgment based on the sealing performance requirements.

[0179] Simplified pressure resistance test:

[0180] Evaluation is conducted using parameters such as voltage, time, voltage boost, and withstand voltage. The pass / fail criteria are: no breakdown, no flashover, and no significant change in current during the test. Partial discharge is monitored simultaneously using infrared imaging. If the monitored values ​​show no significant change from before the withstand voltage test, and the insulation resistance does not decrease significantly, it indicates that the insulation was not damaged during the withstand voltage test.

[0181] Grounding resistance measurement:

[0182] The test is conducted in accordance with T / SMA 0078-2025 "Guideline for Testing Grounding Circuit Resistance of High Voltage Cables". If the grounding resistance is less than the specified value, it is considered qualified; if the grounding resistance exceeds the specified value, it is considered unqualified and must be reprocessed.

[0183] After passing the test, an intelligent detection device for continuous monitoring of the operating status is installed.

[0184] This step is used to monitor partial discharge signals in real time and assess the insulation status of cable joints. The intelligent monitoring device is preferably an HFCT sensor, which is fixed to the cable with clamps. Fiber Bragg gratings and distributed temperature sensors can also be used if necessary.

[0185] All sensor monitoring data is uploaded in real time, associated with the corresponding cable and pre-selected module data, and stored in a digital archive.

[0186] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Anyone skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for installing a high-voltage power cable terminal, characterized in that, Includes the following steps: S100, pre-assembled modules are pre-processed at the factory: The various components that make up the pre-assembled module are assembled, and then a sealing test is performed. The pre-assembled module that passes the test is then sealed and stored. S200, Cable Pretreatment: Pre-treat the cable ends and apply fluorescent positioning marks, then verify the markings. S300, pre-installed modules and cable installation: Unpack the pre-installed module, then insert the corresponding processed cable end into the pre-installed module to complete the overall fixation; S400, final assembly complete: Complete the installation of the cable terminal body according to the process requirements, and conduct an overall test after installation.

2. The installation method for a high-voltage power cable terminal according to claim 1, characterized in that: In step S100, the preprocessing includes the following steps: S110, Component Pre-processing: Under clean conditions, each component is cleaned and defective products are removed through quality inspection. S120, component assembly: Based on positioning fixtures, the various components are assembled sequentially to form a pre-assembled module; S130, Pre-detection: The assembled pre-assembled modules are inspected for quality. Defective pre-assembled modules are disassembled and sent to step S110 for reassembly. S140, markings and packaging: Products that pass quality inspection are marked with traceability tags and sealed tightly before being placed in protective packaging.

3. The installation method for a high-voltage power cable terminal according to claim 2, characterized in that: In step S130, the quality inspection requirements are as follows: Send the pre-installed module into the airtightness testing equipment, introduce dry compressed air into the pre-installed module to 0.02MPa, and start the pressure holding timer after turning off the air source; If the pressure holding time is 30 seconds and the pressure drop is ≤5%, the sealing performance is considered qualified.

4. The installation method for a high-voltage power cable terminal according to claim 2, characterized in that: In step S140, the marking includes at least: The label and traceability QR code are affixed to the pre-installed module and printed on the pre-installed module. The label and traceability QR code contain at least the model specification, testing date, testing result, warranty period, and production date.

5. The installation method for a high-voltage power cable terminal according to claim 1, characterized in that: In step S200, the cable pretreatment includes the following steps: S210, Cable termination treatment: The cable ends are stripped and chamfered using prefabricated cutting tools; S220, fluorescent localization marker: The installation location is determined based on the cable and the corresponding design standards, and then a ring-shaped marking strip is formed at the installation location using fluorescent material. S230, Mark Verification: Use ultraviolet light to illuminate the marked locations to confirm that the fluorescent marks are clearly visible and accurately positioned. If the markings are unclear, remark them.

6. The installation method for a high-voltage power cable terminal according to claim 1, characterized in that: In step S300, the pre-installed module and cable installation steps are as follows: S310, Pre-installed Module Unpacking and Inspection: Remove the pre-installed module that is compatible with the cable, remove the protective packaging, and inspect the appearance and sealing of the pre-installed module, and then inspect the fluorescent positioning mark; S320, assembly and fixing: Clean and lubricate the cable end and the pre-assembly module. Then push the cable end into the pre-assembly module along the cable axis until it fits in place. Finally, fix the cable to the pre-assembly module with fasteners. S330, Tightening check; The tightening force of fasteners is tested using a torque meter to ensure that the tightening force reaches the design torque.

7. The installation method for a high-voltage power cable terminal according to claim 6, characterized in that: In step S320, a multi-stage guide cone sleeve is detachably installed at the open end of the pre-installed module, and the end of the cable is fed into the pre-installed module through a pushing device. During the advancement process, the acoustic emission signal of the contact surface between the seal and the cable outer sheath is collected by the sensor to monitor the sealing status in real time. If an abnormality is detected during monitoring, the advancement is stopped and the seal is replaced. When the cable end is pushed to the predetermined position within the pre-installed module, the mechanical structure on the pre-installed module determines whether the cable end has been pushed into place.

8. The installation method for a high-voltage power cable terminal according to claim 6, characterized in that: In step S330, the fastening check is performed as follows: Detection and warning: Apply torque along the tightening direction using a torque wrench until the set detection torque value is reached, and record the peak torque and cumulative rotation angle; If rotation occurs before the detection torque is reached, the initial rotation torque is recorded; If no rotation occurs when the test torque is reached, the locking force is recorded as qualified. Loosening test: Apply torque in the loosening direction using a torque wrench, and record the breaking torque at the start of rotation; If the ratio of the breaking torque to the detection torque is not less than the set value, it is recorded as qualified; if the ratio of the breaking torque to the detection torque is less than the set value, it is recorded as having a risk of pre-locking attenuation. Re-tightening verification: Apply torque along the tightening direction using a torque wrench, tighten to the detected torque value, and record the torque-angle curve during the re-tightening process; If the curve shape is basically consistent with the standard curve, then the thread condition is normal; If the curve is abnormal, then the thread is abnormal.

9. The installation method for a high-voltage power cable terminal according to claim 8, characterized in that: Data from the inspection process is uploaded to the cloud, linked and archived, and finally an installation inspection report is generated. For those that fail the inspection and warning, the final torque is redesigned and the inspection is repeated. For those that fail the loosening test, loosen the fasteners, check and clean the fit, and then tighten them again. For fasteners that fail the re-tightening verification, repair or replace the fasteners, then re-tighten and test.

10. The installation method for a high-voltage power cable terminal according to claim 1, characterized in that: In step S400, the overall test includes at least: Insulation resistance retest; sealing verification; simplified withstand voltage test; grounding resistance measurement; After passing the test, an intelligent detection device for continuous monitoring of the operating status is installed.