Gas Insulated Metal-Enclosed Transmission Line (GIL) Live Accelerated Vibration Test Method

Abstract

The present application relates to the technical field of power equipment detection, and discloses a gas insulated metal enclosed transmission line (GIL) live accelerated excitation test method, which comprises obtaining a reference vibration response when the GIL is in power-on operation, determining a reference excitation force that can reproduce the real vibration state of the conductor through a two-step calibration method of directly exciting the conductor and equivalently exciting the shell in a non-electric state, amplifying the reference excitation force by N times based on a wear model to obtain an accelerated excitation force, equivalently converting a long-period wear process into a short-time test, and finally, synchronously applying an operating current and the accelerated excitation force to the GIL test piece, and comprehensively monitoring signals such as acceleration, strain and loop resistance to judge equipment failure. The present application replaces the difficult-to-apply electric force with an equivalent mechanical force, realizes accurate simulation of complex working conditions, shortens the test period, and can fully reveal the potential wear and degradation mechanism of the equipment, thereby providing an efficient and practical solution for reliability evaluation of the GIL.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power equipment detection, in particular to a gas insulated metal enclosed transmission line (GIL) live accelerated vibration excitation test method. BACKGROUND

[0002] The gas insulated metal enclosed transmission line (GIL) plays a crucial role in modern high-voltage and ultra-high-voltage power systems due to its large transmission capacity, small footprint, and strong environmental adaptability. Therefore, comprehensive, accurate, and efficient reliability evaluation of GIL is a key link to ensure the safe operation of the power grid.

[0003] However, there are several deficiencies in the existing technology for evaluating the long-term reliability of GIL. First, GIL in actual operation is subjected to the coupling effects of multiple physical fields such as temperature rise effect, electric force, and external environmental vibration caused by current. The thermal expansion of the conductor caused by current will generate continuous mechanical stress on the joint, while the electric force will cause micro-vibration of the conductor. These factors are intertwined and jointly affect the contact state of the conductor joint and the long-term performance of the insulation. Existing test methods often test these physical fields separately, making it difficult to fully reveal the potential defects of the equipment under actual working conditions.

[0004] Secondly, even if the mechanical vibration in operation is simulated in the laboratory, there are still great technical challenges. The main source of vibration in GIL operation is the electric force acting on the internal aluminum alloy conductor, which is difficult to be directly and equivalently applied in the laboratory environment. The commonly used simplification method is to apply external excitation to the aluminum alloy shell of GIL, but due to the complexity of the structural transmission path, there is no clear equivalent relationship between the excitation force applied to the shell and the actual vibration response of the internal conductor. This results in the inability to accurately reproduce the real vibration state of the conductor under field working conditions, limiting the accuracy and reliability of the test results.

[0005] In addition, the mechanical wear and fatigue of GIL is a very slow cumulative process. To evaluate its service life of decades through real-time simulation in the laboratory, the required test period is too long to be practically operable in engineering. The existing test methods generally lack an accelerated aging method based on reliable physical models that can scientifically and reasonably shorten the test period. This makes efficient evaluation of the long-term mechanical reliability of GIL a technical problem that needs to be solved. SUMMARY

[0006] In view of the defects of the prior art, the gas insulated metal enclosed transmission line GIL live accelerated excitation test method is provided, and the problems that the existing gas insulated metal enclosed transmission line GIL test method cannot fully simulate the actual operation condition of the multi-physical field coupling of the electric force, the temperature rise effect and the mechanical vibration, it is difficult to reveal the wear and degradation mechanism of the contact surface of the conductor joint under a large current, and thus the mechanical reliability of the equipment in long-term operation cannot be accurately evaluated are solved.

[0007] To achieve the above object, the technical scheme is as follows: a gas insulated metal enclosed transmission line GIL live accelerated excitation test method, comprising the following steps:

[0008] S1, obtaining a reference vibration response of a gas insulated metal enclosed transmission line under an operation condition;

[0009] S2, calibrating a reference excitation force based on the reference vibration response, wherein the reference excitation force can reproduce the vibration state of a conductor arranged in an outer shell of the gas insulated metal enclosed transmission line under the operation condition when the reference excitation force is applied to the outer shell;

[0010] S3, determining an accelerated excitation force for an accelerated excitation test based on the reference excitation force;

[0011] S4, applying an operating current and the accelerated excitation force to the gas insulated metal enclosed transmission line, and monitoring at least one parameter representing electrical performance or mechanical performance of the gas insulated metal enclosed transmission line to determine whether the gas insulated metal enclosed transmission line fails.

[0012] Preferably, the metal shell and the conductor are both made of aluminum alloy, and the conductor includes a conductor male head and a conductor female head, and the two form a conductive path through plug-in cooperation, and the plug-in interface is a key position where fretting wear occurs under long-term vibration, resulting in an increase in contact resistance and a decrease in connection reliability.

[0013] Preferably, in step S1, the specific operation of obtaining the reference vibration response is as follows: measuring the vibration of the aluminum alloy outer shell under the operation condition of the energized gas insulated metal enclosed transmission line, and taking the measured outer shell acceleration as the reference vibration response.

[0014] Preferably, in step S2, the specific operation of calibrating the reference excitation force based on the reference vibration response includes: First, in a de-energized state, vibration is applied to the aluminum alloy conductor until the vibration acceleration of the aluminum alloy shell is equal to the reference vibration response, and the vibration acceleration of the aluminum alloy conductor at this time is measured and used as the reference conductor acceleration; then, in a de-energized state, vibration is applied to the aluminum alloy shell until the vibration acceleration of the aluminum alloy conductor is equal to the reference conductor acceleration, and the excitation force applied to the aluminum alloy shell at this time is calibrated as the reference excitation force.

[0015] Preferably, in step S3, the specific operation of determining the accelerating excitation force for the accelerated vibration test is as follows: An accelerated vibration test is conducted under a de-energized state. The accelerating excitation force is determined by comparing the wear depth after loading with the reference excitation force and with N times the reference excitation force. The physical principle for confirming the accelerating excitation force is based on the Archard wear model, which establishes the relationship between wear volume, mechanical force, and displacement. Its expression is:

[0016] ;

[0017] in, This represents the wear volume; The wear coefficient of the material; For normal loads; This refers to the sliding friction distance; The value represents the material hardness.

[0018] According to this model, when the excitation force applied to the aluminum alloy shell is amplified N times from the reference excitation force, the normal load at the aluminum alloy conductor joint is... With sliding friction distance Each is magnified N times accordingly, resulting in a wear volume The increment is proportional to the square of N, thereby shortening the test time.

[0019] Preferably, step S4 specifically includes: first, applying only the operating current to the gas-insulated metal-enclosed transmission line to cause a temperature rise; then, monitoring the axial deformation of the aluminum alloy conductor caused by the temperature rise, while recording the three-dimensional 50 Hz harmonic components of the conductor female connector; next, applying the accelerating excitation force to the aluminum alloy shell while maintaining the operating current; and finally, monitoring at least one parameter characterizing the electrical or mechanical performance of the gas-insulated metal-enclosed transmission line to determine whether a fault has occurred in the gas-insulated metal-enclosed transmission line.

[0020] Preferably, the parameters include the change in loop resistance as an electrical performance parameter and the sudden change in acceleration as a mechanical performance parameter.

[0021] Preferably, the parameters further include: the strain at the lower end of the cross-section at the connection between the male conductor and the female conductor, which is a mechanical performance parameter, at a position where the cross-section is deflected by 60 degrees.

[0022] Preferably, the method further includes insulation performance verification steps before step S1 and after step S4.

[0023] Preferably, the insulation performance verification steps include: performing insulation resistance testing, power frequency withstand voltage testing, and partial discharge testing.

[0024] This invention provides a method for accelerated vibration testing of gas-insulated metal-enclosed transmission lines (GILs) under energized conditions, which has the following advantages:

[0025] 1. This invention obtains the reference vibration response under operating conditions on-site and calibrates the reference excitation force that can reproduce the conductor vibration state step by step under no-electricity conditions. It realizes the accurate equivalent simulation of conductor vibration under complex on-site conditions in the laboratory, solves the problem that conductor vibration under on-site electrodynamics is difficult to directly apply and quantify, and improves the accuracy and repeatability of the test.

[0026] 2. This invention determines the accelerating excitation force by amplifying the benchmark excitation force by N times based on the Archard wear model. It equates the wear process under long-term operation of the equipment to a short-time test, making the wear amount proportional to the square of the excitation force multiplier. This shortens the test cycle, improves test efficiency, and enables the assessment of the long-term mechanical reliability of the equipment to be completed within a limited test time.

[0027] 3. By simultaneously applying operating current and accelerating excitation force to gas-insulated metal-enclosed transmission lines, this invention realistically reproduces the coupling effect of multiple physical fields, including electrodynamics, temperature rise effect, and mechanical vibration. It can reveal potential defects and wear and deterioration mechanisms that cannot be shown under a single physical field, making the test results closer to actual operating conditions and comprehensively evaluating the overall mechanical reliability of the equipment in complex environments. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall process of one embodiment of the present invention;

[0029] Figure 2 A schematic diagram of vibration test applied to an aluminum alloy conductor during the excitation stage of GIL and other generations;

[0030] Figure 3 A schematic diagram of vibration test applied to an aluminum alloy shell during the excitation stage of GIL and other generations;

[0031] Figure 4 This is a schematic diagram of the accelerated wear stage test of GIL (no power + power). Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Reference Appendix Figure 1 , Figure 1 This is a schematic diagram of the overall process of one embodiment of the present invention. This embodiment provides a method for accelerated vibration testing of gas-insulated metal-enclosed transmission lines (GILs) under energized conditions. The test method is used in a specific application scenario to evaluate the mechanical reliability of a specific type of GIL equipment under simulated long-term operating conditions.

[0034] To implement this method, a test system needs to be constructed. The test system includes an exciter capable of precise force control, with a frequency response range covering above 100 Hz to effectively simulate harmonic vibrations induced by electrodynamic forces, and an output excitation force sufficient to enable the test piece to achieve a predetermined acceleration response; an acceleration monitoring system capable of accurately capturing minute vibration signals; a strain and resistance monitoring system used to monitor the condition of conductor joints to monitor structural stress and contact surface deterioration in real time; and corresponding high-current generating devices and conventional current-carrying and insulation testing equipment such as power frequency withstand voltage and partial discharge testers.

[0035] The exciter features adjustable loading amplitude and frequency, and is capable of continuous loading, with a frequency response range exceeding 100 Hz. This characteristic allows it to simulate the minute vibrations generated in the aluminum alloy conductors of gas-insulated, metal-enclosed power transmission lines under electrodynamic forces.

[0036] The acceleration monitoring system consists of multiple accelerometers. The specific arrangement of the accelerometers is as follows: at both ends of each section of the aluminum alloy casing of the gas-insulated, metal-enclosed transmission line, and in the middle of the aluminum alloy conductor. This arrangement is used to measure the vibration acceleration of the aluminum alloy casing and the aluminum alloy conductor at different stages of the test.

[0037] The strain and resistance monitoring system is used to monitor the condition of conductor joints. Strain gauges are positioned at a 60-degree angle off the lower end of the cross-section at the connection point of the male and female conductors of the aluminum alloy conductor, detecting collisions between the male and female conductor joint slots during vibration. Simultaneously, a loop resistance monitoring system is connected to both ends of the aluminum alloy conductor to measure its loop resistance in real time, characterizing the degree of degradation of the conductor joint contact surface.

[0038] In this embodiment, the principle of accelerated vibration testing is based on the Archard wear model, which describes the relationship between wear volume, load, and sliding distance. Its expression is:

[0039] ;

[0040] in, This represents the wear volume; The wear coefficient of the material; For normal loads; This refers to the sliding friction distance; The value represents the material hardness.

[0041] This expression shows that the wear volume of the material is proportional to the applied normal load and the resulting sliding friction distance.

[0042] Reference Appendix Figure 1 The specific execution steps of the experimental method in this embodiment are as follows:

[0043] First, step S1, the on-site monitoring phase, is performed. The goal of step S1 is to obtain an objective and quantifiable benchmark vibration response for equivalent calibration in subsequent experimental phases. Step S1 is conducted under normal energized operating conditions on the gas-insulated metal-enclosed transmission line under test, which refers to the state in which the equipment carries a stable operating current.

[0044] In practice, one or more representative measurement sections are first selected on the gas-insulated, metal-enclosed transmission line. A representative measurement section is one whose vibration characteristics can reflect the general response of the main body of the line under electrodynamic forces, without being significantly affected by local structural features (such as supports, corners, and ends). Therefore, the preferred measurement section should be located in the mid-span area of ​​a standard straight pipe section, away from structural discontinuities such as bends, fixed support points, and expansion joints. Selecting such sections for measurement can minimize interference from local stress concentrations or boundary conditions, thereby obtaining a more universal reference vibration response. On the determined measurement section, an accelerometer is mounted on the outer surface of an aluminum alloy casing.

[0045] The accelerometers are specifically positioned at the aluminum alloy casing corresponding to the three-post insulators at the measurement section, and at the mid-span positions at both ends. This arrangement is used to comprehensively capture the vibration response transmitted through the insulators to the aluminum alloy casing, as well as the vibration response of the pipe section itself.

[0046] After setup, the vibration acceleration time-domain signal at each measuring point is recorded over a period of time using a data acquisition system. The acquired vibration acceleration time-domain signal is then processed to obtain the power spectral density map of the acceleration response, for example, by calculating the power spectral density of the acceleration response using Fourier transform.

[0047] By analyzing the power spectral density map, characteristic acceleration values ​​are extracted, such as the acceleration amplitude corresponding to the main frequency of the electrodynamic force (100 Hz). This characteristic acceleration value is defined as the reference shell acceleration, denoted as A1. The reference shell acceleration A1 is the reference vibration response under the field operating conditions and serves as the calibration target for the subsequent step S2.

[0048] Reference Appendix Figure 1 After completing step S1, step S2, the equivalent excitation stage, is executed. Step S2 is performed in a de-energized state, and its purpose is to determine the shell excitation force that can equivalently reproduce the vibration of the aluminum alloy conductor under field conditions. This step includes two stages.

[0049] Reference Appendix Figure 2 , Figure 2 This diagram illustrates the vibration test applied to the aluminum alloy conductor during the excitation stage of the GIL generation. In the first stage of step S1, the exciter is mechanically connected to the aluminum alloy conductor inside the gas-insulated metal-enclosed transmission line using a special clamp to directly apply vibration to the aluminum alloy conductor. At this time, the accelerometers arranged on the aluminum alloy shell and the aluminum alloy conductor are both in working condition.

[0050] Start the vibrator and adjust the vibration frequency and amplitude applied by the vibrator. The goal of the adjustment is to make the vibration acceleration of the aluminum alloy shell measured by the accelerometer, denoted as A2, equal to the reference shell acceleration A1 obtained in step S1 (i.e., A2=A1).

[0051] When the vibration acceleration A2 of the aluminum alloy casing reaches and stabilizes at the reference casing acceleration A1, the vibration acceleration measured by the accelerometer placed on the aluminum alloy conductor at this moment is recorded. This recorded conductor vibration acceleration is defined as the reference conductor acceleration, denoted as A3. This reference conductor acceleration characterizes the actual vibration state of the aluminum alloy conductor under field operating conditions.

[0052] After completing the first stage of step S2 and obtaining the reference conductor acceleration A3, the process proceeds to the second stage of step S2. The goal of this stage is to calibrate the equivalent excitation force applied to the aluminum alloy shell, given that the vibration state of the aluminum alloy conductor is known.

[0053] Reference Appendix Figure 3 , Figure 3This diagram illustrates the vibration test applied to the aluminum alloy casing during the excitation stage of the GIL generation. In the second stage of step S2, the exciter is removed from the aluminum alloy conductor and mechanically connected to the aluminum alloy casing. The accelerometer's position remains unchanged to ensure simultaneous measurement of the vibration of both the aluminum alloy casing and the aluminum alloy conductor.

[0054] Start the vibrator and adjust the excitation force applied to the aluminum alloy shell. At the same time, monitor the vibration acceleration of the aluminum alloy conductor in real time using an accelerometer placed on the aluminum alloy conductor, and record it as A4.

[0055] Continuously adjust the excitation force until the vibration acceleration A4 of the aluminum alloy conductor reaches and stabilizes at the reference conductor acceleration A3 determined in the first stage (i.e., A4=A3). When this condition is met, record the vibration acceleration measured by the accelerometer arranged on the aluminum alloy shell at this moment, denoted as A5, and record the excitation force applied by the exciter to the aluminum alloy shell at this moment.

[0056] The recorded excitation force is defined as the reference excitation force and denoted as... Reference excitation force This forms the basis for determining the acceleration factor N in subsequent accelerated vibration tests.

[0057] After completing step S2 and calibrating the reference excitation force Next, step S3, the acceleration excitation force determination step (electric acceleration stage), is performed. Step S3 is carried out in an electric-free state, and its purpose is to determine the acceleration excitation force used to shorten the overall test cycle based on the physical wear model.

[0058] Reference Appendix Figure 4 , Figure 4 This is a schematic diagram of the GIL (no power + power) accelerated wear stage test. The vibrator is mechanically connected to the aluminum alloy housing. In step S3, a comparative test is conducted to verify the acceleration effect and determine the acceleration factor N.

[0059] First, an excitation force equal to the reference force is applied to the aluminum alloy casing using a vibrator. The vibration is subjected to a preset time period, such as 5 hours. During this period, the wear depth at the conductor joint is measured and recorded at fixed time intervals, such as every 30 minutes.

[0060] Then, the excitation force applied to the aluminum alloy casing is increased to the reference excitation force. N times, that is ,in A coefficient greater than 1 is used. Within the same preset time period, at the same measurement interval, the wear depth at the conductor joint is measured and recorded again.

[0061] The physical principle for determining the accelerating excitation force is based on the Archard wear model, which establishes the relationship between wear volume, mechanical force, and displacement. Its expression is:

[0062] ;

[0063] in, This represents the wear volume; The wear coefficient of the material; For normal loads; This refers to the sliding friction distance; The value represents the material hardness.

[0064] According to the Archard wear model, when the excitation force applied to the aluminum alloy casing changes from... Magnified N times This will cause a normal load at the conductor joint. With sliding friction distance Each is correspondingly magnified N times. Therefore, the wear volume The increment is proportional to the square of N.

[0065] To determine the appropriate acceleration factor N, the excitation force applied to the aluminum alloy casing is increased to the reference excitation force. N times, that is At this point, the vibration acceleration of the aluminum alloy casing increases accordingly, denoted as A6 (under the linear system assumption, A6 is approximately equal to N times A5). By comparing the wear depth data obtained in the two test stages above, and considering the requirements for the total test duration, a suitable acceleration factor N is finally determined. The accelerating excitation force will be used for subsequent live-line tests. Determined as ,Right now .

[0066] After completing step S3 and determining the accelerating excitation force Next, step S4, the accelerated wear stage, is executed. Step S4 is the core experimental stage of this invention, designed to simulate long-term operating conditions involving the coupling of multiple physical fields, including electrical, thermal, and mechanical fields. Step S4 begins with a vibration-free flow stage.

[0067] During the current-carrying, vibration-free phase, the rated operating current is first applied to the gas-insulated, metal-enclosed transmission line, but the exciter is not installed or started, i.e., no external mechanical vibration is applied. The application of current causes the aluminum alloy conductor to heat up due to Joule heating, which in turn generates axial thermal expansion.

[0068] Axial deformation is monitored in real time by placing displacement sensors at the ends of aluminum alloy conductors or other suitable locations until the axial deformation of the aluminum alloy conductor measured by the displacement sensors reaches a stable value, indicating that the entire test system has reached a thermally stable state.

[0069] After the test system reached thermal stability, monitoring sensors placed at the conductor female end, combined with a spectrum analyzer, recorded the 50 Hz harmonic components of the conductor female end in three orthogonal directions. This component data is used to characterize the initial dynamic slip characteristics of the conductor joint contact surface under only electrical and thermal stress, and serves as a benchmark for comparison after subsequent vibration is applied.

[0070] After the gas-insulated, metal-enclosed transmission line reaches thermal stability, it enters the accelerated vibration and comprehensive monitoring stage. During this stage, the rated operating current is maintained to ensure the continued existence of temperature rise and electrodynamic effects.

[0071] Reference Appendix Figure 4 The vibrator, which is mechanically connected to the aluminum alloy housing, is activated, and the accelerating excitation force determined in step S3 is applied to it. This causes the aluminum alloy shell to vibrate with a vibration acceleration of A6. The application of the accelerating excitation force causes the entire test system to operate under the simulated coupling of multiple physical fields, including electrical, thermal, and mechanical fields.

[0072] While applying the accelerating excitation force, the integrated monitoring system is activated to monitor the operating status of the gas-insulated metal-enclosed transmission line in real time and continuously to determine whether a fault has occurred.

[0073] Monitoring includes monitoring for acceleration abrupt changes. Vibration signals are continuously acquired using accelerometers positioned on the aluminum alloy conductor and the aluminum alloy shell. A pulse with an amplitude significantly exceeding the steady-state vibration and an extremely short duration is identified as an acceleration abrupt change. This abrupt change indicates a mechanical collision occurring between the aluminum alloy conductor and the aluminum alloy shell, or within the conductor joint.

[0074] Monitoring also includes strain monitoring. Strain gauges are installed at the connection point between the male and female conductor connectors to record the strain value in real time. Drastic changes in strain directly indicate a collision event occurring within the internal components of the aluminum alloy conductor connector.

[0075] Monitoring also includes monitoring changes in loop resistance. The loop resistance flowing through the aluminum alloy conductor is continuously measured using a loop resistance monitoring system. If the measured loop resistance value shows a continuous, monotonous upward trend over time, it indicates that the contact surface of the conductor joint has experienced wear and deterioration.

[0076] The gas-insulated metal-enclosed transmission line is judged to have a fault based on the above monitoring data. When a partial discharge signal is detected, insulation breakdown occurs, or the measured value of the loop resistance exceeds the preset failure threshold, the gas-insulated metal-enclosed transmission line is judged to have a fault, and the test is terminated.

[0077] To objectively evaluate the comprehensive impact of the live accelerated vibration test in this embodiment on the insulation performance of gas-insulated metal-enclosed transmission lines, this method also performs insulation performance verification at the beginning and end of the test process.

[0078] The insulation performance verification steps are performed once before the first execution of step S1, and once after the completion of step S4 or after termination due to a fault. By comparing the results of the two verifications, the impact of vibration and wear on the equipment's insulation margin can be quantitatively assessed.

[0079] Insulation performance verification includes the following test items:

[0080] First, an insulation resistance test is performed. Using an insulation resistance tester, a DC test voltage is applied between the aluminum alloy conductor and the grounded aluminum alloy casing, and the insulation resistance value between the two is measured.

[0081] Next, a power frequency withstand voltage test is performed. A power frequency AC test voltage of a preset amplitude is applied between the aluminum alloy conductor and the grounded aluminum alloy casing and maintained for a specified time, such as 60 seconds. During this period, any breakdown or surface flashover phenomena are monitored.

[0082] Finally, a partial discharge test was conducted. Using a partial discharge testing system, a gradually increasing AC voltage was applied between the aluminum alloy conductor and the aluminum alloy shell. The partial discharge initiation voltage and the partial discharge quantity at a specific test voltage were measured and recorded.

[0083] By comparing the insulation resistance values, power frequency withstand voltage test results, and partial discharge characteristic parameters measured before and after the entire energized accelerated vibration test, the changes in insulation performance caused by mechanical vibration and wear during the test can be quantitatively analyzed and evaluated.

Claims

1. A method of charged accelerated excitation test for a gas insulated metal enclosed transmission line (GIL), characterized by, The method comprises the following steps: S1, obtaining a reference vibration response of a gas insulated metal enclosed transmission line under an operating condition; S2, calibrating a reference exciting force based on the reference vibration response, the reference exciting force reproducing a vibration state of a conductor arranged in a metal shell of the gas insulated metal enclosed transmission line under the operating condition when applied to the metal shell; S3, determining an accelerated exciting force for an accelerated exciting test based on the reference exciting force; S4, applying the operating current and the accelerated exciting force to the gas insulated metal enclosed transmission line, and monitoring at least one parameter representing electrical performance or mechanical performance of the gas insulated metal enclosed transmission line to determine whether the gas insulated metal enclosed transmission line fails.

2. The gas insulated metal enclosed transmission line (GIL) live-line accelerated excitation test method according to claim 1, characterized in that, Step S1 is specifically: Under the operating condition of energizing the gas insulated metal enclosed transmission line, the vibration of the metal shell is measured, and the measured shell acceleration is taken as the reference vibration response.

3. The gas insulated metal enclosed transmission line (GIL) live-line accelerated excitation test method according to claim 1, characterized in that, In step S2, the step of calibrating the reference exciting force based on the reference vibration response specifically comprises: First, in a de-energized state, the vibration is applied to the conductor until the vibration acceleration of the metal shell is equal to the reference vibration response, and the vibration acceleration of the conductor at this time is measured as the reference conductor acceleration; Then, in a de-energized state, the vibration is applied to the metal shell until the vibration acceleration of the conductor is equal to the reference conductor acceleration, and the exciting force applied to the metal shell at this time is calibrated as the reference exciting force.

4. The gas insulated metal enclosed transmission line (GIL) live-line accelerated excitation test method according to claim 1, characterized by, Step S3 is specifically: The accelerated exciting test in a de-energized state is performed, and the wear depth after the reference exciting force and N times of the reference exciting force are applied is compared to determine the accelerated exciting force, wherein N is a coefficient greater than 1.

5. The gas insulated metal enclosed transmission line (GIL) live-line accelerated excitation test method according to claim 1, characterized in that, The parameters include a loop resistance change as an electrical performance parameter and an acceleration mutation as a mechanical performance parameter.

6. The gas insulated metal enclosed transmission line (GIL) live-line accelerated excitation test method according to claim 1, characterized in that, The metal shell and the conductor are both made of aluminum alloy, and the conductor includes a conductor male head and a conductor female head.

7. The gas insulated metal enclosed transmission line (GIL) live-line accelerated excitation test method according to claim 6, characterized in that, Step S4 specifically comprises: First, only the operating current is applied to the gas insulated metal enclosed transmission line to generate a temperature rise; The axial deformation of the conductor caused by the temperature rise is monitored, and the three-way 50 Hz sub-harmonic component of the conductor female head is recorded; Then, the accelerated exciting force is applied to the metal shell while maintaining the operating current; Finally, at least one parameter representing electrical performance or mechanical performance of the gas insulated metal enclosed transmission line is monitored to determine whether the gas insulated metal enclosed transmission line fails.

8. The gas insulated metal enclosed transmission line (GIL) live-line accelerated excitation test method according to claim 7, characterized in that, The parameters further include: As a mechanical performance parameter, the strain at a position where the cross section of the conductor male head and the conductor female head is deflected by 60 degrees.

9. The gas insulated metal enclosed transmission line (GIL) live-line accelerated excitation test method according to claim 1, characterized in that, The insulation performance verification step is further performed before step S1 and after step S4.

10. The gas insulated metal enclosed transmission line (GIL) live-line accelerated excitation test method according to claim 9, characterized in that, The insulation performance verification step comprises: Performing insulation resistance test, power frequency voltage withstand test and partial discharge test.

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