A method for measuring and evaluating performance state of line insulator in strong airflow and vibration environment

Abstract

The application shows a kind of line insulator performance state evaluation method under strong airflow strong vibration environment, first, a kind of line insulator performance state evaluation platform under strong airflow strong vibration environment is built;Based on the evaluation platform, strong airflow, strong vibration operation environment simulation is carried out for line insulator, and lightning impulse test is carried out;The theoretical calculation value of the transient characteristic voltage U of line insulator is calculated;Based on the theoretical calculation value and measured value of U, particle swarm optimization algorithm is used for optimization modeling, and the optimized line insulator transient characteristic voltage U b Is obtained, and the performance state evaluation factor β of line insulator is calculated;Finally, according to β, the performance state evaluation of line insulator is carried out.The application can effectively simulate the environmental conditions of line insulator suffering from strong airflow and strong vibration;Through lightning impulse test, the performance state of line insulator under strong airflow and strong vibration environment can be analyzed and evaluated, and maintenance suggestions are put forward, which improves the power supply stability of power grid system.

Description

Technical Field

[0001] This invention relates to the field of insulator performance evaluation, and in particular to a method for evaluating the performance status of line insulators under strong airflow and strong vibration environments. Background Technology

[0002] Line insulators play a supporting and insulating role in power transmission line systems, connecting to the transmission conductor at one end and the crossarm of the transmission tower at the other. During their service life, the performance of line insulators gradually deteriorates due to power frequency leakage current and lightning strikes. However, the performance condition of line insulators directly affects the safe and stable operation of the power system.

[0003] Furthermore, transmission towers of 110kV and above are generally over 30 meters high, and the line insulators are subject to swaying or vibration due to airflow. Under strong airflow and vibration conditions, the discharge path of the line insulators exhibits significant uncertainty. Therefore, performance evaluation of line insulators under strong airflow and vibration conditions is of great importance.

[0004] Currently, there is a lack of research both domestically and internationally on line insulators under conditions of strong airflow and vibration. Research is mainly limited to leakage current detection, with no studies on performance evaluation methods for lightning strikes, especially considering the impact of strong airflow and vibration. Therefore, this invention patent establishes a performance status evaluation platform for line insulators under strong airflow and vibration environments, and proposes a method for evaluating the performance status of line insulators under such conditions. This method can accurately evaluate the performance of line insulators under strong airflow and vibration environments and provide maintenance recommendations, further improving the reliability of the power grid system. Summary of the Invention

[0005] To accurately and analytically evaluate the performance status of line insulators under strong airflow and vibration environments, this invention provides a method for evaluating the performance status of line insulators under such conditions. The technical solution for achieving this invention is as follows:

[0006] Step 1: A performance evaluation platform for line insulators under strong airflow and strong vibration environment was built. The platform includes: host computer (1), lightning impulse controller (2), lightning impulse generator (3), lightning impulse generator grounding electrode (31), high voltage switch (41), environmental simulation test chamber (5), high voltage test electrode one (51), line insulator (6), high voltage test electrode two (52), grounding switch (42), grounding cable (7), grounding grid (71), high precision voltage divider (8), voltage divider grounding electrode (81), current test coil (9), experimental data acquisition unit (10), wireless data processing and transmission module 1 (11), airflow controller (12), airflow generator (13), airflow velocity measuring instrument (14), wireless data processing and transmission module 2 (15), vibration control module (16), and high frequency vibration simulation and measurement platform (17).

[0007] The input end of the lightning impact controller (2) is connected to the host computer (1), the output end of the lightning impact controller (2) is connected to the input end of the lightning impact generator (3), the left and right ends of the high voltage switch (41) are connected to the high voltage test electrode one (51) and the output end of the lightning impact generator (3) respectively, the upper and lower ends of the line insulator (6) are fixedly connected to the high voltage test electrode one (51) and the high voltage test electrode two (52) respectively, the upper and lower ends of the grounding switch (42) are connected to the high voltage test electrode two (52) and the grounding cable (7) respectively, and the grounding cable (7) is connected to the grounding grid (71);

[0008] The grounding terminal of the lightning impulse generator (3) is connected to the grounding electrode (31) of the lightning impulse generator;

[0009] The input terminal of the high-precision voltage divider (8) is connected to the high-voltage experimental electrode (51), and the grounding terminal of the high-precision voltage divider (8) is connected to the voltage divider grounding electrode (81); the current test coil (9) is sleeved on the grounding cable (7); the output terminal of the high-precision voltage divider (8) is connected to the input terminal of the experimental data acquisition unit (10); the output terminal of the current test coil (9) is connected to the input terminal of the experimental data acquisition unit (10);

[0010] The output end of the experimental data acquisition unit (10) is connected to the input end of the wireless data processing and transmission module 1 (11); the wireless data processing and transmission module 1 (11) is wirelessly connected to the host computer (1).

[0011] The input end of the airflow controller (12) is connected to the host computer (1), and the output end of the airflow controller (12) is connected to the airflow generator (13); the output end of the airflow velocity measuring instrument (14) is connected to the wireless data processing and transmission module 2 (15); the wireless data processing and transmission module 2 (15) is wirelessly connected to the host computer (1);

[0012] The input end of the vibration control module (16) is connected to the host computer (1), and the output end of the vibration control module (16) is connected to the high-frequency vibration simulation and measurement platform (17); the high-voltage test electrode two (52) is fixed on the high-frequency vibration simulation and measurement platform (17);

[0013] The high-voltage test electrode one (51), the line insulator (6), the high-voltage test electrode two (52), the high-frequency vibration simulation and measurement platform (17), the air flow generator (13), and the air flow velocity measuring instrument (14) are fixed inside the environmental simulation test chamber (5);

[0014] The air flow outlet plane (131) of the air flow generator (13) is perpendicular to the axial direction of the line insulator (6);

[0015] Step 2: Based on the established performance state evaluation platform for line insulators under strong air flow and strong vibration environment, a performance state evaluation method for line insulators under strong air flow and strong vibration environment is proposed, including the following steps:

[0016] S1: Set the air flow velocity V on the host computer (1) a , the host computer (1) controls the rotation speed n of the air flow generator (13) to increase uniformly from 0 by controlling the air flow controller (12); at the same time, the air flow velocity measuring instrument (14) measures the air flow velocity v inside the environmental simulation test chamber (5) in real time, and the wireless data processing and transmission module 2 (15) wirelessly transmits the measurement result of the air flow velocity measuring instrument (14) to the host computer (1), and the host computer (1) judges the air flow velocity v. If |V a -v| < E, then keep the rotation speed n of the air flow generator (13) unchanged;

[0017] S2: Set the vibration frequency of the line insulator as f a and the vibration amplitude as A a on the host computer (1). The host computer (1) controls the high-frequency vibration simulation and measurement platform (17) to start working by controlling the vibration control module (16), generating vibrations with a vibration frequency of f a and a vibration amplitude of A a ;

[0018] S3: Set the lightning voltage U1 on the host computer (1), and close the high-voltage switch (41) and the grounding switch (42);

[0019] S4: The host computer (1) controls the lightning impulse generator (3) to generate a lightning voltage to the high-voltage test electrode one (51) by controlling the lightning impulse controller (2), and the experimental data acquisition unit (10) measures the current value I on the grounding cable (7) through the current test coil (9) rMeanwhile, the experimental data acquisition unit (10) measures the voltage value U of the line insulator (6) through a high-precision voltage divider (8). r ;

[0020] S5: The data collected by the experimental data acquisition unit (10) is wirelessly transmitted to the host computer (1) via the wireless data processing and transmission module 1 (11), and I is judged. r Does it satisfy I? r >I ε If satisfied, the lightning voltage amplitude set by the host computer (1) is reduced by ∆U, and steps S4-S5 are repeated; if not satisfied, the value of U at this time is recorded. r At the same time, disconnect the high-voltage switch (41) and the grounding switch (42), and proceed to step S6;

[0021] S6: Change the vibration frequency of the line insulator set by the host computer (1), repeat steps S2-S5 Q-1 times, and generate Q sets of measurement data;

[0022] The range of vibration frequencies of the line insulators set by the host computer (1) is [f a f d ], with H values ​​taken uniformly at intervals;

[0023] The value of H is (f d -f a ) / (Q-1);

[0024] S7: Calculate the theoretical value of the transient characteristic voltage U of the line insulator (6):

[0025] (1)

[0026] In equation (1), f is the vibration frequency of the line insulator (6), f0 is the power frequency, v is the airflow velocity, φ is the angle between the axial direction and the horizontal direction of the line insulator (6); δ and γ are Gaussian error coefficients, and x is the integral variable;

[0027] S8: The particle swarm optimization algorithm is used to optimize and model formula (1) to obtain a set of γ and δ values ​​that minimize the error between the theoretical calculation value and the measured value of the transient characteristic voltage of the line insulator (6). The specific steps are as follows:

[0028] 1) Generate an initial population with uniformly distributed particles and velocities, and set stopping conditions;

[0029] 2) Calculate the objective function value according to equation (2):

[0030] (2)

[0031] In equation (2), O(δ, γ) represents the objective function, U riU is the measured voltage value of the line insulator (6) in the i-th group of experiments. i Q is the theoretically calculated value of the transient characteristic voltage of the line insulator (6) in the i-th group of experiments, and Q is the number of measurement data groups;

[0032] 3) Update the individual best position of each particle and the best position of the entire swarm;

[0033] 4) Update the velocity and position of each particle;

[0034] 5) If the stopping condition is met, stop the search and output the search results; otherwise, return to step 2).

[0035] 6) Obtain the values ​​of γ0 and δ0 that minimize the error between the calculated and measured values ​​of the characteristic current of the insulating gas;

[0036] S9: Substitute the values ​​of γ0 and δ0 obtained in S8 to minimize the error into formula (1) to obtain the transient characteristic voltage U of the optimized line insulator (6). b Theoretical calculation formula:

[0037] (3)

[0038] S10: Transient characteristic voltage U based on the optimized line insulator (6) b Calculate the performance status evaluation factor β of the line insulator (6):

[0039] (4)

[0040] In equation (4) U b For the optimized transient characteristic voltage of the line insulator (6), U s The transient characteristic voltage reference value of the optimized line insulator (6);

[0041] S11: The performance status of the line insulator (6) is evaluated based on β. When β∈[1,+∞), it indicates that the performance status of the line insulator (6) is normal; when β∈(0,1), it indicates that the line insulator (6) is abnormal and needs to be repaired.

[0042] The beneficial effects of this invention are as follows:

[0043] 1) An insulator performance evaluation platform considering strong airflow and strong vibration factors was built. This platform can effectively simulate the environmental conditions of line insulators subjected to strong airflow and strong vibration.

[0044] 2) Intelligent operation and control can be completed through a host computer, and data collection and transmission are convenient and efficient;

[0045] 3) Through lightning impulse tests, the performance status of line insulators under strong airflow and strong vibration environments can be analyzed and maintenance suggestions can be made to further improve the safety and stability of the power grid system. Attached Figure Description

[0046] To more clearly illustrate the technical solution of the application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0047] Figure 1 This application presents a schematic diagram of a performance status evaluation platform for line insulators under strong airflow and strong vibration environments. Detailed Implementation

[0048] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. A specific embodiment of a method for evaluating the performance status of line insulators under strong airflow and strong vibration environments includes the following steps:

[0049] Step 1: A performance evaluation platform for line insulators under strong airflow and strong vibration environment was built. The platform includes: host computer (1), lightning impulse controller (2), lightning impulse generator (3), lightning impulse generator grounding electrode (31), high voltage switch (41), environmental simulation test chamber (5), high voltage test electrode one (51), line insulator (6), high voltage test electrode two (52), grounding switch (42), grounding cable (7), grounding grid (71), high precision voltage divider (8), voltage divider grounding electrode (81), current test coil (9), experimental data acquisition unit (10), wireless data processing and transmission module 1 (11), airflow controller (12), airflow generator (13), airflow velocity measuring instrument (14), wireless data processing and transmission module 2 (15), vibration control module (16), and high frequency vibration simulation and measurement platform (17).

[0050] The input end of the lightning impact controller (2) is connected to the host computer (1), the output end of the lightning impact controller (2) is connected to the input end of the lightning impact generator (3), the left and right ends of the high voltage switch (41) are connected to the high voltage test electrode one (51) and the output end of the lightning impact generator (3) respectively, the upper and lower ends of the line insulator (6) are fixedly connected to the high voltage test electrode one (51) and the high voltage test electrode two (52) respectively, the upper and lower ends of the grounding switch (42) are connected to the high voltage test electrode two (52) and the grounding cable (7) respectively, and the grounding cable (7) is connected to the grounding grid (71);

[0051] The grounding terminal of the lightning impulse generator (3) is connected to the grounding electrode (31) of the lightning impulse generator;

[0052] The input terminal of the high-precision voltage divider (8) is connected to the high-voltage experimental electrode (51), and the grounding terminal of the high-precision voltage divider (8) is connected to the voltage divider grounding electrode (81); the current test coil (9) is sleeved on the grounding cable (7); the output terminal of the high-precision voltage divider (8) is connected to the input terminal of the experimental data acquisition unit (10); the output terminal of the current test coil (9) is connected to the input terminal of the experimental data acquisition unit (10);

[0053] The output end of the experimental data acquisition unit (10) is connected to the input end of the wireless data processing and transmission module 1 (11); the wireless data processing and transmission module 1 (11) is wirelessly connected to the host computer (1).

[0054] The input end of the airflow controller (12) is connected to the host computer (1), and the output end of the airflow controller (12) is connected to the airflow generator (13); the output end of the airflow velocity measuring instrument (14) is connected to the wireless data processing and transmission module 2 (15); the wireless data processing and transmission module 2 (15) is wirelessly connected to the host computer (1);

[0055] The input end of the vibration control module (16) is connected to the host computer (1), and the output end of the vibration control module (16) is connected to the high-frequency vibration simulation and measurement platform (17); the high-voltage experimental electrode two (52) is fixed on the high-frequency vibration simulation and measurement platform (17);

[0056] The high voltage test electrode one (51), line insulator (6), high voltage test electrode two (52), high frequency vibration simulation and measurement platform (17), airflow generator (13), and airflow velocity measuring instrument (14) are fixed inside the environmental simulation test chamber (5);

[0057] The airflow outlet plane (131) of the airflow generator (13) is perpendicular to the axial direction of the line insulator (6);

[0058] Step 2: Based on the established platform for evaluating the performance status of line insulators under strong airflow and vibration environments, a method for evaluating the performance status of line insulators under strong airflow and vibration environments is proposed, including the following steps:

[0059] S1: Set the airflow velocity V on the host computer (1) a The host computer (1) controls the airflow generator (13) to increase its rotation speed n uniformly from 0 by controlling the airflow controller (12); at the same time, the airflow velocity measuring instrument (14) measures the airflow velocity v in the environmental simulation test chamber (5) in real time, and the wireless data processing and transmission module 2 (15) wirelessly transmits the measurement result of the airflow velocity measuring instrument (14) to the host computer (1). The host computer (1) judges the airflow velocity v. If it satisfies |V aIf -v < E, keep the rotational speed n of the air flow generator (13) unchanged;

[0060] S2: Set the vibration frequency of the line insulator to f a and the vibration amplitude to A a on the host computer (1). The host computer (1) controls the high - frequency vibration simulation and measurement platform (17) to start working through the vibration control module (16), generating vibrations with a vibration frequency of f a and a vibration amplitude of A a ;

[0061] S3: Set the lightning voltage U1 on the host computer (1), and close the high - voltage switch (41) and the grounding switch (42);

[0062] S4: The host computer (1) controls the lightning impulse generator (3) to generate a lightning voltage to the first high - voltage test electrode (51) through the lightning impulse controller (2). The experimental data acquisition unit (10) measures the current value I on the grounding cable (7) through the current test coil (9), and at the same time, the experimental data acquisition unit (10) measures the voltage value U of the line insulator (6) through the high - precision voltage divider (8) r ; r ;

[0063] S5: The acquisition data of the experimental data acquisition unit (10) is wirelessly transmitted to the host computer (1) through the wireless data processing and transmission module 1 (11). Judge whether I r satisfies I r > I ε ; If it satisfies, the host computer (1) reduces the set lightning voltage amplitude by ∆U, and repeat steps S4 - S5; if it does not satisfy, record the current U r , and at the same time, disconnect the high - voltage switch (41) and the grounding switch (42), and go to step S6;

[0064] S6: Change the vibration frequency of the line insulator set by the host computer (1), and repeat steps S2 - S5 Q - 1 times to generate Q groups of measurement data;

[0065] The range of the vibration frequency of the line insulator set by the host computer (1) is [f a , f d , and take evenly spaced values at an interval of H;

[0066] The value of H is (f d -f a ) / (Q - 1);

[0067] S7: Calculate the theoretical calculated value of the transient characteristic voltage U of the line insulator (6):

[0068] (5)

[0069] In equation (1), f is the vibration frequency of the line insulator (6), f0 is the power frequency, v is the airflow velocity, φ is the angle between the axial direction and the horizontal direction of the line insulator (6); δ and γ are Gaussian error coefficients, and x is the integral variable;

[0070] S8: The particle swarm optimization algorithm is used to optimize and model formula (1) to obtain a set of γ and δ values ​​that minimize the error between the theoretical calculation value and the measured value of the transient characteristic voltage of the line insulator (6). The specific steps are as follows:

[0071] 1) Generate an initial population with uniformly distributed particles and velocities, and set stopping conditions;

[0072] 2) Calculate the objective function value according to equation (2):

[0073] (6)

[0074] In equation (2), O(δ, γ) represents the objective function, U ri U is the measured voltage value of the line insulator (6) in the i-th group of experiments. i Q is the theoretically calculated value of the transient characteristic voltage of the line insulator (6) in the i-th group of experiments, and Q is the number of measurement data groups;

[0075] 3) Update the individual best position of each particle and the best position of the entire swarm;

[0076] 4) Update the velocity and position of each particle;

[0077] 5) If the stopping condition is met, stop the search and output the search results; otherwise, return to step 2).

[0078] 6) Obtain the values ​​of γ0 and δ0 that minimize the error between the calculated and measured values ​​of the characteristic current of the insulating gas;

[0079] S9: Substitute the values ​​of γ0 and δ0 obtained in S8 to minimize the error into formula (1) to obtain the transient characteristic voltage U of the optimized line insulator (6). b Theoretical calculation formula:

[0080] (7)

[0081] S10: Transient characteristic voltage U based on the optimized line insulator (6) b Calculate the performance status evaluation factor β of the line insulator (6):

[0082] (8)

[0083] In equation (4) U bFor the optimized transient characteristic voltage of the line insulator (6), U s The transient characteristic voltage reference value of the optimized line insulator (6);

[0084] S11: The performance status of the line insulator (6) is evaluated based on β. When β∈[1,+∞), it indicates that the performance status of the line insulator (6) is normal; when β∈(0,1), it indicates that the line insulator (6) is abnormal and needs to be repaired.

Claims

1. A method for evaluating the performance status of line insulators under strong airflow and strong vibration environments, characterized in that, First, an evaluation platform was built, which includes: host computer (1), lightning impulse controller (2), lightning impulse generator (3), lightning impulse generator grounding electrode (31), high voltage switch (41), environmental simulation test chamber (5), high voltage test electrode one (51), line insulator (6), high voltage test electrode two (52), grounding switch (42), grounding cable (7), grounding grid (71), high precision voltage divider (8), voltage divider grounding electrode (81), current test coil (9), experimental data acquisition unit (10), wireless data processing and transmission module 1 (11), airflow controller (12), airflow generator (13), airflow velocity measuring instrument (14), wireless data processing and transmission module 2 (15), vibration control module (16), and high frequency vibration simulation and measurement platform (17). The input end of the lightning impact controller (2) is connected to the host computer (1), the output end of the lightning impact controller (2) is connected to the input end of the lightning impact generator (3), the left and right ends of the high voltage switch (41) are connected to the high voltage test electrode one (51) and the output end of the lightning impact generator (3) respectively, the upper and lower ends of the line insulator (6) are fixedly connected to the high voltage test electrode one (51) and the high voltage test electrode two (52) respectively, the upper and lower ends of the grounding switch (42) are connected to the high voltage test electrode two (52) and the grounding cable (7) respectively, and the grounding cable (7) is connected to the grounding grid (71); The grounding terminal of the lightning impulse generator (3) is connected to the grounding electrode (31) of the lightning impulse generator; The input terminal of the high-precision voltage divider (8) is connected to the high-voltage experimental electrode (51), and the grounding terminal of the high-precision voltage divider (8) is connected to the voltage divider grounding electrode (81); the current test coil (9) is sleeved on the grounding cable (7); the output terminal of the high-precision voltage divider (8) is connected to the input terminal of the experimental data acquisition unit (10); the output terminal of the current test coil (9) is connected to the input terminal of the experimental data acquisition unit (10); The output end of the experimental data acquisition unit (10) is connected to the input end of the wireless data processing and transmission module 1 (11); the wireless data processing and transmission module 1 (11) is wirelessly connected to the host computer (1). The input end of the airflow controller (12) is connected to the host computer (1), and the output end of the airflow controller (12) is connected to the airflow generator (13); the output end of the airflow velocity measuring instrument (14) is connected to the wireless data processing and transmission module 2 (15); the wireless data processing and transmission module 2 (15) is wirelessly connected to the host computer (1); The input end of the vibration control module (16) is connected to the host computer (1), and the output end of the vibration control module (16) is connected to the high-frequency vibration simulation and measurement platform (17); the high-voltage experimental electrode two (52) is fixed on the high-frequency vibration simulation and measurement platform (17); The high voltage test electrode one (51), line insulator (6), high voltage test electrode two (52), high frequency vibration simulation and measurement platform (17), airflow generator (13), and airflow velocity measuring instrument (14) are fixed inside the environmental simulation test chamber (5); The airflow outlet plane (131) of the airflow generator (13) is perpendicular to the axial direction of the line insulator (6); A method for evaluating the performance status of line insulators under strong airflow and strong vibration environments includes the following steps: S1: Set the air flow velocity V on the host computer (1). a , the host computer (1) controls the rotation speed n of the air flow generator (13) to increase uniformly from 0 by controlling the air flow controller (12); at the same time, the air flow velocity measuring instrument (14) measures the air flow velocity v in the environmental simulation test chamber (5) in real time, and the wireless data processing and transmission module 2 (15) wirelessly transmits the measurement result of the air flow velocity measuring instrument (14) to the host computer (1). The host computer (1) judges the air flow velocity v. If |V a - v| < E, keep the rotation speed n of the air flow generator (13) unchanged; S2: Set the vibration frequency of the line insulator to f on the host computer (1). a The vibration amplitude is A a The host computer (1) controls the high-frequency vibration simulation and measurement platform (17) to start working by controlling the vibration control module (16), generating a vibration frequency of f. a The vibration amplitude is A a The vibration; S3: Set the lightning voltage U1 on the host computer (1), and close the high voltage switch (41) and the grounding switch (42). S4: The host computer (1) controls the lightning impulse controller (2) to control the lightning impulse generator (3) to generate lightning voltage to the high-voltage experimental electrode (51). The experimental data acquisition unit (10) measures the current value on the grounding cable (7) through the current test coil (9). r Meanwhile, the experimental data acquisition unit (10) measures the voltage value U of the line insulator (6) through a high-precision voltage divider (8). r ; S5: The data collected by the experimental data acquisition unit (10) is wirelessly transmitted to the host computer (1) via the wireless data processing and transmission module 1 (11), and I is judged. r Does it satisfy I? r >I ε If satisfied, the lightning voltage amplitude set by the host computer (1) is reduced by ∆U, and steps S4-S5 are repeated; if not satisfied, the value of U at this time is recorded. r At the same time, disconnect the high-voltage switch (41) and the grounding switch (42), and proceed to step S6; S6: Change the vibration frequency of the line insulator set by the host computer (1), repeat steps S2-S5 Q-1 times, and generate Q sets of measurement data; The range of vibration frequencies of the line insulators set by the host computer (1) is [f a f d ], with H values ​​taken uniformly at intervals; The value of H is (f d -f a ) / (Q-1); S7: Calculate the theoretical value of the transient characteristic voltage U of the line insulator (6): （1） In equation (1), f is the vibration frequency of the line insulator (6), f0 is the power frequency, v is the airflow velocity, φ is the angle between the axial direction and the horizontal direction of the line insulator (6); δ and γ are Gaussian error coefficients, and x is the integral variable; S8: The particle swarm optimization algorithm is used to optimize and model formula (1) to obtain a set of γ and δ values ​​that minimize the error between the theoretical calculation value and the measured value of the transient characteristic voltage of the line insulator (6). The specific steps are as follows: 1) Generate an initial population with uniformly distributed particles and velocities, and set stopping conditions; 2) Calculate the objective function value according to equation (2): （2） In equation (2), O(δ, γ) represents the objective function, U ri U is the measured voltage value of the line insulator (6) in the i-th group of experiments. i Q is the theoretically calculated value of the transient characteristic voltage of the line insulator (6) in the i-th group of experiments, and Q is the number of measurement data groups; 3) Update the individual best position of each particle and the best position of the entire swarm; 4) Update the velocity and position of each particle; 5) If the stopping condition is met, stop the search and output the search results; otherwise, return to step 2). 6) Obtain the values ​​of γ0 and δ0 that minimize the error between the calculated and measured values ​​of the characteristic current of the insulating gas; S9: Substitute the values ​​of γ0 and δ0 obtained in S8 to minimize the error into formula (1) to obtain the transient characteristic voltage U of the optimized line insulator (6). b Theoretical calculation formula: （3） S10: Transient characteristic voltage U based on the optimized line insulator (6) b Calculate the performance status evaluation factor β of the line insulator (6): （4） In equation (4) U b For the optimized transient characteristic voltage of the line insulator (6), U s The transient characteristic voltage reference value of the optimized line insulator (6); S11: The performance status of the line insulator (6) is evaluated based on β. When β∈[1,+∞), it indicates that the performance status of the line insulator (6) is normal; when β∈(0,1), it indicates that the line insulator (6) is abnormal and needs to be repaired.

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