An insulator service performance evaluation method considering multiple lightning strikes and air flow factors

Abstract

The application shows a kind of insulator service performance evaluation method considering multiple lightning and airflow factors, first, a kind of insulator service performance evaluation platform considering multiple lightning and airflow factors is built;Based on the evaluation platform, multiple lightning impact test and strong airflow operating environment simulation are carried out for line insulator;The strong convection influence factor σ of line insulator is calculated;The service performance evaluation factor τ of line insulator under multiple lightning is calculated;Finally, the service performance evaluation of insulator is carried out according to the calculated service performance evaluation factor τ of line insulator under multiple lightning.The application can not only effectively simulate the strong airflow effect on line insulator, but also effectively simulate the multiple lightning working condition of line insulator;Intelligent operation and control can be completed through host computer;The service performance of line insulator considering airflow factor and multiple lightning impact can be comprehensively evaluated and analyzed, 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 service performance of insulators that takes into account multiple lightning strikes and airflow factors. Background Technology

[0002] Thundercloud discharge is a common natural discharge phenomenon. Statistics show that 70% of negative-polarity lightning strikes involve multiple return strokes, with extremely short intervals between each stroke and carrying enormous energy, posing a serious threat to transmission line system equipment and power quality. The IEC has defined this phenomenon of multiple lightning discharges as multiple lightning strikes. Therefore, condition monitoring and assessment of transmission line system equipment under multiple lightning strikes are particularly important.

[0003] 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, multiple lightning strikes significantly accelerate the performance degradation of line insulators. Furthermore, transmission towers of 110kV and above are generally over 30 meters high, and the line insulators are subject to swaying due to airflow. Strong airflow can affect the discharge path of line insulators subjected to multiple lightning strikes. Therefore, performance evaluation of line insulators subjected to multiple lightning strikes under strong airflow conditions is of great significance.

[0004] Current research on line insulators, both domestically and internationally, largely focuses on simulation analysis or leakage current detection. There is a lack of research on performance evaluation methods under multiple lightning strikes, especially considering airflow factors in such conditions. Therefore, this invention patent establishes an insulator service performance evaluation platform that considers both multiple lightning strikes and airflow factors. Based on this platform, a method for evaluating insulator service performance considering both factors is proposed. This method can accurately evaluate the performance of line insulators under strong airflow conditions and multiple lightning strikes, and provide maintenance recommendations to improve the safety and stability of the power grid system. Summary of the Invention

[0005] To accurately and analytically evaluate the performance of line insulators under the combined effects of airflow factors and multiple lightning strikes, this invention provides a method for evaluating the service performance of insulators that takes into account both multiple lightning strikes and airflow factors. The technical solution for achieving the objective of this invention is as follows:

[0006] Step 1: An insulator service performance evaluation platform considering multiple lightning strikes and airflow factors was built. The platform includes: host computer (1), multiple lightning strike 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 terminal of the multiple lightning strike controller (2) is connected to the host computer (1), the output terminal of the multiple lightning strike controller (2) is connected to the input terminal of the lightning impulse 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 terminal of the lightning impulse 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 multiple lightning strike controller (2) contains a time-sequential high-voltage disconnect switch 1 (21), a time-sequential high-voltage disconnect switch 2 (22), a time-sequential high-voltage disconnect switch 3 (23), a time-sequential high-voltage disconnect switch 4 (24), a time-sequential high-voltage disconnect switch 5 (25), and a time-sequential high-voltage disconnect switch 6 (26).

[0010] The environmental simulation test chamber (5) is a cylindrical test chamber;

[0011] The angle between the axial direction of the line insulator (6) and the axial direction of the environmental simulation test chamber (5) is φ.

[0012] 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);

[0013] 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; the wireless data processing and transmission module 1 (11) is wirelessly connected to the host computer (1);

[0014] 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);

[0015] 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 (52) is fixed on the high-frequency vibration simulation and measurement platform (17);

[0016] 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);

[0017] The airflow outlet plane (131) of the airflow generator (13) is parallel to the axial direction of the environmental simulation test chamber (5); Second step: Based on the insulator service performance evaluation platform that takes into account multiple lightning strikes and airflow factors, a method for evaluating the insulator service performance that takes into account multiple lightning strikes and airflow factors is proposed, including the following steps:

[0018] S1: Set the vibration frequency of the line insulator to f in 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;

[0019] S2: 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, the rotational speed n of the air flow generator (13) remains unchanged;

[0020] S3: Set the lightning voltage amplitude U1 of multiple lightning strikes on the host computer (1), and close the high - voltage switch (41) and the grounding switch (42);

[0021] The number of pulses of the multiple lightning strikes is Y, and the time interval between pulses is ΔT;

[0022] S4: Control the host computer (1) to issue timing commands to control the opening and closing of the timing high - voltage disconnector 1 (21), timing high - voltage disconnector 2 (22), timing high - voltage disconnector 3 (23), timing high - voltage disconnector 4 (24), timing high - voltage disconnector 5 (25), and timing high - voltage disconnector 6 (26) in the multiple lightning strike controller (2), thereby controlling the lightning impulse generator (3) to output a multiple lightning voltage signal to the high - voltage test electrode 1 (51). The experimental data acquisition unit (10) measures the current value I on the grounding cable (7) through the current test coil (9), r 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 ;

[0023] S5: The collected 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). The host computer (1) judges whether the waveform peak value I r of I rF satisfies I rF >I ε ; If it is satisfied, the lightning voltage amplitude set by the host computer (1) is reduced by ΔU, and steps S4 - S5 are repeated; if not, record the U r at this time, and at the same time, disconnect the high - voltage switch (41) and the grounding switch (42);

[0024] S6: Calculate the strong convection influence factor σ of the line insulator (6):

[0025]

[0026] In formula (1), f is the vibration frequency of the line insulator (6), f0 is the power frequency, α is the angle between the axial direction and the horizontal direction of the line insulator (6); k1, k2, k3 are weight coefficients;

[0027] S7: Calculate the service performance evaluation factor τ of the line insulator (6) under multiple lightning strikes:

[0028]

[0029] In formula (2), U riθ represents the peak voltage of the line insulator (6) corresponding to the i-th pulse in a multiple lightning strike. i μ0 is the correction coefficient, η is the integral variable, Y is the number of pulses in multiple lightning strikes, and v is the airflow velocity in the environmental simulation test chamber (5).

[0030] S8: The service performance of line insulator (6) under multiple lightning strikes is evaluated based on the evaluation factor τ. When τ∈[1.5, +∞), it indicates that the line insulator (6) has excellent performance; when τ∈[0.9, 1.5), it indicates that the line insulator (6) has normal performance; when τ∈(0, 0.9), it indicates that the line insulator (6) is in abnormal condition and needs to be repaired.

[0031] The beneficial effects of this invention are as follows:

[0032] 1) An insulator service performance evaluation platform that takes into account multiple lightning strikes and airflow factors was built. This platform can not only simulate the strong airflow of line insulators, but also effectively simulate the multiple lightning strikes of line insulators.

[0033] 2) Intelligent operation and control can be completed through a host computer, and data collection and transmission are convenient and efficient;

[0034] 3) The analytical assessment comprehensively considers the service performance of line insulators under airflow factors and multiple lightning strikes, and proposes maintenance suggestions to further improve the safety and stability of the power grid system. Attached Figure Description

[0035] 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.

[0036] Figure 1 This application illustrates a schematic diagram of an insulator service performance evaluation platform that takes into account multiple lightning strikes and airflow factors. Detailed Implementation

[0037] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. A specific embodiment of an insulator service performance evaluation method considering multiple lightning strikes and airflow factors includes the following steps:

[0038] Step 1: An insulator service performance evaluation platform considering multiple lightning strikes and airflow factors was built. The platform includes: host computer (1), multiple lightning strike 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).

[0039] The input terminal of the multiple lightning strike controller (2) is connected to the host computer (1), the output terminal of the multiple lightning strike controller (2) is connected to the input terminal of the lightning impulse 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 terminal of the lightning impulse 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);

[0040] The grounding terminal of the lightning impulse generator (3) is connected to the grounding electrode (31) of the lightning impulse generator;

[0041] The multiple lightning strike controller (2) contains a time-sequential high-voltage disconnect switch 1 (21), a time-sequential high-voltage disconnect switch 2 (22), a time-sequential high-voltage disconnect switch 3 (23), a time-sequential high-voltage disconnect switch 4 (24), a time-sequential high-voltage disconnect switch 5 (25), and a time-sequential high-voltage disconnect switch 6 (26).

[0042] The environmental simulation test chamber (5) is a cylindrical test chamber;

[0043] The angle between the axial direction of the line insulator (6) and the axial direction of the environmental simulation test chamber (5) is φ.

[0044] 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);

[0045] 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; the wireless data processing and transmission module 1 (11) is wirelessly connected to the host computer (1);

[0046] 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);

[0047] 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 (52) is fixed on the high-frequency vibration simulation and measurement platform (17);

[0048] 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);

[0049] The airflow outlet plane (131) of the airflow generator (13) is parallel to the axial direction of the environmental simulation test chamber (5); Second step: Based on the insulator service performance evaluation platform that takes into account multiple lightning strikes and airflow factors, a method for evaluating the insulator service performance that takes into account multiple lightning strikes and airflow factors is proposed, including the following steps:

[0050] S1: Set the vibration frequency of the line insulator to f in 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;

[0051] S2: 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, then keep the rotational speed n of the air flow generator (13) unchanged;

[0052] S3: Set the lightning voltage amplitude U1 of multiple lightning strikes on the host computer (1), and close the high - voltage switch (41) and the grounding switch (42);

[0053] The number of pulses of the multiple lightning strikes is Y, and the time interval between pulses is ΔT; the waveform of the pulses of the multiple lightning strikes is 8 / 20 μs;

[0054] S4: Control the opening and closing of the timing high - voltage disconnector 1 (21), timing high - voltage disconnector 2 (22), timing high - voltage disconnector 3 (23), timing high - voltage disconnector 4 (24), timing high - voltage disconnector 5 (25), and timing high - voltage disconnector 6 (26) in the multiple lightning strike controller (2) by controlling the timing commands issued by the host computer (1), so as to control the lightning impulse generator (3) to output a multiple lightning voltage signal to the high - voltage test electrode 1 (51). The experimental data acquisition unit (10) measures the current value I 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 the high - precision voltage divider (8) r ;

[0055] 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). The host computer (1) judges whether the waveform peak value I r of I rF meets I rF >I ε ; If it meets, the host computer (1) reduces the set lightning voltage amplitude by ΔU, and repeats steps S4 - S5; if it does not meet, record the U r at this time, and at the same time, disconnect the high - voltage switch (41) and the grounding switch (42);

[0056] S6: Calculate the strong convection influence factor σ of the line insulator (6):

[0057]

[0058] In formula (1), f is the vibration frequency of the line insulator (6), f0 is the power frequency, α is the angle between the axial direction and the horizontal direction of the line insulator (6); k1, k2, and k3 are weight coefficients;

[0059] S7: Calculate the service performance evaluation factor τ of the line insulator (6) under multiple lightning strikes:

[0060]

[0061] In formula (2), Uri θ represents the peak voltage of the line insulator (6) corresponding to the i-th pulse in a multiple lightning strike. i μ0 is the correction coefficient, η is the integral variable, Y is the number of pulses in multiple lightning strikes, and v is the airflow velocity in the environmental simulation test chamber (5).

[0062] S8: The service performance of line insulator (6) under multiple lightning strikes is evaluated based on the evaluation factor τ. When τ∈[1.5, +∞), it indicates that the line insulator (6) has excellent performance; when τ∈[0.9, 1.5), it indicates that the line insulator (6) has normal performance and maintains normal maintenance frequency; when τ∈(0, 0.9), it indicates that the line insulator (6) is in abnormal condition and needs to be replaced.

Claims

1. A method for evaluating the service performance of insulators considering multiple lightning strikes and airflow factors, characterized in that, First, an insulator service performance evaluation platform considering multiple lightning strikes and airflow factors was built. The platform includes: host computer (1), multiple lightning strike 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 terminal of the multiple lightning strike controller (2) is connected to the host computer (1), the output terminal of the multiple lightning strike controller (2) is connected to the input terminal of the lightning impulse 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 terminal of the lightning impulse 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 multiple lightning strike controller (2) contains a time-sequential high-voltage disconnect switch 1 (21), a time-sequential high-voltage disconnect switch 2 (22), a time-sequential high-voltage disconnect switch 3 (23), a time-sequential high-voltage disconnect switch 4 (24), a time-sequential high-voltage disconnect switch 5 (25), and a time-sequential high-voltage disconnect switch 6 (26). The environmental simulation test chamber (5) is a cylindrical test chamber; The angle between the axial direction of the line insulator (6) and the axial direction of the environmental simulation test chamber (5) is φ. 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; 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 (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 parallel to the axial direction of the environmental simulation test chamber (5); A method for evaluating the service performance of insulators that takes into account multiple lightning strikes and airflow factors includes the following steps: S1: Set the vibration frequency of the line insulator to f in 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; S2: 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); meanwhile, 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; S3: Set the lightning voltage amplitude U1 of multiple lightning strikes on the host computer (1), and close the high voltage switch (41) and the grounding switch (42); The number of pulses in the multiple lightning strikes is Y, and the time interval between the pulses is ΔT; S4: By controlling the host computer (1) to issue timing commands to control the opening and closing of the timing high voltage disconnect switches 1 (21), 2 (22), 3 (23), 4 (24), 5 (25), and 6 (26) in the multiple lightning strike controller (2), the lightning impulse generator (3) outputs multiple lightning voltage signals to the high voltage experimental electrode (51). The experimental data acquisition unit (10) measures the current value I 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). The host computer (1) then determines I. r waveform peak I rF Does it satisfy I? rF >I ε If satisfied, the lightning voltage amplitude set by the host computer (1) is reduced by ΔU, 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); S6: Calculate the strong convection influence factor σ of the line insulator (6): In equation (1), f is the vibration frequency of the line insulator (6), f0 is the power frequency, α is the angle between the axial direction and the horizontal direction of the line insulator (6); k1, k2, and k3 are weighting coefficients. S7: Calculate the service performance evaluation factor τ of line insulator (6) under multiple lightning strikes: In equation (2), U ri θ represents the peak voltage of the line insulator (6) corresponding to the i-th pulse in a multiple lightning strike. i μ0 is the correction coefficient, η is the integral variable, Y is the number of pulses in multiple lightning strikes, and v is the airflow velocity in the environmental simulation test chamber (5). S8: The service performance of line insulator (6) under multiple lightning strikes is evaluated based on the evaluation factor τ. When τ∈[1.5, +∞), it indicates that the line insulator (6) has excellent performance; when τ∈[0.9, 1.5), it indicates that the line insulator (6) has normal performance; when τ∈(0, 0.9), it indicates that the line insulator (6) is in abnormal condition and needs to be repaired.

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