Zero-value insulator detection method and system for direct-current ultra-high-voltage power transmission line

Abstract

The invention provides a zero-value insulator detection method for a direct-current ultra-high-voltage power transmission line. The method comprises the following steps: acquiring an infrared image of the direct-current ultra-high-voltage power transmission line; if the infrared image is abnormal, acquiring an ultraviolet image; if the ultraviolet image has the abnormal discharge characteristic, determining that a zero-value insulator and a corresponding potential abnormal region exist; performing ultrasonic detection on the potential abnormal region to obtain an ultrasonic signal; if abnormal signals exist in the ultrasonic signals, electric field distribution analysis is carried out on the direct-current ultra-high-voltage power transmission line; and if electric field distortion exists in the electric field distribution of the direct-current ultra-high-voltage power transmission line, determining that a zero-value insulator exists, and generating a zero-value insulator detection report of the direct-current ultra-high-voltage power transmission line. According to the invention, the zero-value insulator can be accurately identified and positioned, and the detection efficiency of the zero-value insulator is improved. The invention further provides a zero-value insulator detection system of the direct-current ultra-high-voltage power transmission line, a computer readable storage medium and electronic equipment, which have the above beneficial effects.

Description

Technical Field

[0001] The present application relates to the field of high-voltage power transmission technology, and in particular to a method and system for detecting zero-value insulators of a DC ultra-high voltage transmission line. Background Art

[0002] Insulators, core components of ultra-high voltage transmission lines, perform both electrical insulation and mechanical support. However, due to prolonged exposure to harsh environments such as high voltage and strong electric fields, high temperatures and sunlight, high humidity, and contaminants, insulators inevitably degrade and even experience zero-value deterioration, significantly reducing insulation performance. This loss of insulation capacity in zero-value insulators poses a serious threat to the safe operation of transmission lines. Therefore, timely detection and location of zero-value insulators is crucial to ensuring stable power system operation.

[0003] Detecting the zero-value phenomenon on porcelain insulators primarily relies on manual inspections. Maintenance personnel regularly patrol transmission lines and visually inspect the appearance and condition of insulators to determine if they are damaged or defective. This method is inefficient, labor-intensive, and highly dangerous, especially during overhead inspections of high-voltage transmission lines, where it poses significant safety risks. Due to the limitations of visual inspections, the accuracy of test results is low.

[0004] Therefore, how to improve the detection accuracy of insulators is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0005] The purpose of this application is to provide a method and system for detecting zero-value insulators of a DC ultra-high voltage transmission line, a system, a computer-readable storage medium and an electronic device, which can effectively improve the detection accuracy of zero-value insulators.

[0006] To solve the above technical problems, the present application provides a method for detecting zero-value insulators in a DC ultra-high voltage transmission line. The specific technical solution is as follows:

[0007] Acquiring an infrared image of the ultra-high voltage direct current transmission line;

[0008] If the infrared image indicates an abnormality, obtaining an ultraviolet image of the UHVDC transmission line;

[0009] If the ultraviolet image has abnormal discharge characteristics, determining the presence of a zero-value insulator and a corresponding potential abnormal area;

[0010] Performing ultrasonic detection on the potential abnormal area to obtain an ultrasonic signal;

[0011] If there is an abnormal signal in the ultrasonic signal, performing electric field distribution analysis on the UHVDC transmission line;

[0012] If electric field distortion exists in the electric field distribution of the ultra-high voltage direct current transmission line, it is confirmed that there are zero-value insulators, and a zero-value insulator detection report of the ultra-high voltage direct current transmission line is generated.

[0013] Optionally, after obtaining the infrared image of the UHVDC transmission line, the method further includes:

[0014] identifying temperature changes of the ultra-high voltage direct current transmission line in the infrared image;

[0015] If a temperature change of an insulator in the UHVDC transmission line exceeds a set change threshold within a set time period, it is determined that the infrared image representation is abnormal.

[0016] Optionally, if a temperature change of an insulator in the UHVDC transmission line exceeds a set change threshold within a set time period, determining that the infrared image representation is abnormal includes:

[0017] determining an initial temperature of the insulator and a rate of temperature change within a set time period;

[0018] The temperature change rate comparison table is called to determine the pollution degree of the insulator; the temperature change rate comparison table contains a mapping relationship between insulators of different pollution degrees and relative temperature increase ratios.

[0019] Optionally, if the ultraviolet image has abnormal discharge characteristics, determining the presence of a zero-value insulator includes:

[0020] Counting the number of photons captured in the ultraviolet image;

[0021] The degree of wet contamination of the insulator is determined according to the number of photons.

[0022] determining a discharge area based on the wet contamination level and the captured photons;

[0023] Position information of the zero-value insulator is located according to the discharge area.

[0024] Optionally, performing ultrasonic detection on the potential abnormal area to obtain an ultrasonic signal includes:

[0025] Performing ultrasonic testing on insulators in the UHVDC transmission line to obtain ultrasonic signals of each insulator;

[0026] The ultrasonic signal of each insulator is compared with the standard ultrasonic signal standard range of a normal insulator. If there is an ultrasonic signal exceeding the standard ultrasonic signal standard range, it is confirmed that there is an abnormal signal in the ultrasonic signal.

[0027] Optionally, performing electric field distribution analysis on the UHVDC transmission line includes:

[0028] Performing electric field detection on the suspected zero-value insulator in the UHVDC transmission line to determine the electric field distribution curve and electric field strength of the suspected zero-value insulator;

[0029] If the electric field distribution curve has a peak drop or the electric field intensity fluctuates abnormally, it is confirmed that electric field distortion exists, and the insulator with electric field distortion is a zero-value insulator.

[0030] Optionally, confirming the existence of zero-value insulators and generating a zero-value insulator detection report for the UHVDC transmission line includes:

[0031] Determining the position information and quantity information of the zero-value insulators and abnormal data corresponding to each zero-value insulator;

[0032] A zero-value insulator detection report is generated according to the position information, the quantity information and the abnormal data.

[0033] The present application also provides a zero-value insulator detection system for a DC ultra-high voltage transmission line, comprising:

[0034] an infrared image acquisition module, configured to acquire an infrared image of the UHVDC transmission line;

[0035] an ultraviolet image acquisition module, configured to acquire an ultraviolet image of the UHVDC transmission line if the infrared image indicates an abnormality;

[0036] an ultrasonic detection module, configured to determine the presence of a zero-value insulator and a corresponding potential abnormal area if abnormal discharge characteristics are present in the ultraviolet image; and perform ultrasonic detection on the potential abnormal area to obtain an ultrasonic signal;

[0037] an electric field detection module, configured to perform electric field distribution analysis on the UHVDC transmission line if an abnormal signal is present in the ultrasonic signal;

[0038] The report generating module is used to confirm the presence of zero-value insulators if electric field distortion exists in the electric field distribution of the DC ultra-high voltage transmission line, and generate a zero-value insulator detection report for the DC ultra-high voltage transmission line.

[0039] The present application also provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the above-described method when executed by a processor.

[0040] The present application also provides an electronic device, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps of the above-mentioned method when calling the computer program in the memory.

[0041] The present application provides a method for detecting zero-value insulators of a DC ultra-high voltage transmission line, comprising: obtaining an infrared image of the DC ultra-high voltage transmission line; if the infrared image indicates an abnormality, obtaining an ultraviolet image of the DC ultra-high voltage transmission line; if the ultraviolet image shows abnormal discharge characteristics, determining the presence of a zero-value insulator and a corresponding potential abnormal area; performing ultrasonic detection on the potential abnormal area to obtain an ultrasonic signal; if an abnormal signal is present in the ultrasonic signal, performing electric field distribution analysis on the DC ultra-high voltage transmission line; if electric field distortion is present in the electric field distribution of the DC ultra-high voltage transmission line, confirming the presence of a zero-value insulator, and generating a zero-value insulator detection report for the DC ultra-high voltage transmission line.

[0042] When detecting zero-value insulators, the present application obtains infrared images, ultraviolet images, ultrasonic signals and electric field distribution analysis of the DC ultra-high voltage transmission line, determines abnormal areas in the line by using the infrared images and ultraviolet images, and further determines zero-value insulators based on the ultrasonic signals and electric field distribution. This can accurately identify and locate zero-value insulators, thereby improving the detection efficiency of zero-value insulators.

[0043] The present application also provides a zero-value insulator detection system for a DC ultra-high voltage transmission line, a computer-readable storage medium, and an electronic device, which have the above-mentioned beneficial effects and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0045] Figure 1 A flow chart of a method for detecting zero-value insulators of a DC ultra-high voltage transmission line provided in an embodiment of the present application;

[0046] Figure 2 This is a graph showing the maximum temperature rise of an insulator string with different pollution levels provided in an embodiment of the present application;

[0047] Figure 3 This is a diagram of an uncharged UV imager of an insulator provided in an embodiment of the present application;

[0048] Figure 4 UV imaging images of zero-value insulators at different positions in dry conditions provided by the embodiments of the present application;

[0049] Figure 5 A schematic diagram of the interference signal waveform provided in an embodiment of the present application;

[0050] Figure 6 Schematic diagram of the zero-value insulator detection method for a DC ultra-high voltage transmission line provided in an embodiment of the present application;

[0051] Figure 7 A schematic structural diagram of a zero-value insulator detection system for a DC ultra-high voltage transmission line provided in an embodiment of the present application;

[0052] Figure 8 This is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0054] See also Figure 1 , Figure 1 A flowchart of a method for detecting zero-value insulators of a DC ultra-high voltage transmission line provided in an embodiment of the present application, the method comprising:

[0055] S101: Acquire an infrared image of the UHVDC transmission line;

[0056] S102: If the infrared image indicates an abnormality, obtaining an ultraviolet image of the UHVDC transmission line;

[0057] S103: If the ultraviolet image has abnormal discharge characteristics, determine the presence of a zero-value insulator and a corresponding potential abnormal area;

[0058] S104: Performing ultrasonic detection on the potential abnormal area to obtain an ultrasonic signal;

[0059] S105: If an abnormal signal exists in the ultrasonic signal, performing electric field distribution analysis on the UHVDC transmission line;

[0060] S106: If electric field distortion exists in the electric field distribution of the UHVDC transmission line, it is confirmed that there are zero-value insulators, and a zero-value insulator detection report of the UHVDC transmission line is generated.

[0061] First, infrared and ultraviolet images of the UHVDC transmission line are acquired sequentially. To improve acquisition efficiency, unmanned aerial vehicles (UAVs) can be used. Specifically, a UAV can take off along a pre-set path and fly to the transmission line inspection area. The UAV, equipped with an infrared imager, captures the insulators and acquires infrared images of them.

[0062] Perform pre-processing operations such as noise reduction and enhancement on the captured infrared images to improve image quality and facilitate subsequent analysis. Analyze the pre-processed infrared images to identify the temperature distribution of the insulators, especially the temperature changes at the steel legs, and determine whether there is any abnormal temperature rise.

[0063] The so-called temperature rise anomaly can identify temperature changes in the UHVDC transmission line in the infrared image. If the temperature change of an insulator in the UHVDC transmission line exceeds a set change threshold within a set time period, the infrared image is determined to be abnormal. The set time period is not specifically limited and can be set by those skilled in the art.

[0064] See also Figure 2 , Figure 2 This is a graph showing the maximum temperature rise of an insulator string at different levels of contamination provided in the embodiments of the present application. Pressure tests were performed on intact insulator strings under different levels of wet contamination, with the contamination levels remaining at 0.05 mg / cm², 0.08 mg / cm², and 0.15 mg / cm². The maximum temperatures of the insulator strings were recorded before the start of the test and 15 minutes, 30 minutes, 60 minutes, 90 minutes, and 120 minutes after the start of the test, respectively. The graph is shown in Figure 5. It can be seen that the temperature rise of the contaminated insulator string increases linearly, then decreases and stabilizes, reaching a nearly stable state 60 minutes after the start of the test. As the test continued, the temperature rise decreased slightly, reaching 2.9°C, 3.9°C, and 5.1°C, respectively, two hours after the test.

[0065] According to experimental measurements, when the pollution level is 0.05mg / cm², 60 minutes after the test begins, the average maximum temperature rise of the infrared imaging images of zero-value insulators at different positions is 3.8℃, which is 0.4℃ higher than that of the intact insulator string.

[0066] When the pollution level was 0.08mg / cm², 60 minutes after the test began, the average maximum temperature rise of the infrared imaging images of zero-value insulators at different locations was 4.7℃, which was 0.3℃ higher than that of the intact insulator string;

[0067] When the pollution level was 0.15 mg / cm², 60 minutes after the test began, the average maximum temperature rise of the infrared images of the zero-value insulators at different locations was 6.5°C, 0.7°C higher than that of the intact insulator strings. The relative temperature rises were 6.4%, 9.5%, and 10.7%, respectively.

[0068] It can be seen that the temperature rise of a normal insulator string varies within a narrow range, while the temperature rise of a string containing zero-value insulators varies relatively widely. The temperature of the zero-value insulators is lower than that of the other normal insulators, and the ambient temperature has little effect on the temperature rise of the insulator string itself. Under clean and dry contamination conditions, the temperature rise of the zero-value insulator string is small; under saturated and moist contamination conditions, the temperature rise of the zero-value insulator string is large. The greater the contamination level, the higher the temperature rise, and the greater the difference between the temperature of the zero-value insulator and the other normal insulators.

[0069] The judgment basis is: when the relative temperature rise (the difference between the temperature of the insulator and its surrounding environment temperature, or the temperature difference with other normal insulators in the same string) exceeds 6%, it is abnormal.

[0070] If an abnormal temperature rise is found, mark the insulator as a potential zero-value insulator; if there is no abnormality, continue to inspect the UHVDC transmission line.

[0071] Thereafter, UV imaging detection is performed on the insulators marked as potential zero values to obtain UV images.

[0072] Analyze the UV image to identify whether there is corona discharge. Judge the defect of the insulator by the number of UV photons and the discharge area to determine whether there is abnormal discharge.

[0073] Specifically, you can refer to the following steps:

[0074] The first step is to calculate the number of photons captured in the ultraviolet image;

[0075] The second step is to determine the wetness and contamination degree of the insulator according to the number of photons.

[0076] Step 3: determining the discharge area based on the wet contamination level and the captured photons;

[0077] Step 4: Locate the position information of the zero-value insulator according to the discharge area.

[0078] To calculate the number of photons, we need to determine the sensitivity of the UV imaging device (i.e., its efficiency in detecting photons). This is expressed by the device's quantum efficiency (QE), which varies between devices and wavelengths. We also need to determine the pixel values of the UV image. The value of each pixel reflects the number of photons it receives, allowing us to calculate the number of photons.

[0079] See also Figure 3 and Figure 4 , Figure 3 This is a non-charged UV imager diagram of an insulator provided in an embodiment of the present application. Figure 4 UV imaging images of zero-value insulators at different positions in a dry state provided by the embodiment of the present application. Figure 3Shown are UV images of an insulator string in a dry, intact state without any charge. Figure 4 shows UV images of zero-value insulators at different positions under dry conditions. (a), (b), (c), and (d) are images of zero-value insulators at positions 1, 3, 5, and 7, respectively. It can be seen that when the insulator string is dry, the UV images of an insulator string containing zero-value insulators are essentially the same as those of intact insulator strings and insulator strings containing low-value insulators. Regardless of the position of a single zero-value insulator, the UV images still show only low background noise, making it impossible to identify a single zero-value insulator within the insulator string.

[0080] UV imaging of intact insulator strings also shows differences at different levels of contamination. For insulator strings with a contamination level of 0.05 mg / cm², the number of photons captured by the UV imager is below 1,500, for those with a contamination level of 0.08 mg / cm², it is between 6,000 and 15,000, and for those with a contamination level of 0.15 mg / cm², it is between 30,000 and 110,000. As the contamination level increases, the number of photons captured by the UV imager increases rapidly. The heavier the contamination, the more pronounced the discharge. Field tests also clearly show that the heavier the contamination, the more intense the discharge sound, accompanied by arc sparks, and the discharge area is primarily concentrated near the high-voltage terminal.

[0081] At high contamination levels, the discharge still tends to be concentrated at certain discharge points, and is more intense than at low contamination levels. However, unlike at low contamination levels, the discharge location is still primarily near the low-voltage side when the low-value insulator is in the first piece. When the low-value insulator is in the third piece, the discharge area is close to the high-voltage side, just like in the fifth and seventh pieces. Furthermore, visible discharge light can still be clearly observed on the first insulator piece, and is even more intense than in previous tests, with even breakdown between the piece sheds occurring.

[0082] Therefore, abnormal discharge can be determined based on the photon count and discharge area. Under wet and contaminated conditions, the UV photon count of zero-value insulators is significantly higher than that of normal insulators. For example, when the ESDD is 0.05 mg / cm², the photon count is below 2,300; when the ESDD is 0.15 mg / cm², the photon count is between 40,000 and 140,000. Discharge Area: The discharge area of zero-value insulators is typically concentrated at the high-voltage end, and the discharge area is uneven and intermittent.

[0083] If abnormal discharge is found, further confirm that the insulator is a suspected zero-value insulator; if there is no abnormality, continue the inspection.

[0084] During the ultrasonic testing phase, ultrasonic testing is performed on the suspected zero-value insulator to obtain ultrasonic signals.

[0085] Specifically, ultrasonic signals need to be analyzed to determine the presence of partial discharge and to assist in determining the degree of insulator deterioration. Ultrasonic testing is used to identify cracks or physical damage within insulators, particularly those that are contaminated or aged. Ultrasonic signals are typically used to determine the condition of insulators by transmitting and receiving ultrasonic signals and analyzing their reflected signals to detect anomalies.

[0086] In one feasible implementation, an ultrasonic sensor can be used to scan potential abnormal areas and collect noise signals with a sampling frequency of no less than 48 kHz to satisfy the Nyquist sampling theorem.

[0087] When collecting signals, it is necessary to eliminate environmental noise interference (such as wind noise, equipment vibration, etc.). Adaptive filtering technology can be used to filter out background noise.

[0088] The collected ultrasonic signal is compared with a standard signal library of healthy insulators. The standard signal library contains typical waveforms at different levels of contamination (e.g., 0.05 mg / cm², 0.08 mg / cm², and 0.15 mg / cm²). The signal amplitude and frequency characteristics can then be analyzed:

[0089] Clean and dry insulator: The signal amplitude is stable between 0.005 and 0.008 V, with no obvious peaks.

[0090] Contaminated insulators: The signal amplitude increases with the contamination level (for example, the peak value reaches 0.02 to 0.03 V at 0.15 mg / cm²), and the frequency domain shows high-frequency components (10 to 20 kHz).

[0091] If the signal amplitude exceeds the upper limit of the standard range (such as 0.01 V), or if significant partial discharge characteristics appear in the frequency domain (such as intermittent high-frequency pulses), it is judged to be abnormal.

[0092] The pollution level can be preliminarily determined based on the amplitude (e.g. 0.05 mg / cm² corresponds to an amplitude of 0.008 to 0.01 V, and 0.15 mg / cm² corresponds to an amplitude of 0.02 to 0.03 V). Figure 5 , Figure 5 The interference signal waveform diagram provided in the embodiment of the present application shows the interference signal waveform generated by the test equipment, background environment and acquisition equipment when the insulator string is not energized under dry conditions.

[0093] Under dry conditions, the noise signal waveform of an insulator string containing zero-value insulators has an amplitude that is essentially the same as that of an intact insulator string. Regardless of the position of a single zero-value insulator, the noise signal waveform is essentially the same as the interference signal waveform, confirming the presence of an abnormal signal in the ultrasonic signal, indicating damage or deterioration of the insulator. In actual application, if the signal strength within a certain frequency range deviates from the normal insulator signal by more than a set value (e.g., 10%), it is considered abnormal.

[0094] The noise signal waveform of an intact insulator string under different wet contamination conditions shows that the amplitude of the noise signal waveform of the insulator string increases significantly with the increase of contamination levels of 0.05mg / cm², 0.08mg / cm², and 0.15mg / cm². The heavier the contamination, the more obvious the discharge.

[0095] At different contamination levels, the noise signal waveform amplitudes at different locations on zero-value insulators are similar. As the contamination level increases, the number of discharge points within the insulator string increases, reflected in an increase in the average amplitude of the insulator noise signal. At a contamination level of 0.05 mg / cm², the signal peaks between 0.008 and 0.01 V, with the overall waveform amplitude concentrated between 0.005 and 0.008 V. At a contamination level of 0.08 mg / cm², the peaks are around 0.01 to 0.015 V, with the overall waveform amplitude concentrated between 0.005 and 0.01 V. At a contamination level of 0.15 mg / cm², the peaks are around 0.02 to 0.03 V, with the overall waveform amplitude concentrated between 0.01 and 0.02 V. The discharge intensity within the insulator string increases, reflected in a significant increase in the peak value of the noise signal. The heavier the contamination, the more pronounced the discharge phenomenon within the insulator string and the greater the discharge intensity.

[0096] Under varying contamination conditions, the ultrasonic signal amplitude of a zero-value insulator is significantly higher than that of a normal insulator. The ultrasonic signal frequency of a zero-value insulator is typically higher and exhibits distinct partial discharge characteristics. If an abnormal signal is detected, it can be used to confirm that the insulator is a zero-value insulator. If no abnormality is detected, the inspection continues.

[0097] Finally, the electric field test is performed. It should be noted that the battery test performed at least includes the electric field test of the suspected zero-value insulator with abnormalities. The suspected zero-value insulator is any insulator that has abnormalities after the above tests.

[0098] Perform electric field detection on the suspected zero-value insulators in the UHVDC transmission line to determine the electric field distribution curve and electric field strength of the suspected zero-value insulator. If there is a peak drop in the electric field distribution curve or abnormal fluctuations in the electric field strength, it is confirmed that electric field distortion exists and the insulator with electric field distortion is a zero-value insulator. Electric field distortion is an important characteristic of zero-value insulators. Potential zero-value insulators are identified by measuring changes in the electric field strength around the insulator. Normal insulators maintain a uniform electric field distribution, while degraded zero-value insulators will cause electric field distortion due to the loss of insulation ability. This is particularly noticeable under wet and dirty conditions.

[0099] If the electric field distribution curve shows a peak drop or the electric field intensity fluctuation exceeds a set threshold (for example, the electric field change rate exceeds a set 10%), it can be determined to be electric field distortion, and the insulator experiencing electric field distortion is considered a zero-value insulator. The electric field intensity fluctuation can be set to a standard value through numerical simulation or actual measurement.

[0100] Under wet and dirty conditions, the electric field strength around the zero-value insulator will change significantly. When the electric field suddenly increases or decreases by several to tens of kilovolts per meter, and the difference fluctuates positively or negatively, there is a zero-value insulator there.

[0101] If the electric field at the measurement point within the influence range of the grading ring is lower under wet and contaminated conditions than under intact conditions, and the electric field strength in the space between adjacent insulators near the center of the string increases significantly, then a zero-value insulator is present. When the zero-value insulator is located in the middle of the string, the electric field distribution will reach a local minimum. When the zero-value insulator is located near the grading rings at both ends, the electric field strength of the adjacent insulators will increase significantly. Electric field distribution curve: Zero-value insulators can cause qualitative or quantitative changes in the electric field distribution curve. When the zero-value insulator is located at the high-voltage end, the peak value of the electric field distribution curve will be significantly reduced.

[0102] If electric field distortion is found, it is finally confirmed that the insulator is a zero-value insulator; if there is no distortion, continue the inspection.

[0103] The following is a feasible implementation of this application:

[0104] Electric field testing is performed on suspected zero-value insulators in the aforementioned UHVDC transmission line. Electric field distortion is a key characteristic of zero-value insulators. Potential zero-value insulators are identified by measuring changes in the electric field strength around the insulator. Normal insulators maintain a uniform electric field distribution, while degraded zero-value insulators, due to loss of insulation capacity, can cause electric field distortion. This is particularly noticeable under wet and contaminated conditions. The specific method is as follows:

[0105] Electric field measurement: Use a non-contact electric field sensor to measure the electric field strength at each point along the insulator string, 30 cm from the center axis. The measurement points should avoid the area affected by the grading ring (usually near the first and last three insulators).

[0106] During data analysis, for the normal electric field distribution: the electric field of the clean insulator string is "saddle-shaped", with a peak of about 270 kV / m at the high-voltage end, about 139 kV / m at the low-voltage end, and a stable middle part (about 27 kV / m).

[0107] The characteristics of zero-value insulators are local depressions in the electric field curve and sudden changes in the electric field strength at adjacent points (such as a drop of 5 to 15 kV / m or a fluctuation of more than 10%).

[0108] If the zero-value insulator is located at the high-voltage end (the 1st to 3rd pieces), the peak value at the grading ring will drop by 5 to 25%; if it is located in the middle (near the 40th piece), the electric field strength will drop by about 4.85%.

[0109] The judgment conditions can be as follows:

[0110] Distortion threshold: The electric field intensity at a single point differs by more than ±10 kV / m from that at adjacent points. The depth of a local depression in the electric field curve exceeds 15% of the average value.

[0111] Correction for pollution effects: Under wet pollution conditions, the overall electric field strength increases, but the distortion characteristics are more obvious (need to be compared with the baseline curve of an intact insulator under the same pollution level).

[0112] When generating a zero-value insulator detection report, the position information, quantity information and abnormal data corresponding to each zero-value insulator can be determined first, and then the zero-value insulator detection report can be generated based on the position information, quantity information and abnormal data.

[0113] When detecting zero-value insulators, the embodiment of the present application obtains infrared images, ultraviolet images, ultrasonic signals and electric field distribution analysis of the DC ultra-high voltage transmission line, determines abnormal areas in the line by using the infrared images and ultraviolet images, and further determines zero-value insulators based on the ultrasonic signals and electric field distribution. This can accurately identify and locate zero-value insulators, thereby improving the detection efficiency of zero-value insulators.

[0114] By integrating infrared imaging, ultraviolet imaging, ultrasonic detection, and electric field measurement technologies, the insulator status can be comprehensively detected. This application can be combined with deep learning algorithms to accurately identify zero-value insulators and improve detection accuracy. If drone inspections are used, they can be equipped with a sensing module to obtain infrared and ultraviolet images in real time, enabling efficient and flexible high-altitude inspections. More importantly, this application can perform inspections while the transmission line is energized, reducing power outages and ensuring power supply. The output inspection report can assist in operation and maintenance decision-making.

[0115] Furthermore, to improve detection accuracy, a comprehensive assessment can be made by combining multiple parameters, such as infrared and electric field measurements. If the temperature rise of an insulator is lower than that of adjacent insulators (difference ≥ 0.5°C) and the electric field exhibits distortion, it is identified as a zero-value insulator. During this comprehensive assessment, the corresponding thresholds can be optimized and adjusted accordingly. For example, under moist and contaminated conditions, the temperature rise of a zero-value insulator is 1 to 2.5°C lower than that of a normal insulator (the difference is greatest at a contamination level of 0.15 mg / cm²). During ultraviolet imaging, if the photon count in the discharge area exceeds 20% of that of an intact insulator (for example, >40,000 photons at 0.15 mg / cm²), the insulator requires focused investigation and testing.

[0116] See also Figure 6 , Figure 6 This is a schematic diagram of a method for detecting zero-value insulators in a DC ultra-high voltage transmission line provided in an embodiment of the present application. Figure 6 The complete working principle of this application in actual application and the data flow between each module are demonstrated. The system is carried out by a drone platform carrying a multimodal perception module for inspection, collecting infrared images, ultraviolet images, ultrasonic signals and electric field distribution data of insulators. The collected data is preprocessed to remove noise and interference, and then key features such as temperature rise, number of photons, ultrasonic signal amplitude and electric field strength are extracted. The intelligent recognition model analyzes the features and uses algorithms to identify zero-value insulators and output the recognition results. A detailed inspection report is generated by the data processing and analysis module, and the communication module transmits the report to the ground control center for operators to monitor and analyze.

[0117] It should also be noted that in other embodiments of the present application, infrared and ultraviolet images of the UHVDC transmission line can be acquired simultaneously. During the detection process, identification and detection are first performed based on the infrared image. After determining that the infrared image represents an abnormality, an ultraviolet image of the corresponding location or area is further acquired from the captured ultraviolet image. In other words, the infrared and ultraviolet image acquisition process described in this application does not necessarily refer to the actual image acquisition process; it can also be understood as the actual application and processing process of the infrared and ultraviolet images in this application.

[0118] See also Figure 7 , Figure 7 This is a schematic structural diagram of a zero-value insulator detection system for a DC ultra-high voltage transmission line provided in an embodiment of the present application. The system includes:

[0119] an infrared image acquisition module, configured to acquire an infrared image of the UHVDC transmission line;

[0120] an ultraviolet image acquisition module, configured to acquire an ultraviolet image of the UHVDC transmission line if the infrared image indicates an abnormality;

[0121] an ultrasonic detection module, configured to determine the presence of a zero-value insulator and a corresponding potential abnormal area if abnormal discharge characteristics are present in the ultraviolet image; and perform ultrasonic detection on the potential abnormal area to obtain an ultrasonic signal;

[0122] an electric field detection module, configured to perform electric field distribution analysis on the UHVDC transmission line if an abnormal signal is present in the ultrasonic signal;

[0123] The report generating module is used to confirm the presence of zero-value insulators if electric field distortion exists in the electric field distribution of the DC ultra-high voltage transmission line, and generate a zero-value insulator detection report for the DC ultra-high voltage transmission line.

[0124] Based on the above embodiment, as a preferred embodiment, it also includes:

[0125] The infrared image detection module is used to identify temperature changes of the ultra-high voltage DC transmission line in the infrared image; if the temperature change of an insulator in the ultra-high voltage DC transmission line exceeds a set change threshold within a set time period, it is determined that the infrared image represents an abnormality.

[0126] Based on the above embodiment, as a preferred embodiment, the infrared image detection module includes:

[0127] a temperature change measuring unit, for determining the initial temperature of the insulator and the temperature change rate within a set time period;

[0128] The insulator infrared detection unit is used to call a temperature change rate comparison table to determine the degree of contamination of the insulator; the temperature change rate comparison table contains a mapping relationship between insulators of different contamination levels and relative temperature increase ratios.

[0129] Based on the above embodiment, as a preferred embodiment, the ultrasonic detection module includes:

[0130] a photon calculation unit, configured to calculate the number of photons captured in the ultraviolet image;

[0131] a moisture detection unit, configured to determine a moisture contamination degree of the insulator based on the number of photons;

[0132] a photon positioning unit for determining a discharge area based on the wet contamination level and captured photons;

[0133] The insulator positioning unit is used to locate the position information of the zero-value insulator according to the discharge area.

[0134] Based on the above embodiment, as a preferred embodiment, the ultrasonic detection module includes:

[0135] The ultrasonic detection unit is used to perform ultrasonic detection on the insulators in the ultra-high voltage direct current transmission line to obtain an ultrasonic signal of each insulator; compare the ultrasonic signal of each insulator with a standard ultrasonic signal standard range of a normal insulator; if there is an ultrasonic signal exceeding the standard ultrasonic signal standard range, it is confirmed that there is an abnormal signal in the ultrasonic signal.

[0136] Based on the above embodiment, as a preferred embodiment, the electric field detection module is a module for performing the following steps:

[0137] Performing electric field detection on the suspected zero-value insulator in the UHVDC transmission line to determine the electric field distribution curve and electric field strength of the suspected zero-value insulator;

[0138] If the electric field distribution curve has a peak drop or the electric field intensity fluctuates abnormally, it is confirmed that electric field distortion exists, and the insulator with electric field distortion is a zero-value insulator.

[0139] Based on the above embodiment, as a preferred embodiment, the report generation module includes:

[0140] an abnormal data acquisition unit, configured to determine the position information and quantity information of the zero-value insulators and the abnormal data corresponding to each zero-value insulator;

[0141] A report generating unit is used to generate a zero-value insulator detection report based on the position information, the quantity information and the abnormal data.

[0142] This application also provides a computer-readable storage medium having a computer program stored thereon. When executed, the computer program can implement the steps provided in the above embodiments. The storage medium may include: a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, an optical disk, or other medium capable of storing program code.

[0143] This application also provides an electronic device, see Figure 8 , a structural diagram of an electronic device provided in an embodiment of the present application, such as Figure 8 As shown, a processor 1410 and a memory 1420 may be included.

[0144] The processor 1410 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 1410 may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), or PLA (Programmable Logic Array). The processor 1410 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 1410 may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 1410 may also include an AI (Artificial Intelligence) processor, which is used to process computing operations related to machine learning.

[0145] The memory 1420 may include one or more computer-readable storage media, which may be non-transitory. The memory 1420 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In this embodiment, the memory 1420 is at least used to store the following computer program 1421, wherein, after the computer program is loaded and executed by the processor 1410, it can implement the relevant steps in the method performed by the electronic device side disclosed in any of the aforementioned embodiments. In addition, the resources stored in the memory 1420 may also include an operating system 1422 and data 1423, etc., and the storage method may be temporary storage or permanent storage. Among them, the operating system 1422 may include Windows, Linux, Android, etc.

[0146] In some embodiments, the electronic device may further include a display screen 1430 , an input / output interface 1440 , a communication interface 1450 , a sensor 1460 , a power supply 1470 , and a communication bus 1480 .

[0147] certainly, Figure 8 The structure of the electronic device shown does not constitute a limitation on the electronic device in the embodiment of the present application. In actual applications, the electronic device may include Figure 8 More or fewer components than shown, or combinations of certain components.

[0148] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the systems provided in the embodiments, since they correspond to the methods provided in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0149] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core ideas of this application. It should be noted that for those skilled in the art, without departing from the principles of this application, various improvements and modifications can be made to this application, and such improvements and modifications also fall within the scope of protection of this application.

[0150] It should also be noted that, in this specification, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

Claims

1. A method for detecting zero-value insulators of a DC ultra-high voltage transmission line, characterized in that: include: Acquiring an infrared image of the ultra-high voltage direct current transmission line; If the infrared image indicates an abnormality, obtaining an ultraviolet image of the UHVDC transmission line; If the ultraviolet image has abnormal discharge characteristics, determining the presence of a zero-value insulator and a corresponding potential abnormal area; Performing ultrasonic detection on the potential abnormal area to obtain an ultrasonic signal; If there is an abnormal signal in the ultrasonic signal, performing electric field distribution analysis on the UHVDC transmission line; If electric field distortion exists in the electric field distribution of the ultra-high voltage direct current transmission line, it is confirmed that there are zero-value insulators, and a zero-value insulator detection report of the ultra-high voltage direct current transmission line is generated.

2. The method according to claim 1, characterized in that After obtaining the infrared image of the UHVDC transmission line, the method further includes: identifying temperature changes of the ultra-high voltage direct current transmission line in the infrared image; If a temperature change of an insulator in the UHVDC transmission line exceeds a set change threshold within a set time period, it is determined that the infrared image representation is abnormal.

3. The method according to claim 2, characterized in that If the temperature change of an insulator in the UHVDC transmission line exceeds a set change threshold within a set time period, determining that the infrared image representation is abnormal includes: determining an initial temperature of the insulator and a rate of temperature change within a set time period; The temperature change rate comparison table is called to determine the pollution degree of the insulator; the temperature change rate comparison table contains a mapping relationship between insulators of different pollution degrees and relative temperature increase ratios.

4. The method according to claim 1, wherein If the ultraviolet image has abnormal discharge characteristics, determining the presence of a zero-value insulator includes: Counting the number of photons captured in the ultraviolet image; determining a degree of wet contamination of the insulator based on the number of photons; determining a discharge area based on the wet contamination level and the captured photons; Position information of the zero-value insulator is located according to the discharge area.

5. The method according to claim 4, characterized in that Performing ultrasonic detection on the potential abnormal area to obtain ultrasonic signals includes: Performing ultrasonic testing on insulators in the UHVDC transmission line to obtain ultrasonic signals of each insulator; The ultrasonic signal of each insulator is compared with the standard ultrasonic signal standard range of a normal insulator. If there is an ultrasonic signal exceeding the standard ultrasonic signal standard range, it is confirmed that there is an abnormal signal in the ultrasonic signal.

6. The method according to claim 1, characterized in that The electric field distribution analysis of the UHVDC transmission line includes: Performing electric field detection on the suspected zero-value insulator in the UHVDC transmission line to determine the electric field distribution curve and electric field strength of the suspected zero-value insulator; If the electric field distribution curve has a peak drop or the electric field intensity fluctuates abnormally, it is confirmed that electric field distortion exists, and the insulator with electric field distortion is a zero-value insulator.

7. The method according to claim 1, characterized in that Confirming the existence of zero-value insulators and generating a zero-value insulator inspection report for the DC UHV transmission line include: Determining the position information and quantity information of the zero-value insulators and abnormal data corresponding to each zero-value insulator; A zero-value insulator detection report is generated according to the position information, the quantity information and the abnormal data.

8. A zero-value insulator detection system for a DC ultra-high voltage transmission line, characterized in that: include: an infrared image acquisition module, configured to acquire an infrared image of the UHVDC transmission line; an ultraviolet image acquisition module, configured to acquire an ultraviolet image of the UHVDC transmission line if the infrared image indicates an abnormality; an ultrasonic detection module, configured to determine the presence of a zero-value insulator and a corresponding potential abnormal area if abnormal discharge characteristics are present in the ultraviolet image; and perform ultrasonic detection on the potential abnormal area to obtain an ultrasonic signal; an electric field detection module, configured to perform electric field distribution analysis on the UHVDC transmission line if an abnormal signal is present in the ultrasonic signal; The report generating module is used to confirm the presence of zero-value insulators if electric field distortion exists in the electric field distribution of the DC ultra-high voltage transmission line, and generate a zero-value insulator detection report for the DC ultra-high voltage transmission line.

9. An electronic device, characterized in that: include: memory for storing computer programs; A processor, configured to implement the steps of the method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, which implements the steps of the method according to any one of claims 1 to 7 when executed.

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