A fault diagnosis method for a gas-insulated metal-enclosed switchgear

Abstract

The application discloses a kind of fault diagnosis methods for gas insulated metal enclosed switchgear, specifically relates to fault diagnosis technical field;It is through infrared thermal imaging data and visible light image data analysis equipment abnormal heat zone distribution and structural deformation characteristics, generates image analysis result, judges whether there is gas leakage based on sulfur hexafluoride gas density data, and outputs gas analysis result;Based on vibration signal data, it is judged whether there is abnormal vibration in equipment, and vibration analysis result is output;Based on image analysis result and gas and vibration analysis result, establish fault correlation, generate comprehensive diagnosis result and determine fault type and risk level;Combined with control rule base, control signal or operation and maintenance execution instruction is generated, cross-modal synchronous diagnosis is realized, and the accuracy and response real-time of gas insulated metal enclosed switchgear fault diagnosis.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fault diagnosis, and more particularly, to a fault diagnosis method for a gas insulated metal-enclosed switchgear. BACKGROUND

[0002] The operation state of the gas insulated metal-enclosed switchgear is directly related to the safety and reliability of the power grid system. The current monitoring method for the gas insulated metal-enclosed switchgear has gradually shifted from single-mode monitoring to multi-modal data collaborative diagnosis.

[0003] Since the existing multi-modal data cannot establish the correlation between different faults, the multi-modal collaborative diagnosis logical link is interrupted, it is difficult to accurately diagnose and timely maintain the potential faults of the equipment, and the safety of the equipment operation and the efficiency of the maintenance management are seriously affected. SUMMARY

[0004] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present application provide a fault diagnosis method for a gas insulated metal-enclosed switchgear to solve the problems raised in the background art.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] A fault diagnosis method for a gas insulated metal-enclosed switchgear, comprising the following steps:

[0007] S1: acquiring multi-source operation data of the gas insulated metal-enclosed switchgear, including sulfur hexafluoride gas density data, infrared thermal imaging data, visible light image data and vibration signal data;

[0008] S2: performing cross-modal time synchronization and alignment compensation on the multi-source operation data;

[0009] S3: detecting abnormal thermal zone distribution and structural deformation characteristics of the equipment based on the infrared thermal imaging data and the visible light image data, and outputting an image analysis result;

[0010] S4: calculating a gas density change rate based on the sulfur hexafluoride gas density data, judging whether the equipment has a gas leakage, and outputting a gas analysis result;

[0011] S5: calculating a vibration frequency offset based on the vibration signal data, judging whether the equipment has abnormal vibration, and outputting a vibration analysis result;

[0012] S6: establishing a fault correlation based on the image analysis result and the gas and vibration analysis result, and generating a comprehensive diagnosis result;

[0013] S7: Determine the risk level and fault type of the equipment according to the comprehensive diagnosis result, match with the control rule library, and generate control signals or operation and maintenance execution instructions.

[0014] In a preferred embodiment, S1, specifically:

[0015] Collecting sulfur hexafluoride gas density data inside the gas chamber of the gas insulated metal enclosed switchgear;

[0016] Collecting infrared thermal imaging data on the outer surface of the gas chamber of the gas insulated metal enclosed switchgear;

[0017] Collecting visible light image data on the outer surface of the gas chamber of the gas insulated metal enclosed switchgear;

[0018] Collecting vibration signal data at the connection position of the key mechanical components of the gas insulated metal enclosed switchgear.

[0019] In a preferred embodiment, S2, specifically:

[0020] Selecting the collection time stamp of the vibration signal data as the reference time axis;

[0021] Calibrating the collection time stamps of the sulfur hexafluoride gas density data, infrared thermal imaging data and visible light image data with the reference time axis respectively;

[0022] If there is a missing data collection time point after calibration, supplement the data value of the missing time point by linear interpolation method.

[0023] In a preferred embodiment, S3, specifically:

[0024] Based on the infrared thermal imaging data, identifying abnormal heat zone distribution areas exceeding the normal operating temperature range, and determining the position coordinate information and temperature value of the abnormal heat zone distribution areas;

[0025] Based on the visible light image data, extracting structure contour features and surface texture features;

[0026] Comparing the structure contour features and surface texture features with standard image features to determine the coordinate information of structure contour abnormal positions and surface texture abnormal areas;

[0027] Taking the position coordinate information and temperature value of the abnormal heat zone distribution areas, the coordinate information of the structure contour abnormal positions and the coordinate information of the surface texture abnormal areas as the image analysis results.

[0028] In a preferred embodiment, S4, specifically:

[0029] The rate of change of the density of the sulfur hexafluoride gas is calculated based on a ratio of a change in the density of the sulfur hexafluoride gas in a preset time period to a corresponding time period;

[0030] It is determined whether there is gas leakage in the gas chamber of the gas insulated metal-enclosed switchgear according to whether the rate of change of the density of the sulfur hexafluoride gas exceeds a preset threshold of the rate of change of the density of the sulfur hexafluoride gas;

[0031] The rate of change of the density of the sulfur hexafluoride gas and the result of the gas leakage determination are taken as a gas analysis result.

[0032] In a preferred embodiment, S5 specifically includes:

[0033] The vibration frequency offset is calculated by a spectrum analysis method based on a difference between an actual vibration frequency in the vibration signal data and a preset normal vibration frequency.

[0034] It is determined whether there is abnormal vibration at the connection position of the key mechanical component of the gas insulated metal-enclosed switchgear according to whether the vibration frequency offset exceeds a preset threshold of the vibration frequency offset.

[0035] The vibration frequency offset and the result of the abnormal vibration determination are taken as a vibration analysis result.

[0036] In a preferred embodiment, S6 specifically includes:

[0037] A correlation between the gas leakage and the abnormal temperature phenomenon is established based on a spatial position relationship between the position coordinate information and the temperature value of the abnormal heat area distribution region and the result of the gas leakage determination.

[0038] A correlation between the abnormal vibration phenomenon and the structural deformation feature is established based on a spatial position relationship between the coordinate information of the abnormal position of the structural contour, the coordinate information of the abnormal region of the surface texture and the result of the abnormal vibration determination.

[0039] A comprehensive diagnosis result is generated based on the correlation between the gas leakage and the abnormal temperature phenomenon and the correlation between the abnormal vibration phenomenon and the structural deformation feature.

[0040] In a preferred embodiment, S7 specifically includes:

[0041] A fault type of the gas insulated metal-enclosed switchgear is determined according to the comprehensive diagnosis result.

[0042] A risk level of the current fault type of the gas insulated metal-enclosed switchgear is determined according to the comprehensive diagnosis result.

[0043] A control rule corresponding to the risk level and the fault type is matched from a control rule library.

[0044] According to the matched control rule, a control signal or operation and maintenance execution instruction of the gas insulated metal enclosed switchgear is generated.

[0045] The technical effect and advantages of the fault diagnosis method for the gas insulated metal enclosed switchgear are as follows:

[0046] By uniformly collecting and time-aligning the data such as sulfur hexafluoride gas density, infrared thermal imaging, visible light image and vibration signal, the diagnostic link interruption caused by asynchronous collection of multi-modal data is effectively solved; on the basis of image analysis, gas leakage determination and vibration frequency anomaly identification, a cross-modal feature correlation mechanism is established, and the logical construction between internal leakage and external structural anomaly and vibration anomaly of the equipment is realized. Combined with the comprehensive diagnosis result and the control rule library, the risk level determination and the generation of control signal or operation and maintenance execution instruction are completed, the real-time of fault response and the accuracy of decision are improved, and the safety of operation of the gas insulated metal enclosed switchgear and the efficiency of diagnostic decision are improved. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 A schematic diagram of the fault diagnosis method for the gas insulated metal enclosed switchgear is given. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0049] EMBODIMENT

[0050] Figure 1 A fault diagnosis method for a gas insulated metal enclosed switchgear is given, which comprises the following steps:

[0051] S1: acquiring multi-source operation data of the gas insulated metal enclosed switchgear, including sulfur hexafluoride gas density data, infrared thermal imaging data, visible light image data and vibration signal data;

[0052] S2: cross-modal time synchronization and alignment compensation are performed on the multi-source operation data;

[0053] S3: based on the infrared thermal imaging data and the visible light image data, the abnormal thermal zone distribution and the structural deformation characteristics of the equipment are detected, and the image analysis result is output;

[0054] S4: Calculate the gas density change rate based on the sulfur hexafluoride gas density data, determine whether there is a gas leak in the equipment, and output the gas analysis result;

[0055] S5: Calculate the vibration frequency offset based on the vibration signal data, determine whether there is abnormal vibration in the equipment, and output the vibration analysis result;

[0056] S6: Establish a fault correlation relationship according to the image analysis result and the gas and vibration analysis result, and generate a comprehensive diagnosis result;

[0057] S7: Determine the risk level and fault type of the equipment according to the comprehensive diagnosis result, and match it with the control rule library to generate a control signal or operation and maintenance execution instruction.

[0058] S1: Obtain multi-source operation data of gas insulated metal enclosed switchgear, including sulfur hexafluoride gas density data, infrared thermal imaging data, visible light image data and vibration signal data, including:

[0059] Multi-source operation data of gas insulated metal enclosed switchgear: sulfur hexafluoride gas density data, infrared thermal imaging data, visible light image data and vibration signal data. The sulfur hexafluoride gas density data refers to the density change data of the sulfur hexafluoride gas inside the gas chamber of the gas insulated metal enclosed switchgear, which reflects whether there is a gas leak inside the equipment through the change of the gas mass per unit volume. The infrared thermal imaging data refers to the temperature distribution data obtained by using an infrared thermal imaging camera to shoot the thermal radiation of the outer surface of each gas chamber of the gas insulated metal enclosed switchgear, which is presented in the form of an infrared thermal imaging image, and is used to determine whether the temperature of the outer surface of each gas chamber is within the normal range. The visible light image data refers to the visible light image information shot by a visible light image camera on the outer surface of each gas chamber of the gas insulated metal enclosed switchgear, which reflects the image of the structure, texture, color and other information of the outer surface of the equipment. Through the visible light image data, it can be seen whether there is a structural abnormality on the outer surface of the gas chamber, such as cracks, deformation or oil stain marks. The vibration signal data refers to the vibration fluctuation data of the connection position of the key mechanical components of the gas insulated metal enclosed switchgear obtained by a vibration sensor in real time, which is the curve information of the amplitude, frequency and other parameters changing with time, and can reflect whether there is abnormal vibration at the connection position of the key mechanical components of the equipment, such as connection loosening, mechanical wear or component damage.

[0060] Collect the sulfur hexafluoride gas density data inside the gas chamber of the gas insulated metal enclosed switchgear;

[0061] A plurality of sulfur hexafluoride gas density sensors are installed in each gas chamber of the gas insulated metal-enclosed switchgear, and the installation positions are distributed at different key points in the gas chamber, such as the bottom, middle and top of the gas chamber. For example, sulfur hexafluoride gas density sensors are installed at the bottom, middle and top of the gas chamber of the gas insulated metal-enclosed switchgear, and the sulfur hexafluoride gas density at each position is measured in real time by each sulfur hexafluoride gas density sensor. The sulfur hexafluoride gas density sensor is a capacitive or resonant sensor, the density measurement range is 10 kg / m3 to 50 kg / m3, the density measurement accuracy is above 0.1 kg / m3, the sampling frequency is usually set to 1 Hz to 10 Hz, and the dynamic trend of the gas density change in the gas chamber can be recorded in real time. The installation method is screw connection or flange connection, which is firmly connected with the gas chamber shell to avoid loosening or falling off between the sensor and the equipment during measurement.

[0062] Infrared thermal imaging data of the outer surface of the gas chamber of the gas insulated metal-enclosed switchgear is collected;

[0063] Infrared thermal imaging cameras are installed at different positions on the outer surface of each gas chamber of the gas insulated metal-enclosed switchgear to realize real-time and continuous collection of infrared thermal radiation data on the outer surface of each gas chamber. At least one or more infrared thermal imaging cameras are installed on the outer surface of each gas chamber according to the size and shape of the gas chamber, the resolution of the camera is set to above 640×480 pixels, and the field of view is selected in the range of 45° to 90° to ensure that the infrared thermal radiation data on the outer surface of each gas chamber can be fully collected. For example, an infrared thermal imaging camera with a resolution of 640×480 pixels and a field of view of 60° is installed on the outer surface of a certain gas chamber to record the thermal radiation data in real time, and the frame rate of the camera is usually set to 10 frames per second to 30 frames per second to ensure that continuous and stable temperature field image data is obtained.

[0064] Visible light image data of the outer surface of the gas chamber of the gas insulated metal-enclosed switchgear is collected;

[0065] Visible light image cameras are installed at different positions on the outer surface of each gas chamber of the gas insulated metal-enclosed switchgear to realize real-time and continuous shooting of the image on the outer surface of the equipment. The camera uses a high-definition camera with a resolution of 1920×1080 pixels or above, a field of view of 60° to 120°, and a frame rate of 10 frames per second to 30 frames per second. For example, two high-definition cameras with a resolution of 1920×1080 pixels are installed on the outer surface of the gas chamber, which are located at the front and rear positions of the outer surface of the gas chamber to realize comprehensive shooting and monitoring of the structure and texture information of the outer surface of the gas chamber.

[0066] Vibration signal data of the connection position of the key mechanical components of the gas insulated metal-enclosed switchgear is collected;

[0067] High-sensitivity vibration sensors are installed at the connection positions of key mechanical components of gas-insulated metal-enclosed switchgear, such as flange connections, contact connections, and support insulator bottom connections. Piezoelectric or capacitive vibration sensors are used, with a sensitivity of not less than 0.1 millimeter per second and a frequency range of 1 hertz to 5000 hertz. The sampling frequency is more than 1000 times per second. For example, high-sensitivity piezoelectric vibration sensors are installed at the flange connection positions to record vibration frequency and amplitude in real time.

[0068] S2: Cross-modal time synchronization and alignment compensation of multi-source operation data, including:

[0069] The collection time stamp of the vibration signal data is selected as the reference time axis.

[0070] Since various sensors and cameras use independent time recording systems when collecting data, the time starting point, time interval, and sampling time of data recording may differ during data collection by each sensor and camera. For example, the collection time stamp of a sulfur hexafluoride gas density sensor may not be synchronized with that of a vibration sensor, and the collection time stamps of an infrared thermal imaging camera and a visible light image camera may also differ. Therefore, a unified time reference axis needs to be determined between different data to facilitate comparison of data on the same time axis. Vibration signal data generally has high sampling frequency, strong sampling stability, and high time precision, so the collection time stamp of the vibration signal data is used as the reference time axis. For example, the sampling frequency of a vibration sensor is more than 1000 times per second, with extremely high time resolution, providing vibration signal data collection time stamps with millisecond-level time precision. Therefore, the collection time stamp of the vibration signal data as the reference time axis has sufficient precision and stability. For example, during actual operation of a gas-insulated metal-enclosed switchgear, a vibration sensor starts collecting vibration signal data at 13:00 on May 1, 2024, and records vibration signal data every millisecond thereafter. The data time stamp recorded during this process starts from 2024-05-01 13:00:00.000 and is continuously recorded at millisecond intervals. This millisecond-level vibration signal data time stamp is set as the reference time axis.

[0071] The collection time stamps of the sulfur hexafluoride gas density data, infrared thermal imaging data, and visible light image data are respectively calibrated for time difference with the reference time axis.

[0072] The time stamp recorded at each data collection time of the sulfur hexafluoride gas density data is compared with the reference time axis formed by the vibration signal data collection to determine the time difference value between each sulfur hexafluoride gas density data collection time and the corresponding collection time on the reference time axis. For example, one data collection time stamp of the sulfur hexafluoride gas density sensor is 13:00:01,500 on May 1, 2024, and the closest time on the reference time axis is 13:00:01,503 on May 1, 2024, so the time difference value is 3 milliseconds. Compare the time stamp of each sulfur hexafluoride gas density data with the reference time axis and record the time difference value of each data point. Similarly, compare the data time stamps collected by the infrared thermal imaging camera and the visible light image camera with the reference time axis. For example, the time stamp of an infrared image frame taken by the infrared thermal imaging camera at 13:00:02 on May 1, 2024, is 13:00:02,020 on May 1, 2024, and the closest time on the reference time axis is 13:00:02,018 on May 1, 2024, so the time difference of this frame of infrared thermal imaging data is recorded as 2 milliseconds; the time stamp of an image frame taken by the visible light image camera at the same time is 13:00:02,030 on May 1, 2024, and the closest time on the reference time axis is 13:00:02,031 on May 1, 2024, so the time difference of this frame of visible light image data is recorded as 1 millisecond. The time difference calibration process is carried out frame by frame and point by point to determine the time difference value between each data point and the reference time axis to ensure that all data can be accurately corresponded on a unified time axis and eliminate time errors in the data collection process.

[0073] If there are missing data collection time points after calibration, the data values of the missing time points are supplemented by linear interpolation method;

[0074] After the time difference calibration of the collection time stamp of multi-source operation data and the reference time axis, some data collection time points may not completely correspond to the reference time axis, that is, some time points on the reference time axis lack matching sulfur hexafluoride gas density data, infrared thermal imaging data or visible light image data. This data loss is usually due to differences in sampling frequencies of different types of sensors or accidental loss of data during transmission. In order to ensure one-to-one correspondence of data points on the reference time axis, the missing data points need to be effectively supplemented. Linear interpolation method is used to supplement the value of missing data points. Specifically, if there are known adjacent data points before and after a missing data point, the data value of the missing point is calculated through linear relationship between the known data points. For example, the data point of sulfur hexafluoride gas density data is missing at 13:00:01,500 milliseconds on May 1, 2024, on the reference time axis, the previous data point at 13:00:01,490 milliseconds on May 1, 2024 is 20.0 kg / m3, and the next data point at 13:00:01,510 milliseconds on May 1, 2024 is 20.2 kg / m3, then the data value of the missing point is calculated by linear interpolation method as 20.1 kg / m3. Similarly, for infrared thermal imaging data and visible light image data, if data is missing at a reference time point, the data is supplemented by the adjacent data point interpolation method. Through the above method, the missing data points of all types of data are supplemented, ensuring that all types of data have valid data values at each unified sampling time point, thereby forming complete, continuous and accurate multi-source operation data corresponding to the unified reference time axis.

[0075] S3: Based on the infrared thermal imaging data and the visible light image data, detecting the abnormal heat zone distribution and the structural deformation characteristics of the equipment, and outputting the image analysis results, including:

[0076] Based on the infrared thermal imaging data, identifying the abnormal heat zone distribution area exceeding the normal operation temperature range, and determining the position coordinate information and temperature value of the abnormal heat zone distribution area;

[0077] In order to identify the abnormal hot area exceeding the normal operating temperature range, it is necessary to set the reference range of the normal operating temperature of the gas insulated metal enclosed switchgear, and the normal operating temperature reference range is determined by the historical temperature data recorded during the long-term normal operation of the equipment. Taking the gas insulated metal enclosed switchgear as an example, the normal temperature reference range of the outer surface of the gas chamber is 10-50℃. If the temperature value exceeding the normal temperature reference range appears in the infrared thermal imaging data collected during the operation of the equipment, such as the temperature of the local area of the outer surface of the gas chamber is higher than 50℃ or lower than 10℃, it is determined that the local area is an abnormal hot area distribution area. The position coordinate information of the abnormal hot area distribution area is usually recorded in the pixel coordinates of the infrared thermal imaging image, for example, the center point of the image is taken as the coordinate origin, the right direction is the positive direction of the horizontal coordinate, and the downward direction is the positive direction of the vertical coordinate. The coordinate range of the abnormal hot area is recorded in pixels, for example, the coordinate range of the abnormal hot area distribution area in the infrared thermal imaging image is 250-350 in horizontal coordinate pixel points and 200-300 in vertical coordinate pixel points. The temperature values of all pixels in the abnormal hot area distribution area are counted to determine the temperature value of the abnormal hot area distribution area, and the highest or lowest temperature value in the area is taken as the representative, for example, the highest temperature measured in the abnormal hot area distribution area is 65℃, and 65℃ is taken as the temperature value of the abnormal hot area distribution area. The abnormal hot area identification process of the infrared thermal imaging data is usually realized by image processing algorithm, including pixel-by-pixel traversal detection, threshold segmentation method, pixel region clustering, etc., to determine the position coordinate information and temperature value of each abnormal hot area of the outer surface of the gas chamber.

[0078] Based on the visible light image data, the structural contour features and surface texture features are extracted;

[0079] The visible light image data is image data of the outer surface of the gas chamber of the gas insulated metal-enclosed switchgear captured by a visible light image camera installed on the outer surface of the gas chamber of the gas insulated metal-enclosed switchgear. The image resolution is 1920*1080 pixels or more, the field of view is 60-120 degrees, and the frame rate is 10-30 frames per second. Each frame of image can clearly present the structural features, contour edges and surface texture information of the outer surface of the gas chamber. The structural contour features refer to the contour boundary information such as obvious edge lines, joints and connection positions of the outer surface of the gas chamber in the visible light image, for example, the edge lines of the outer shell, flange connection and gas chamber joint are clear and continuous. The surface texture features refer to the texture pattern and details of the outer surface of the gas chamber in the image, such as the glossiness, roughness or presence of oil stains, dirt, discoloration and other abnormal conditions of the surface material. The extraction process of structural contour features and surface texture features is usually realized by image edge detection algorithm and texture analysis algorithm. For example, the Canny edge detection algorithm is used to extract the structural contour features of the outer surface of the equipment, and the contour edges of the outer surface of the equipment are obtained by gray scale conversion, image denoising, edge gradient calculation, non-maximum suppression and double threshold connection processing. The surface texture features are extracted by texture analysis method, such as gray level co-occurrence matrix method, and the contrast, energy and uniformity of the texture are obtained by analyzing the spatial relationship between the pixels in the local region of the image to determine the abnormal texture region. Through the above method, the structural contour features and surface texture features can be accurately extracted from the visible light image data of the outer surface of the gas chamber.

[0080] The structural contour features and surface texture features are compared with the standard image features to determine the coordinate information of the structural contour abnormal position and the surface texture abnormal region.

[0081] The standard image features of the structure of the outer surface of the gas chamber of the gas insulated metal-enclosed switchgear are the visible light image feature data of the equipment in the absence of abnormal state, including standard structural contour and normal texture pattern. The extracted structural contour features of the outer surface of the gas chamber are compared with the standard structural contour features pixel by pixel to determine the difference between the contour shape, position or continuity and the standard state. If there is a significant difference, such as the edge position offset exceeding the set threshold (such as 10 pixels), it is determined that the structural contour is abnormal, and the image coordinate information of the structural contour abnormal position is recorded. The extracted surface texture features of the outer surface of the gas chamber are compared with the standard texture features region by region. If the texture pattern contrast, glossiness or roughness has a significant change compared with the standard texture features (for example, the gray value difference is greater than 20 levels), it is judged that the region is a surface texture abnormal region, and the image coordinate information of the specific position is recorded. Through the above pixel-by-pixel and region-by-region comparison, the coordinate information of the structural contour abnormal position and the surface texture abnormal region of the equipment can be determined.

[0082] The position coordinate information of the abnormal heat zone distribution area, the temperature value, the coordinate information of the structural contour abnormal position, and the coordinate information of the surface texture abnormal area are taken as the image analysis results;

[0083] The position coordinate information of the abnormal heat zone, the temperature value, the coordinate information of the structural contour abnormal position, and the coordinate information of the surface texture abnormal area are taken as the image analysis results. The data format is unified, for example, the coordinate information of the abnormal heat zone and the temperature value are recorded as (horizontal coordinate 250 to 350 pixels, vertical coordinate 200 to 300 pixels, temperature 65 degrees Celsius), the structural contour abnormal position is recorded as (horizontal coordinate 600 to 650 pixels, vertical coordinate 500 to 550 pixels), and the texture abnormal area is recorded as (horizontal coordinate 700 to 750 pixels, vertical coordinate 400 to 450 pixels).

[0084] S4: Based on the sulfur hexafluoride gas density data, calculate the gas density change rate, judge whether the equipment has gas leakage, and output the gas analysis results, including:

[0085] Based on the density change amount of the sulfur hexafluoride gas density data in the preset time period and the ratio of the corresponding time period, calculate the sulfur hexafluoride gas density change rate;

[0086] The selection of the preset time period is usually based on the application environment and monitoring requirements of the equipment, for example, set the preset time period to 1 minute, 5 minutes or 10 minutes. Taking the gas insulated metal enclosed switchgear as an example, the preset time period is set to 5 minutes, that is, all sulfur hexafluoride gas density data from 10:00:00 on May 1, 2024 to 10:05:00 on May 1, 2024 is recorded.

[0087] Calculate the sulfur hexafluoride gas density change amount in the preset time period, specifically: take the gas density at the beginning of the preset time period as the initial value, and take the gas density at the end of the period as the terminal value. The terminal value minus the initial value is the density change amount. For example, the sulfur hexafluoride gas density at the beginning of the preset time period, 10:00:00 on May 1, 2024, is 30.0 kg / m3, and the gas density at the end of the period, 10:05:00 on May 1, 2024, is 29.0 kg / m3. Therefore, the gas density change amount in the preset time period is 29.0 minus 30.0, which is equal to -1.0 kg / m3.

[0088] After obtaining the density change amount, the sulfur hexafluoride gas density change rate can be calculated by dividing the density change amount by the corresponding preset time period length. If the density change amount is -1.0 kg / m3 and the time period length is 5 minutes, the calculation formula of the sulfur hexafluoride gas density change rate is the density change amount divided by the time length, i.e. -1.0 kg / m3 divided by 5 minutes, and the obtained sulfur hexafluoride gas density change rate is -0.2 kg / m3 / min. The density change rate reflects the speed of the change of the sulfur hexafluoride gas density in the gas chamber of the gas insulated metal-enclosed switchgear with time, and can reflect whether the sulfur hexafluoride gas leakage occurs in the gas chamber.

[0089] According to whether the sulfur hexafluoride gas density change rate exceeds the preset sulfur hexafluoride gas density change rate threshold value, it is determined whether the gas leakage occurs in the gas chamber of the gas insulated metal-enclosed switchgear.

[0090] The threshold value of the sulfur hexafluoride gas density change rate, i.e. the critical value of the gas leakage determination, is preset. The sulfur hexafluoride gas density change rate threshold value is usually set according to the design specification, industry standard or actual operation experience of the equipment. For example, the sulfur hexafluoride gas density change rate threshold value set by the industry standard for the gas insulated metal-enclosed switchgear is -0.05 kg / m3 / min, i.e. if the gas density change rate reaches or exceeds the threshold value, it indicates that the gas leakage occurs in the gas chamber of the equipment.

[0091] The calculated sulfur hexafluoride gas density change rate is compared with the preset sulfur hexafluoride gas density change rate threshold value to determine whether the leakage occurs in the equipment. For example, the calculated gas density change rate -0.2 kg / m3 / min exceeds the preset sulfur hexafluoride gas density change rate threshold value -0.05 kg / m3 / min, and therefore it is determined that the obvious sulfur hexafluoride gas leakage occurs in the gas chamber of the gas insulated metal-enclosed switchgear.

[0092] Through the above method, it can be determined whether the sulfur hexafluoride gas leakage occurs in the gas chamber of the gas insulated metal-enclosed switchgear, and the serious problems such as the decrease of the insulation performance of the gas chamber and the decrease of the operation safety of the equipment can be effectively avoided.

[0093] The sulfur hexafluoride gas density change rate and the gas leakage determination result are taken as the gas analysis result.

[0094] The gas analysis result includes the sulfur hexafluoride gas density change rate and the gas leakage determination result, and is recorded in the form of unified data format or data table, for example, the sulfur hexafluoride gas density change rate is recorded as -0.2 kg / m3 / min, and the gas leakage determination result is recorded as “gas leakage exists”.

[0095] S5: Based on the vibration signal data, calculate the vibration frequency offset, judge whether the equipment has abnormal vibration, output the vibration analysis result, including:

[0096] Calculate the offset between the actual vibration frequency in the vibration signal data and the preset normal vibration frequency through the spectrum analysis method to determine the vibration frequency offset.

[0097] The connection positions of the key mechanical components of the gas insulated metal enclosed switchgear include flange connection positions, contact connection positions, and support insulator bottom connection positions, and other important connection points in the equipment structure. Based on the vibration signal data, the spectrum analysis method is used for analysis. The spectrum analysis method is a signal processing method, which specifically uses the fast Fourier transform algorithm to process the vibration signal data, converts the vibration signal waveform in the time domain into the frequency spectrum distribution data in the frequency domain, and thus displays the frequency components contained in the vibration signal and the corresponding vibration amplitudes of each frequency component. The time domain vibration signal data is preprocessed (such as detrending, removing direct current components, and signal filtering), an appropriate data window (such as a Hanning window or a rectangular window) is selected for window function processing, and the fast Fourier transform algorithm is used to convert the processed time domain signal into a frequency domain signal to obtain the frequency spectrum distribution result of the vibration signal.

[0098] After obtaining the vibration signal spectrum, the actual vibration frequency is determined according to the vibration amplitudes corresponding to each frequency point in the spectrum diagram. The actual vibration frequency refers to the peak frequency point with the maximum vibration amplitude in the spectrum diagram, i.e., the frequency position with the most concentrated vibration signal energy. For example, in the vibration signal spectrum diagram of the connection position of the key mechanical components of the gas insulated metal enclosed switchgear, the frequency with the most concentrated vibration signal energy is 120 Hz, and thus 120 Hz is the actual vibration frequency.

[0099] The preset normal vibration frequency is the normal vibration frequency pre-acquired and recorded when the gas insulated metal enclosed switchgear is in a fault-free state, which is used as the reference value for vibration frequency offset judgment. The normal vibration frequency is usually determined after multiple measurements and statistics in the initial stage of equipment operation, for example, the vibration frequency measured in the normal operation state of the equipment is stable at 115 Hz, and thus 115 Hz is set as the preset normal vibration frequency reference value.

[0100] The vibration frequency offset is determined by comparing the difference between the actual vibration frequency and the preset normal vibration frequency, that is, the actual vibration frequency is subtracted from the normal vibration frequency. For example, if the actual vibration frequency is 120 Hz and the normal vibration frequency is 115 Hz, the vibration frequency offset is +5 Hz. If the actual vibration frequency is lower than the normal vibration frequency, for example, the actual vibration frequency is 110 Hz, then the vibration frequency offset is 110 Hz minus 115 Hz, resulting in a vibration frequency offset of -5 Hz. The vibration frequency offset directly represents the degree of change in the actual operating state of the mechanical component connection position compared to the normal state.

[0101] According to whether the vibration frequency offset exceeds the preset vibration frequency offset threshold, it is determined whether there is abnormal vibration at the key mechanical component connection position of the gas insulated metal enclosed switchgear;

[0102] The vibration frequency offset threshold is predetermined as a critical value for determining whether there is abnormal vibration at the key mechanical component connection position of the equipment. The vibration frequency offset threshold is usually determined by equipment design specifications, industry standards or operating experience. For example, according to the industry standard for safe operation of electrical equipment or related technical specifications, the vibration frequency offset threshold is set to ±3 Hz, that is, when the difference between the actual vibration frequency and the normal vibration frequency exceeds 3 Hz, it indicates that there is abnormal vibration at the key mechanical component connection position of the equipment.

[0103] The absolute value of the vibration frequency offset is compared with the vibration frequency offset threshold. If the absolute value of the vibration frequency offset is greater than or equal to the absolute value of the preset threshold, it is determined that there is abnormal vibration at the key mechanical component connection position of the equipment, otherwise it is determined that there is no abnormal vibration. For example, the calculated vibration frequency offset is +5 Hz, and its absolute value 5 Hz exceeds the preset threshold 3 Hz, so it is determined that there is abnormal vibration. If the calculated vibration frequency offset is +2 Hz, its absolute value 2 Hz is less than the threshold 3 Hz, so it is determined that there is no abnormal vibration. Through the above judgment, it can be determined whether there is abnormal vibration at the mechanical component connection position of the equipment, which provides protection for the safe operation of the equipment.

[0104] The vibration frequency offset and the abnormal vibration judgment result are used as the vibration analysis result;

[0105] The vibration analysis result includes the vibration frequency offset and the abnormal vibration judgment result obtained according to whether the vibration frequency offset exceeds the preset threshold, which reflects the current vibration state of the mechanical component connection position of the equipment. For example, the vibration analysis result is recorded as: "the vibration frequency offset is +5 Hz, and there is abnormal vibration".

[0106] S6: According to the image analysis result and the gas and vibration analysis result, a fault correlation relationship is established, and a comprehensive diagnosis result is generated, including:

[0107] Based on the spatial position relationship between the position coordinate information and temperature value of the abnormal heat zone distribution area and the spatial position relationship of the gas leakage judgment result, a correlation relationship between the gas leakage situation and the abnormal temperature phenomenon is established;

[0108] The spatial correlation relationship is established by comparing the position coordinate information and temperature value of the abnormal heat zone with the spatial position of the gas leakage judgment result. The correlation relationship establishment process is: the spatial position mapping of the gas leakage judgment result corresponding to the internal leakage position of the equipment and the abnormal heat zone position on the surface of the equipment. The method of spatial position mapping includes the spatial position coordinate corresponding method of the actual equipment structure, that is, through the equipment structure diagram, the spatial coordinate model or the equipment three-dimensional space modeling method, the spatial position coordinates of the gas chamber and the abnormal heat zone position coordinates on the surface of the gas chamber are corresponded and converted. For example, the gas leakage position is determined at the flange connection position in the gas chamber, that is, the internal spatial coordinates of the equipment are the three-dimensional position coordinates of the flange connection position calibrated in the equipment design drawing, and the abnormal heat zone coordinates on the surface are the pixel coordinate points of the flange connection position recorded in the image. Through the pre-constructed spatial mapping model or the equipment structure size conversion, the spatial consistency of the internal leakage point and the abnormal heat zone on the surface can be accurately corresponded. After spatial position correspondence, if the internal gas leakage point and the external abnormal heat zone position are spatially overlapped, the spatial correlation relationship between the gas leakage situation and the abnormal temperature phenomenon is established. Through the above method, the spatial correlation relationship between the internal sulfur hexafluoride gas leakage situation of the equipment gas chamber and the abnormal temperature phenomenon on the surface of the gas chamber is established.

[0109] Based on the spatial position relationship between the coordinate information of the structure contour abnormal position and the coordinate information of the surface texture abnormal area and the abnormal vibration judgment result, a correlation relationship between the abnormal vibration phenomenon and the structure deformation feature is established;

[0110] The spatial mapping correspondence is carried out by using the equipment design drawing, the three-dimensional spatial coordinate position of the key mechanical component connection position of the equipment is determined, such as the coordinate position of the flange connection position in the design drawing, the spatial position matching of the coordinate information of the structure contour abnormal position and the coordinate information of the surface texture abnormal area is carried out through the actual equipment size or the spatial coordinate conversion model, and it is determined whether the external structure deformation position and the internal abnormal vibration position of the equipment are spatially overlapped. For example, if the abnormal vibration position coordinates of the internal flange connection position of the equipment and the structure contour abnormal position coordinates of the external flange connection position are overlapped, the correlation relationship between the abnormal vibration phenomenon and the structure deformation feature on the surface of the equipment is established. Through the above spatial mapping and corresponding method, the spatial corresponding relationship between the abnormal vibration phenomenon of the key mechanical component connection position of the equipment and the structure deformation feature on the surface of the equipment can be accurately confirmed.

[0111] Based on the correlation relationship between the gas leakage situation and the abnormal temperature phenomenon and the correlation relationship between the abnormal vibration phenomenon and the structure deformation feature, a comprehensive diagnosis result is generated;

[0112] The comprehensive diagnosis result is a comprehensive evaluation of the equipment state, including: whether there is a leakage of sulfur hexafluoride gas inside the gas chamber, the position coordinates and temperature values of the abnormal hot area on the outer surface of the gas chamber, whether there is abnormal vibration at the connection position of the key mechanical components of the equipment, the position coordinate information of the abnormal position of the outer surface structure profile and the abnormal area of the surface texture.

[0113] For example, in a gas insulated metal enclosed switchgear, there is a leakage of sulfur hexafluoride gas inside the gas chamber No. 1 flange connection (gas density change rate -0.2 kg / m3 / min), the temperature of the outer surface flange connection position abnormally rises to 65 degrees Celsius, and there is an abnormal vibration phenomenon at the equipment No. 1 flange connection position (vibration frequency offset +5 Hz), and there is a profile deformation and texture abnormality phenomenon (such as cracks, rust, oil stains) in the same area on the outer surface. According to the above correlation, the comprehensive diagnosis result is: "sulfur hexafluoride gas leakage occurs inside the equipment No. 1 gas chamber flange connection position, accompanied by abnormal temperature rise on the outer surface, and abnormal vibration occurs at the equipment flange connection position, causing deformation of the outer surface structure profile and texture abnormalities". The comprehensive diagnosis result can guide the equipment maintenance and maintenance strategy formulation to ensure safe and reliable operation of the equipment.

[0114] S7: According to the comprehensive diagnosis result, determine the risk level and fault type of the equipment, and match it with the control rule library to generate control signals or operation and maintenance execution instructions, including:

[0115] According to the comprehensive diagnosis result, determine the fault type of the gas insulated metal enclosed switchgear;

[0116] The fault types of the gas insulated metal enclosed switchgear include but are not limited to the following types: gas leakage type fault, mechanical structure vibration abnormality type fault, structure deformation type fault and multiple fault combination type fault, etc. Each fault type corresponds to a specific combination of diagnostic features. The gas leakage type fault refers to the presence of sulfur hexafluoride gas leakage inside the equipment gas chamber, which is determined by the gas density change rate exceeding the preset threshold. The mechanical structure vibration abnormality type fault refers to the occurrence of vibration abnormality at the connection position of the key mechanical components of the equipment, which is determined by the vibration frequency offset exceeding the preset threshold. The structure deformation type fault refers to the occurrence of abnormal profile and texture features on the outer surface structure of the equipment, which is determined by comparing with the standard image features. The multiple fault combination type fault refers to the simultaneous occurrence or mutual accompaniment of multiple single fault features.

[0117] For example, by integrating the diagnostic results, it is determined that there is a leakage of sulfur hexafluoride gas (gas density change rate -0.2 kg / m3 / min) in the gas chamber No. 1 flange connection position of the gas insulated metal enclosed switchgear, and at the same time, abnormal vibration (vibration frequency offset +5 Hz) occurs at the flange connection position, the temperature of the flange connection area on the outer surface of the equipment rises to 65°C, and cracks appear in the structural profile, and the surface texture is rusted and discolored. It can be determined that the fault type of the equipment is a combination of multiple faults, specifically, a combination of gas leakage type fault, mechanical structure vibration abnormality type fault and structural deformation type fault.

[0118] According to the integrated diagnostic results, the risk level of the current fault type of the gas insulated metal enclosed switchgear is determined;

[0119] Generally, the risk level division standard is determined according to the equipment operation safety standard, maintenance specification or industry technical specification. The fault risk level of the gas insulated metal enclosed switchgear is divided into several different levels, for example, into three levels of slight risk, medium risk and serious risk, each level corresponds to a specific risk state index and condition threshold.

[0120] For example, according to the gas leakage situation, the gas density change rate within -0.05 kg / m3 / min is determined as a slight risk, the gas density change rate within -0.05 to -0.1 kg / m3 / min is determined as a medium risk, and the gas density change rate exceeding -0.1 kg / m3 / min is determined as a serious risk. Similarly, the risk level of abnormal vibration of the equipment is also divided according to the vibration frequency offset, and the vibration frequency offset within ±3 Hz is a slight risk, the offset of ±3 to ±5 Hz is a medium risk, and the offset exceeding ±5 Hz is a serious risk.

[0121] According to the integrated diagnostic results, the gas density change rate in the gas chamber of the equipment is -0.2 kg / m3 / min, reaching the serious risk level; the vibration frequency offset is +5 Hz, reaching the medium risk level; at the same time, cracks and rust appear in the structural deformation, which is divided into the serious risk level according to the degree of structural deformation. Finally, the risk level of the overall fault of the equipment is determined according to the highest level of the risk level in each fault characteristic, so the final fault risk level of the equipment is determined as the serious risk level. The determination of the risk level is used to guide the emergency degree of the equipment maintenance management measures and the maintenance strategy.

[0122] Match the control rules corresponding to the risk level and the fault type from the control rule library;

[0123] The control rule library is a set of device maintenance and control rules established in advance according to device maintenance management experience, industry standards and safety management requirements. Each rule in the control rule library corresponds to a specific risk level and fault type. The rule content includes device operation adjustment measures, maintenance measures, alarm instructions and device shutdown instructions and other maintenance or control actions.

[0124] For example, the control rule for the gas leakage type fault of the severe risk level in the rule library is to immediately shut down and dispatch maintenance personnel to the site to investigate the leakage position; the control rule for the mechanical vibration abnormal type fault of the medium risk level is to immediately adjust the device operation state, reduce the load operation and arrange on-site maintenance; the control rule for the structure deformation type fault of the severe risk level is to immediately shut down and immediately dispatch the maintenance team to the site to replace the damaged structure component. Based on the comprehensive diagnosis evaluation result, the device takes the risk level and the fault type as the input condition, matches the corresponding rule in the control rule library one by one, and determines that the matched rule is applicable to the current diagnosis state.

[0125] According to the matched control rule, a control signal or operation and maintenance execution instruction of the gas insulated metal enclosed switchgear is generated;

[0126] According to the matched control rule, a control signal or operation and maintenance execution instruction is generated. The control signal refers to an instruction sent to the device control system for execution, such as a shutdown instruction, an operation state adjustment instruction or an alarm signal; the operation and maintenance execution instruction refers to a specific operation requirement or suggestion sent to the device maintenance personnel or the maintenance system.

[0127] For example, the matched rule is the immediate shutdown and alarm rule corresponding to the gas leakage severe risk level, and the rule of immediately replacing the damaged component on site corresponding to the structure deformation severe risk level, so the generated control signal is an immediate shutdown signal, and an alarm signal is triggered at the same time and sent to the central control system; the generated operation and maintenance execution instruction includes immediately dispatching the on-site maintenance team, replacing the damaged structure component of the No. 1 flange connection of the gas chamber and investigating the leakage source.

[0128] The control signal and the operation and maintenance execution instruction can immediately guide the device and the on-site maintenance personnel to implement specific operations, quickly eliminate the safety hazards of the device, and ensure the long-term stable operation of the device.

[0129] The above formulas are dimensionless values calculated. The formula is obtained by software simulation of a large amount of data to obtain a formula of the latest real situation. The preset parameters and threshold values in the formula are set by a person skilled in the art according to the actual situation.

[0130] The above-described embodiments can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented by software, the above-described embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions described in the embodiments of the present application are wholly or partially generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center through a wired (for example, infrared, wireless, microwave, etc.) manner. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. containing one or more available medium collections. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state disk.

[0131] Those of ordinary skill in the art can realize that the modules and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0132] Those of ordinary skill in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device, and module can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0133] In several embodiments provided in the present application, it should be understood that the disclosed system, device, and method can be implemented in other ways. For example, the above-described device embodiments are only schematic, for example, the division of the modules is only a logical function division, and actual implementation can have another division manner, for example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed ones can be indirect coupling or communication connection through some interfaces, devices, or modules, which can be electrical, mechanical, or other forms.

[0134] The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules, and may be located in one place or distributed on multiple network modules. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment.

[0135] In addition, the functional modules in each embodiment of the present application can be integrated into one processing module, or each module can exist physically alone, or two or more modules can be integrated into one module.

[0136] The functions, if realized in the form of software functional modules and sold or used as independent products, can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various program code storage media.

[0137] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0138] Finally: the above is only the preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application, should be included in the protection scope of the present application.

Claims

1. A method for diagnosing a fault of a gas-insulated metal-enclosed switchgear, characterized by, The method comprises the following steps: S1: acquiring multi-source operation data of the gas insulated metal enclosed switchgear, including sulfur hexafluoride gas density data, infrared thermal imaging data, visible light image data, and vibration signal data; S2: cross-modal time synchronization and alignment compensation of the multi-source operation data; S3: based on the infrared thermal imaging data and the visible light image data, detecting abnormal heat zone distribution and structural deformation characteristics of the equipment, and outputting image analysis results; Based on the infrared thermal imaging data, identify the abnormal heat zone distribution area that exceeds the normal operating temperature range, and determine the position coordinate information and temperature value of the abnormal heat zone distribution area; Based on the visible light image data, extract the structural contour feature and surface texture feature; Compare the structural contour feature and surface texture feature with the standard image feature to determine the coordinate information of the structural contour abnormal position and the surface texture abnormal area; The position coordinate information and temperature value of the abnormal heat zone distribution area, the coordinate information of the structural contour abnormal position, and the coordinate information of the surface texture abnormal area are used as the image analysis results; S4: based on the sulfur hexafluoride gas density data, calculate the gas density change rate, judge whether the equipment exists gas leakage, and output the gas analysis result; S5: based on the vibration signal data, calculate the vibration frequency offset, judge whether the equipment exists abnormal vibration, and output the vibration analysis result; S6: according to the image analysis result and the gas and vibration analysis result, establish the fault correlation relationship, and generate the comprehensive diagnosis result; Based on the spatial position relationship between the position coordinate information and temperature value of the abnormal heat zone distribution area and the gas leakage judgment result, the correlation relationship between the gas leakage situation and the abnormal temperature phenomenon is established; Based on the spatial position relationship between the coordinate information of the structural contour abnormal position, the coordinate information of the surface texture abnormal area, and the abnormal vibration judgment result, the correlation relationship between the abnormal vibration phenomenon and the structural deformation characteristics is established; Based on the correlation relationship between the gas leakage situation and the abnormal temperature phenomenon and the correlation relationship between the abnormal vibration phenomenon and the structural deformation characteristics, the comprehensive diagnosis result is generated; S7: according to the comprehensive diagnosis result, determine the risk level and fault type of the equipment, and match with the control rule library to generate control signals or operation and maintenance execution instructions.

2. The fault diagnosis method for a gas insulated metal-enclosed switchgear according to claim 1, characterized by, S1, specifically: Collecting sulfur hexafluoride gas density data inside the gas chamber of the gas insulated metal enclosed switchgear; Collecting infrared thermal imaging data on the outer surface of the gas chamber of the gas insulated metal enclosed switchgear; Collecting visible light image data on the outer surface of the gas chamber of the gas insulated metal enclosed switchgear; Collecting vibration signal data at the connection position of the key mechanical components of the gas insulated metal enclosed switchgear.

3. The fault diagnosis method for a gas insulated metal-enclosed switchgear according to claim 2, characterized by, S2, specifically: Select the vibration signal data collection time stamp as the reference time axis; Calibrate the time difference of the sulfur hexafluoride gas density data, infrared thermal imaging data, and visible light image data collection time stamp with the reference time axis respectively; If there is a missing data collection time point after calibration, supplement the data value of the missing time point by linear interpolation method.

4. The fault diagnosis method for a gas insulated metal-enclosed switchgear according to claim 3, characterized by, S4, specifically: Based on the ratio of the density change amount of the sulfur hexafluoride gas density data in the preset time period to the corresponding time period, calculate the sulfur hexafluoride gas density change rate; According to whether the sulfur hexafluoride gas density change rate exceeds a preset sulfur hexafluoride gas density change rate threshold, it is judged whether there is gas leakage in the gas chamber of the gas insulated metal-enclosed switchgear; The sulfur hexafluoride gas density change rate and the gas leakage judgment result are taken as the gas analysis result.

5. The fault diagnostic method for a gas-insulated metal-enclosed switchgear according to claim 4, characterized by, S5, specifically: The vibration frequency offset is calculated by a spectrum analysis method, which is the offset between the actual vibration frequency in the vibration signal data and the preset normal vibration frequency; According to whether the vibration frequency offset exceeds a preset vibration frequency offset threshold, it is judged whether there is abnormal vibration at the connection position of the key mechanical component of the gas insulated metal-enclosed switchgear; The vibration frequency offset and the abnormal vibration judgment result are taken as the vibration analysis result.

6. The fault diagnostic method for a gas-insulated metal-enclosed switchgear according to claim 5, characterized by, S7, specifically: According to the comprehensive diagnosis result, the fault type of the gas insulated metal-enclosed switchgear is determined; According to the comprehensive diagnosis result, the risk level of the current fault type of the gas insulated metal-enclosed switchgear is determined; The control rule corresponding to the risk level and the fault type is matched from the control rule library; According to the matched control rule, the control signal or operation and maintenance execution instruction of the gas insulated metal-enclosed switchgear is generated.

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