A high-voltage switchgear insulation fault characteristic gas detection system and diagnosis method

Abstract

The present invention discloses a method for detecting and diagnosing characteristic gases of insulation faults in high-voltage switchgear. The method comprises the following steps: determining the components of a selected characteristic gas for insulation faults in the high-voltage switchgear; performing gas detection and comparing the detected gas with a preset characteristic gas; employing an electrochemical sensor to react with the detected gas and generate an electrical signal proportional to the gas concentration for detection to obtain gas data; determining whether the preset gas is present in the gas data; if the preset gas is present in the gas data, obtaining the concentration of the preset gas; determining whether the concentration of the preset gas is greater than a preset value; outputting fault warning information for the switchgear when the concentration of the preset gas is greater than or equal to the preset value; and processing and displaying the comparison results. This method can address the problem of being unable to effectively and accurately detect insulation hazards in equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of power operation, maintenance and repair, and in particular to a high-voltage switch cabinet insulation fault characteristic gas detection system and diagnosis method. Background Art

[0002] Currently, China's power grid encompasses over 10,000 substations with voltage levels of 35 kV and above, and houses tens of thousands of bays of 10 kV and 35 kV high-voltage switchgear. Statistics show that hundreds of high-voltage switchgear units fail to detect problems in a timely manner each year, leading to burnouts and severe power outages for users. Various insulation defects can occur within high-voltage switchgear during production, transportation, installation, commissioning, and long-term operation. These defects can include surface metal burrs caused during production, loose components or poor contact during installation and transportation, and metal particles trapped within the switchgear during maintenance and testing. These insulation defects can easily cause electric field distortion during switchgear operation, potentially inducing partial discharge. Failure to promptly detect these internal insulation defects can lead to insulation failure, resulting in major power grid incidents and severe economic losses and negative social impacts.

[0003] Because high-voltage switchgear in power grids typically operates in a semi-enclosed, indoor environment, gases generated by the decomposition of insulating materials within the switchgear diffuse into the air within the switchgear chamber through the side or top grilles. This results in very low concentrations of characteristic gases in air samples, making them difficult to detect effectively. Furthermore, the raw materials, formulations, synthesis processes, and product quality control technologies used by manufacturers of high-voltage switchgear insulation materials of different models and voltage levels can vary greatly in their composition, thermal decomposition characteristics, and partial discharge decomposition products. Consequently, the characteristic gases produced by different manufacturers of insulation materials can vary significantly.

[0004] Therefore, how to ensure and improve the safe and stable operation of high-voltage switchgear is of great significance. It is crucial to effectively improve the means of detecting early fault hazards of high-voltage switchgear to prevent equipment operation accidents. Summary of the Invention

[0005] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0006] In view of the above existing problems, the present invention is proposed.

[0007] Therefore, the present invention provides a high-voltage switch cabinet insulation fault characteristic gas detection system and diagnosis method, which can solve the problem of being unable to effectively and accurately detect equipment insulation hidden dangers.

[0008] To solve the above technical problems, the present invention provides the following technical solution: a method for detecting and diagnosing characteristic gases of insulation faults in high-voltage switchgear, comprising:

[0009] Determine the characteristic gas components of insulation faults in selected high-voltage switchgear;

[0010] Perform gas detection and compare with the preset characteristic gas;

[0011] The comparison result is processed and displayed.

[0012] As a preferred solution of the method for detecting and diagnosing characteristic gases of insulation faults in high-voltage switchgear according to the present invention, the determination of the characteristic gas components includes:

[0013] By analyzing the relationship between the main characteristic gas decomposition products of the main insulating polymer materials of high-voltage switchgear, epoxy resin, cross-linked polyethylene, and silicone rubber and air molecules, and analyzing the correspondence between latent fault types and characteristic gases, it was determined through preliminary research and analysis that the characteristic gas components range from oxygen, nitrogen, and carbon compounds.

[0014] As a preferred solution of the method for detecting and diagnosing characteristic gases of insulation faults in high-voltage switchgear described in the present invention, the characteristic gas components include ozone, carbon monoxide, nitrogen dioxide, methane, ammonia, ethylene, carbon dioxide, and nitric oxide.

[0015] As a preferred solution of the method for detecting and diagnosing characteristic gases of insulation faults in high-voltage switchgear according to the present invention, the detection and comparison of the gases includes:

[0016] An electrochemical sensor is used to detect and obtain gas data by reacting with the gas being measured and generating an electrical signal proportional to the gas concentration, and to determine whether a preset gas is present in the gas data;

[0017] When a preset gas exists in the gas data, the concentration of the preset gas is obtained to determine whether the concentration of the preset gas is greater than a preset value. When the concentration of the preset gas is greater than or equal to the preset value, the fault warning information of the switch cabinet is output. When the concentration of the preset gas is less than the preset value, the performance of the insulation material inside the switch cabinet is good.

[0018] As a preferred embodiment of the method for detecting and diagnosing characteristic gases of insulation faults in high-voltage switchgear according to the present invention, when the content of any one of carbon monoxide, carbon dioxide, nitric oxide, and nitrogen dioxide is greater than or equal to a preset observation attention threshold, it is determined that the insulation material inside the switchgear has a material property change caused by partial discharge, that is, partial discharge and sharp discharge occur between the material and the air, and the energy release time exceeds 24 hours;

[0019] When the ozone content is greater than or equal to the preset observation attention threshold, it is judged that the insulation material inside the switch cabinet has material performance changes caused by partial discharge, that is, there is air breakdown discharge of a certain energy on the surface and metal tip position;

[0020] When the methane content is greater than or equal to the preset observation threshold, it is determined that the insulation material inside the switchgear has deteriorated due to partial discharge, that is, partial discharge occurs inside the material, and low-temperature overheating below 300 degrees Celsius exists;

[0021] When the ethylene content is greater than or equal to the preset observation threshold, it is determined that the insulation material inside the switchgear has deteriorated due to partial discharge, that is, there is medium-temperature overheating discharge inside the material, and there is overheating of about 400 to 600 degrees Celsius;

[0022] When the ammonia content is greater than or equal to a preset observation attention threshold, it is determined that the insulation performance of the insulation material inside the switch cabinet has deteriorated.

[0023] As a preferred solution of the method for detecting and diagnosing characteristic gases of insulation faults in high-voltage switchgear described in the present invention, when two or more gas contents are greater than or equal to a preset observation attention threshold, the insulation performance of the insulation material inside the switchgear has deteriorated, and it is necessary to evaluate the internal fault category and fault severity of the high-voltage switchgear based on the 8 gas content proportion relationships, that is, 8 mutual ratio relationships. The internal fault categories of the high-voltage switchgear include metal material tip discharge, insulating material surface discharge, insulating material arc erosion, insulating material thermal aging, and insulating component floating potential discharge.

[0024] As a preferred solution of the method for detecting and diagnosing characteristic gases of insulation faults in high-voltage switchgear described in the present invention, the preset observation attention threshold values of ozone are 20 ppm, carbon monoxide is 20 ppm, carbon dioxide is 200 ppm, nitric oxide is 5 ppm, nitrogen dioxide is 20 ppm, methane is 5 ppm, ethylene is 5 ppm, and ammonia is 3 ppm.

[0025] The invention also provides the following technical solution: a high-voltage switchgear insulation fault characteristic gas detection system, comprising:

[0026] Gas collection module, used to collect characteristic gases of insulation faults in high-voltage switchgear;

[0027] A signal conditioning module, connected to the gas acquisition module and the power supply module, for converting the gas sensor output current signal into a voltage signal, i.e., performing analog-to-digital conversion through a precision operational amplifier;

[0028] A data processing module, connected to the signal conditioning module, is used to calculate the correlation of eight gas components on the collected signal data and analyze the validity of the ratios between the gas components;

[0029] A data storage module, connected to the data processing module, for temporarily storing the analyzed and processed data in a flash memory capacity;

[0030] a data display module, connected to the data storage module, for simultaneously displaying the concentrations of eight gas components;

[0031] The alarm module is connected to the data display module and is used to output fault warning information of the switch cabinet when the concentration of the preset gas is greater than or equal to the preset value.

[0032] Beneficial effects of the present invention: (1) The gas detector for insulation fault characteristics of a high-voltage switchgear of the present invention uses a chemical analysis method to study the essential changes in insulation degradation of switchgear. Compared with existing detection technologies, it has higher sensitivity and more authentic data;

[0033] (2) The present invention detects the operating status of the switch cabinet by using a non-electrical connection method when the switch cabinet is in an energized operating state, and does not require any changes to the existing primary and secondary circuit equipment of the switch cabinet, thereby reducing personal and equipment safety risks and achieving low cost;

[0034] (3) The characteristic gas collection method of the present invention adopts an enrichment sampling method, which is suitable for situations where the concentration of characteristic gases in the air inside the switch cabinet is low. The gas sample is concentrated by a gas collection pump to facilitate analysis and measurement. It has a good detection effect on ozone O3, carbon monoxide CO, nitrogen dioxide NO2, carbon dioxide CO2, and nitric oxide NO, with a measurement accuracy of 10ppm.

[0035] (4) The detection technology of the present invention adopts preset characteristic gas detection technology. By judging whether the concentration of the preset gas is greater than the preset value, the fault warning information of the switch cabinet is output, providing simple and intuitive equipment status information to the operation and maintenance personnel, which is conducive to the early detection and timely handling of faults;

[0036] (5) The auxiliary mobile tool of the present invention is easy to use in a mobile state, can fully meet the requirements of regular inspections, is easy to operate, and has high detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0038] Figure 1 A schematic structural diagram of a high-voltage switchgear insulation fault characteristic gas detection system provided by one embodiment of the present invention;

[0039] Figure 2 A schematic diagram of the internal connections of a high-voltage switchgear insulation fault characteristic gas detection system provided by one embodiment of the present invention;

[0040] Figure 3 A schematic structural diagram of a signal conditioning module of a high-voltage switchgear insulation fault characteristic gas detection system provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0041] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0042] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0043] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0044] The present invention is described in detail with reference to schematic diagrams. For ease of illustration, cross-sectional views of device structures may be partially enlarged and not to scale when describing embodiments of the present invention. Furthermore, the schematic diagrams are merely illustrative and should not limit the scope of the present invention. Furthermore, in actual production, the three-dimensional dimensions of length, width, and depth should be included.

[0045] In the description of the present invention, it should be noted that the terms "upper, lower, inner, and outer" and other references to orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first, second, or third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] In this disclosure, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be interpreted broadly. For example, they may refer to fixed, removable, or integral connections. They may also refer to mechanical, electrical, or direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure.

[0047] Example 1

[0048] Reference Figure 1 , is an embodiment of the present invention, which provides a method for detecting and diagnosing characteristic gases of insulation faults in high-voltage switchgear, comprising:

[0049] S1: Determine the characteristic gas components of the selected high-voltage switchgear insulation fault;

[0050] Furthermore, by analyzing the relationship between the decomposition products of characteristic gases from air molecules and polymer composite materials used in high-voltage switchgear insulation—such as epoxy resin, cross-linked polyethylene, and silicone rubber—the researchers also examined the relationship between potential fault types and characteristic gases. Preliminary research and analysis have determined that the characteristic gas components range from oxygen, nitrogen, and carbon compounds. The research uses electrochemical sensors, which react with the measured gas and generate an electrical signal proportional to the gas concentration, to detect gases. The sensors demonstrate excellent detection of ozone, with an estimated measurement accuracy of 10 ppm.

[0051] It should be noted that the characteristic gas components of insulation fault of high-voltage switchgear (ozone O3, carbon monoxide CO, nitrogen dioxide NO2, methane CH4, ammonia NH3, ethylene C2H4, carbon dioxide CO2, nitric oxide NO) are selected.

[0052] S2: Perform gas detection and compare with the preset characteristic gas;

[0053] Furthermore, based on the acoustic, photoelectric, and chemical effects of partial discharge after a switchgear fault, two types of detection technologies were initially designed through preliminary cost accounting and expected effect analysis. The detection technology is expected to use preset characteristic gas detection technology. The gas detection device collects gas data from the switchgear and determines whether the preset gas is present in the gas data. If the preset gas is present in the gas data, the concentration of the preset gas is determined. If the concentration of the preset gas is greater than the preset value, a fault warning message for the switchgear is output.

[0054] It should be noted that an external gas sampling pump is required for sampling of enriched gas. The pipeline is flexible and can achieve sampling at high and low positions between the gaps of high-voltage switchgear.

[0055] Furthermore, electrochemical gas sensors (fault-characteristic gas components (ozone O3, carbon monoxide CO, nitrogen dioxide NO2, ammonia NH3, ethylene C2H4, nitric oxide NO)) and infrared gas sensors (fault-characteristic gas components (methane CH4, carbon dioxide CO2)) are used to collect the content of fault-characteristic gases within the operating high-voltage switchgear. Based on the relationship between the collected fault-characteristic gas content and the change in gas production rate, the nature and characteristics of the internal insulation defect types of the insulating materials within the high-voltage switchgear are evaluated and analyzed. If the content of any gas exceeds a threshold, it is determined that the material properties of the solid insulation material within the switchgear have changed due to partial discharge.

[0056] It should be noted that when the ozone O3 content is greater than or equal to the preset observation attention threshold S1, it is judged that the performance of the insulation material inside the switch cabinet has changed, that is, there is air breakdown discharge of a certain energy on the surface and metal tip position;

[0057] When the carbon monoxide (CO) content is greater than or equal to the preset observation attention threshold S2, it is determined that partial discharge and tip discharge occur between the internal material of the switch cabinet and the air;

[0058] When the CO2 content is not less than the preset observation attention threshold S3, it is judged that partial discharge and tip discharge occur between the solid insulation material and the air inside the switch cabinet, and the energy release time exceeds 24 hours;

[0059] When the nitric oxide (NO) content is greater than or equal to the preset observation attention threshold S4, it is determined that partial discharge and tip discharge occur between the insulating material and the air inside the switch cabinet, and the energy release time exceeds 24 hours;

[0060] When the nitrogen dioxide NO2 content is greater than or equal to the preset observation attention threshold S5, it is judged that partial discharge and tip discharge occur between the insulating material and the air inside the switch cabinet, and the energy release time exceeds 24 hours;

[0061] When the methane CH4 content is greater than or equal to the preset observation attention threshold S6, it is determined that partial discharge occurs inside the insulation material inside the switch cabinet, and there is low-temperature overheating below 300 degrees Celsius;

[0062] When the ethylene C2H4 content is greater than or equal to the pre-set observation attention threshold S7, it is determined that there is a medium-temperature overheat discharge inside the insulation material inside the switch cabinet, and there is an overheat of about 400 to 600 degrees Celsius;

[0063] When the ammonia NH3 content is greater than or equal to the preset observation attention threshold S8, it is determined that the insulation performance of the insulation material inside the switch cabinet has deteriorated;

[0064] When the concentration of any of the above gases is greater than the preset value, the fault warning information of the switch cabinet will be output. When the gas content does not exceed the warning value, the insulation material inside the switch cabinet has good insulation performance;

[0065] Furthermore, when the contents of two or more of the above gases are greater than or equal to the pre-set observation attention threshold, the insulation performance of the insulation material inside the switchgear has deteriorated. It is necessary to assess the internal fault type and fault severity of the high-voltage switchgear based on the eight gas content ratios, that is, the eight mutual ratios.

[0066] Internal fault categories of high-voltage switchgear include metal material tip discharge, insulation material surface discharge, insulation material arc erosion, insulation material thermal aging, and insulation component floating potential discharge.

[0067] It should be noted that the pre-set observation attention threshold S1 of the fault characteristic gas is 20ppm, S2 is 20ppm, S3 is 200ppm, S4 is 5ppm, S5 is 20ppm, S6 is 5ppm, S7 is 5ppm, and S8 is 3ppm.

[0068] Furthermore, the fault type analysis and diagnosis is performed based on the fault characteristic gas production rate:

[0069] Statistical analysis and evaluation of the absolute gas production rate test case of fault characteristic gas CO,

[0070] When the CO gas production rate increases to less than or equal to the preset observation attention threshold T1ppm / D, and the NO2 gas production rate reaches the preset observation attention threshold T2ppm / D, it is determined that there is a solid metal protrusion discharge defect inside the switchgear;

[0071] When the CO gas production rate reaches the preset observation attention threshold T3ppm / D, and the NO2 gas production rate reaches the preset observation attention threshold T2ppm / D, it is judged that there is a metal contamination defect on the surface of the insulator inside the switchgear;

[0072] When the CO gas production rate reaches the preset observation attention threshold T3ppm / D and the NO2 gas production rate reaches the preset observation attention threshold T1ppm / D, it is judged that there is an insulator gap discharge defect inside the switch cabinet.

[0073] The fault characteristic gas production rate pre-set observation attention threshold T1 ranges from 10ppm / D to 20ppm / D, T2 ranges from 15ppm / D to 25ppm / D, T3 ranges from 20ppm / D to 30ppm / D, and T4 ranges from 5ppm / D to 15ppm / D.

[0074] S3: Process and display the comparison results.

[0075] Furthermore, data processing and real-time display functions are realized through the characteristic gas detector data processing and display module.

[0076] Example 2

[0077] Reference Figure 2-3 , as one embodiment of the present invention, provides a high-voltage switchgear insulation fault characteristic gas detection system, comprising:

[0078] Gas collection module, used to collect characteristic gases of insulation faults in high-voltage switchgear;

[0079] The signal conditioning module is connected to the gas acquisition module and the power supply module. When the gas sensor outputs a current signal to the signal conditioning module, the module uses a TIA transimpedance amplifier to convert the current signal into a voltage signal, that is, performs analog-to-digital conversion through a precision operational amplifier.

[0080] The data processing module is connected to the signal conditioning module and is used to calculate the correlation of the eight gas components on the collected signal data and analyze the validity of the ratio between the gas components;

[0081] The data storage module is connected to the data processing module to temporarily store the analyzed and processed data in the flash memory capacity, and is connected to the U3 port (USB) to facilitate later reading and copying at any time;

[0082] The data display module is connected to the data storage module and displays the concentrations of 8 gas components simultaneously through the LCD color touch screen;

[0083] The alarm module is connected to the data display module and is used to output fault warning information of the switch cabinet when the concentration of the preset gas is greater than or equal to the preset value.

[0084] Furthermore, the hardware connections are as follows: flexible gas sampling line – gas sampling pump – electrochemical gas sensor (fault characteristic gas components (ozone O3, carbon monoxide CO, nitrogen dioxide NO2, ammonia NH3, ethylene C2H4, nitric oxide NO)), infrared gas sensor (fault characteristic gas components (methane CH4, carbon dioxide CO2)) – signal conditioning module – data processing module – data storage module – data display unit. The power module is a rechargeable lithium battery, and the entire system is also equipped with an auxiliary movement tool in the form of a detachable mobile roller pull rod, which makes operation convenient and fast, and the ergonomics high.

[0085] Example 3

[0086] As an embodiment of the present invention, a method for suppressing induced lightning overvoltage in a distribution network is provided. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through experiments.

[0087] Taking the ozone O3 observation attention threshold S1 value as an example, a comparative experiment was conducted.

[0088] S1 value (ppm) Accuracy of judging performance changes The incidence of performance changes 18 76％ 80％ 19 84％ 83％ 20 90％ 96％ 21 81％ 78％ 22 70％ 72％

[0089] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0090] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiment of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal translation scripting language JavaScript, etc.

[0091] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0092] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A method for detecting and diagnosing characteristic gases of insulation faults in high-voltage switchgear, characterized by: include, Determine the characteristic gas components of insulation faults in selected high-voltage switchgear; Perform gas detection and compare with the preset characteristic gas; Processing and displaying the comparison results; determining the characteristic gas components includes: By analyzing the relationship between the characteristic gas decomposition products of high-voltage switchgear insulating polymer materials epoxy resin, cross-linked polyethylene, silicone rubber and air molecules, and analyzing the corresponding relationship between latent fault types and characteristic gases, it is determined through preliminary research and analysis that the characteristic gas components range from oxygen, nitrogen, and carbon compounds; the characteristic gas components include ozone, carbon monoxide, nitrogen dioxide, methane, ammonia, ethylene, carbon dioxide, and nitric oxide; the detection comparison of the gas includes, An electrochemical sensor is used to detect and obtain gas data by reacting with the gas being measured and generating an electrical signal proportional to the gas concentration, and to determine whether a preset gas is present in the gas data; When a preset gas exists in the gas data, the concentration of the preset gas is obtained to determine whether the concentration of the preset gas is greater than a preset value. When the concentration of the preset gas is greater than or equal to the preset value, fault warning information of the switch cabinet is output. When the concentration of the preset gas is less than the preset value, the performance of the internal insulation material of the switch cabinet is good. When the content of any one of carbon monoxide, carbon dioxide, nitric oxide, and nitrogen dioxide is greater than or equal to a preset observation attention threshold, it is determined that the insulation material inside the switch cabinet has a material performance change caused by partial discharge, that is, partial discharge and tip discharge occur between the material and the air, and the energy release time exceeds 24 hours. When the ozone content is greater than or equal to the preset observation attention threshold, it is judged that the insulation material inside the switch cabinet has material performance changes caused by partial discharge, that is, there is air breakdown discharge of a certain energy on the surface and metal tip position; When the methane content is greater than or equal to the preset observation threshold, it is determined that the insulation material inside the switchgear has deteriorated due to partial discharge, that is, partial discharge occurs inside the material, and low-temperature overheating below 300 degrees Celsius exists; When the ethylene content is greater than or equal to the preset observation threshold, it is determined that the insulation material inside the switchgear has deteriorated due to partial discharge, that is, there is medium-temperature overheating discharge inside the material, and there is overheating of about 400 to 600 degrees Celsius; When the ammonia content is greater than or equal to the preset observation attention threshold, it is determined that the insulation performance of the insulation material inside the switch cabinet has deteriorated; Electrochemical gas sensors and infrared gas sensors are used to collect the fault characteristic gas content in the high-voltage switch cabinet during operation; the gas detection and comparison also includes: When two or more gas contents are greater than or equal to a preset observation attention threshold, the insulation performance of the insulation material inside the switch cabinet has deteriorated. It is necessary to evaluate the internal fault type and fault severity of the high-voltage switch cabinet based on the proportional relationship of the 8 gas contents, that is, the 8 mutual ratio relationships. The internal fault types of the high-voltage switch cabinet include metal material tip discharge, insulation material surface discharge, insulation material arc erosion, insulation material thermal aging, and insulation component floating potential discharge; the preset observation attention threshold for ozone is 20ppm, carbon monoxide is 20ppm, carbon dioxide is 200ppm, nitric oxide is 5ppm, nitrogen dioxide is 20ppm, methane is 5ppm, ethylene is 5ppm, and ammonia is 3ppm; Based on the relationship between the collected fault characteristic gas content and gas production rate, the nature and characteristics of the internal insulation defect types of the insulating material in the high-voltage switchgear are evaluated and analyzed. When the content of any gas exceeds the threshold, it is determined that the material properties of the solid insulation material inside the switchgear have changed due to partial discharge; When the CO gas production rate increases to less than or equal to the preset observation attention threshold T1ppm / D, and the NO2 gas production rate reaches the preset observation attention threshold T2ppm / D, it is determined that there is a solid metal protrusion discharge defect inside the switchgear; When the CO gas production rate reaches the preset observation attention threshold T3ppm / D, and the NO2 gas production rate reaches the preset observation attention threshold T2ppm / D, it is judged that there is a metal contamination defect on the surface of the insulator inside the switchgear; When the CO gas production rate reaches the preset observation attention threshold T3ppm / D and the NO2 gas production rate reaches the preset observation attention threshold T1ppm / D, it is judged that there is an insulator gap discharge defect inside the switch cabinet.

2. A high-voltage switchgear insulation fault characteristic gas detection system, using the high-voltage switchgear insulation fault characteristic gas detection and diagnosis method according to claim 1, characterized in that: include, Gas collection module, used to collect characteristic gases of insulation faults in high-voltage switchgear; A signal conditioning module, connected to the gas acquisition module and the power supply module, for converting the gas sensor output current signal into a voltage signal, i.e., performing analog-to-digital conversion through a precision operational amplifier; A data processing module, connected to the signal conditioning module, is used to calculate the correlation of eight gas components on the collected signal data and analyze the validity of the ratios between the gas components; A data storage module, connected to the data processing module, for temporarily storing the analyzed and processed data in a flash memory capacity; a data display module, connected to the data storage module, for simultaneously displaying the concentrations of eight gas components; The alarm module is connected to the data display module and is used to output fault warning information of the switch cabinet when the concentration of the preset gas is greater than or equal to a preset value.

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