Integrated detection system for gas state in direct-current wall bushing
By designing a combination of gas collection, sensor analysis and data processing modules, the problem of real-time monitoring of SF6 gas decomposition products inside DC wall bushings is solved, and efficient and low-cost gas status detection is achieved to ensure the safe and stable operation of power equipment.
Patent Information
- Application Number
- CN202510949055.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-10
- Publication Date
- 2025-09-12
AI Technical Summary
Existing technologies are unable to monitor the decomposition products of SF6 gas inside DC wall bushings in real time, resulting in low detection efficiency and high equipment costs.
A system including a gas acquisition module, a sensor analysis module and a data processing module was designed. The system adopted a combination design of a gas connection device and a three-way switching valve, combined with a composite structure of capacitive dew point detection, piezoresistive pressure sensor and platinum resistance temperature measurement, MEMS technology was used to construct the decomposition product sensor array unit, and data processing was performed through a multi-source data fusion algorithm.
It realizes real-time monitoring of the gas status inside the DC wall bushing, improves the accuracy and reliability of detection, reduces equipment costs, and simplifies the operation process.
Smart Images
Figure CN120628207A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of electrical equipment monitoring and diagnosis, and in particular relates to an integrated detection system for the internal gas state of a DC wall bushing. Background Art
[0002] DC wall bushings are critical equipment in HVDC transmission systems, providing electrical connections between the valve hall and external equipment. Currently, mainstream DC bushings use sulfur hexafluoride (SF6) as the insulation medium. Its dielectric strength is approximately three times that of air, providing excellent insulation and arc-extinguishing properties. However, under fault conditions such as arc discharge and localized overheating, some SF6 gas decomposes, producing a series of low-fluorinated sulfides, such as SF4, SF3, and SF2. In the presence of trace amounts of water or impurity gases, these low-fluorinated sulfides further decompose into highly toxic and corrosive gas components, such as SO2, CO, H2S, SOF2, and SO2F2. These decomposition products not only accelerate the aging of insulation materials but can also be released into the environment during equipment failure, posing a serious threat to human health. By monitoring the gas composition within the equipment, it is possible to promptly identify discharge conditions within the wall bushing and assess the operating status of the power equipment.
[0003] Traditional detection methods typically require periodic gas sampling from the bushing and sending the gas back to the laboratory for analysis. This method is inefficient and costly, and it also fails to meet the demand for real-time monitoring of equipment status. Therefore, there is an urgent need to design an integrated detection device for the SF6 gas status inside DC wall bushings. This device can achieve online monitoring of the SF6 gas status inside the equipment, thereby promptly determining the equipment's operating status and ensuring the safe and stable operation of power equipment.
[0004] Existing methods for detecting SF6 decomposition gas mainly include gas chromatography, infrared spectroscopy, detection tube method, electrochemical sensor method, and semiconductor sensor method. Gas chromatography uses an inert gas as the mobile phase to adsorb the gas to be detected onto a fixed carrier and then perform column chromatography separation. The detector uses a sensitive response to components such as carbides and sulfides in the gas sample, making it suitable for laboratory and on-site gas component detection. However, the equipment required for gas chromatography is large and difficult to install inside the casing. The equipment is also expensive, maintenance is complex, gas calibration is frequent, and the detection steps are relatively cumbersome. Infrared spectroscopy detects the differences in infrared light absorption of specific bands by different component gases and has the characteristics of rapid detection and high accuracy. However, trace water and carbon dioxide in the environment can significantly interfere with the infrared spectrum. Moreover, due to the different infrared wavelengths required by the gases, the number of lasers increases, the equipment cost rises, the gas chamber needs to be vacuumed, and the operation steps are complicated. Therefore, it is mostly used for laboratory analysis. The detection tube method is relatively simple to operate, but has low detection accuracy. It is usually only used for equipment fault location and requires manual operation and visual reading of the results, which is prone to human error. In addition, the detection tube is usually disposable, and the cost of long-term monitoring is high. Electrochemical sensors have a limited lifespan and a long response time, which may not meet the demand for rapid response. In comparison, semiconductor gas sensors have the advantages of low cost, small size, and easy integration. However, existing detection devices still have many problems, such as insufficient selectivity, large overall equipment size, and complex supporting circuits, and cannot fully meet the development needs of sensor miniaturization. Summary of the Invention
[0005] The purpose of the present invention is to provide an integrated detection system for the gas state inside a DC wall bushing, so as to solve the problems in the prior art of being unable to monitor SF6 gas decomposition products in real time, having low detection efficiency and high equipment cost.
[0006] The technical solution of the present invention is: it includes a gas collection module, a sensor analysis module and a data processing module. The gas collection module is composed of a gas circuit connection device, a three-way switching valve and an air supply channel. The gas circuit connection device is fixedly connected to the three-way switching valve by argon arc welding. The other end of the three-way switching valve is connected to the air supply channel through a pneumatic joint. The pneumatic joint has a built-in sealing rubber ring to enhance air tightness. The sensor analysis module includes a micro-water pressure sensor unit and a decomposition product sensor array unit. The micro-water pressure sensor unit adopts a composite structure design that combines capacitive dew point detection with piezoresistive pressure sensing and platinum resistance temperature measurement. The decomposition product sensor array unit is constructed based on MEMS technology and includes multiple independent gas-sensitive material loading areas. The data processing module is connected to the sensor analysis module through the RS485 communication protocol and uploads the collected data to the host computer for comprehensive analysis.
[0007] Furthermore, the design method of the gas collection module is as follows: the inlet end of the gas connection device is connected to the internal gas channel of the DC wall bushing, and the gas is diverted to the sensor analysis module or the gas supply channel through the three-way switching valve. The mechanical interface design of the three-way switching valve includes a bolt connection and a double-layer sealing structure. The first layer is a metal gasket seal, and the second layer is a fluororubber rubber ring seal. The two-layer sealing structure works together to prevent gas leakage. A quick connector is provided at the end of the gas supply channel to support the sampling and replenishment operations of SF6 gas. Finite element simulation modeling is used to analyze the diffusion characteristics of the characteristic decomposition molecules in the DC wall bushing, and the area with the fastest concentration change is selected as the installation location of the sensor analysis module.
[0008] Furthermore, the micro-water pressure sensor unit is implemented as follows: the capacitive dew point detection section reflects the micro-water content by measuring the change in dielectric constant caused by water condensation in the gas; the piezoresistive pressure sensing section reflects gas pressure through the change in resistance of the strain gauge; and the platinum resistance temperature measurement section reflects temperature through the change in resistance value. Combining these three elements, a real-time algorithm performs temperature compensation for micro-water content, converting micro-water values at different temperatures to values at standard conditions of 20°C. This design avoids micro-water measurement errors caused by temperature fluctuations and improves data accuracy.
[0009] Furthermore, the decomposition product sensor array unit is implemented as follows: the core of the array unit is an integrated silicon-based chip, the surface of which is divided into four independent gas-sensitive material load areas. The material resistance of each load area is controlled by interdigitated electrodes. Microheaters are arranged in a serpentine pattern to cover all load areas, ensuring that the gas-sensitive material is evenly heated. The thickness and area of the heating resistors are precisely designed to meet the optimal operating temperature requirements of different gas-sensitive materials. The circuit design of a single load area is a voltage divider structure, in which the sensitive material is connected in series with a matching resistor. When the target gas passes through, the resistance of the sensitive material changes, and the voltage at the voltage divider point changes accordingly. By collecting the voltage at the voltage divider point of the four load areas through the acquisition circuit, the component content of the target gas can be obtained.
[0010] The data processing module operates as follows: The moisture, pressure, temperature, and gas composition data collected by the sensor analysis module are transmitted to the data processing module via the RS485 communication protocol. The data processing module performs preliminary filtering and calibration on the received data before uploading it to the host computer. The host computer performs a comprehensive analysis of the data using a multi-source data fusion algorithm and, incorporating real-time temperature and pressure information, calculates compensation for gas composition. This compensation algorithm accounts for the effects of temperature drift and background gas interference, improving the accuracy of identifying decomposition product composition.
[0011] Furthermore, the gas connection device and the three-way switching valve are connected as follows: the outlet of the gas connection device is fixed to the inlet of the three-way switching valve via argon arc welding, with a double-layer weld design to enhance the connection strength. The outlet of the three-way switching valve is connected to the sensor analysis module and the air supply channel, respectively. The connection points are equipped with sealing rubber rings and metal gaskets to ensure the airtightness of the gas circuit. The quick connector of the air supply channel is made of stainless steel and has an internal spring self-locking mechanism. It automatically locks when inserted and requires pressing the unlock button when removed, which is convenient for operation and avoids gas leaks caused by improper operation.
[0012] Furthermore, the micro-water pressure sensor unit is installed as follows: the sensor unit is threadedly fixed to a cavity adjacent to the air connection device. The cavity is designed in a stepped shape, with the sensor unit's probe portion extending into the airflow path, while the remainder is located outside the cavity. A deflector is installed within the cavity to minimize the impact of airflow on the sensor response. The sensor unit's signal output is connected to the data processing module via a shielded cable wrapped in aluminum foil to reduce electromagnetic interference.
[0013] Furthermore, the decomposition product sensor array unit is installed as follows: the array unit is secured to the other side of the gas connection device via a snap-on bracket within the cylindrical cavity, which houses a constant-temperature heating module to maintain a stable operating temperature for the gas-sensitive material. The array unit's pins are connected to the data processing module via a flexible printed circuit board (FPCB). The FPCB's trace width and spacing are optimized to reduce noise interference during signal transmission.
[0014] The data processing module further expands its functionality by integrating a memory chip and a communication interface. The memory chip caches collected raw data, and the communication interface supports multiple protocols, including MODBUS, CAN, and Ethernet, facilitating data exchange with various host computers. The module also incorporates a built-in fault diagnosis algorithm that analyzes historical data trends to identify potential equipment failures and issue early warning signals.
[0015] The present invention provides an integrated detection system for the gas state inside a DC wall bushing through improvements. Compared with the prior art, the system has the following improvements and features: By adopting a combined design of a gas path connection device and a three-way switching valve, the integration of gas collection and gas replenishment functions is achieved, the equipment structure is simplified, and at the same time, the sealing of the gas path is enhanced through a double-layer sealing structure, avoiding the risk of gas leakage.
[0016] By adopting a composite structure design that combines capacitive dew point detection with piezoresistive pressure sensing and platinum resistance temperature measurement, the synchronous measurement of trace water, pressure and temperature is achieved, and temperature compensation of trace water content is performed through a real-time algorithm, thereby improving the accuracy and reliability of the data.
[0017] By adopting a decomposition sensor array unit based on MEMS technology, high-sensitivity detection of gases without infrared characteristics such as SO2, H2S, and CO is achieved. The microheater design of the array unit ensures uniform heating of the gas-sensitive material, improving the response speed and stability of the sensor.
[0018] By adopting a multi-source data fusion algorithm and combining real-time temperature and pressure information to compensate for the gas component content, the impact of temperature drift and background gas interference is reduced, the accuracy of identifying the decomposition product component content is improved, and reliable data support is provided for equipment status assessment. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is an overall schematic diagram of the present invention.
[0020] Figure 2 Schematic diagram of the gas collection module.
[0021] Figure 3 Schematic diagram of the micro-water pressure sensor unit.
[0022] Figure 4 Schematic diagram of the decomposition product sensor array unit.
[0023] Figure 5 This is the functional block diagram of the data processing module. DETAILED DESCRIPTION
[0024] The present invention provides an integrated detection system for the gas state inside a DC wall bushing, which comprises a gas acquisition module, a sensor analysis module and a data processing module. Figure 1 To the attached Figure 5 The components shown in the accompanying drawings are described in detail.
[0025] like Figure 1As shown, the gas collection module consists of a gas connection device, a three-way switching valve, and a gas supply channel. The inlet of the gas connection device connects to the internal gas channel of the DC wall bushing, while the outlet is securely connected to the three-way switching valve via argon arc welding. The welds utilize a double-layer weld design to enhance connection strength and prevent gas leakage. The two outlets of the three-way switching valve connect to the sensing and analysis module and the gas supply channel, respectively. Sealing rubber rings and metal gaskets are installed at each connection to ensure a tight seal. A stainless steel quick connector with an internal spring-loaded self-locking mechanism is installed at the end of the gas supply channel. It automatically locks when inserted and requires a button to unlock when removed, facilitating operation and preventing gas leaks caused by misoperation. The mechanical interface design of the three-way switching valve includes a bolted connection and a double-layer sealing structure: a metal gasket seal on the first layer and a fluororubber rubber ring seal on the second layer. These two sealing layers work together to prevent gas leakage. The cavity of the gas connection device is designed to have a stepped shape. The micro-water pressure sensor unit is fixed to the side cavity of the gas connection device via a threaded connection. The sensor unit's probe portion extends into the airflow channel, while the remaining portion is located outside the cavity. A deflector is installed inside the cavity to minimize the impact of airflow on the sensor response. The decomposition product sensor array unit is fixed to the other side cavity of the gas connection device via a snap-on bracket. The cavity is designed to be cylindrical and contains a constant temperature heating module to maintain a stable working environment temperature for the gas-sensitive material.
[0026] The sensing and analysis module includes a micro-water pressure sensor unit and a decomposition sensor array unit. Figure 3 As shown, the micro-water pressure sensor unit adopts a composite structure design that combines capacitive dew point detection with piezoresistive pressure sensing and platinum resistance temperature measurement. The capacitive dew point detection part reflects the micro-water content by measuring the change in dielectric constant caused by the condensation of water in the gas. The piezoresistive pressure sensing part reflects the gas pressure through the resistance change of the strain gauge, and the platinum resistance temperature measurement part reflects the temperature through the change in resistance value. After the three are combined, the micro-water content is temperature compensated through a real-time algorithm, and the micro-water values at different temperatures are converted to values under standard conditions of 20°C. The signal output end of the sensor unit is connected to the data processing module through a shielded cable, and the outer layer of the shielded cable is wrapped with aluminum foil to reduce electromagnetic interference. As shown Figure 4As shown, the core of the decomposition product sensor array unit is an integrated silicon-based chip. The chip surface is divided into four independent gas-sensitive material load zones, each of which uses interdigitated electrodes to control the material resistance. Microheaters are arranged in a serpentine pattern across all load zones to ensure uniform heating of the gas-sensitive material. The thickness and area of the heating resistors are precisely designed to meet the optimal operating temperature requirements of different gas-sensitive materials. The circuit design of each load zone uses a voltage divider structure, with the sensitive material connected in series with a matching resistor. When the target gas passes through, the resistance of the sensitive material changes, and the voltage at the voltage divider point changes accordingly. The voltage at the voltage divider point of each of the four load zones is collected by an acquisition circuit to determine the component content of the target gas. The pins of the decomposition product sensor array unit are connected to the data processing module via a flexible printed circuit board. The trace width and spacing of the flexible printed circuit board are optimized to reduce noise interference during signal transmission.
[0027] The data processing module is connected to the sensor analysis module through the RS485 communication protocol and uploads the collected data to the host computer for comprehensive analysis. Figure 5 The functional block diagram of the data processing module, shown in Figure 2, illustrates its communication interface with the sensor and analysis module, its storage chip, and the operational flow of the multi-source data fusion algorithm. The sensor and analysis module collects trace moisture, pressure, temperature, and gas composition data, which are transmitted to the data processing module via the RS485 communication protocol. The data processing module performs preliminary filtering and calibration on the received data before uploading it to the host computer. The host computer performs a comprehensive analysis of the data based on the multi-source data fusion algorithm and calculates compensation for gas composition content based on real-time temperature and pressure information. This compensation algorithm accounts for the effects of temperature drift and background gas interference, improving the accuracy of identifying decomposition product composition. The data processing module integrates a storage chip and a communication interface. The storage chip caches the collected raw data, and the communication interface supports multiple protocols, including MODBUS, CAN, and Ethernet, facilitating data exchange with different host computers. The module also incorporates a built-in fault diagnosis algorithm that analyzes historical data trends to identify potential equipment failures and issue early warning signals.
[0028] In practical applications, the gas collection module is designed as follows: the inlet of the gas connection device is connected to the internal gas channel of the DC wall bushing. Gas is diverted via a three-way switching valve to the sensor and analysis module or the gas supply channel. Finite element simulation modeling is used to analyze the diffusion characteristics of characteristic decomposition molecules within the DC wall bushing, and the area with the fastest concentration change is selected as the installation location for the sensor and analysis module. The micro-water pressure sensor unit is implemented as follows: the capacitive dew point detection component measures the change in dielectric constant caused by water condensation in the gas to reflect the micro-water content; the piezoresistive pressure sensor component reflects gas pressure through the resistance change of the strain gauge; and the platinum resistance temperature measurement component reflects temperature through the change in resistance value. Combining these three components, a real-time algorithm is used to compensate for the micro-water content, converting the micro-water values at different temperatures to the values at standard conditions of 20°C. The decomposition product sensor array unit is implemented as follows: the core of the array unit is an integrated silicon-based chip. The chip surface is divided into four independent gas-sensitive material load zones. Each load zone uses interdigitated electrodes to control the material resistance. Microheaters are arranged in a serpentine pattern across all load zones to ensure uniform heating of the gas-sensitive material. The thickness and area of the heating resistors are precisely designed to meet the optimal operating temperature requirements of different gas-sensing materials. The circuit design for each load zone uses a voltage divider structure, with the sensitive material connected in series with a matching resistor. When the target gas passes through, the resistance of the sensitive material changes, and the voltage at the voltage divider point changes accordingly. The voltage at the voltage divider point of each of the four load zones is collected by an acquisition circuit to determine the target gas component content.
[0029] The above describes the specific implementation of the present invention in detail, clearly demonstrating the connection, positional, and coordination relationships between the various components. Through the above-described structure and operating principle, the present invention achieves integrated detection of the SF6 gas state inside a DC wall bushing, resolving the problems existing in the prior art.
[0030] In order to better enable relevant personnel in this technical field to fully understand and implement the present invention, the specific implementation principle of the present invention is further supplemented below in combination with a specific application scenario.
[0031] In the actual operation scenario of SF6 gas status detection inside a DC wall bushing, the gas collection module is first connected to the internal gas channel of the wall bushing through the gas connection device. The inlet end of the gas connection device is designed as a stepped cavity structure, and a guide plate is provided inside it to reduce the impact of airflow on the sensor response. When SF6 gas flows into the gas connection device from the wall bushing, it is diverted to the sensor analysis module or the gas supply channel through the three-way switching valve. The three-way switching valve adopts a double-layer sealing structure. The first layer is a metal gasket seal and the second layer is a fluororubber rubber ring seal. The two-layer sealing structure works together to prevent gas leakage. The quick connector is set at the end of the gas supply channel. It automatically locks when inserted and requires pressing the unlock button when removed. It is easy to operate and avoids gas leakage caused by misoperation.
[0032] The micro-water pressure sensor unit then begins operating. The capacitive dew point sensor measures the change in dielectric constant caused by condensation in the gas to indicate micro-water content. The piezoresistive pressure sensor measures gas pressure through changes in strain gauge resistance. The platinum resistance temperature sensor measures temperature through changes in resistance. Data from these three components is processed using a real-time algorithm to compensate for micro-water content and convert micro-water values at different temperatures to values at standard conditions of 20°C. The signal is transmitted to the data processing module via a shielded cable wrapped in aluminum foil to reduce electromagnetic interference and ensure stable data transmission.
[0033] At the same time, the decomposition product sensor array unit detects the decomposition products in the SF6 gas. The surface of the silicon-based chip is divided into four independent gas-sensitive material load areas, and the material resistance of each load area is controlled by interdigitated electrodes. The microheater is arranged in a serpentine pattern to cover all load areas, ensuring that the gas-sensitive material is evenly heated. The thickness and area of the heating resistor are precisely designed to meet the optimal operating temperature requirements of different gas-sensitive materials. When the target gas passes through, the resistance of the sensitive material changes, and the voltage at the divider point changes accordingly. The voltage at the divider point of the four load areas is collected and transmitted to the data processing module via a flexible circuit board. The trace width and spacing of the flexible circuit board are optimized to reduce noise interference during signal transmission.
[0034] The data processing module receives the data collected by the sensor analysis module through the RS485 communication protocol, performs preliminary filtering and calibration on the data, and then uploads it to the host computer. The host computer performs a comprehensive analysis of the data based on a multi-source data fusion algorithm, and combines real-time temperature and pressure information to compensate for the gas component content. The compensation algorithm takes into account the effects of temperature drift and background gas interference, improving the accuracy of identifying the component content of the decomposition product. In addition, the storage chip integrated within the data processing module caches the raw data, and the communication interface supports multiple communication protocols, including MODBUS, CAN, and Ethernet, facilitating data interaction with different types of host computers. The module also has a built-in fault diagnosis algorithm that determines the potential failure risk of the equipment through trend analysis of historical data and issues early warning signals.
[0035] Throughout the entire detection process, the constant temperature heating module maintains a stable working environment temperature for the gas-sensitive material, ensuring that its performance is unaffected by external temperature fluctuations. At the same time, the cavity of the gas connection device is designed to be stepped, and the micro-water pressure sensor unit is fixed to the side cavity via a threaded connection. The probe portion of the sensor unit extends into the airflow channel, and the remaining portion is located outside the cavity. The guide plate inside the cavity further reduces the impact of airflow on the sensor response. The decomposition product sensor array unit is fixed to the cavity on the other side of the gas connection device via a snap-on bracket. The cavity is designed to be cylindrical to ensure uniform airflow distribution.
[0036] Through the above steps, the present invention achieves integrated detection of the SF6 gas state within DC wall bushings. Finite element simulation modeling analyzes the diffusion characteristics of characteristic decomposition molecules within DC wall bushings, selecting the area with the fastest concentration changes as the installation location for the sensing and analysis module, thereby improving detection sensitivity and accuracy. The close coordination and optimized design of the modules enable this system to operate stably under complex operating conditions, resolving issues existing in existing technologies and providing reliable assurance for the safe and stable operation of power equipment.
[0037] Any content not described in detail in the specification belongs to the prior art known to those skilled in the art, and the model parameters of each electrical appliance are not specifically limited, and conventional equipment can be used. In this technical solution, electrical control components not mentioned are not shown in the figures because they belong to the prior art and will not be described here.
[0038] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.
[0039] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.
Claims
1. An integrated detection system for the gas state inside a DC wall bushing, characterized by: It includes a gas collection module, a sensing and analysis module and a data processing module. The gas collection module consists of a gas circuit connection device, a three-way switching valve and a gas supply channel. The gas circuit connection device is fixedly connected to the three-way switching valve by argon arc welding. The other end of the three-way switching valve is connected to the gas supply channel through a pneumatic joint. The pneumatic joint has an embedded sealing rubber ring. The sensing and analysis module includes a micro-water pressure sensor unit and a decomposition product sensor array unit. The micro-water pressure sensor unit adopts a composite structure design of capacitive dew point detection combined with piezoresistive pressure sensing and platinum resistance temperature measurement. The decomposition product sensor array unit is constructed based on MEMS technology and includes multiple independent gas-sensitive material loading areas. The data processing module is connected to the sensing and analysis module through the RS485 communication protocol and uploads the collected data to the host computer.
2. The integrated detection system for the gas state inside a DC wall bushing according to claim 1, characterized in that: The inlet end of the gas path connection device is connected to the internal gas channel of the DC wall bushing, and the gas is diverted to the sensing analysis module or the gas supply channel through the three-way switching valve. The mechanical interface of the three-way switching valve includes a bolt connection and a double-layer sealing structure, the first layer is a metal gasket seal, and the second layer is a fluororubber rubber ring seal.
3. The integrated detection system for the gas state inside a DC wall bushing according to claim 1, characterized in that: A quick connector is provided at the end of the air supply channel. The quick connector is made of stainless steel and has a spring self-locking mechanism inside. It automatically locks when inserted and an unlocking button needs to be pressed when pulled out.
4. The integrated detection system for the gas state inside a DC wall bushing according to claim 1, characterized in that: The micro-water pressure sensor unit is fixed in the side cavity of the air path connection device through a threaded connection. The cavity is designed to be stepped. The probe part of the sensor unit extends into the air flow channel, and the rest is located outside the cavity. A guide plate is provided inside the cavity.
5. The integrated detection system for the gas state inside a DC wall bushing according to claim 1, characterized in that: The signal output end of the micro-water pressure sensor unit is connected to the data processing module through a shielded cable, and the outer layer of the shielded cable is wrapped with aluminum foil.
6. The integrated detection system for the gas state inside a DC wall bushing according to claim 1, characterized in that: The decomposition product sensor array unit is fixed to the cavity on the other side of the gas path connection device through a snap-on bracket. The cavity is designed to be cylindrical and has a constant temperature heating module inside.
7. The integrated detection system for the gas state inside a DC wall bushing according to claim 1, characterized in that: The core of the decomposition product sensor array unit is an integrated silicon-based chip. The chip surface is divided into four independent gas-sensitive material loading areas. The material resistance of each loading area is regulated by interdigitated electrodes, and the microheater is arranged in a serpentine pattern to cover all loading areas.
8. The integrated detection system for the gas state inside a DC wall bushing according to claim 1, characterized in that: The pins of the decomposition product sensor array unit are connected to the data processing module through a flexible circuit board.
9. The integrated detection system for the gas state inside a DC wall bushing according to claim 1, characterized in that: The data processing module integrates a storage chip and a communication interface. The storage chip is used to cache the collected raw data, and the communication interface supports MODBUS, CAN and Ethernet communication protocols.
10. The integrated detection system for the gas state inside a DC wall bushing according to claim 1, characterized in that: The data processing module has a built-in fault diagnosis algorithm that determines the potential fault risk of the equipment by analyzing the trend of historical data.