Ultraviolet and infrared composite optical method measuring system and method for SF6 gas

Abstract

The invention provides an ultraviolet and infrared composite optical method measuring system and method for SF6 gas, and relates to the field of SF6 gas measuration.The system comprises a composite light source module, the composite light source module comprises an ultraviolet light source and an infrared light source, and the ultraviolet light source and the infrared light source are coupled into the same light path in a wavelength division multiplexing mode; the device comprises an ultraviolet light source, an infrared light source, a single-light-path multi-pass absorption gas chamber and a dual-channel detection module, the single-light-path multi-pass absorption gas chamber is composed of a Herriott type multi-reflection pool, the ultraviolet light source and the infrared light source enter the Herriott type multi-reflection pool after being subjected to beam splitting and beam combining to delay an effective absorption light path, and the dual-channel detection module is composed of an ultraviolet photomultiplier and an MCT detector. The high sensitivity of the ultraviolet channel and the high specificity of the infrared channel are combined, complementary information is obtained from a physical source, and the detection sensitivity and the measurement accuracy of the SF6 gas concentration are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of SF6 gas measurement technology, and in particular to an ultraviolet-infrared composite optical measurement system and method for SF6 gas. Background Technology

[0002] SF6 gas is widely used in power equipment such as high-voltage switches and GIS (gas-insulated switchgear) due to its excellent insulation and arc-quenching properties. However, SF6 is also a potent greenhouse gas, and its leakage monitoring is crucial. Currently, optical detection methods for SF6 are mainly divided into two categories: infrared absorption method and ultraviolet absorption method. Neither infrared nor ultraviolet methods alone can simultaneously meet the stringent requirements of high sensitivity, strong anti-interference capability, and long-term stability for power field monitoring. Although simply using the two methods in parallel can obtain two independent concentration values, it cannot solve the problem of false alarms caused by a single interference source. Therefore, this invention proposes an ultraviolet-infrared composite optical measurement system and method for SF6 gas to solve the problems existing in the prior art. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes an ultraviolet-infrared composite optical measurement system and method for SF6 gas. This system combines the high sensitivity of the ultraviolet channel with the high specificity of the infrared channel to acquire complementary information from the physical source, significantly improving the detection sensitivity and measurement accuracy of SF6 gas concentration. It is particularly suitable for monitoring low-concentration leaks. Employing a combined ultraviolet-infrared physical model and optimized inversion algorithm, it can simultaneously invert the SF6 concentration and the concentration of interfering gases, effectively identifying and eliminating water vapor, etc. Various on-site disturbances such as oil vapor and VOCs.

[0004] To achieve the objectives of this invention, the invention is implemented through the following technical solution: an ultraviolet-infrared composite optical measurement system for SF6 gas, comprising; A composite light source module, comprising an ultraviolet light source and an infrared light source, wherein the ultraviolet light source and the infrared light source are coupled into the same optical path via wavelength division multiplexing; A single-path multi-pass absorption gas chamber is composed of a Herriott-type multiple reflection cell. The ultraviolet light source and the infrared light source enter the Herriott-type multiple reflection cell after beam splitting and beam combining to delay the effective absorption optical path. A dual-channel detection module is provided, which consists of an ultraviolet photomultiplier tube and an MCT detector. The ultraviolet light source and the infrared light source are received by the ultraviolet photomultiplier tube and the MCT detector respectively after passing through a single-path multi-pass absorption gas chamber. The ultraviolet photomultiplier tube is used to receive ultraviolet signals, and the MCT detector is used to receive infrared signals. The environmental sensing module, the single-optical-path multi-pass absorption chamber is also equipped with a high-precision temperature sensor and a pressure sensor, which are used to compensate for the influence of environmental parameters on the absorption model in real time. The signal processing and main control module is configured to execute the joint optimization and inversion algorithm of the ultraviolet-infrared composite physical model and realize intelligent collaborative diagnosis and verification. The output and interaction module is used for SF6 concentration display, interference type indication, alarm triggering, and maintenance reminders.

[0005] The further improvement lies in the fact that the joint optimization and inversion algorithm of the ultraviolet-infrared composite physical model simultaneously solves for the concentration of SF6 gas and the concentration of interfering gases by constructing and minimizing a composite objective function that includes the ultraviolet absorbance residual and the infrared absorbance residual.

[0006] A further improvement is that the intelligent collaborative diagnosis and verification includes calculating the ultraviolet-infrared prediction consistency coefficient, and classifying and labeling the measurement results or triggering alarms based on the coefficient.

[0007] A further improvement lies in the following steps in constructing the joint optimization and inversion algorithm of the ultraviolet-infrared composite physical model: S1. Signal preprocessing and absorbance calculation: This involves processing the original ultraviolet signal... and infrared signals Perform filtering, baseline correction, and absorbance calculation: ; ; in, The ultraviolet reference light intensity without SF6 gas. The infrared reference light intensity without SF6 gas. The intensity of ultraviolet light detected by the ultraviolet photomultiplier tube. The infrared light intensity detected by the MCT detector; S2. Construct a composite physical model, in which... Ultraviolet channel model: The absorption of SF6 in the ultraviolet band can be approximated as a continuous absorption band, and the relationship between absorbance and concentration is as follows: ; in Where is the temperature-dependent absorption cross section, c is the SF6 gas concentration, T is the temperature, and L is the optical path length; Infrared channel model: The absorption of SF6 in the infrared band needs to consider the spectral line shape and pressure broadening. The absorbance is: ; in The linear intensity is a function of temperature. It is a linear function that describes the absorption line at its center frequency. The shape of the surrounding area depends on temperature T and pressure P; S3. Joint optimization inversion: When interfering gases are present, the total absorbance is the sum of the contributions from SF6 and interfering gases. The SF6 concentration is directly solved by constructing and minimizing the composite residual objective function. and the concentration of main interfering gases .

[0008] The further improvement lies in: the objective function for minimizing the composite residual is: ; in and These are the calculated original ultraviolet and infrared absorbances, respectively. and These are the model-predicted absorbances of SF6 gas in the ultraviolet and infrared channels, respectively. and It is a model that predicts absorbance for the ultraviolet and infrared channels of the interfering gas. It is a weighting factor, with a value range of 0.1-10, used to balance the residuals of the two channels.

[0009] A further improvement is made in that the steps of the intelligent collaborative diagnosis and verification include: T1, Consistency cross-validation, and the joint optimization inversion algorithm of the ultraviolet-infrared composite physical model invert the optimal result. ,Will Substituting the values ​​into independent ultraviolet and infrared channel models respectively, the theoretical absorbance is predicted. and Calculate the UV-IR prediction consistency coefficient. ,like A value close to 1 indicates that the height measurement is reliable. If the value is below the threshold, an interference alarm or a reliability downgrade will be triggered. T2. Identification of interference types and factors: Establishing a two-dimensional database of ultraviolet-infrared absorption features for typical interference scenarios (such as water vapor interference, oil vapor interference, and VOCs interference), and calculating the current measured (…). , The location of the point in the feature space is used to determine the most likely type of interference through a lightweight neural network, and the result is labeled accordingly. T3, closed-loop diagnosis and calibration trigger, long-term monitoring of health indicators such as light source intensity and detector responsivity. When the dual-channel signal deviates from the expected relationship for a long time and is not caused by external interference, it is judged that the performance of a certain optical channel has degraded (such as aging of the ultraviolet light source or wavelength drift of the infrared light source), and a maintenance reminder is triggered.

[0010] A further improvement lies in: the ultraviolet-infrared prediction consistency coefficient The calculation method is as follows: .

[0011] The measurement method of the above-mentioned ultraviolet-infrared combined optical method measurement system for SF6 gas includes the following steps: Step 1: Simultaneously collect ultraviolet and infrared absorption signals of the gas; Step 2: Perform joint optimization and inversion on the dual-channel signal based on the complex ultraviolet-infrared composite physical model to obtain the SF6 concentration; Step 3: Perform UV-IR prediction consistency verification on the inversion results. If the verification indicates interference, then calculate the current measurement based on real-time data. , The location of the point in the feature space is determined, and the specific type of interference factor is judged by using a lightweight neural network in conjunction with a two-dimensional feature database of ultraviolet absorption and infrared absorption.

[0012] The beneficial effects of this invention are as follows: By combining the high sensitivity of the ultraviolet channel and the high specificity of the infrared channel, complementary information is obtained from the physical source, significantly improving the detection sensitivity and measurement accuracy of SF6 gas concentration. It is particularly suitable for low-concentration leak monitoring. Employing a combined ultraviolet-infrared physical model and optimized inversion algorithm, it can simultaneously invert SF6 concentration and interfering gas concentrations, effectively identifying and eliminating water vapor, etc. The system effectively mitigates various on-site interferences such as oil vapor and VOCs, significantly reducing false alarm rates and improving monitoring reliability. It incorporates high-precision temperature and pressure sensors to monitor chamber environmental parameters in real time and dynamically compensates for absorption model fluctuations, minimizing the impact of environmental fluctuations on measurement results and enhancing system adaptability under complex operating conditions. The introduction of an ultraviolet-infrared prediction consistency coefficient enables dual-channel cross-validation, allowing for reliability grading and anomaly alarms for measurement results. Combined with a lightweight neural network and feature database, it can identify interference types in real time, enhancing system intelligence. The system continuously monitors key health indicators such as light source intensity and detector responsivity, proactively triggering maintenance reminders when optical channel performance degrades, achieving closed-loop diagnosis and calibration to ensure long-term stable operation. Attached Figure Description

[0013] Figure 1 This is an assembly diagram of the present invention. Detailed Implementation

[0014] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0015] according to Figure 1 As shown, this embodiment proposes an ultraviolet-infrared composite optical measurement system for SF6 gas, including: A composite light source module, comprising an ultraviolet light source and an infrared light source, wherein the ultraviolet light source and the infrared light source are coupled into the same optical path via wavelength division multiplexing; A single-path multi-pass absorption gas chamber is composed of a Herriott-type multiple reflection cell. The ultraviolet light source and the infrared light source enter the Herriott-type multiple reflection cell after beam splitting and beam combining to delay the effective absorption optical path. A dual-channel detection module is provided, which consists of an ultraviolet photomultiplier tube and an MCT detector. The ultraviolet light source and the infrared light source are received by the ultraviolet photomultiplier tube and the MCT detector respectively after passing through a single-path multi-pass absorption gas chamber. The ultraviolet photomultiplier tube is used to receive ultraviolet signals, and the MCT detector is used to receive infrared signals. The environmental sensing module, the single-optical-path multi-pass absorption chamber is also equipped with a high-precision temperature sensor and a pressure sensor, which are used to compensate for the influence of environmental parameters on the absorption model in real time. The signal processing and main control module is configured to execute the joint optimization and inversion algorithm of the ultraviolet-infrared composite physical model and realize intelligent collaborative diagnosis and verification. The output and interaction module is used for SF6 concentration display, interference type indication, alarm triggering, and maintenance reminders.

[0016] The ultraviolet-infrared composite physical model joint optimization inversion algorithm solves for SF6 gas concentration and interfering gas concentration simultaneously by constructing and minimizing a composite objective function that includes ultraviolet absorbance residuals and infrared absorbance residuals.

[0017] The intelligent collaborative diagnosis and verification includes calculating the ultraviolet-infrared prediction consistency coefficient and classifying and labeling the measurement results or triggering alarms based on the coefficient.

[0018] The construction steps of the joint optimization inversion algorithm of the ultraviolet-infrared composite physical model include: S1. Signal preprocessing and absorbance calculation: This involves processing the original ultraviolet signal... and infrared signals Perform filtering, baseline correction, and absorbance calculation: ; ; in, The ultraviolet reference light intensity without SF6 gas. The infrared reference light intensity without SF6 gas. The intensity of ultraviolet light detected by the ultraviolet photomultiplier tube. The infrared light intensity detected by the MCT detector; S2. Construct a composite physical model, in which... Ultraviolet channel model: The absorption of SF6 in the ultraviolet band can be approximated as a continuous absorption band, and the relationship between absorbance and concentration is as follows: ; in Where is the temperature-dependent absorption cross section, c is the SF6 gas concentration, T is the temperature, and L is the optical path length; Infrared channel model: The absorption of SF6 in the infrared band needs to consider the spectral line shape and pressure broadening. The absorbance is: ; in The linear intensity is a function of temperature. It is a linear function that describes the absorption line at its center frequency. The shape of the surrounding area depends on temperature T and pressure P; S3. Joint optimization inversion: When interfering gases are present, the total absorbance is the sum of the contributions from SF6 and interfering gases. The SF6 concentration is directly solved by constructing and minimizing the composite residual objective function. and the concentration of main interfering gases .

[0019] The objective function for minimizing the composite residual is: ; in and These are the calculated original ultraviolet and infrared absorbances, respectively. and These are the model-predicted absorbances of SF6 gas in the ultraviolet and infrared channels, respectively. and It is a model that predicts absorbance for the ultraviolet and infrared channels of the interfering gas. It is a weighting factor, with a value range of 0.1-10, used to balance the residuals of the two channels.

[0020] The steps of the intelligent collaborative diagnosis and verification include: T1, Consistency cross-validation, and the joint optimization inversion algorithm of the ultraviolet-infrared composite physical model invert the optimal result. ,Will Substituting the values ​​into independent ultraviolet and infrared channel models respectively, the theoretical absorbance is predicted. and Calculate the UV-IR prediction consistency coefficient. ,like A value close to 1 indicates that the height measurement is reliable. If the value is below the threshold, an interference alarm or a reliability downgrade will be triggered. T2. Identification of interference types and factors: Establishing a two-dimensional database of ultraviolet-infrared absorption features for typical interference scenarios (such as water vapor interference, oil vapor interference, and VOCs interference), and calculating the current measured (…). , The location of the point in the feature space is used to determine the most likely type of interference through a lightweight neural network, and the result is labeled accordingly. T3, closed-loop diagnosis and calibration trigger, long-term monitoring of health indicators such as light source intensity and detector responsivity. When the dual-channel signal deviates from the expected relationship for a long time and is not caused by external interference, it is judged that the performance of a certain optical channel has degraded (such as aging of the ultraviolet light source or wavelength drift of the infrared light source), and a maintenance reminder is triggered.

[0021] The ultraviolet-infrared prediction consistency coefficient The calculation method is as follows: .

[0022] The measurement method for the ultraviolet-infrared composite optical method measurement system used for the above-mentioned SF6 gas includes the following steps: Step 1: Simultaneously collect ultraviolet and infrared absorption signals of the gas; Step 2: Perform joint optimization and inversion on the dual-channel signal based on the complex ultraviolet-infrared composite physical model to obtain the SF6 concentration; Step 3: Perform UV-IR prediction consistency verification on the inversion results. If the verification indicates interference, then calculate the current measurement based on real-time data. , The location of the point in the feature space is determined, and the specific type of interference factor is judged by using a lightweight neural network in conjunction with a two-dimensional feature database of ultraviolet absorption and infrared absorption.

[0023] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A system for measurement of SF6 gas by UV-IR combined optical method, characterized in that: include; A composite light source module, comprising an ultraviolet light source and an infrared light source, wherein the ultraviolet light source and the infrared light source are coupled into the same optical path via wavelength division multiplexing; A single-path multi-pass absorption gas chamber is composed of a Herriott-type multiple reflection cell. The ultraviolet light source and the infrared light source enter the Herriott-type multiple reflection cell after beam splitting and beam combining to delay the effective absorption optical path. A dual-channel detection module is provided, which consists of an ultraviolet photomultiplier tube and an MCT detector. The ultraviolet light source and the infrared light source are received by the ultraviolet photomultiplier tube and the MCT detector respectively after passing through a single-path multi-pass absorption gas chamber. The ultraviolet photomultiplier tube is used to receive ultraviolet signals, and the MCT detector is used to receive infrared signals. The environmental sensing module, the single-optical-path multi-pass absorption chamber is also equipped with a high-precision temperature sensor and a pressure sensor, which are used to compensate for the influence of environmental parameters on the absorption model in real time. The signal processing and main control module is configured to execute the joint optimization and inversion algorithm of the ultraviolet-infrared composite physical model and realize intelligent collaborative diagnosis and verification. The output and interaction module is used for SF6 concentration display, interference type indication, alarm triggering, and maintenance reminders.

2. The system for measuring SF6 gas according to claim 1, wherein: The ultraviolet-infrared composite physical model joint optimization inversion algorithm solves for SF6 gas concentration and interfering gas concentration simultaneously by constructing and minimizing a composite objective function that includes ultraviolet absorbance residuals and infrared absorbance residuals.

3. The system for measuring SF6 gas according to claim 2, wherein: The intelligent collaborative diagnosis and verification includes, Calculate the UV-IR prediction consistency coefficient, and classify and label the measurement results or trigger alarms based on the coefficient.

4. The system for measuring SF6 gas according to claim 3, wherein: The construction steps of the joint optimization inversion algorithm of the ultraviolet-infrared composite physical model include: S1, signal pretreatment and absorbance calculation, the original ultraviolet signal and infrared signal are filtered, baseline corrected, and absorbance is calculated: ； ； in, The ultraviolet reference light intensity without SF6 gas. The infrared reference light intensity without SF6 gas. The intensity of ultraviolet light detected by the ultraviolet photomultiplier tube. The infrared light intensity detected by the MCT detector; S2. Construct a composite physical model, in which... Ultraviolet channel model: The absorption of SF6 in the ultraviolet band can be approximated as a continuous absorption band, and the relationship between absorbance and concentration is as follows: ； in Where is the temperature-dependent absorption cross section, c is the SF6 gas concentration, T is the temperature, and L is the optical path length; Infrared channel model: The absorption of SF6 in the infrared band needs to consider the spectral line shape and pressure broadening. The absorbance is: ； in The linear intensity is a function of temperature. It is a linear function that describes the absorption line at its center frequency. The shape of the surrounding area depends on temperature T and pressure P; S3. Joint optimization inversion: When interfering gases are present, the total absorbance is the sum of the contributions from SF6 and interfering gases. The SF6 concentration is directly solved by constructing and minimizing the composite residual objective function. and the concentration of main interfering gases .

5. The ultraviolet-infrared composite optical measurement system for SF6 gas according to claim 4, characterized in that: The objective function for minimizing the composite residual is: ； in and These are the calculated original ultraviolet and infrared absorbances, respectively. and These are the model-predicted absorbances of SF6 gas in the ultraviolet and infrared channels, respectively. and It is a model that predicts absorbance for the ultraviolet and infrared channels of the interfering gas. It is a weighting factor with a value range of 0.1-10, used to balance the residuals of the two channels.

6. The ultraviolet-infrared composite optical measurement system for SF6 gas according to claim 5, characterized in that: The steps of the intelligent collaborative diagnosis and verification include: T1, Consistency cross-validation, and the joint optimization inversion algorithm of the ultraviolet-infrared composite physical model invert the optimal result. ,Will Substituting the values ​​into independent ultraviolet and infrared channel models respectively, the theoretical absorbance is predicted. and Calculate the UV-IR prediction consistency coefficient. ,like A value close to 1 indicates that the height measurement is reliable. If the value is below the threshold, an interference alarm or a reliability downgrade will be triggered. T2. Identification of interference types and factors: Establishing a two-dimensional database of ultraviolet-infrared absorption features for typical interference scenarios (such as water vapor interference, oil vapor interference, and VOCs interference), and calculating the current measured (…). , The location of the point in the feature space is used to determine the most likely type of interference through a lightweight neural network, and the result is labeled accordingly. T3, closed-loop diagnosis and calibration trigger, long-term monitoring of health indicators such as light source intensity and detector responsivity. When the dual-channel signal deviates from the expected relationship for a long time and is not caused by external interference, it is judged that the performance of a certain optical channel has degraded (such as aging of the ultraviolet light source or wavelength drift of the infrared light source), and a maintenance reminder is triggered.

7. The ultraviolet-infrared composite optical measurement system for SF6 gas according to claim 6, characterized in that: The ultraviolet-infrared prediction consistency coefficient The calculation method is as follows: 。 8. A measurement method for an ultraviolet-infrared composite optical measurement system for SF6 gas according to claim 7, characterized in that: Includes the following steps: Step 1: Simultaneously collect ultraviolet and infrared absorption signals of the gas; Step 2: Perform joint optimization and inversion on the dual-channel signal based on the complex ultraviolet-infrared composite physical model to obtain the SF6 concentration; Step 3: Perform UV-IR prediction consistency verification on the inversion results. If the verification indicates interference, then calculate the current measurement based on real-time data. , The location of the point in the feature space is determined, and the specific type of interference factor is judged by using a lightweight neural network in conjunction with a two-dimensional feature database of ultraviolet absorption and infrared absorption.

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