A method for detecting the gas tightness of ring main units based on sensor and temperature control calibration

Abstract

This invention discloses a method for detecting the gas tightness of a ring main unit based on sensor and temperature control calibration, belonging to the field of gas tightness detection technology. It addresses the problem of decreased detection accuracy in low-temperature and high-humidity environments. By deploying pressure and gas concentration sensors and corresponding temperature control sensors within the ring main unit, the surface temperature is monitored in real time, and a heating range is set. The heating device is activated based on the temperature. During heating, detection points are set to collect pressure and gas concentration changes, calculate the rate of change to generate a calibration delay factor, and adjust the calibration time. After heating, an observation time is set to collect temperature drop characteristics and calculate the drop efficiency. Candidate sensors are selected through comparison, and a sensitivity test is performed to calculate the sensitivity temperature coefficient. The drop efficiency is then used to determine whether to enter the calibration state prematurely, thereby improving the measurement accuracy of gas tightness detection in ring main units and the response stability of sensors in low-temperature and high-humidity environments.

Description

Technical Field

[0001] This invention relates to the field of gas tightness detection technology, and more specifically, to a method for detecting the gas tightness status of a ring main unit based on sensor and temperature control calibration. Background Technology

[0002] As an important piece of equipment in the power distribution system, the ring main unit is usually filled with sulfur hexafluoride or other insulating gases to ensure electrical insulation performance and arc extinguishing capability. The gas sealing performance is directly related to the safety and stability of the ring main unit operation. Once the sealing performance deteriorates, gas leakage will not only lead to reduced insulation performance and increased risk of partial discharge of the equipment, but also cause environmental pollution and misjudgment of detection.

[0003] The existing technology has the following shortcomings:

[0004] Currently, existing technologies rely solely on single pressure or concentration monitoring methods. Over time, fine moisture seeps into the ring main unit, and the lack of dynamic temperature calibration and condensation risk assessment mechanisms prevents real-time compensation for sensor thermal stability and adaptive adjustment of calibration timing. This results in decreased detection accuracy and unstable response characteristics in low-temperature and high-humidity environments, and detection delays and inaccuracies after condensation. Consequently, it is difficult to ensure accurate identification of leakage status under complex operating conditions, reducing the reliability and long-term stability of seal detection. Therefore, a gas sealing status detection method for ring main units based on sensor and temperature control calibration is proposed.

[0005] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide a method for detecting the gas sealing status of a ring main unit based on sensor and temperature control calibration. This method addresses the problems mentioned in the background art by employing dual-sensor collaborative detection, dynamic temperature compensation, and a pre-calibration mechanism for condensation risk.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for detecting the gas sealing status of a ring main unit based on sensor and temperature control calibration, comprising the following steps:

[0008] Step S1: Use the temperature control sensors at the corresponding positions of the pressure sensor and gas concentration sensor installed inside the ring network cabinet to monitor the surface temperature of the pressure sensor and gas concentration sensor in real time, set the heating zone, and activate the heating device to heat the pressure sensor and gas concentration sensor according to the heating zone where the surface temperature is located.

[0009] Step S2: During the heating process of the pressure sensor and the gas concentration sensor, a detection point is set. Pressure and gas concentration are detected at the detection point to obtain the pressure change rate and gas change rate. The pressure change rate and gas change rate are combined to generate a calibration delay factor.

[0010] Step S3: Call the calibration time point, delay the calibration time point according to the calibration delay factor, set the observation time after heating is completed, collect the temperature drop characteristics of the pressure sensor and gas concentration sensor and calculate the corresponding temperature drop efficiency.

[0011] Step S4: Compare the temperature drop efficiency of the pressure sensor and the gas concentration sensor to select candidate sensors, input the test command to perform sensitivity tests on the candidate sensors and calculate the sensitivity temperature coefficient, and analyze whether to enter the calibration state in advance based on the corresponding temperature drop efficiency.

[0012] In a preferred embodiment, in step S1, the surface temperature of the pressure sensor and the gas concentration sensor at the corresponding positions inside the ring main unit is monitored in real time using a temperature control sensor.

[0013] The logic for obtaining the surface temperature of the pressure sensor is that the temperature control sensor collects the output temperature value of the pressure sensor surface and uses it as the ambient temperature of the pressure sensor.

[0014] The logic for obtaining the ambient temperature of the gas concentration sensor is that the temperature control sensor collects the output temperature value of the gas concentration sensor surface and uses it as the ambient temperature of the gas concentration sensor.

[0015] In a preferred embodiment, in step S1, the surface temperatures of the pressure sensor and the gas concentration sensor are respectively substituted into the temperature threshold for comparative analysis.

[0016] If the surface temperature of the pressure sensor is greater than or equal to the temperature threshold, the pressure sensor will not be heated.

[0017] If the surface temperature of the pressure sensor is lower than the temperature threshold, then the surface temperature of the pressure sensor is substituted into the set heating range.

[0018] If the surface temperature of the gas concentration sensor is greater than or equal to the temperature threshold, the gas concentration sensor will not be heated.

[0019] If the surface temperature of the gas concentration sensor is lower than the temperature threshold, then the surface temperature of the gas concentration sensor is substituted into the set heating range.

[0020] Once the surface temperatures of the pressure sensor and the gas concentration sensor are substituted into the heating range, the heating device is activated to heat the pressure sensor and the gas concentration sensor according to the range in which the surface temperature is located.

[0021] In a preferred embodiment, in step S2, during the heating process of the pressure sensor and the gas concentration sensor, multiple detection points are set during the heating process, and pressure detection and gas concentration detection are performed on the pressure sensor and the gas concentration sensor at the detection points.

[0022] During the heating process, pressure values ​​are continuously collected at each detection point. The pressure difference between adjacent detection points is calculated and the ratio of the pressure difference to the time interval between adjacent detection points is calculated to obtain the pressure change rate. All pressure change rates during the heating process are accumulated and the ratio of the total number of pressure change rates is calculated to obtain the pressure change percentage.

[0023] In a preferred embodiment, in step S2, gas concentration values ​​are continuously collected at detection points during the heating process. The difference between the gas concentration values ​​at adjacent detection points is calculated and the ratio of the time interval between adjacent detection points is calculated to obtain the concentration change rate. The average of all concentration change rates during the heating process is calculated to obtain the gas change rate.

[0024] The pressure change rate and gas change rate are standardized, and the calibration delay factor is obtained by weighted summation of the standardized pressure change rate and gas change rate.

[0025] In a preferred embodiment, in step S3, the calibration time point closest to the current time point is retrieved from the calibration database, and the difference between the current time point and the calibration time point is calculated to obtain the distance to the calibration period.

[0026] The distance calibration period is calculated by multiplying the distance calibration period and the calibration delay factor. The distance calibration period and the delay period are then added together to obtain the calibration delay period. The end time of the calibration delay period is taken as the delayed calibration time point.

[0027] In a preferred embodiment, in step S3, after the heating is completed, an observation time is set, and the temperature drop characteristics of the pressure sensor and the gas concentration sensor are collected to obtain the temperature drop values ​​of the pressure sensor and the gas concentration sensor during the observation time.

[0028] Within the set observation time, the initial temperature at the start of the observation time and the end temperature at the end of the observation time for the pressure sensor and the gas concentration sensor were recorded respectively. The temperature reduction efficiency of the pressure sensor was calculated by calculating the difference between the initial temperature at the start of the observation time and the end temperature at the end of the observation time and then comparing it with the observation time. Similarly, the temperature reduction efficiency of the gas concentration sensor was calculated by calculating the difference between the initial temperature at the start of the observation time and the end temperature at the end of the observation time and then comparing it with the observation time.

[0029] In a preferred embodiment, in step S4, the temperature drop efficiency of the pressure sensor and the temperature drop efficiency of the gas concentration sensor are compared numerically.

[0030] If the temperature drop efficiency of the pressure sensor is greater than that of the gas concentration sensor, then the pressure sensor is marked as a candidate sensor.

[0031] If the temperature drop efficiency of the gas concentration sensor is greater than that of the pressure sensor, then the gas concentration sensor is marked as a candidate sensor.

[0032] If the temperature drop efficiency of the pressure sensor and the temperature drop efficiency of the gas concentration sensor are the same, then either the pressure sensor or the gas concentration sensor is randomly selected as the candidate sensor.

[0033] In a preferred embodiment, in step S4, a test command is input to the candidate sensor to perform a sensitivity test on the candidate sensor, the current temperature at the candidate sensor after the observation time ends is recorded, the detection temperature is set, and the temperature of the candidate sensor is recorded when it drops to the detection temperature. At the current temperature and the detection temperature after the observation time ends, the same standard input is applied and the corresponding output changes are recorded.

[0034] The output difference is obtained by calculating the difference between the signal amplitude output by the candidate sensor at the detection temperature and the signal amplitude output at the current temperature after the observation period ends. The temperature difference is obtained by calculating the difference between the detection temperature and the current temperature. The sensitivity temperature coefficient is obtained by calculating the difference between the output difference and the product of the temperature difference and the signal amplitude output at the current temperature, and taking the absolute value.

[0035] In a preferred embodiment, in step S4, the temperature drop efficiency and the sensitivity temperature coefficient are standardized and substituted into the polynomial regression formula to calculate the condensation risk coefficient.

[0036] The condensation risk coefficient is compared and analyzed with the preset condensation threshold.

[0037] If the condensation risk coefficient is greater than or equal to the condensation threshold, then the calibration state will be entered in advance.

[0038] If the condensation risk coefficient is less than the condensation threshold, there is no need to enter the calibration state in advance.

[0039] The technical effects and advantages of this invention are as follows:

[0040] This invention utilizes temperature control sensors at corresponding locations of pressure sensors and gas concentration sensors within a ring main unit to monitor their surface temperatures in real time and set heating zones. Heating devices are activated based on these temperature zones to heat both types of sensors. During heating, detection points are set to monitor pressure and gas concentration to calculate pressure and gas change rates. A calibration delay factor is generated, and the calibration time point is adjusted accordingly. After heating, an observation period is set, and the temperature drop characteristics of both types of sensors are collected to calculate the drop efficiency. Candidate sensors are selected through comparison, and a test command is input to perform sensitivity testing and calculate the sensitivity temperature coefficient. The drop efficiency is used to determine whether to prematurely enter calibration mode. This improves the measurement accuracy of gas seal detection in ring main units and the response stability of sensors in low-temperature and high-humidity environments. It reduces detection delays and inaccuracies caused by sensor condensation or sensitivity decay, ensuring accurate identification of leaks even under low-temperature and high-humidity conditions, and enhancing the reliability and long-term stability of seal detection. Attached Figure Description

[0041] Figure 1 This is a flowchart illustrating the implementation of the gas sealing status detection method for ring main units based on sensor and temperature control calibration according to the present invention.

[0042] Figure 2 This is a schematic diagram illustrating the steps of the ring main unit gas sealing status detection method based on sensor and temperature control calibration according to the present invention. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] This invention utilizes temperature control sensors at corresponding locations of pressure sensors and gas concentration sensors deployed within a ring main unit to monitor their surface temperatures in real time and set heating zones. Heating devices are activated based on these temperature zones to heat both types of sensors. During heating, detection points are set to monitor pressure and gas concentration to calculate pressure and gas change rates. A calibration delay factor is generated, and the calibration time point is adjusted accordingly. After heating, an observation period is set, and the temperature drop characteristics of both types of sensors are collected to calculate the drop efficiency. Candidate sensors are selected through comparison, and a test command is input to perform sensitivity testing and calculate the sensitivity temperature coefficient. The drop efficiency is used to determine whether to prematurely enter the calibration state. This improves the measurement accuracy of gas sealing detection in ring main units and the response stability of sensors in low-temperature and high-humidity environments, while reducing detection delays and inaccuracies caused by sensor condensation or sensitivity decay.

[0045] Example 1

[0046] Please see Figures 1 to 2 The specific operation procedure for detecting the gas sealing status of ring main units based on sensor and temperature control calibration is as follows:

[0047] Step S1: Use the temperature control sensors at the corresponding positions of the pressure sensor and gas concentration sensor installed inside the ring network cabinet to monitor the surface temperature of the pressure sensor and gas concentration sensor in real time, set the heating zone, and activate the heating device to heat the pressure sensor and gas concentration sensor according to the heating zone where the surface temperature is located.

[0048] Step S2: During the heating process of the pressure sensor and the gas concentration sensor, a detection point is set. Pressure and gas concentration are detected at the detection point to obtain the pressure change rate and gas change rate. The pressure change rate and gas change rate are combined to generate a calibration delay factor.

[0049] Step S3: Call the calibration time point, delay the calibration time point according to the calibration delay factor, set the observation time after heating is completed, collect the temperature drop characteristics of the pressure sensor and gas concentration sensor and calculate the corresponding temperature drop efficiency.

[0050] Step S4: Compare the temperature drop efficiency of the pressure sensor and the gas concentration sensor to select candidate sensors, input the test command to perform sensitivity tests on the candidate sensors and calculate the sensitivity temperature coefficient, and analyze whether to enter the calibration state in advance based on the corresponding temperature drop efficiency.

[0051] The specific implementation process is as follows:

[0052] In step S1, pressure sensors and gas concentration sensors installed inside the ring main unit are used to monitor the gas chamber pressure and target gas concentration inside the ring main unit in real time, respectively. The pressure fluctuation characteristics and concentration decay curve during the gas leakage process are obtained. Combined with the monitoring time sequence information, the gas leakage trend is analyzed to complete the detection of the gas sealing status of the ring main unit.

[0053] The pressure sensor and gas concentration sensor are placed inside the ring main unit to directly collect pressure and gas concentration data inside the cavity, avoid interference from external environmental factors, and ensure the correspondence and real-time nature of the detection data with the gas sealing status inside the ring main unit.

[0054] The surface temperature of the pressure sensor and gas concentration sensor is monitored in real time using temperature control sensors located at corresponding positions inside the ring main unit.

[0055] The temperature control sensor was placed in the positions corresponding to the pressure sensor and gas concentration sensor by the researchers based on the airflow circulation path inside the ring main unit and the heat dissipation rate distribution of the sensor. The specific location and angle of the sensor were not limited and will not be described in detail here.

[0056] It should be noted that the temperature control sensor is a detection element used to collect the surface temperature changes of the pressure sensor and the gas concentration sensor in real time. It converts the temperature signal into an electrical signal output through a built-in high-precision thermistor to realize the monitoring of the working surface temperature of the pressure sensor and the adjustment and control of the heating range.

[0057] The logic for obtaining the surface temperature of the pressure sensor is that the temperature control sensor collects the output temperature value of the pressure sensor surface and uses it as the ambient temperature of the pressure sensor.

[0058] The logic for obtaining the ambient temperature of the gas concentration sensor is that the temperature control sensor collects the output temperature value of the gas concentration sensor surface and uses it as the ambient temperature of the gas concentration sensor.

[0059] The surface temperatures of the pressure sensor and the gas concentration sensor were respectively substituted into the temperature threshold for comparative analysis.

[0060] If the surface temperature of the pressure sensor is greater than or equal to the temperature threshold, the pressure sensor will not be heated.

[0061] If the surface temperature of the pressure sensor is lower than the temperature threshold, then the surface temperature of the pressure sensor is substituted into the set heating range.

[0062] If the surface temperature of the gas concentration sensor is greater than or equal to the temperature threshold, the gas concentration sensor will not be heated.

[0063] If the surface temperature of the gas concentration sensor is lower than the temperature threshold, then the surface temperature of the gas concentration sensor is substituted into the set heating range.

[0064] It should be noted that the temperature threshold was set by our researchers based on the optimal operating temperature range of the pressure sensor and the gas concentration sensor and the critical condensation temperature of the gas inside the ring main unit, which will not be elaborated here.

[0065] Furthermore, if the surface temperatures of both the pressure sensor and the gas concentration sensor are greater than or equal to the temperature threshold, no further operations are performed, and the message "Current ring main unit internal temperature is compatible" is generated and sent to the visualization port. If the surface temperature of either the pressure sensor or the gas concentration sensor (sensor refers to the pressure sensor and the gas concentration sensor) is greater than or equal to the temperature threshold, the sensor with a temperature lower than the temperature threshold is substituted into the set heating range and monitored separately, without performing any further operations, and a "Real-time monitoring result visualization table" is generated and sent to the visualization port. If the surface temperatures of both the pressure sensor and the gas concentration sensor are lower than the temperature threshold, then the subsequent operations are performed.

[0066] The heating zone is set by the power response rate and temperature linear adjustment law of the heating device, and the corresponding heating zone is selected for heating according to the range of surface temperature.

[0067] Specific examples are as follows: When the surface temperatures of both the pressure sensor and the gas concentration sensor are below the temperature threshold, the heating zone is set with the first, second, and third zones of recognition temperature. Each zone corresponds to three heating levels: high, medium, and low. If the surface temperature of the pressure sensor is in the second zone, the medium heating level is executed; if the surface temperature of the gas concentration sensor is in the third zone, the low heating level is executed, and so on. The specific number of heating levels is not limited. The adjustment and setting of the zone range are set by the researchers based on the thermal stability of the gas inside the ring main unit and the efficiency of gas pressure change with temperature, which will not be elaborated here.

[0068] Once the surface temperatures of the pressure sensor and the gas concentration sensor are substituted into the heating range, the heating device is activated to heat the pressure sensor and the gas concentration sensor according to the range in which the surface temperature is located.

[0069] In step S2, during the heating process of the pressure sensor and the gas concentration sensor, multiple detection points are set during the heating process, and pressure detection and gas concentration detection are performed on the pressure sensor and the gas concentration sensor at the detection points.

[0070] Specifically, the detection points were set by our personnel based on the gas flow path inside the ring main unit and the sensor response time distribution. The specific number of points set is not limited and will not be elaborated here.

[0071] Furthermore, at the detection point, pressure and gas concentration are detected by directly reading the pressure signal and gas concentration signal of the pressure sensor and gas concentration sensor, respectively. The specific detection process is as follows: the experimenter or control system directly records the pressure reading of the pressure sensor and the concentration reading of the gas concentration sensor at the detection point. The pressure change and gas concentration change are calculated by combining the time series data before and after the detection point. This data is used to analyze the gas leakage trend and sealing status inside the ring main unit.

[0072] Furthermore, the detection points are set up until the heating process ends, meaning the detection points cover the entire heating process;

[0073] The pressure change rate is the rate at which pressure changes during the entire heating process. Its acquisition logic is to continuously collect pressure values ​​at detection points during the heating process, calculate the difference between the pressure values ​​of adjacent detection points and the ratio of the time interval between adjacent detection points to obtain the pressure change rate, and accumulate all pressure change rates during the heating process and the ratio of the sum of all pressure change rates to the number of pressure change rates to obtain the pressure change rate.

[0074] It should be noted that the pressure values ​​at adjacent detection points are the instantaneous pressure values ​​collected by the pressure sensor at the continuous detection points. The time interval between adjacent detection points is the sampling time between two consecutive detection points. The value of this time interval is not limited, but is set by the researchers based on the rate of change of gas pressure inside the ring main unit and the power response characteristics of the heating device, and will not be elaborated here.

[0075] The gas change rate is the rate at which the gas concentration changes during the entire heating process by the gas concentration sensor. It is used to reflect the stability of the gas sealing state inside the ring main unit. Its acquisition logic is to continuously collect gas concentration values ​​at detection points during the heating process, calculate the difference between the gas concentration values ​​at adjacent detection points and the ratio of the difference to the time interval between adjacent detection points to obtain the concentration change rate, and average all concentration change rates during the heating process to obtain the gas change rate.

[0076] It should be noted that the process of averaging all concentration change rates during the heating process involves summing all concentration change rates during the heating process and calculating the gas change rate by ratio with the number of concentration change rates. This will not be elaborated here.

[0077] Furthermore, to ensure the reliability and representativeness of the gas change rate, abnormal or abrupt concentration change rates can be eliminated or weighted during the calculation process to reduce the impact of occasional interference on the gas change rate.

[0078] The pressure change rate and the gas change rate are standardized so that they are under the same dimension and the numerical range is between 0 and 1.

[0079] It should be noted that the standardization methods include, but are not limited to, standard linear transformation based on interval scaling, statistical Z-Score standardization method, or normalization method based on nonlinear mapping function. The application methods of standardization will not be elaborated here.

[0080] The calibration delay factor is obtained by weighted summation of the pressure change rate and gas change rate after standardization.

[0081] The specific calculation formula is as follows:

[0082] ;

[0083] In the formula, To calibrate the lag factor, The pressure change rate after standardization. The gas change rate after standardization. and Here, c is the weighting parameter, and c is the adjustment parameter to prevent the calibration delay factor from being negative.

[0084] It should be noted that when the pressure change rate and gas change rate are larger, it indicates that the gas sealing state inside the ring main unit is unstable or there is a tendency to leak. In this case, the smaller the calibration delay factor, the less the calibration time point should be delayed. Conversely, when the pressure change rate and gas change rate are smaller, it indicates that the gas sealing state inside the ring main unit is relatively stable. In this case, the larger the calibration delay factor, the more the calibration time point can be delayed.

[0085] Specifically, the calibration time point is a predetermined calibration time set based on the historical calibration records of the sensors inside the ring main unit and the operating cycle. At the calibration time, the pressure sensor and the gas concentration sensor are calibrated using a standard gas source or a known reference pressure and gas concentration to ensure the accuracy and reliability of the gas sealing status detection of the ring main unit.

[0086] Furthermore, the calibration time point is preset into the execution command by the experimenters according to the system control program. When the built-in clock reaches the calibration time point, a calibration trigger signal is generated to calibrate the pressure sensor and the gas concentration sensor, which will not be elaborated here.

[0087] In step S3, the calibration database is used to retrieve the calibration time point closest to the current time point, and the difference between the current time point and the calibration time point is calculated to obtain the distance to the calibration period.

[0088] The calibration database is used to store the historical calibration records and corresponding time information of the pressure sensor and gas concentration sensor inside the ring network cabinet. The calibration time point closest to the current time point refers to the preset calibration time point that is closest to the current time point on the time axis after the current time point, that is, the first subsequent calibration time point. The current time point is the current time point when the calibration time point is called.

[0089] The distance calibration period is calculated by multiplying the distance calibration period and the calibration delay factor. The distance calibration period and the delay period are added together to obtain the calibration delay period. The end time of the calibration delay period is taken as the delayed calibration time point, thus completing the delay processing of the calibration time point.

[0090] After heating is complete, set the observation time, collect the temperature drop characteristics of the pressure sensor and gas concentration sensor, and obtain the temperature drop values ​​of the pressure sensor and gas concentration sensor during the observation time.

[0091] It should be noted that the observation time was set by the researchers based on the thermal response characteristics of the pressure sensor and the gas concentration sensor and the heating power adjustment law, which will not be elaborated here.

[0092] The temperature decay efficiency of pressure sensors and gas concentration sensors characterizes the rate at which the temperature of the pressure sensors and gas concentration sensors decays per unit time after heating ends. The acquisition logic is as follows: within a set observation time, the initial temperature at the start of the observation time and the end temperature at the end of the observation time for pressure sensors and gas concentration sensors are recorded respectively. The difference between the initial temperature at the start of the observation time and the end temperature at the end of the observation time for pressure sensors is calculated, and then the ratio is calculated to obtain the temperature decay efficiency of pressure sensors. Similarly, the difference between the initial temperature at the start of the observation time and the end temperature at the end of the observation time for gas concentration sensors is calculated, and then the ratio is calculated to obtain the temperature decay efficiency of gas concentration sensors.

[0093] It should be explained that the initial temperature and the end temperature of the observation time for the pressure sensor and the gas concentration sensor are provided by the temperature signal collected and output by the temperature control sensor. The specific collection method is not limited and will not be elaborated here.

[0094] In step S4, the temperature drop efficiency of the pressure sensor and the temperature drop efficiency of the gas concentration sensor are compared numerically.

[0095] If the temperature drop efficiency of the pressure sensor is greater than that of the gas concentration sensor, then the pressure sensor is marked as a candidate sensor.

[0096] If the temperature drop efficiency of the gas concentration sensor is greater than that of the pressure sensor, then the gas concentration sensor is marked as a candidate sensor.

[0097] If the temperature drop efficiency of the pressure sensor and the temperature drop efficiency of the gas concentration sensor are the same, then either the pressure sensor or the gas concentration sensor is randomly selected as the candidate sensor.

[0098] Furthermore, when randomly selecting a pressure sensor or a gas concentration sensor as a candidate sensor, the randomization rule is based on a random number generation algorithm or probability allocation strategy set by the researchers. The specific implementation of the algorithm or strategy is common knowledge to those skilled in the art and will not be elaborated here.

[0099] Input test commands to the candidate sensor to perform sensitivity tests on the candidate sensor, record the current temperature at the candidate sensor after the observation time ends, set the detection temperature, and wait for the candidate sensor temperature to drop to the detection temperature before recording. At the current temperature and detection temperature after the observation time ends, apply the same and known standard input (standard pressure or standard gas concentration) and record the corresponding output changes.

[0100] Among them, the sensitivity test is to execute the sensitivity calibration command to trigger the temperature sensitivity measurement process of the candidate sensor;

[0101] Furthermore, the detection temperature was set by the researchers based on the temperature operating range of the candidate sensor and the rate of change of the temperature gradient after heating. The same, known standard input was applied as a standard pressure source or standard concentration gas source for sensitivity comparison. The output change was the response difference signal of the candidate sensor to the same standard input at two temperature points.

[0102] The logic for obtaining the sensitivity temperature coefficient is to calculate the difference between the signal amplitude output by the candidate sensor at the detection temperature and the signal amplitude output at the current temperature after the observation period ends, obtain the output difference, calculate the difference between the detection temperature and the current temperature, calculate the temperature difference by multiplying the output difference by the product of the temperature difference and the signal amplitude output at the current temperature, and take the absolute value to obtain the sensitivity temperature coefficient.

[0103] Specifically, the formula for calculating the temperature coefficient of sensitivity is as follows:

[0104] ;

[0105] In the formula, The temperature coefficient of sensitivity. This represents the relative rate of change of sensor sensitivity with temperature. To detect the amplitude of the output signal at the temperature, The signal amplitude output at the current temperature after the observation period ends. To output the difference, To detect temperature, The current temperature after the observation period ends. For temperature difference;

[0106] The temperature reduction efficiency and the sensitivity temperature coefficient are standardized so that they are on the same dimension and their values ​​are between 0 and 1.

[0107] It should be noted that the standardization process has been described in the above embodiments and will not be repeated here;

[0108] The condensation risk coefficient is calculated by substituting the standardized temperature drop efficiency and sensitivity temperature coefficient into a multinomial regression formula, as shown in the following formula:

[0109] ;

[0110] In the formula, To account for the condensation risk factor, To standardize the temperature drop efficiency, The temperature coefficient of sensitivity after standardization. To adjust the parameters, as well as The weighting coefficients corresponding to the temperature drop efficiency and sensitivity temperature coefficient after standardization;

[0111] It should be noted that when the temperature reduction efficiency and the temperature coefficient of sensitivity are larger, it means that the response characteristics of the candidate sensor are more unstable due to temperature, the thermal drift effect is more obvious, the temperature change has a stronger impact on the output characteristics, and the condensation risk coefficient is greater. This proves that the probability of condensation caused by the current heating treatment is greater, and it is more necessary to enter the calibration state in advance to avoid spectral signal distortion, decreased detection sensitivity, and the resulting misjudgment or missed detection.

[0112] The condensation risk coefficient is compared and analyzed with the preset condensation threshold.

[0113] If the condensation risk coefficient is greater than or equal to the condensation threshold, then the calibration state will be entered in advance.

[0114] If the condensation risk coefficient is less than the condensation threshold, there is no need to enter the calibration state in advance;

[0115] It should be noted that the condensation threshold was set by our researchers based on the frequency of humidity change inside the ring main unit and the difference between the surface temperature of the candidate sensor and the ambient dew point temperature, which will not be elaborated here.

[0116] Furthermore, when entering the calibration state ahead of schedule, the experimenters can set up an advance signal to switch the calibration time point to the immediate calibration state and send it to the visualization port with the words "early calibration".

[0117] Finally, it should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0118] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0119] In this document, the singular forms “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that terms such as “comprising / including” or “having” specify the presence of the stated features, integrals, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integrals, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0120] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0121] The above description of the disclosed embodiments will enable those skilled in the art to make or use various modifications to these embodiments. It will be readily apparent to those skilled in the art that the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting the gas sealing state of a ring main unit based on sensor and temperature control calibration, characterized in that: Comprising the following steps: Step S1: The surface temperature of the pressure sensor and the gas concentration sensor is monitored in real time by using the pressure sensor and the temperature control sensor at the corresponding position of the gas concentration sensor arranged inside the ring main unit, a heating interval is set, and the heating device is enabled according to the heating interval where the surface temperature is located to heat the pressure sensor and the gas concentration sensor; Step S2: During the heating process of the pressure sensor and the gas concentration sensor, a detection point is set, the pressure sensor and the gas concentration sensor are detected at the detection point to obtain the pressure change rate and the gas change rate, and the calibration delay factor is generated by comprehensively considering the pressure change rate and the gas change rate; Step S3: The calibration time point is called, the calibration time point is delayed according to the calibration delay factor, an observation time is set after heating is completed, the temperature drop characteristics of the pressure sensor and the gas concentration sensor are collected, and the corresponding temperature drop efficiency is calculated; Step S4: The temperature drop efficiency of the pressure sensor and the gas concentration sensor is compared to select a candidate sensor, a test instruction is input to test the sensitivity of the candidate sensor and calculate the sensitivity temperature coefficient, and whether to enter the calibration state in advance is analyzed in combination with the corresponding temperature drop efficiency.

2. The ring main unit gas sealing state detection method based on sensor and temperature control calibration according to claim 1, characterized in that: In step S1, the surface temperature of the pressure sensor and the gas concentration sensor is monitored in real time by using the temperature control sensor arranged at the corresponding position of the pressure sensor and the gas concentration sensor inside the ring main unit; The acquisition logic of the surface temperature of the pressure sensor is that the temperature control sensor collects the output temperature value of the surface of the pressure sensor as the environmental temperature of the pressure sensor; The acquisition logic of the environmental temperature of the gas concentration sensor is that the temperature control sensor collects the output temperature value of the surface of the gas concentration sensor as the environmental temperature of the gas concentration sensor.

3. The ring main unit gas sealing state detection method based on sensor and temperature control calibration according to claim 2, characterized in that: In step S1, the surface temperature of the pressure sensor and the gas concentration sensor is compared and analyzed by being substituted into the temperature threshold value respectively; If the surface temperature of the pressure sensor is greater than or equal to the temperature threshold value, the pressure sensor is not heated; If the surface temperature of the pressure sensor is less than the temperature threshold value, the surface temperature of the pressure sensor is substituted into the set heating interval; If the surface temperature of the gas concentration sensor is greater than or equal to the temperature threshold value, the gas concentration sensor is not heated; If the surface temperature of the gas concentration sensor is less than the temperature threshold value, the surface temperature of the gas concentration sensor is substituted into the set heating interval; After the surface temperature of the pressure sensor and the gas concentration sensor is substituted into the heating interval, the heating device is enabled to heat the pressure sensor and the gas concentration sensor according to the interval where the surface temperature is located.

4. The ring main unit gas sealing state detection method based on sensor and temperature control calibration according to claim 1, characterized in that: In step S2, during the heating process of the pressure sensor and the gas concentration sensor, a plurality of detection points are set during the heating process, and the pressure sensor and the gas concentration sensor are subjected to pressure detection and gas concentration detection at the detection points; During the heating process, the pressure values at the detection points are continuously collected, the pressure values at adjacent detection points are subjected to difference calculation, and the time intervals of the adjacent detection points are subjected to ratio calculation to obtain a pressure change rate, and all the pressure change rates during the heating process are accumulated and subjected to ratio calculation with the number of pressure change rates to obtain a pressure change rate.

5. The ring main unit gas sealing state detection method based on sensor and temperature control calibration according to claim 4, characterized in that: In step S2, during the heating process, the gas concentration values at the detection points are continuously collected, the gas concentration values at adjacent detection points are subjected to difference calculation, and the time intervals of the adjacent detection points are subjected to ratio calculation to obtain a concentration change rate, and all the concentration change rates during the heating process are subjected to average calculation to obtain a gas change rate; The pressure change rate and the gas change rate are subjected to standardization processing, and the pressure change rate and the gas change rate after the standardization processing are subjected to weighted summation operation to obtain a calibration delay factor.

6. The ring main unit gas sealing state detection method based on sensor and temperature control calibration according to claim 1, characterized in that: In step S3, the calibration database is called to obtain the calibration time point closest to the current time point, and the current time point and the calibration time point are subjected to difference calculation to obtain a distance calibration period; The distance calibration period and the calibration delay factor are subjected to product calculation to obtain a delay period, and the distance calibration period and the delay period are added to obtain a calibration delay period, and the end time point of the calibration delay period is taken as a delay calibration time point.

7. The ring main unit gas sealing state detection method based on sensor and temperature control calibration according to claim 6, characterized in that: In step S3, after waiting for the heating to be completed, an observation time is set, the temperature drop characteristics of the pressure sensor and the gas concentration sensor are collected to obtain the temperature drop values of the pressure sensor and the gas concentration sensor at the observation time; During the set observation time, the initial temperature and the observation time end temperature of the pressure sensor at the beginning of the observation time and the initial temperature and the observation time end temperature of the gas concentration sensor at the beginning of the observation time are recorded respectively, the initial temperature and the observation time end temperature of the pressure sensor at the beginning of the observation time are subjected to difference calculation and ratio calculation with the observation time to obtain a temperature drop efficiency of the pressure sensor, and the initial temperature and the observation time end temperature of the gas concentration sensor at the beginning of the observation time are subjected to difference calculation and ratio calculation with the observation time to obtain a temperature drop efficiency of the gas concentration sensor.

8. The ring main unit gas sealing state detection method based on sensor and temperature control calibration according to claim 1, characterized in that: In step S4, the temperature drop efficiency of the pressure sensor and the temperature drop efficiency of the gas concentration sensor are compared in value; If the temperature drop efficiency of the pressure sensor is greater than the temperature drop efficiency of the gas concentration sensor, the pressure sensor is marked as a candidate sensor. If the temperature drop efficiency of the gas concentration sensor is greater than that of the pressure sensor, the gas concentration sensor is marked as a candidate sensor; If the temperature drop efficiency of the pressure sensor and that of the gas concentration sensor are consistent, the pressure sensor or the gas concentration sensor is randomly selected as a candidate sensor.

9. The ring main unit gas sealing state detection method based on sensor and temperature control calibration according to claim 8, characterized in that: In step S4, the candidate sensor is subjected to sensitivity test by inputting a test instruction to the candidate sensor, the current temperature after the end of the observation time is recorded, the detection temperature is set, and the candidate sensor temperature is recorded when the candidate sensor temperature drops to the detection temperature; the same standard input is applied and the corresponding output change is recorded at the current temperature after the end of the observation time and the detection temperature; The output difference is obtained by difference calculation of the signal amplitude output by the candidate sensor at the detection temperature and the signal amplitude output at the current temperature after the end of the observation time, the temperature difference is obtained by difference calculation of the detection temperature and the current temperature, and the sensitivity temperature coefficient is obtained by difference calculation of the output difference, the product of the temperature difference and the signal amplitude output at the current temperature, and taking the absolute value.

10. The ring main unit gas sealing state detection method based on sensor and temperature control calibration according to claim 9, characterized in that: In step S4, the temperature drop efficiency and the sensitivity temperature coefficient are standardized, and the dew risk coefficient is calculated by substituting them into the polynomial regression formula; The dew risk coefficient is compared and analyzed with the preset dew threshold value; If the dew risk coefficient is greater than or equal to the dew threshold value, the calibration state is entered in advance; If the dew risk coefficient is less than the dew threshold value, the calibration state does not need to be entered in advance.

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