Insulation performance monitoring method for buried insulation facility

Abstract

The invention discloses a buried insulation facility insulation performance monitoring method. The method comprises the following steps: collecting power-on potentials; calculating and judging whether an average value of power-on potential differences is greater than or equal to a threshold value or not; collecting the power-on potentials more densely; calculating a variable coefficient and judging whether the variable coefficient exceeds the threshold value or not, calculating a correlation coefficient between the power-on potentials and judging whether the correlation coefficient exceeds the threshold value or not; the potential difference exceeds a threshold value after the current is applied. The monitoring method disclosed by the invention can be automatically executed by equipment, does not have tedious measurement steps, has low professional requirements on operators, realizes insulation performance judgment when potential fluctuation does not exist on the two sides of the insulation facility, eliminates the defect of performing insulation performance judgment through correlation under interference, ensures the reliability and accuracy of a monitoring result, and improves the reliability and the accuracy of the monitoring result. And misjudgment possibly caused by a single judgment condition is effectively avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of pipeline cathodic protection, and in particular relates to a method for monitoring the insulation performance of buried insulation facilities. Background Art

[0002] Buried insulation systems (such as insulating joints and flanges) are core components of cathodic protection systems for oil and gas pipelines. They provide regional cathodic protection, isolate stray current zones, and ensure effective dispersal of cathodic protection current. A deterioration or failure of their insulation performance will cause the cathodic protection current to dissipate from the protected object, leading to abnormal output of the cathodic protection control power supply and poor protection of the protected object. Buried insulation systems are typically tested using the potentiometric method, which measures the potential difference across the buried insulation system to determine insulation performance. When cathodic protection is applied to both sides of a buried insulation system, the protection current is adjusted for the pipeline at one end of the buried insulation system, while the pipe-to-ground potential at the other end is observed. If there is no significant change in the pipe-to-ground potential, the insulation performance of the buried insulation is considered good. Otherwise, the performance is questionable and requires retesting using methods such as voltage or leakage current methods. However, the potentiometric method has significant drawbacks: the measurement steps are cumbersome, the operator expertise is extremely high, and accurate assessments are difficult for ordinary managers to perform. Furthermore, continuous monitoring of insulation performance is difficult.

[0003] To this end, the prior art proposes a "Real-time Monitoring, Detection and Evaluation Method and Device for Insulation Devices" (Publication No. CN113866543A). By installing an intelligent potential collector on the inside and outside of the insulating joint, the on-state potential, off-state potential, AC interference voltage, DC current density and AC current density on the inside and outside of the insulating joint are synchronously collected. The collected data are grouped in pairs. Taking the on-state potential as an example, the on-state potential on one side of the insulating joint is used as the horizontal coordinate, and the on-state potential on the other side of the insulating joint is used as the vertical coordinate. A scatter plot is drawn, and then the scatter plot is linearly fitted to obtain the square of the Pearson correlation coefficient R. When the coefficient R is greater than 0.75, it is considered that the correlation is high and the insulating joint is abnormal, otherwise it is normal.

[0004] However, this existing technology still has shortcomings. When the potential inside and outside the insulating joint does not fluctuate, it cannot be monitored. More importantly, when there is interference from the regional cathodic protection on the line cathodic protection, the potential change on one side of the insulating joint will also cause the potential change on the other side of the insulating joint. In this case, if the insulating joint is tested and evaluated according to the working method of this existing technology, the evaluation results will inevitably be highly correlated, thus determining that the insulating joint is abnormal, which is an incorrect judgment. Summary of the Invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] To this end, one aspect of this application provides a method for monitoring the insulation performance of buried insulation facilities, comprising the following steps:

[0007] S10: The insulation detector collects the energized potential V of the pipelines at both ends of the insulation facility through sampling channels S1 and S2 respectively. on-1 and V on-2 , the acquisition time is T1, the acquisition frequency is f1, and multiple groups of power-on potentials V are obtained on-1 and V on-2 ;

[0008] S20: Calculate the average potential difference ΔV on-avg , ΔV on-avg =avg(V on-1 -V on-2 ); judge |ΔV on-avg | Is the potential difference greater than or equal to the set threshold M1? If the judgment result is yes, it is determined that the insulation performance of the insulation facility is good; if the judgment result is no, the process proceeds to step S30;

[0009] S30: The insulation detector collects the electrical potential V of the pipelines at both ends of the insulation facility through sampling channels S1 and S2 respectively. on-1 ' and V on-2 ', the acquisition time is T2, the acquisition frequency is f2, and multiple groups of power-on potentials V on-1 ' and V on-2 ', T2 is greater than T1, f2 is greater than f1;

[0010] S40: V on-1 ' and V on-2 'Collect and form the power-on potential arrays A1 and A2 respectively; calculate the coefficient of variation CV of the power-on potential arrays A1 and A2 respectively on1 and CV on2 ; Determine the coefficient of variation CV on1 and CV on2 Are they both greater than the volatility setting threshold M2? If the judgment result is yes, then go to step S50; if the judgment result is no, then go to step S60;

[0011] S50: Calculate the Pearson correlation coefficient R(A1, A2) between the energized potential arrays A1 and A2; determine whether R(A1, A2) is less than or equal to the correlation set threshold M3. If the judgment result is yes, it is determined that the insulation performance of the insulation facility is good; if the judgment result is no, proceed to step S60;

[0012] S60: Start the output power supply and apply a test current to the pipeline at one end of the insulation facility; the test current is set according to the set step size ΔI testIncrease gradually; each time the test current is increased, the insulation tester collects the energized potential V of the pipelines at both ends of the insulation facility through sampling channels S1 and S2 respectively. on-test-1 and V on-test-2 ;

[0013] S70: Obtain the potential difference ΔV between the two ends of the pipeline of the insulation facility under the applied test current on-test , judge ΔV on-test Whether the absolute value of is less than the potential difference setting threshold M1, if the judgment result is yes, it is determined that the insulation performance of the insulation facility is abnormal; if the judgment result is no, it is determined that the insulation performance of the insulation facility is good.

[0014] In the technical solution, the method is designed to first use the potential method to judge the insulation performance. When the potential method cannot make a judgment, a longer and more intensive power-on potential sampling is carried out, and the volatility is judged by the coefficient of variation of the sampling data. Then, according to the volatility, a correlation judgment method is selected, or manual current is applied and it is judged whether the absolute value of the potential difference between the two sections after the current is applied is large enough. Finally, it is accurately determined whether the insulation facility is good. This method can be automatically executed by the equipment without cumbersome measurement steps and low professional requirements for operators. It realizes the insulation performance judgment when there is no potential fluctuation on both sides of the insulation facility, eliminates the defect of insulation performance judgment by correlation under interference, ensures the reliability and accuracy of the monitoring results, and effectively avoids the misjudgment that may be caused by a single judgment condition.

[0015] In some embodiments, in step S10, sampling channels S1 and S2 synchronously collect the power-on potential V on-1 and V on-2 When the AC interference voltage V ac-1 and V ac-2 ;

[0016] In step S20, the average interference voltage difference ΔV is further calculated. ac-avg , ΔV ac-avg =avg(V ac-1 -V ac-2 ); further determine |ΔV ac-avg |Whether the potential difference is greater than or equal to the set threshold M1, if both judgment results are yes, it is determined that the insulation performance of the insulation facility is good; if either of the two judgment results is no, then enter step S30.

[0017] In the technical solution, this method is designed to further analyze the voltage difference of the AC interference voltage at both ends of the insulation facility when using the potential method to judge the insulation performance. When there are large differences in the power-on potential and the AC interference voltage at both ends, the insulation performance is determined to be good, avoiding misjudgment caused by considering only a single potential factor, and further improving the accuracy of insulation performance judgment.

[0018] In some embodiments, in step S30, sampling channels S1 and S2 synchronously collect AC voltage change waveforms W1 and W2, and the collection time of collecting the AC voltage change waveforms is T1 and the collection frequency is f3;

[0019] In step S50, the Pearson correlation coefficient R(W1, W2) between the voltage change waveforms W1 and W2 is further calculated; it is further determined whether R(W1, W2) is less than or equal to the correlation setting threshold M3. If both judgment results are yes, it is determined that the insulation performance of the insulation facility is good; if either of the two judgment results is no, then step S60 is entered.

[0020] In the technical solution, this method is designed to further judge the insulation performance of the insulation facility through the correlation of the AC waveforms on both sides of the insulation facility during intensive and long-term sampling, fully considering various factors that may affect the insulation performance, and further improving the accuracy of the insulation status judgment results; on the other hand, it can more deeply analyze the impact of AC interference on the insulation performance of the insulation facility, which helps to distinguish whether it is a performance problem of the insulation facility itself or an abnormality caused by external interference, providing a more accurate basis for subsequent measures.

[0021] In some embodiments, in step S70 , after determining that the insulation performance of the insulation facility is good, the process proceeds to step S80 ;

[0022] S80: All the energized potentials V obtained in step S60 are on-test-1 and V on-test-2 They are collected separately and form test potential arrays B1 and B2 respectively. The Pearson correlation coefficient R(B1, B2) of the test potential arrays B1 and B2 is calculated. It is judged whether R(B1, B2) is greater than or equal to the correlation setting threshold M3. If the judgment result is yes, it is determined that the type of interference of regional cathodic protection on line cathodic protection is anodic interference; if the judgment result is no, and R(B1, B2) is less than the correlation setting threshold M4, it is determined that the type of interference of regional cathodic protection on line cathodic protection is cathodic interference.

[0023] In the technical proposal, the method is designed to, after determining that the insulation performance of the insulation facility is good, further perform correlation analysis on the array of energized potentials at both ends of the insulation facility, and can identify whether the interference type is anodic interference or cathodic interference, providing targeted guidance for subsequent interference suppression and processing, and helping to take effective measures in a timely manner to reduce the impact of interference on the insulation facility and cathodic protection system, thereby ensuring the safe operation of the pipeline.

[0024] In some embodiments, before step S10 , the output power is in a turned-off state.

[0025] In the technical solution, this method design avoids interference from the output power supply before data collection, ensuring that the data collected in the initial state can truly reflect the natural operating state of the insulation facilities, improving the accuracy and reliability of the data, and laying a good foundation for subsequent analysis and judgment.

[0026] In some embodiments, T1 ≥ 1 min, and T2 ≥ 5 min.

[0027] In the technical solution, the method design ensures the adequacy and representativeness of the collected data, so that subsequent analysis and judgment are based on a sufficient number of data samples, thereby improving the accuracy and reliability of the monitoring results and avoiding misjudgments that may be caused by too short collection time and insufficient data.

[0028] In some embodiments, the potential difference setting threshold M1 is 100-200 mV, and the fluctuation setting threshold M2 is 0.045-0.055.

[0029] In the technical proposal, the method design provides a specific threshold range, which is convenient for reasonable selection and setting according to different pipeline and insulation facilities in actual application, making the monitoring method more operational and targeted, while also providing a relatively stable reference standard for judging insulation performance; the method design clarifies the reasonable range of the coefficient of variation, which helps to accurately judge whether the degree of fluctuation of the data is normal after calculating the coefficient of variation, thereby providing a clearer quantitative basis for evaluating insulation performance and improving the accuracy and consistency of judgment.

[0030] In some embodiments, the correlation threshold M3 is set to 0.65 to 0.75, and the correlation threshold M4 is set to -0.65 to -0.7.

[0031] In the technical solution, the method is designed to provide a reasonable reference range for the judgment of the correlation coefficient, so that when analyzing the correlation between the power-on potential array and the interference voltage array, the insulation performance and the interference type can be judged more accurately, thereby enhancing the scientificity and reliability of the monitoring method.

[0032] In some embodiments, f3 ≥ 200 Hz.

[0033] In the technical solution, since the frequency of AC interference is usually 50 Hz, this frequency setting can accurately reflect the waveform of the AC voltage, so that the subsequent correlation analysis is based on a sufficient number of data samples, thereby improving the accuracy and reliability of the monitoring results.

[0034] In some embodiments, in step S60, the applied test current is not less than 1A; the step length ΔI is set test The test current is 0.18~0.22A; the test current is increased for no less than 10 times; in the process of gradually increasing the test current, if the output voltage of the output power supply exceeds the limit, the adjustment of the test current is stopped.

[0035] In the technical solution, this method ensures that the test current adjustment fully and meticulously produces changes in the energized potential of the pipes at both ends of the insulation facility, improving the accuracy and reliability of the test. Furthermore, if the output voltage of the output power supply exceeds the limit during the test, adjustment is stopped, effectively protecting the safety of equipment and personnel, demonstrating the safety and practicality of the monitoring method.

[0036] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0038] Figure 1 Schematic diagram of a hardware system for implementing a method for monitoring insulation performance of buried insulation facilities according to an embodiment of the present application;

[0039] Figure 2 The method flow of the method for monitoring the insulation performance of buried insulation facilities according to the embodiment of the present application is as follows Figure 1 ;

[0040] Figure 3 The method flow of the method for monitoring the insulation performance of buried insulation facilities according to the embodiment of the present application is as follows Figure 2 .

[0041] In the picture:

[0042] 100. Insulation facilities; 200. Insulation monitor; 201. Sampling channel S1; 202. Sampling channel S2; 203. Output power supply; 300. Test piece; 400. Long-lasting reference electrode; 500. Auxiliary ground bed; 600. Pipeline; 601. First section of pipeline; 602. Second section of pipeline. DETAILED DESCRIPTION

[0043] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0044] In the description of the present invention, it should be understood that the terms "center", "transverse", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0045] The terms "first," "second," and "third" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly specify the quantity of the technical features indicated. Therefore, a feature specified as "first," "second," or "third" may explicitly or implicitly include one or more of such features.

[0046] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0047] like Figure 1 、 Figure 2 As shown, in an exemplary embodiment of the method for monitoring insulation performance of buried insulation facilities of the present invention, see Figure 1The two sections of pipeline are connected by an insulating facility, so that the two ends of the insulating facility 100 are respectively connected to the two sections of pipeline 600; the sampling channel S1201 and the sampling channel S2202 of the insulation monitor 200 are respectively electrically connected to the two sections of pipeline connected to the two ends of the insulating facility 100; the sampling channel S1201 and the sampling channel S2202 are also respectively electrically connected to the test pieces 300 buried on one side of the two sections of pipeline. The two test pieces 300 are respectively electrically connected to the two sections of pipeline through the sampling channel S1201 and the sampling channel S2202, so that each test piece 300 The potential of the pipeline to which they are electrically connected is the same; the sampling channel S1201 and the sampling channel S2202 are simultaneously electrically connected to the long-term reference electrode 400 buried on one side of the pipeline, so that each sampling channel can obtain the power-on potential or power-off potential of the corresponding pipeline by detecting the potential difference between the test piece 300 to which it is electrically connected and the long-term reference electrode 400; the insulation monitor 200 further has an output power supply 203, the positive pole of the output power supply 203 is electrically connected to one section of the pipeline, and the negative pole of the output power supply 203 is electrically connected to the auxiliary ground bed 500 buried on one side of the pipeline.

[0048] See also Figure 2 The insulation performance monitoring method of the buried insulation facility is carried out according to the following steps.

[0049] S10: The insulation detector collects the energized potential V of the pipelines at both ends of the insulation facility through sampling channels S1 and S2 respectively. on-1 and V on-2 , the acquisition time is T1, the acquisition frequency is f1, and the collected multiple sets of power-on potentials V on-1 and V on-2 If 10 sets of on-state potentials are obtained within the acquisition time, the 10 sets of on-state potentials are (V on-1-1 , V on-2-1 )、(V on-1-2 , V on-2-2 )、(V on-1-3 , V on-2-3 ),……、(V on-1-10 , V on-2-10 ).

[0050] S20: Calculate the average potential difference ΔV on-avg , ΔV on-avg =avg(V on-1 -V on-2 ); If 10 sets of energized potentials are collected in step S10, then (V on-1-1 -V on-2-1 )、(V on-1-2 -V on-2-2 )、(V on-1-3 -V on-2-3 ),……、(V on-1-10 -Von-2-10 ) and then divided by 10 to get ΔV on-avg . Judgment |ΔV on-avg |Whether the potential difference is greater than or equal to the set threshold value M1. If the judgment result is yes, it indicates that the difference in the energized potential between the pipelines at both ends of the insulating facility is large, and it is determined that the insulation performance of the insulating facility is good. If the judgment result is no, it indicates that the difference in the energized potential between the pipelines at both ends of the insulating facility is small. However, if there is interference between the regional cathodic protection and the line cathodic protection, the potential change of the pipeline at one end of the insulating facility will also cause the potential change of the pipeline at the other end of the insulating facility, resulting in a small difference in the energized potential. At this time, it cannot be determined that there is any abnormality in the insulation state of the insulating facility, and it is necessary to proceed to step S30 to perform potential acquisition for a longer time and at a higher frequency.

[0051] S30: The insulation detector collects the electrical potential V of the pipelines at both ends of the insulation facility through sampling channels S1 and S2 respectively. on-1 ' and V on-2 ', the acquisition time is T2, the acquisition frequency is f2, and multiple groups of power-on potentials V on-1 ' and V on-2 ', T2 is greater than T1, f2 is greater than f1. In step S30, more groups of power-on potentials are collected at a longer time and higher frequency. If 50 groups of power-on potentials are obtained within the collection time, the 50 groups of power-on potentials are (V on-1-1 ', V on-2-1 '),(V on-1-2 ', V on-2-2 '),(V on-1-3 ', V on-2-3 '),……、(V on-1-50 ', V on-2-50 ').

[0052] S40: All V on-1 ' and all V on-2 'Collect and form the power-on potential arrays A1 and A2 respectively; if 50 sets of power-on potentials are collected in step S30, the power-on potential array A1 is V on-1-1 '、V on-1-2 '、V on-1-3 '……、V on-2-50 ', the power-on potential array A2 is V on-2-1 '、V on-2-2 '、V on-2-3 '……、V on-2-50 '. Calculate the coefficient of variation CV of the power-on potential arrays A1 and A2 respectively on1 and CV on2 The coefficient of variation is the standard deviation of all the data in the array divided by the average value of all the data in the array. Determine the coefficient of variation CV on1 and CVon2 Whether they are all greater than the volatility setting threshold M2, if the judgment result is yes, it indicates that the power-on potentials collected more frequently and for a longer time on the pipelines at both ends of the insulation facility have obvious fluctuations, then the process goes to step S50 to perform the correlation insulation performance judgment step; if the judgment result is no, it indicates that the power-on potentials of at least one end of the pipelines in the power-on potentials collected more frequently and for a longer time on both ends of the insulation facility have no obvious fluctuations, at this time, the correlation evaluation of the data without fluctuations will only get a high correlation conclusion, and this conclusion cannot be used to judge whether the insulation state is good or not, then it is necessary to go to step S60 to perform the insulation performance judgment step of the external current.

[0053] S50: Calculate the Pearson correlation coefficient R(A1, A2) between the energized potential arrays A1 and A2. The Pearson correlation coefficient is also called the correlation coefficient or the linear correlation coefficient and is calculated according to the defined formula. Cov(A1, A2) is the covariance of arrays A1 and A2, Var[A1] is the variance of array A1, and Var[A2] is the variance of array A2. Determine whether R(A1, A2) is less than or equal to the correlation threshold M3. If so, this indicates that the energized potentials of the pipelines at both ends of the insulation facility fluctuate in a dissimilar manner, meaning that similar potential fluctuations do not occur between the pipelines due to conduction. In this case, the insulation performance of the insulation facility is considered good. If not, this indicates that the energized potentials of the pipelines at both ends of the insulation facility fluctuate in a similar manner. However, if regional cathodic protection interferes with line cathodic protection, potential changes at one end of the pipeline will also cause potential changes at the other end, resulting in similar potential fluctuations at both ends. In this case, it cannot be determined that the insulation of the insulation facility is abnormal. The process then proceeds to step S60 to determine the insulation performance of the applied current.

[0054] S60: Start the output power supply and apply the test current to the pipeline at one end of the insulation facility. The test current is set according to the set step size ΔI test Each time the test current is increased, the insulation tester collects the electrical potential V of the pipelines at both ends of the insulation facility through sampling channels S1 and S2 respectively. on-test-1 and V on-test-2 If the test current increases 10 times, the 10 sets of collected power-on potentials are (V on-test-1-1 , V on-test-2-1 )、(V on-test-1-2 , V on-test-2-2 )、(V on-test-1-3 , V on-test-2-3 )……(V on-test-1-10 , V on-test-2-10 ).

[0055] S70: Obtain the potential difference ΔV between the two ends of the pipeline of the insulation facility under the applied test current on-test When 10 sets of on-state potentials are collected in step S60, 10 ΔV on-test , respectively ΔV on-test-1 , ΔV on-test-2 , ΔV on-test-3 ,……,ΔV on-test-10 ;ΔV on-test-1 =V on-test-1-1 -V on-test-2-1 , ΔV on-test-2 =V on-test-1-2 -V on-test-2-2 , ΔV on-test-3 =V on-test-1-3 -V on-test-2-3 ,……,ΔV on-test-10 =V on-test-1-10 -V on-test-2-10 . Determine all ΔV on-test Whether the absolute value of is less than the potential difference setting threshold M1; if the judgment result is yes, it means that there is still no obvious potential difference on both sides of the insulating joint after the current is applied, and the insulation performance of the insulating facility is determined to be abnormal; if the judgment result is no, it means that there is still an obvious potential difference on both sides of the insulating joint after the current is applied, and the insulating facility effectively prevents the applied current from being transferred from one end of the pipeline to the other end of the pipeline, and the insulation performance of the insulating facility is determined to be good.

[0056] The method is designed to first use the potential method to judge the insulation performance, and immediately determine that the insulation performance is good when the average power-on potential difference meets the standard; when the potential method cannot make a judgment, the power-on potential is sampled for a longer time and more intensively, and its volatility is judged by the coefficient of variation of the sampling data. Then, according to the judgment method of correlation when the data volatility is sufficient, when the data volatility is insufficient, artificial current is selected to judge whether the average value of the potential difference between the two ends after the current is applied is large enough, so as to judge whether the insulation performance is good or not when the amplitude of the potential difference is artificially increased. Under natural conditions, when there is no potential fluctuation on both sides of the insulation facility and when the cathodic protection of the two sections of the area and the cathodic protection of the line interfere with each other, it is accurate to determine whether the insulation facility is good, thereby ensuring the reliability and accuracy of the monitoring results and effectively avoiding the misjudgment that may be caused by a single judgment condition. In addition, this method can be automatically executed by the equipment, without cumbersome measurement steps, and has low professional requirements for operators.

[0057] In this application, see Figure 3 In step S10, sampling channels S1 and S2 synchronously collect the power-on potential V on-1 and V on-2 When the AC interference voltage V ac-1 and V ac-2If 10 sets of on-state potentials are obtained within the acquisition time, 10 sets of AC interference voltages are obtained simultaneously. The 10 sets of AC interference voltages are (V ac-1-1 , V ac-2-1 )、(V ac-1-2 , V ac-2-2 )、(V ac-1-3 , V ac-2-3 ),……、(V ac-1-10 , V ac-2-10 ).

[0058] In step S20, the average interference voltage difference ΔV is further calculated. ac-avg , ΔV ac-avg =avg(V ac-1 -V ac-2 ); If 10 groups of AC interference voltages are collected in step S10, then (V ac-1-1 -V ac-2-1 )、(V ac-1-2 -V ac-2-2 )、(V ac-1-3 -V ac-2-3 ),……、(V ac-1-10 -V ac-2-10 ) and then divided by 10 to get ΔV ac-avg . Judgment |ΔV on-avg | is greater than or equal to the potential difference setting threshold M1, and further determines |ΔV ac-avg | Is it greater than or equal to the set potential difference threshold M1? If both judgment results are yes, it indicates that the difference in the energized potential between the pipelines at both ends of the insulation facility is large, and the voltage difference in the AC interference voltage is also large. The insulation facility effectively blocks the conduction between the two sections of the pipeline, avoiding the conduction between the two pipelines resulting in a small or zero energized potential difference and a small or zero AC interference voltage difference. The insulation performance of the insulation facility is determined to be good. If either of the two judgment results is no, it indicates that the difference in the energized potential between the pipelines at both ends of the insulation facility is small. However, the potential change of the pipeline at one end of the insulation facility will also cause the potential change of the pipeline at the other end of the insulation facility, resulting in a small energized potential difference. At this time, it cannot be determined that there is any abnormality in the insulation state of the insulation facility, and the process proceeds to step S30 to perform potential acquisition for a longer time and at a higher frequency.

[0059] This method is designed to further analyze the voltage difference of the AC interference voltage at both ends of the insulation facility when using the potential method to judge the insulation performance. When there are large differences in the power-on potential and the AC interference voltage at both ends, the insulation performance is determined to be good, avoiding misjudgment caused by considering only a single potential factor, and further improving the accuracy of insulation performance judgment.

[0060] In this application, see Figure 3In step S30, sampling channels S1 and S2 synchronously collect the power-on potential V on-1 ' and V on-2 ', further synchronously collect AC voltage variation waveforms W1 and W2; the acquisition duration of the AC voltage variation waveforms is T1, and the acquisition frequency is f3. AC voltage variation waveform W1 is composed of the lines connecting the AC voltages collected by sampling channel S1 during the acquisition period, and AC voltage variation waveform W2 is composed of the lines connecting the AC voltages collected by sampling channel S2 during the acquisition period. The AC voltages of sampling channels S1 and S2 are collected synchronously, that is, sampling channels S1 and S2 each collect two AC voltages at the same time.

[0061] In step S50, while calculating the Pearson correlation coefficient R(A1, A2) between the on-state potential arrays A1 and A2, the Pearson correlation coefficient R(W1, W2) between the voltage change waveforms W1 and W2 is also calculated. To calculate the Pearson correlation coefficient R(W1, W2), the entire AC voltage sampled by sampling channel S1 is used as the array of voltage change waveform W1, and the entire AC voltage sampled by sampling channel S2 is used as the array of voltage change waveform W2. These two arrays are then substituted into the definition formula to obtain the Pearson correlation coefficient R(W1, W2). While judging whether R(A1, A2) is less than or equal to the correlation setting threshold M3, further judge whether R(W1, W2) is greater than or equal to the correlation setting threshold M3. If both judgment results are yes, it indicates that the power-on potential and AC voltage of the pipelines at both ends of the insulation facility have different fluctuation states, that is, similar potential fluctuations and voltage fluctuations will not be generated between the pipelines at both ends due to conduction. At this time, it is determined that the insulation performance of the insulation facility is good; if either of the two judgment results is no, it indicates that the power-on potential or AC voltage of the pipelines at both ends of the insulation facility have similar fluctuation states, but if there is interference between the regional cathodic protection and the line cathodic protection, the potential change of the pipeline at one end of the insulation facility will also cause the potential change of the pipeline at the other end of the insulation facility, thereby resulting in a situation where the potential fluctuations of the pipelines at both ends are similar. At this time, it is still impossible to judge whether the insulation state of the insulation facility is abnormal, then enter step S60, and perform the insulation performance judgment step of the external current.

[0062] This method, designed to assess the insulation performance of insulation facilities by further analyzing the correlation of AC waveforms on both sides of the insulation during intensive, long-term sampling, fully considers various factors that may affect insulation performance and further improves the accuracy of insulation status determination results. Furthermore, when either the on-state potential or the AC voltage exhibits subtle fluctuations or exhibits high array correlation, the method uses the impressed current method to determine insulation performance, ensuring accurate insulation status determination results. Furthermore, the introduction of AC voltage allows for a more in-depth analysis of the impact of AC interference on the insulation performance of insulation facilities, providing a more accurate basis for subsequently distinguishing between inherent performance issues within the insulation facilities and those caused by external interference.

[0063] In this application, see Figure 3 In step S70, after determining that the insulation performance of the insulation facility is good, proceed to step S80.

[0064] S80: All the energized potentials V obtained in step S60 are on-test-1 and V on-test-2 are collected separately and form test potential arrays B1 and B2 respectively; if the test current is increased 10 times in step S60, 10 power-on potentials V on-test-1 The test potential array B1 is composed of V on-test-1 、V on-test-1-2 、V on-test-1-3 ,……,V on-test-1-10 , 10 energized potentials V on-test-2 The test potential array B2 is composed of V on-test-2-1 、V on-test-2-2 、V on-test-2-3 ,……,V on-test-2-10 Calculate the Pearson correlation coefficient R(B1, B2) of the test potential arrays B1 and B2, and determine whether R(B1, B2) is greater than or equal to the correlation setting threshold M3. If the judgment result is yes, it indicates that the potential changes on both sides are positively correlated, and the interference type of the regional cathodic protection on the line cathodic protection is determined to be anodic interference; if the judgment result is no, and R(B1, B2) is less than the correlation setting threshold M4, it indicates that the potential changes on both sides are negatively correlated, and the negative correlation is high, then the interference type of the regional cathodic protection on the line cathodic protection is determined to be cathodic interference.

[0065] More specifically, when the current in the first section of pipeline 601 (the pipeline located at one end of the insulation facility) increases and its potential shifts to a negative level, the second section of pipeline 602 (the pipeline located at the other end of the insulation facility) is forced to absorb current in the anode voltage field of the anode bed of the cathodic protection system of the first section of pipeline, and its potential also shifts to a negative level. Conversely, if the current in the first section of pipeline decreases, the current absorbed by the second section of pipeline also decreases, and its potential also shifts to a positive level. This results in a positive correlation between the potential changes on both sides due to the anode interference.

[0066] When the cathodic protection current of the first section of the pipeline increases, the potential shifts to a negative direction, while the second section of the pipeline is forced to release current in the cathode voltage field of the cathodic protection system of the first section of the pipeline, and the potential shifts to a positive direction. Conversely, if the current of the first section of the pipeline decreases, the current released by the second section of the pipeline will also decrease, and the potential will shift negatively. As a result of the cathodic interference, the potential changes on both sides are negatively correlated.

[0067] This method is designed to identify whether the interference type is anodic interference or cathodic interference by performing a correlation analysis on an array of energized potential differences at both ends of the insulating facility after confirming that the insulation performance of the insulating facility is good. The method utilizes the potential change characteristics generated by anodic interference and cathodic interference to provide targeted guidance for subsequent interference suppression and processing, and helps to take effective measures in a timely manner to reduce the impact of interference on the insulating facility and cathodic protection system, thereby ensuring the safe operation of the pipeline.

[0068] In this application, the output power supply is in the off state before step S10. This method design avoids interference with the output power supply before data collection, ensuring that the data collected in the initial state can truly reflect the natural operating state of the insulation facility, improving the accuracy and reliability of the data and laying a good foundation for subsequent analysis and judgment.

[0069] In this application, T1 ≥ 1 min, T2 ≥ 5 min. This method is designed to ensure that the duration of the on-state potential acquisition is sufficient, and more data can be collected during long-term high-frequency acquisition, ensuring the adequacy and representativeness of the collected data. Subsequent analysis and judgment are based on a sufficient number of data samples, thereby improving the accuracy and reliability of the monitoring results and avoiding misjudgments that may result from too short an acquisition time and insufficient data.

[0070] In this application, the potential difference threshold M1 is set to 100-200mV. This method design provides a specific threshold range to ensure that identifying the potential difference can reflect the good insulation performance. This facilitates reasonable selection and setting based on different pipeline and insulation facilities in actual application, making the monitoring method more operational and targeted, and also provides a relatively stable reference standard for judging insulation performance.

[0071] In this application, the volatility threshold M2 is set to 0.045-0.055. This method design clarifies the reasonable range of the coefficient of variation, which helps to accurately determine whether the degree of data fluctuation is normal after calculating the coefficient of variation. This provides a clearer quantitative basis for evaluating insulation performance. That is, when the volatility is less than approximately 5%, the data volatility is considered insufficient. This ensures that the correlation of certain volatility data can accurately determine whether the insulation performance is good or not, improving the accuracy and consistency of the judgment.

[0072] In this application, the correlation threshold M3 is set to 0.65-0.75, and the correlation threshold M4 is set to -0.65--0.7. This method design provides a reasonable reference range for determining the correlation coefficient, that is, when the correlation reaches approximately 70% or above, the two sets of data are considered highly correlated. This allows for more accurate judgment of insulation performance and interference type when analyzing the correlation between the power-on potential array and the interference voltage array, enhancing the scientific nature and reliability of the monitoring method.

[0073] In this application, f3 ≥ 200 Hz. Since the frequency of AC interference is usually 50 Hz, this frequency setting can accurately reflect the waveform of the AC voltage, so that subsequent correlation analysis is based on a sufficient number of data samples, thereby improving the accuracy and reliability of the monitoring results.

[0074] In this application, in step S60, the applied test current is not less than 1A; the step length ΔI is set test The test current is increased from 0.18 to 0.22A; the test current is increased no less than 10 times; and if the output voltage of the output power supply exceeds the limit during the gradual increase of the test current, the test current adjustment is stopped. This method ensures that the applied current is sufficiently large and the adjustment range is sufficiently wide. This allows for sufficient and detailed changes in the energized potential of the pipes at both ends of the insulation facility during test current adjustment. Based on the potential difference or the resulting array of energized potentials after the change, the insulation condition or the type of interference can be determined, thereby improving the accuracy and reliability of the test. Furthermore, if the output voltage of the output power supply exceeds the limit during the test, the adjustment is stopped, effectively protecting the safety of equipment and personnel, and demonstrating the safety and practicality of the monitoring method.

[0075] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0076] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the same. Although the present invention has been described in detail with reference to preferred embodiments, persons skilled in the art should understand that the specific implementation methods of the present invention may still be modified or some technical features may be replaced by equivalents without departing from the spirit of the technical solutions of the present invention, and all of these should fall within the scope of the technical solutions claimed for protection by the present invention.

Claims

1. A method for monitoring insulation performance of buried insulation facilities, characterized in that: Here are the steps: S10: The insulation detector collects the energized potential V of the pipelines at both ends of the insulation facility through sampling channels S1 and S2 respectively. on-1 and V on-2 , the acquisition time is T1, the acquisition frequency is f1, and multiple groups of power-on potentials V are obtained on-1 and V on-2 ; S20: Calculate the average potential difference ΔV on-avg , ΔV on-avg =avg(V on-1 -V on-2 ); judge |ΔV on-avg | Is the potential difference greater than or equal to the set threshold value M1? If the judgment result is yes, it is determined that the insulation performance of the insulation facility is good; If the judgment result is no, then go to step S30; S30: The insulation detector collects the electrical potential V of the pipelines at both ends of the insulation facility through sampling channels S1 and S2 respectively. on-1 ' and V on-2 ', the acquisition time is T2, the acquisition frequency is f2, and multiple groups of power-on potentials V on-1 ' and V on-2 ', T2 is greater than T1, f2 is greater than f1; S40: V on-1 ' and V on-2 'Collect and form the power-on potential arrays A1 and A2 respectively; calculate the coefficient of variation CV of the power-on potential arrays A1 and A2 respectively on1 and CV on2 ; Determine the coefficient of variation CV on1 and CV on2 Are they both greater than the volatility setting threshold M2? If the judgment result is yes, then go to step S50; if the judgment result is no, then go to step S60; S50: Calculate the Pearson correlation coefficient R(A1, A2) between the energized potential arrays A1 and A2; determine whether R(A1, A2) is less than or equal to the correlation set threshold M3. If the determination result is yes, it is determined that the insulation performance of the insulation facility is good; If the judgment result is no, then go to step S60; S60: Start the output power supply and apply a test current to the pipeline at one end of the insulation facility; the test current is set according to the set step size ΔI test Increase gradually; each time the test current is increased, the insulation tester collects the energized potential V of the pipelines at both ends of the insulation facility through sampling channels S1 and S2 respectively. on-test-1 and V on-test-2 ; S70: Obtain the potential difference ΔV between the two ends of the pipeline of the insulation facility under the applied test current on-test , judge ΔV on-test Whether the absolute value of is less than the potential difference setting threshold M1, if the judgment result is yes, it is determined that the insulation performance of the insulation facility is abnormal; If the judgment result is no, it is determined that the insulation performance of the insulation facility is good.

2. The method for monitoring insulation performance of buried insulation facilities according to claim 1, characterized in that: In step S10, sampling channels S1 and S2 synchronously collect the power-on potential V on-1 and V on-2 When the AC interference voltage V ac-1 and V ac-2 ; In step S20, the average interference voltage difference ΔV is further calculated. ac-avg , ΔV ac-avg =avg(V ac-1 -V ac-2 ); further determine |ΔV ac-avg |Whether the potential difference is greater than or equal to the set threshold M1, if both judgment results are yes, it is determined that the insulation performance of the insulation facility is good; if either of the two judgment results is no, then enter step S30.

3. The method for monitoring insulation performance of buried insulation facilities according to claim 2, characterized in that: In step S30, sampling channels S1 and S2 synchronously collect AC voltage change waveforms W1 and W2, and the collection time of collecting the AC voltage change waveforms is T1 and the collection frequency is f3; In step S50, the Pearson correlation coefficient R(W1, W2) between the voltage change waveforms W1 and W2 is further calculated; it is further determined whether R(W1, W2) is less than or equal to the correlation setting threshold M3. If both judgment results are yes, it is determined that the insulation performance of the insulation facility is good; if either of the two judgment results is no, then step S60 is entered.

4. The method for monitoring insulation performance of buried insulation facilities according to claim 3, characterized in that: In step S70, after determining that the insulation performance of the insulation facility is good, the process proceeds to step S80; S80: All the energized potentials V obtained in step S60 are on-test-1 and V on-test-2 They are collected separately and form test potential arrays B1 and B2 respectively. The Pearson correlation coefficient R(B1, B2) of the test potential arrays B1 and B2 is calculated. It is judged whether R(B1, B2) is greater than or equal to the correlation setting threshold M3. If the judgment result is yes, it is determined that the type of interference of regional cathodic protection on line cathodic protection is anodic interference; if the judgment result is no, and R(B1, B2) is less than the correlation setting threshold M4, it is determined that the type of interference of regional cathodic protection on line cathodic protection is cathodic interference.

5. The method for monitoring insulation performance of buried insulation facilities according to any one of claims 1 to 4, characterized in that: Before step S10, the output power is in an off state.

6. The method for monitoring insulation performance of buried insulation facilities according to any one of claims 1 to 4, characterized in that: T1≥1min, T2≥5min.

7. The method for monitoring insulation performance of buried insulation facilities according to any one of claims 1 to 4, characterized in that: The potential difference setting threshold M1 is 100-200 mV, and the fluctuation setting threshold M2 is 0.045-0.

055.

8. The method for monitoring insulation performance of buried insulation facilities according to claim 4, characterized in that: The correlation threshold M3 is set to 0.65 to 0.75, and the correlation threshold M4 is set to -0.65 to -0.

7.

9. The method for monitoring insulation performance of buried insulation facilities according to claim 4, characterized in that: f3≥200Hz.

10. The method for monitoring insulation performance of buried insulation facilities according to any one of claims 1 to 4, characterized in that: In step S60, the test current applied is not less than 1A; the step length ΔI is set test The test current is 0.18~0.22A; the test current is increased for no less than 10 times; in the process of gradually increasing the test current, if the output voltage of the output power supply exceeds the limit, the adjustment of the test current is stopped.

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