Stable Single-Source Steady-State DC Interference Analysis Method

Abstract

This invention provides a method for analyzing steady-state DC interference from a random single interference source, including analysis and judgment, extraction of a monitoring reference pipe section, establishment of an analysis array set, first correlation calculation, first correlation judgment, second correlation calculation, and second correlation judgment. This invention utilizes the inherent potential distribution characteristics of steady-state DC current interference. First, it truncates the target pipe section, removing parts of the potential waveform that are not clearly characteristic. Then, it truncates the pipe section in a way that best preserves the potential distribution characteristics of steady-state DC current interference. Finally, it performs correlation analysis on the potentials of multiple test points on the monitoring reference pipe section before, during, and after interference. This confirms whether the correlation between adjacent points, especially around the interference point, is positive, and whether the correlation between the interference point and the beginning and end is negative. This confirms whether the energized potential exhibits the potential distribution characteristics of steady-state DC interference, thus determining whether it is steady-state DC current interference and achieving the identification of steady-state DC current interference.

Description

Technical Field

[0001] This invention belongs to the field of cathodic protection and corrosion prevention technology, and particularly relates to a method for analyzing steady-state DC interference from a random single interference source. Background Technology

[0002] Cathodic protection technology is a type of electrochemical protection technology. Its principle is to apply an external current to the surface of the corroded metal structure, and the protected structure becomes the cathode, thereby inhibiting electron migration that occurs during metal corrosion and avoiding or reducing corrosion.

[0003] Cathodic protection technology is often used in pipelines for long-distance transportation. The potential of the protected structure needs to be maintained within the standard potential range of cathodic protection in order to achieve a good cathodic protection effect. The environment along the pipeline is complex and is easily affected by stray current interference. Stray current interference will affect the potential of the protected structure, and thus affect the cathodic protection effect.

[0004] Steady-state DC current interference, such as HVDC, is a common type of stray DC current interference. It has the following characteristics: ① It occurs randomly; ② It lasts for a long time, generally from half an hour to several days, or even more than ten days; ③ The polarity and intensity of the interference are stable within a relatively short period of time; ④ The interference intensity is large, the potential deviation is significant, and the range of influence is large, exceeding tens of kilometers, or even one or two hundred kilometers; ⑤ The potential distribution has certain characteristics; ⑥ It may be cathode interference or anode interference.

[0005] Staff need to know for sure whether the current interference is a steady-state DC current interference in order to adjust the potentiostat that applies current to the protected structure in a targeted manner so that the potential of the protected structure reaches the standard. However, there is currently no effective method to identify steady-state DC current interference. Summary of the Invention

[0006] To address the shortcomings of related technologies, this invention provides a method for analyzing steady-state DC interference from a random single interference source, thereby solving the problem that current methods cannot effectively identify steady-state DC interference from a single interference source.

[0007] This invention provides a method for analyzing random steady-state DC interference, the steps of which are as follows:

[0008] Entering the analysis and judgment: When the dynamic deviation potential ΔE at any test point on the target pipe section... n When the absolute value of the interference potential is greater than the interference potential threshold ΔV, it is determined that abnormal interference has occurred in the target pipe section, and the current time T is set to... n The corresponding reference time T m Record this as the reference time T0, and proceed to the step of extracting the monitoring reference pipe section; where ΔE n =En -E ref E n For the test point at the current time T n The average value of all monitored energized potential data within the corresponding window period, E ref For the test point at reference time T m The average value of all monitored energized potential data within the corresponding window period, with reference time T. m Earlier than the current time T n ;

[0009] Extracting the monitoring reference pipe section: The first and last ends of the target pipe section are cut off to obtain the initial treatment monitoring pipe section. The cut-off lengths of the first and last ends of the target pipe section are the third cut-off length and the fourth cut-off length, respectively. The third cut-off length is α% of the distance between the monitoring interference point and the first end of the target pipe section, and the fourth cut-off length is α% of the distance between the monitoring interference point and the last end of the target pipe section. The point with the largest absolute value of the energized potential difference with the monitoring interference point between the first end of the initial treatment monitoring pipe section and the monitoring interference point is extracted and recorded as the monitoring start point. The point with the largest absolute value of the energized potential difference with the monitoring interference point between the last end of the initial treatment monitoring pipe section and the monitoring interference point is extracted and recorded as the monitoring end point. The initial treatment monitoring pipe section between the monitoring start point and the monitoring end point is used as the monitoring reference pipe section.

[0010] An analysis array set is established as follows: the test point at the monitoring starting point is designated as the first analysis point; the test point adjacent to the first analysis point is designated as the second analysis point; the test point adjacent to the monitoring interference point is designated as the third analysis point; the monitoring interference point is designated as the fourth analysis point; the test point adjacent to the monitoring interference point is designated as the fifth analysis point; the test point at the monitoring ending point is designated as the seventh analysis point; and the test point adjacent to the seventh analysis point is designated as the sixth analysis point. The reference potential data, baseline potential data, and prognostic potential data for the same analysis point are arranged in chronological order to form an analysis array. The analysis arrays corresponding to each analysis point are then combined into an analysis array set. The reference potential data is the data obtained at the test point at reference time T. m The corresponding window period contains all monitored energized potentials, with the reference potential data being the test point at the current time T. n The average prognostic potential of all monitored energizing potentials within the corresponding window period is the test point at the prognostic time T. l All monitored energized potential data within the corresponding window period, and the prognostic time T. l Later than the current time T n And reference time T m and prognostic time T l All are related to the current time T nWith the same time interval, the reference potential data, baseline potential data, and prognostic potential data all have the same number of data acquisitions and are acquired at the same time interval.

[0011] First correlation calculation: Calculate the Pearson correlation coefficient r1 between the analysis array of the fourth analysis point and the analysis array of the fifth analysis point; calculate the Pearson correlation coefficient r2 between the analysis array of the fourth analysis point and the analysis array of the third analysis point; calculate the Pearson correlation coefficient r3 between the analysis array of the first analysis point and the analysis array of the second analysis point; calculate the Pearson correlation coefficient r4 between the analysis array of the sixth analysis point and the analysis array of the seventh analysis point.

[0012] First correlation judgment: If both r1 and r2 are greater than or equal to the correlation coefficient R1, and at least one of r3 and r4 is greater than or equal to the correlation coefficient R1, then proceed to the second correlation calculation step; if at least one of r1 and r2 is less than the correlation coefficient R1, or both r3 and r4 are less than the correlation coefficient R1, then the current interference is identified as non-steady-state interference; where the correlation coefficient R1 is a positive number.

[0013] Second correlation calculation: Calculate the Pearson correlation coefficient r5 between the analysis array of the fourth analysis point and the analysis array of the first analysis point, and calculate the Pearson correlation coefficient r6 between the analysis array of the fourth analysis point and the analysis array of the seventh analysis point;

[0014] Second correlation judgment: If both r5 and r6 are less than or equal to the correlation coefficient R2, or at least one of r5 and r6 is less than or equal to the correlation coefficient R3, then the current interference is identified as steady-state DC interference; if at least one of r5 and r6 is greater than the correlation coefficient R2, and both r5 and r6 are greater than the correlation coefficient R3, then the current interference is identified as non-steady-state interference; wherein, the correlation coefficient R2 is negative and greater than the correlation coefficient R3.

[0015] In some embodiments, the following steps are further included:

[0016] Historical data input: Input multiple sets of historical data. One set of historical data is the energized potential data measured at each test point when a certain steady-state DC interference occurs in the target pipe section.

[0017] Establish a historical potential curve: Fit the energized potential data in each set of historical data into a historical potential curve;

[0018] Extracting historical reference pipe segments: The beginning and end of the target pipe segment corresponding to each set of historical data are cut off to obtain the initial processed historical pipe segment. The cutting lengths of the beginning and end of the target pipe segment are the first cutting length and the second cutting length, respectively. The first cutting length is α% of the distance between the historical interference point corresponding to the set of historical data and the beginning of the target pipe segment. The second cutting length is α% of the distance between the historical interference point corresponding to the set of historical data and the end of the target pipe segment. The point with the largest absolute value of the energized potential difference with the historical interference point is extracted between the beginning of the initial processed historical pipe segment of the set of historical data and the historical interference point and recorded as the historical starting point. The point with the largest absolute value of the energized potential difference with the historical interference point is extracted between the end of the initial processed historical pipe segment of the set of historical data and the historical interference point and recorded as the historical ending point. The initial processed historical pipe segment between the historical starting point and the historical ending point is used as the historical reference pipe segment.

[0019] Establish a historical array set: On the historical reference pipe segment corresponding to each historical data, set N reference points at equal intervals from its historical start point to its historical end point. Obtain the energizing potential of all reference points corresponding to each set of historical data according to each historical potential curve, and arrange them in order from the beginning to the end of the target pipe segment to form a historical array. Combine the historical arrays corresponding to each historical data into a historical array set.

[0020] Establish a monitoring potential curve: Fit the energized potentials monitored at each test point in the reference pipe section at the reference time T0 into a monitoring potential curve;

[0021] Establish a monitoring array: Set N monitoring points at equal intervals from the reference start point to the reference end point on the monitoring reference pipe section. Obtain the de-energization potential of each monitoring point according to the monitoring potential curve, and arrange them into a monitoring array in the order from the monitoring start point to the monitoring end point.

[0022] Third correlation calculation: Calculate the Pearson correlation coefficient r between the monitored array and each historical array in the historical array set. a ;

[0023] Third correlation judgment: If the Pearson correlation coefficient r a The one with the largest absolute value is greater than or equal to the correlation coefficient R. a or less than or equal to the correlation coefficient R b If the current interference is considered to be a previously occurring steady-state DC interference, then the Pearson correlation coefficient r is considered to be present. a The one with the largest absolute value is less than the correlation coefficient R. a Or greater than the correlation coefficient R b If so, the current interference is considered to be a newly occurring steady-state DC interference. The correlation coefficient R... b If it is negative, the correlation coefficient R a It is a positive number.

[0024] In some embodiments, during the analysis and judgment step, when it is determined that abnormal interference has occurred in the target pipe section, the dynamic deviation potential ΔE will be... n The test point with the largest absolute value is used as the monitoring interference point. The reference potential E0 of each test point at the reference time T0 is extracted and further pre-analysis steps are performed.

[0025] Preliminary analysis: Calculate the current potential standard deviation σ at the monitoring interference point. n and the standard deviation of the reference potential σ m Current potential standard deviation σ n To monitor the interference point at the current time T n The standard deviation of all monitored energized potential data within the corresponding window period, and the standard deviation of the reference potential σ. m To monitor the interference point at reference time T m The standard deviation of the current potential is calculated by taking the standard deviation of all monitored energized potential data within the corresponding window period. n Subtract the standard deviation of the reference potential σ m If the difference is greater than the interference potential threshold ΔV, the current interference is considered to be non-steady-state interference, and subsequent steps are stopped; if the difference is less than or equal to the interference potential threshold ΔV, the step of extracting the monitoring reference pipe section is initiated.

[0026] In some embodiments, in the pre-analysis step, if the difference is less than or equal to the interference potential threshold ΔV, a compliance judgment step is further performed;

[0027] Compliance judgment: Compare the de-energized potential of each test point in the target pipe section with the compliant potential range. If the de-energized potential of all test points is within the compliant potential range, then stop the subsequent steps; if the de-energized potential of any test point is outside the compliant potential range, then proceed to the step of extracting the monitoring reference pipe section.

[0028] In some embodiments, during the analysis and judgment step, an electrically continuous pipe segment is selected as the target pipe segment.

[0029] In some embodiments, the correlation coefficient R1 is greater than or equal to 0.5 and less than or equal to 0.8.

[0030] In some embodiments, the correlation coefficient R2 is less than or equal to -0.5, and the correlation coefficient R3 is less than or equal to -0.7.

[0031] In some embodiments, the correlation coefficient R a A correlation coefficient R0.5 is greater than or equal to 0.5 and less than or equal to 0.8. b Less than or equal to -0.5 and greater than or equal to -0.8.

[0032] In some of these embodiments, 0 < α ≤ 10.

[0033] In some embodiments, N is a natural number greater than or equal to 10.

[0034] Based on the above technical solution, this embodiment of the invention utilizes the inherent potential distribution characteristics of steady-state DC current interference. When abnormal interference occurs in the target pipe section, the current potential waveform is recorded. First, the part of the potential waveform with indistinct characteristics is removed. Then, the monitoring reference pipe section is extracted in a way that best preserves the potential distribution characteristics of steady-state DC current interference. Finally, correlation analysis is performed on the potentials of multiple test points on the monitoring reference pipe section before, during, and after the interference. This confirms whether the correlation between two adjacent points, especially around the interference point, is positive, and whether the correlation between the interference point and the beginning and end is negative. This confirms whether the energized potential on the monitoring reference pipe section exhibits the potential distribution characteristics of steady-state DC interference, thereby determining whether the current abnormal interference is steady-state DC current interference. This achieves the identification of steady-state DC current interference, enabling staff to quickly adjust the potentiostat for steady-state DC current interference, and more efficiently adjust the pipeline to the optimal state for cathodic protection. This solves the current problem of not being able to effectively identify steady-state DC interference. Detailed Implementation

[0035] The embodiments described below are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0036] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] In one illustrative embodiment of the random steady-state DC interference analysis method of the present invention, the random steady-state DC interference analysis method includes entering the analysis judgment, extracting the monitoring reference pipe section, establishing an analysis array set, first correlation calculation, first correlation judgment, second correlation calculation and second correlation judgment.

[0039] The potential distribution of steady-state DC interference has certain characteristics. The current potential curve formed by steady-state DC interference on the pipeline has specific waveform characteristics. The absolute value of the potential is the largest at the location of the interference point in the curve. The interference point is located at the peak (or trough) of the curve. When the interference point is at the end of the pipe section, there is a trough (or peak) on one side of the interference point. When the interference point is not at the end of the pipe section, there is a trough (or peak) on both sides of the interference point. The waveform gradually flattens as the curve extends further away from the interference point beyond the trough (or peak). The most distinctive part of the curve is the section from the trough (or peak) on one side of the interference point to the trough (or trough) on the other side of the interference point.

[0040] The analysis and judgment are performed when the dynamic deviation potential ΔE at any test point on the target pipe section is entered. n When the absolute value of the interference potential is greater than the interference potential threshold ΔV, it is determined that abnormal interference has occurred in the target pipe section, and the current time T is set to... n The corresponding reference time T m Recorded as reference time T0, proceed to the step of extracting the monitoring reference pipe section. The target pipe section is an actual existing section of pipeline, used to analyze whether it is subject to steady-state DC interference. Several test piles are located along the target pipe section, each test pile being a test point. Each test pile monitors the on-state and off-state potentials of the corresponding test point on the target pipe section. Wherein, ΔE n =E n -E ref E n For the test point at the current time T n The average value of all monitored energized potential data within the corresponding window period, E ref For the test point at reference time T m The average value of all monitored energized potential data within the corresponding window period, with reference time T. m Earlier than the current time T n Since the electrical potential on a pipeline is not stable and fluctuates slightly, taking the average value over a window of time can accurately reflect the magnitude of the electrical potential during that period. By comparing the average electrical potential values ​​of two consecutive time periods of equal length, it is possible to accurately detect abnormal changes in the electrical potential on the pipeline caused by steady-state DC interference. Thus, when the absolute value of the change exceeds a threshold, it can be accurately determined that the pipeline is experiencing steady-state DC interference.

[0041] The reference pipe section for extraction and monitoring is obtained by cutting off the first and last ends of the target pipe section to obtain the initial processed monitoring pipe section. The cut-off lengths of the first and last ends of the target pipe section are the third cut-off length and the fourth cut-off length, respectively. The third cut-off length is α% of the distance between the monitoring interference point and the first end of the target pipe section, and the fourth cut-off length is α% of the distance between the monitoring interference point and the last end of the target pipe section. The detection interference point is the test point with the largest absolute value of the average value of the energized potential data within the window period corresponding to the reference time T0 on the target pipe section. Between the beginning of the initial treatment monitoring pipe section and the monitoring interference point, the point with the largest absolute value of the potential difference between the two points is extracted and marked as the monitoring start point. The monitoring start point is one of the test points, thus finding the peak or trough of the potential curve on one side of the monitoring interference point. Between the end of the initial treatment monitoring pipe section and the monitoring interference point, the point with the largest absolute value of the potential difference between the two points is extracted and marked as the monitoring end point. The monitoring end point is one of the test points, thus finding the peak or trough of the potential curve on the other side of the monitoring interference point. The initial treatment monitoring pipe section between the monitoring start point and the monitoring end point is used as the monitoring reference pipe section. This step essentially obtains the monitoring reference pipe section in the target pipe section. Compared with the potential curve of the entire target pipe section, the potential curve of this part removes the gradually flattening parts on both sides and retains the most distinctive part, including the part where the interference point is located and the peaks or troughs on both sides.

[0042] An analysis array set is established, with the test point at the monitoring starting point as the first analysis point, the test point adjacent to the first analysis point as the second analysis point, the test point adjacent to the monitoring interference point as the third analysis point, the monitoring interference point as the fourth analysis point, the test point adjacent to the monitoring interference point as the fifth analysis point, the test point at the monitoring ending point as the seventh analysis point, and the test point adjacent to the seventh analysis point as the sixth analysis point. The reference potential data, baseline potential data, and prognostic potential data for the same analysis point are arranged in chronological order to form an analysis array. The analysis arrays corresponding to each analysis point are then combined into an analysis array set. The reference potential data is the data obtained at the test point at reference time T. m The corresponding window period contains all monitored energized potentials, with the reference potential data being the test point at the current time T. n The average prognostic potential of all monitored energizing potentials within the corresponding window period is the test point at the prognostic time T. l All monitored energized potential data within the corresponding window period, and the prognostic time T. l Later than the current time T n And reference time T m and prognostic time T l All are related to the current time T nThe reference potential data, baseline potential data, and prognostic potential data all have the same number of data acquisitions and are collected at the same time intervals. The energized potentials collected within these three equal-length time periods reflect the energized potential status on the pipeline before, during, and after the interference. The number of energized potentials collected in each time period is the same, and the energized potentials are collected at equal time intervals from the beginning to the end of each time period.

[0043] Perform the first correlation calculation, calculate the Pearson correlation coefficient r1 between the analysis array of the fourth analysis point and the analysis array of the fifth analysis point, calculate the Pearson correlation coefficient r2 between the analysis array of the fourth analysis point and the analysis array of the third analysis point, calculate the Pearson correlation coefficient r3 between the analysis array of the first analysis point and the analysis array of the second analysis point, and calculate the Pearson correlation coefficient r4 between the analysis array of the sixth analysis point and the analysis array of the seventh analysis point.

[0044] The first correlation judgment is performed. If both r1 and r2 are greater than or equal to the correlation coefficient R1, and at least one of r3 and r4 is greater than or equal to the correlation coefficient R1, and the correlation coefficient R1 is positive, it indicates that there is a significant positive correlation between the potentials before, during, and after the interference point and between the interference point and the point after the interference point. This conforms to the characteristics of a steady-state DC interference potential distribution from a single interference source, and the second correlation calculation step is then performed. If at least one of r1 and r2 is less than the correlation coefficient R1, or if both r3 and r4 are less than the correlation coefficient R1, it indicates that there is no significant positive correlation between the potentials before, during, and after the interference point and between the interference point and the point after the interference point. This does not conform to the characteristics of a steady-state DC interference potential distribution from a single interference source, and the current interference is identified as a non-single-source steady-state DC interference.

[0045] Perform a second correlation calculation, calculate the Pearson correlation coefficient r5 between the analysis array of the fourth analysis point and the analysis array of the first analysis point, and calculate the Pearson correlation coefficient r6 between the analysis array of the fourth analysis point and the analysis array of the seventh analysis point.

[0046] A second correlation judgment is performed. If both r5 and r6 are less than or equal to the correlation coefficient R2, or at least one of r5 and r6 is less than or equal to the correlation coefficient R3, and the correlation coefficient R2 is negative and greater than the correlation coefficient R3, it indicates that the potentials before, during, and after the interference occur between the interference point and the beginning of the monitoring reference pipe section, as well as between the interference point and the end of the monitoring reference pipe section, show a significant negative correlation. This is consistent with the characteristics of a steady-state DC interference potential distribution from a single interference source, and the current interference is identified as steady-state DC interference. If at least one of r5 and r6 is greater than the correlation coefficient R2, and both r5 and r6 are greater than the correlation coefficient R3, it indicates that the potentials before, during, and after the interference occur between the interference point and the beginning of the monitoring reference pipe section, as well as between the interference point and the end of the monitoring reference pipe section, do not show a significant negative correlation. This is inconsistent with the characteristics of a steady-state DC interference potential distribution from a single interference source, and the current interference is identified as a non-single-source steady-state DC interference.

[0047] In the above illustrative embodiments, the random steady-state DC interference analysis method of this application utilizes the inherent potential distribution characteristics of steady-state DC current interference from a single interference source. It extracts a portion of the actual measured energized potential curve on the target pipeline, preserving the characteristics of the single-source steady-state DC interference. Seven analysis points are selected: the beginning, beginning +1, interference point -1, interference point, interference point +1, end -1, and the end. The correlation between the potentials before, during, and after interference between adjacent analysis points is analyzed to determine if the correlation is significantly positive. Then, the potentials before, during, and after interference between the interference point and the beginning and end are analyzed. The correlation analysis determines whether a significant negative correlation exists, thereby confirming whether the potential distribution of the monitoring reference section in the characteristic part of the target pipe segment conforms to the potential distribution characteristics of steady-state DC interference. When the two correlation analyses show significant positive and negative correlations respectively, the current interference is identified as steady-state DC interference, achieving effective identification of this type of interference. Furthermore, after efficient identification, the subsequent adjustment of the potentiostat can be more timely and targeted, ensuring that the protected target pipe segment can eliminate steady-state DC interference and achieve the optimal state of cathodic protection, thus solving the current problem of not being able to effectively identify steady-state DC interference.

[0048] Before calculating the correlation coefficient, the target pipe section is selected, i.e., the monitoring reference pipe section is extracted, in a way that retains the most characteristic steady-state DC interference. The first α% is selected to ensure that the non-characteristic part of the waveform is removed. Then, the part before the starting point and after the ending point is selected to ensure that the remaining part can fully reflect the most characteristic part from the peak (or trough) on one side of the interference point to the peak (or trough) on the other side of the interference point. This allows the subsequent correlation coefficient calculation to show a significant positive correlation between the potentials before, during, and after the interference between adjacent analysis points, and a significant negative correlation between the potentials before, during, and after the interference between the interference point and the beginning and end. This conforms to the waveform characteristics of steady-state DC interference potential distribution, which is high (or low) in the middle and low (or high) on both sides, as well as the waveform change characteristics before and after the interference. This accurately determines that the current interference is steady-state DC interference.

[0049] In some embodiments, the random steady-state DC interference analysis method further includes historical data input, establishing historical potential curves, extracting historical reference pipe sections, establishing a historical array set, establishing monitoring potential curves, establishing monitoring arrays, calculating the third correlation, and judging the third correlation.

[0050] Input historical data. Input multiple sets of historical data. One set of historical data is the energized potential data measured at each test point when a certain steady-state DC interference occurs in the target pipe section.

[0051] A historical potential curve is established by fitting the energized potential data in each set of historical data into a historical potential curve.

[0052] To extract historical reference pipe sections, the beginning and end of the target pipe section corresponding to a set of historical data are cut off to obtain the initial processed historical pipe section. The cut-off lengths at the beginning and end of the target pipe section are the first cut-off length and the second cut-off length, respectively. The first cut-off length is α% of the distance between the historical interference point corresponding to the set of historical data and the beginning of the target pipe section, and the second cut-off length is α% of the distance between the historical interference point corresponding to the set of historical data and the end of the target pipe section. The point with the largest absolute value of the potential difference between the initial processed historical pipe section and the historical interference point is extracted and recorded as the historical starting point. The historical starting point is one of the test points. The point with the largest absolute value of the potential difference between the initial processed historical pipe section and the historical interference point is extracted and recorded as the historical ending point. The historical ending point is one of the test points. The initial processed historical pipe section between the historical starting point and the historical ending point is used as the historical reference pipe section. Following the above method, the historical reference pipe section corresponding to the next set of historical data is extracted until all historical reference pipe sections corresponding to all historical data are obtained. This step essentially obtains the energized potential curve of each historical data point on its corresponding historical reference pipe segment. Compared with the historical potential curve on the target pipe segment, this curve removes the gradually flattening parts on both sides of the waveform and retains the most distinctive parts, including the parts where the interference points are located and the peaks or troughs on both sides.

[0053] A historical array set is established. N reference points are set at equal intervals from the historical start point to the historical end point on the historical reference pipe segment corresponding to each historical data point. The energizing potential of all reference points corresponding to each set of historical data is obtained based on the historical potential curves. These reference points are then arranged sequentially from the beginning to the end of the target pipe segment to form a historical array. The historical arrays corresponding to each historical data point are then combined into a historical array set. This step essentially obtains a dataset of the most characteristic parts of the historical potential curves of multiple historical steady-state DC interferences on the target pipe segment. In a historical array, the x-axis of each data point represents the location of the reference point, and the y-axis represents the energizing potential.

[0054] A monitoring potential curve is established by fitting the energized potentials monitored at each test point in the reference pipe section at the reference time T0 into a monitoring potential curve.

[0055] A monitoring array is established by setting N monitoring points at equal intervals from the reference start point to the reference end point on the monitoring reference pipe section. That is, the monitoring points are distributed across the monitoring start point, the monitoring end point, and the pipe section in between, and the number of monitoring points on the monitoring reference pipe section is the same as the number of reference points on the historical reference pipe section. The de-energization potential of each monitoring point is obtained from the monitoring potential curve, and these points are arranged sequentially from the monitoring start point to the monitoring end point to form the monitoring array. This step essentially replicates the arrangement of reference points on the historical reference pipe section, ensuring that the number and arrangement of data points are identical across both pipe sections for subsequent correlation coefficient calculations.

[0056] A third correlation calculation is performed, which calculates the Pearson correlation coefficient r between the monitored array and each historical array in the historical array set. a More specifically, the monitoring array is compared with a historical array using the Pearson correlation coefficient r. a During the calculation, the monitoring reference pipe segment corresponding to the monitoring array and the historical reference pipe segment corresponding to the historical array were both set with the same number of data points, N, and the same data point setting method was used, which was to set the data points at equal intervals from one end to the other. That is, the Pearson correlation coefficient r was calculated. a Data points were set at the same locations on both sections of the pipeline. The Pearson correlation coefficient r... a The calculation formula uses the average and standard deviation of the energized potential of all monitoring points, as well as the average and standard deviation of the energized potential of all reference points.

[0057] To determine the third correlation, if the Pearson correlation coefficient r... a The one with the largest absolute value is greater than or equal to the correlation coefficient R. a or less than or equal to the correlation coefficient R b Correlation coefficient R b If it is negative, the correlation coefficient R a A positive value indicates that the current interference's potential curve on the monitoring reference section, the most characteristic part of the target pipe section, has a high degree of similarity to the potential curves of historical interferences on the target pipe section. This confirms that the current interference is a previously occurring steady-state DC interference. The Pearson correlation coefficient r... a When the value is negative, the direction of the current interference is opposite to the direction of historical interference; if the Pearson correlation coefficient r a The one with the largest absolute value is less than the correlation coefficient R. a Or greater than the correlation coefficient R bIf the current interference is not similar to the current interference curve in the monitoring reference section of the most characteristic part of the target pipe section, it indicates that the current interference is not similar to the current interference curve in the target pipe section of the past. Therefore, the current interference is identified as a newly occurring steady-state DC interference.

[0058] By comparing the characteristics of historical data with those of current data, it can be determined whether the current steady-state DC interference is a previous occurrence. If it is determined that the current interference is a previously occurring steady-state DC interference, the interference point and source can be located based on historical records, thereby quickly eliminating the interference and restoring the target pipeline to the optimal cathodic protection potential state.

[0059] In some embodiments, when the analysis and judgment step is initiated and it is determined that abnormal interference has occurred in the target pipe section, the dynamic deviation potential ΔE will be... n The test point with the largest absolute value is used as the monitoring interference point. The reference potential E0 of each test point at the reference time T0 is extracted, and further pre-analysis steps are performed.

[0060] Perform a preliminary analysis and calculate the current potential standard deviation σ at the monitored interference points. n and the standard deviation of the reference potential σ m Current potential standard deviation σ n To monitor the interference point at the current time T n The standard deviation of all monitored energized potential data within the corresponding window period, and the standard deviation of the reference potential σ. m To monitor the interference point at reference time T m The standard deviation of the current potential is calculated by taking the standard deviation of all monitored energized potential data within the corresponding window period. n Subtract the standard deviation of the reference potential σ m If the difference is greater than the interference potential threshold ΔV, the current interference is considered to be non-steady-state interference, and subsequent steps are stopped; if the difference is less than or equal to the interference potential threshold ΔV, the step of extracting the monitoring reference pipe section is initiated.

[0061] Because the current potential generated by unsteady DC interference on the target pipeline fluctuates significantly, the standard deviation of the current potential at the moment the interference occurs will be higher, while the standard deviation of the current potential at the reference moment when no interference occurs will remain stable, thus making the current potential standard deviation σ lower. n and the standard deviation of the reference potential σ m If the difference increases and the absolute value of the difference exceeds the threshold, it indicates that the current interference is not a steady-state DC interference, thus stopping subsequent steps, allowing the analysis to be completed quickly and the overall process to be more efficient.

[0062] In some embodiments, during the pre-analysis step, if the difference is less than or equal to the interference potential threshold ΔV, a further compliance judgment step is performed.

[0063] To determine compliance, the de-energization potential of each test point in the target pipe section is compared with the compliant potential range. If the de-energization potential of all test points is within the compliant potential range, the subsequent steps are stopped. If the de-energization potential of any test point is outside the compliant potential range, the step of extracting the monitoring reference pipe section is initiated.

[0064] If the interference is not a steady-state DC interference, but the de-energization potential of the target pipe section is within the standard and the cathodic protection is in good condition, there is no need to adjust the potentiostat. It is not very meaningful to judge whether the interference type is a steady-state DC interference. At this time, stop the subsequent steps to complete the analysis quickly and make the whole process more efficient.

[0065] In some embodiments, during the analysis and judgment step, an electrically continuous pipe segment is selected as the target pipe segment. To prevent electrochemical corrosion, pipelines are generally divided into multiple segments connected by insulating joints. The pipes on both sides of the insulating joints are bridging with wires, allowing the current applied by the potentiostat to flow from one pipe segment to the adjacent pipe segment, ensuring that the entire pipeline reaches the potential level required for cathodic protection. However, the bridging wires may fail. If the entire pipeline is used as the target pipeline, the potential state on the target pipeline will not accurately reflect the true potential state under interference. Selecting an electrically continuous pipe segment as the target pipe segment ensures that the potential on the target pipe segment reflects the true potential state under interference. That is, when steady-state DC interference occurs, the current-carrying potential curve of the target pipe segment will exhibit the characteristics of steady-state DC interference, ensuring accurate identification of steady-state DC interference.

[0066] In some embodiments, the correlation coefficient R1 is greater than or equal to 0.5 and less than or equal to 0.8, which can ensure that the potentials of adjacent analysis points before, during, and after interference show a significant positive correlation, which is consistent with the potential distribution characteristics of steady-state DC interference.

[0067] In some embodiments, the correlation coefficient R2 is less than or equal to -0.5 and the correlation coefficient R3 is less than or equal to -0.7, which can ensure that the potentials of the interference point and the beginning and end before, during and after the interference have a relatively obvious negative correlation, which is consistent with the potential distribution characteristics of steady-state DC interference.

[0068] In some embodiments, the correlation coefficient R a A correlation coefficient R0.5 is greater than or equal to 0.5 and less than or equal to 0.8. bIf the value is less than or equal to -0.5 and greater than or equal to -0.8, it can be determined that the energized potential curve of the reference pipe section has a strong similarity to the historical potential curve in the historical data, and it can be confirmed relatively accurately that the current interference has occurred before.

[0069] In some embodiments, 0 < α ≤ 10, that is, when extracting the monitoring reference pipe segment and extracting the historical reference pipe segment, the interference point is used as the decomposition, and the first and last parts are cut off by less than 10% at the beginning and end. This can ensure that the cut-off part is the part with a relatively smooth waveform, and can also avoid cutting off the part that best reflects the steady-state DC interference, thus ensuring the accuracy of the subsequent correlation coefficient calculation.

[0070] In some embodiments, N is a natural number greater than or equal to 10. At least 10 data points are extracted from the monitoring reference pipe section and the historical reference pipe section to ensure that the data group arranged in the data points can reflect the potential curve characteristics of steady-state DC interference.

[0071] 0 < ΔV ≤ 10V. A potential difference within 10V can sensitively detect the occurrence of abnormal interference or determine the occurrence of non-steady-state interference.

[0072] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0073] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A method for analyzing steady-state DC interference from a random single interference source, characterized in that, The steps are as follows: Entering the analysis and judgment: When the dynamic deviation potential ΔE at any test point on the target pipe section... n When the absolute value of the interference potential is greater than the interference potential threshold ΔV, it is determined that abnormal interference has occurred in the target pipe section, and the current time T is set to... n The corresponding reference time T m Record this as the reference time T0, and proceed to the step of extracting the monitoring reference pipe section; where ΔE n =E n -E ref E n For the test point at the current time T n The average value of all monitored energized potential data within the corresponding window period, E ref For the test point at reference time T m The average value of all monitored energized potential data within the corresponding window period, with reference time T. m Earlier than the current time T n ; Extracting the monitoring reference pipe section: The first and last ends of the target pipe section are cut off to obtain the initial treatment monitoring pipe section. The cut-off lengths of the first and last ends of the target pipe section are the third cut-off length and the fourth cut-off length, respectively. The third cut-off length is α% of the distance between the monitoring interference point and the first end of the target pipe section, and the fourth cut-off length is α% of the distance between the monitoring interference point and the last end of the target pipe section. The point with the largest absolute value of the energized potential difference with the monitoring interference point between the first end of the initial treatment monitoring pipe section and the monitoring interference point is extracted and recorded as the monitoring start point. The point with the largest absolute value of the energized potential difference with the monitoring interference point between the last end of the initial treatment monitoring pipe section and the monitoring interference point is extracted and recorded as the monitoring end point. The initial treatment monitoring pipe section between the monitoring start point and the monitoring end point is used as the monitoring reference pipe section. An analysis array set is established as follows: the test point at the monitoring starting point is designated as the first analysis point; the test point adjacent to the first analysis point is designated as the second analysis point; the test point adjacent to the monitoring interference point is designated as the third analysis point; the monitoring interference point is designated as the fourth analysis point; the test point adjacent to the monitoring interference point is designated as the fifth analysis point; the test point at the monitoring ending point is designated as the seventh analysis point; and the test point adjacent to the seventh analysis point is designated as the sixth analysis point. The reference potential data, baseline potential data, and prognostic potential data for the same analysis point are arranged in chronological order to form an analysis array. The analysis arrays corresponding to each analysis point are then combined into an analysis array set. The reference potential data is the data obtained at the test point at reference time T. m The corresponding window period contains all monitored energized potentials, with the reference potential data being the test point at the current time T. n The average prognostic potential of all monitored energizing potentials within the corresponding window period is the test point at the prognostic time T. l All monitored energized potential data within the corresponding window period, and the prognostic time T. l Later than the current time T n And reference time T m and prognostic time T l All are related to the current time T n With the same time interval, the reference potential data, baseline potential data, and prognostic potential data all have the same number of data acquisitions and are acquired at the same time interval. First correlation calculation: Calculate the Pearson correlation coefficient r1 between the analysis array of the fourth analysis point and the analysis array of the fifth analysis point; calculate the Pearson correlation coefficient r2 between the analysis array of the fourth analysis point and the analysis array of the third analysis point; calculate the Pearson correlation coefficient r3 between the analysis array of the first analysis point and the analysis array of the second analysis point; calculate the Pearson correlation coefficient r4 between the analysis array of the sixth analysis point and the analysis array of the seventh analysis point. First correlation judgment: If both r1 and r2 are greater than or equal to the correlation coefficient R1, and at least one of r3 and r4 is greater than or equal to the correlation coefficient R1, then proceed to the second correlation calculation step; if at least one of r1 and r2 is less than the correlation coefficient R1, or both r3 and r4 are less than the correlation coefficient R1, then the current interference is identified as a non-single interference source steady-state DC interference; where the correlation coefficient R1 is a positive number. Second correlation calculation: Calculate the Pearson correlation coefficient r5 between the analysis array of the fourth analysis point and the analysis array of the first analysis point, and calculate the Pearson correlation coefficient r6 between the analysis array of the fourth analysis point and the analysis array of the seventh analysis point; Second correlation judgment: If both r5 and r6 are less than or equal to the correlation coefficient R2, or at least one of r5 and r6 is less than or equal to the correlation coefficient R3, then the current interference is considered to be a steady-state DC interference from a single interference source; if at least one of r5 and r6 is greater than the correlation coefficient R2, and both r5 and r6 are greater than the correlation coefficient R3, then the current interference is considered to be a steady-state DC interference from a non-single interference source; wherein, the correlation coefficient R2 is negative and greater than the correlation coefficient R3. 3。 2. The method for analyzing steady-state DC interference from a random single interference source according to claim 1, characterized in that, Further steps include the following: Historical data input: Input multiple sets of historical data. One set of historical data is the energized potential data measured at each test point when a certain steady-state DC interference occurs in the target pipe section. Establish a historical potential curve: Fit the energized potential data in each set of historical data into a historical potential curve; Extracting historical reference pipe segments: The beginning and end of the target pipe segment corresponding to each set of historical data are cut off to obtain the initial processed historical pipe segments. The cutting lengths of the beginning and end of the target pipe segment are the first cutting length and the second cutting length, respectively. The first cutting length is α% of the distance between the historical interference point corresponding to the set of historical data and the beginning of the target pipe segment, and the second cutting length is α% of the distance between the historical interference point corresponding to the set of historical data and the end of the target pipe segment. In the initial processing of the historical data, the point with the largest absolute value of the potential difference between the historical interference point and the historical interference point is extracted between the beginning of the historical pipe section and the historical interference point and recorded as the historical starting point. In the initial processing of the historical data, the point with the largest absolute value of the potential difference between the historical interference point and the historical interference point is extracted between the end of the historical pipe section and the historical interference point and recorded as the historical ending point. The initial processing historical pipe section between the historical starting point and the historical ending point is used as the historical reference pipe section. Establish a historical array set: On the historical reference pipe segment corresponding to each historical data, set N reference points at equal intervals from its historical start point to its historical end point. Obtain the energizing potential of all reference points corresponding to each set of historical data according to each historical potential curve, and arrange them in order from the beginning to the end of the target pipe segment to form a historical array. Combine the historical arrays corresponding to each historical data into a historical array set. Establish a monitoring potential curve: Fit the energized potentials monitored at each test point in the reference pipe section at the reference time T0 into a monitoring potential curve; Establish a monitoring array: Set N monitoring points at equal intervals from the reference start point to the reference end point on the monitoring reference pipe section. Obtain the de-energization potential of each monitoring point according to the monitoring potential curve, and arrange them into a monitoring array in the order from the monitoring start point to the monitoring end point. Third correlation calculation: Calculate the Pearson correlation coefficient r between the monitored array and each historical array in the historical array set. a ; Third correlation judgment: If the Pearson correlation coefficient r a The one with the largest absolute value is greater than or equal to the correlation coefficient R. a or less than or equal to the correlation coefficient R b If so, the current interference is considered to be a steady-state DC interference that has already occurred; If the Pearson correlation coefficient r a The one with the largest absolute value is less than the correlation coefficient R. a Or greater than the correlation coefficient R b If the current interference is identified as a newly occurring steady-state DC interference, then the correlation coefficient R is considered to be... b If it is negative, the correlation coefficient R a It is a positive number.

3. The method for analyzing steady-state DC interference from a random single interference source according to claim 1, characterized in that, During the analysis and judgment process, if abnormal interference is identified in the target pipe section, the dynamic deviation potential ΔE will be adjusted. n The test point with the largest absolute value is used as the monitoring interference point. The reference potential E0 of each test point at the reference time T0 is extracted and further pre-analysis steps are performed. Preliminary analysis: Calculate the current potential standard deviation σ at the monitoring interference point. n and the standard deviation of the reference potential σ m Current potential standard deviation σ n To monitor the interference point at the current time T n The standard deviation of all monitored energized potential data within the corresponding window period, and the standard deviation of the reference potential σ. m To monitor the interference point at reference time T m The standard deviation of the current potential is calculated by taking the standard deviation of all monitored energized potential data within the corresponding window period. n Subtract the standard deviation of the reference potential σ m If the difference is greater than the interference potential threshold ΔV, the current interference is considered to be non-steady-state interference, and subsequent steps are stopped; if the difference is less than or equal to the interference potential threshold ΔV, the step of extracting the monitoring reference pipe section is initiated.

4. The method for analyzing steady-state DC interference from a random single interference source according to claim 3, characterized in that, In the pre-analysis step, if the difference is less than or equal to the interference potential threshold ΔV, a further compliance judgment step is performed; Compliance judgment: Compare the de-energized potential of each test point in the target pipe section with the compliant potential range. If the de-energized potential of all test points is within the compliant potential range, then stop the subsequent steps; if the de-energized potential of any test point is outside the compliant potential range, then proceed to the step of extracting the monitoring reference pipe section.

5. The method for analyzing steady-state DC interference from a random single interference source according to claim 1, characterized in that, In the analysis and judgment step, the electrically continuous pipe segment is taken as the target pipe segment.

6. The method for analyzing steady-state DC interference from a random single interference source according to claim 1, characterized in that, The correlation coefficient R1 is greater than or equal to 0.5 and less than or equal to 0.

8.

7. The method for analyzing steady-state DC interference from a random single interference source according to claim 1, characterized in that, The correlation coefficient R2 is less than or equal to -0.5, and the correlation coefficient R3 is less than or equal to -0.

7.

8. The method for analyzing steady-state DC interference from a random single interference source according to claim 1, characterized in that, Correlation coefficient R a A correlation coefficient R0.5 is greater than or equal to 0.5 and less than or equal to 0.

8. b Less than or equal to -0.5 and greater than or equal to -0.

8.

9. The method for analyzing steady-state DC interference from a random single interference source according to claim 1, characterized in that, 0＜α≤10。 10. The method for analyzing steady-state DC interference from a random single interference source according to claim 1, characterized in that, N is a natural number greater than or equal to 10.