Method for analyzing steady-state direct current interference of uncertain single interference source

Abstract

The application provides a method for analyzing steady-state direct current interference of an uncertain single interference source, which comprises simulation parameter setting, simulation calculation, extraction of a simulation reference pipe section, establishment of a reference array set, entry into analysis and judgment, extraction of a monitoring reference pipe section, establishment of a monitoring potential curve, establishment of a monitoring array set, correlation calculation and correlation judgment. Embodiments of the application utilize inherent potential distribution characteristics of steady-state direct current interference, simulate potential waveforms generated on a pipeline by different interference points at different distances from an interference source, intercept a part with unclear characteristics in the potential waveforms through extraction of a simulation reference pipe section, record a current potential waveform when a target pipe section appears abnormal interference, intercept a part with unclear characteristics in the potential waveforms through extraction of a monitoring reference pipe section, and determine whether the current abnormal interference is steady-state direct current interference through similarity between the potential waveform with characteristics in the abnormal state and the simulation characteristic potential waveform, so that identification of steady-state direct current interference is realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cathodic protection corrosion prevention, and particularly relates to a steady-state direct current interference analysis method of an uncertain single interference source. BACKGROUND

[0002] Cathodic protection technology is a kind of electrochemical protection technology, and its principle is to apply an external current to the surface of a corroded metal structure, so that the protected structure becomes a cathode, thereby inhibiting the electron migration of metal corrosion and avoiding or weakening the occurrence of corrosion.

[0003] Cathodic protection technology is often used for long-distance pipelines, and the environment along the pipeline is complex and is easily affected by stray current interference. Since the potential of the protected structure needs to be maintained within the standard potential range of cathodic protection, the stray current interference will affect the potential of the protected structure, and then affect the cathodic protection effect.

[0004] HVDC and other steady-state direct current interference is one of the common direct current stray current interferences, which has the following characteristics: ① the occurrence time is random; ② the duration is relatively long, generally half an hour to several days, or even ten days; ③ in a relatively short period of time, the polarity of the interference is stable, and the interference intensity is also stable; ④ the interference intensity is large, the potential deviation is significant, the influence range is large, and it exceeds dozens of kilometers, or even one or two hundred kilometers; ⑤ the potential distribution has certain characteristics; ⑥ it may be cathodic interference, or it may be anodic interference.

[0005] The staff needs to know whether the current interference is a steady-state direct current interference, so as to adjust the constant potential instrument for applying current to the protected structure, so that the potential of the protected structure meets the standard. At present, there is no effective method to identify steady-state direct current interference. SUMMARY

[0006] In view of the deficiencies in the related art, the present application provides a steady-state direct current interference analysis method of an uncertain single interference source to solve the problem that the steady-state direct current interference cannot be effectively identified at present.

[0007] The present application provides a steady-state direct current interference analysis method of an uncertain single interference source, and the steps are as follows:

[0008] Simulation parameter setting: set the pipeline parameters of the simulation interference pipe section, set the soil environment parameters, and set the length of the simulation interference pipe section A plurality of simulation interference points are set on the simulation interference pipe section, a plurality of simulation interference sources are arranged along the vertical direction of each simulation interference point, and the interference intensity of the simulation interference sources is set;

[0009] Simulation calculation: using numerical simulation calculation software, the energized potential curve formed by each simulation interference source on the simulation interference pipe section is calculated;

[0010] Extracting simulation reference pipe section: the head end and the tail end of the simulation interference pipe section corresponding to each simulation interference source are cut off to obtain a preliminary processing simulation pipe section, the cutting-off length of the head end and the tail end of the simulation interference pipe section is a first cutting-off length and a second cutting-off length respectively, the first cutting-off length is the distance between the simulation interference point corresponding to the simulation interference source and the head end of the simulation interference pipe section, the second cutting-off length is the distance between the simulation interference point corresponding to the simulation interference source and the tail end of the simulation interference pipe section; the point with the maximum absolute value of energized potential difference between the simulation interference point and the head end and the tail end of the preliminary processing simulation pipe section of the simulation interference source is extracted as a reference starting point and a reference ending point respectively, and the preliminary processing simulation pipe section between the reference starting point and the reference ending point is taken as the simulation reference pipe section of the interference source;

[0011] Establishing reference array set: N reference points are set at equal intervals from the reference starting point to the reference ending point on the simulation reference pipe section of each simulation interference source, the energized potential of all reference points corresponding to each interference source is obtained according to the energized potential curve formed by each simulation interference source on the simulation reference pipe section, and the energized potential is arranged in order from the reference starting point to the reference ending point to form a reference array, and the reference arrays corresponding to each simulation interference source are combined to form a reference array set;

[0012] Entering analysis and judgment: when the absolute value of the dynamic deviation potential of any one test point on the target pipe section is greater than the interference potential threshold , it is determined that the target pipe section has abnormal interference, the time corresponding to the current time is recorded as a reference time , and the step of extracting the monitoring reference pipe section is entered; wherein, , is the average value of all monitored energized potential data in the window period corresponding to the current time , is the average value of all monitored energized potential data in the window period corresponding to the reference time , the reference time is earlier than the current time

[0013] Extracting the monitoring reference pipe section: cutting off the head and tail of the target pipe section to obtain a preliminary processing monitoring pipe section, the cutting-off length of the head and tail of the target pipe section is the third cutting-off length and the fourth cutting-off length respectively, the third cutting-off length is the distance between the monitoring interference point and the head of the target pipe section , and the fourth cutting-off length is the distance between the monitoring interference point and the tail of the target pipe section ; extracting the point with the largest absolute value of the energized potential difference from the monitoring interference point between the head of the preliminary processing monitoring pipe section and the monitoring interference point as the monitoring starting point, and extracting the point with the largest absolute value of the energized potential difference from the monitoring interference point between the tail of the preliminary processing monitoring pipe section and the monitoring interference point as the monitoring ending point, and taking the preliminary processing monitoring pipe section between the monitoring starting point and the monitoring ending point as the monitoring reference pipe section;

[0014] Establishing a monitoring potential curve: fitting the energized potential of each test point in the monitoring reference pipe section at the reference time into a monitoring potential curve;

[0015] Establishing a monitoring array: setting N monitoring points on the monitoring reference pipe section at equal intervals from the reference starting point to the reference ending point, obtaining the energized potential of each monitoring point according to the monitoring potential curve, and arranging them in order from the monitoring starting point to the monitoring ending point into a monitoring array;

[0016] Correlation calculation: calculating the Pearson correlation coefficient of each reference array in the monitoring array and the reference array set;

[0017] Correlation determination: if the maximum absolute value in the Pearson correlation coefficient is greater than or equal to the correlation coefficient , it is determined that the current interference is a steady-state direct current interference of a single interference source; if the maximum absolute value in the Pearson correlation coefficient is less than the correlation coefficient , it is determined that the current interference is not a steady-state direct current interference of a single interference source.

[0018] In some embodiments, when it is determined in the correlation determination step that there is a steady-state direct current interference of a single interference source, a result output step is further performed;

[0019] Result output: extracting the simulated reference pipe section corresponding to the maximum absolute value in the Pearson correlation coefficient , further extracting the simulated interference pipe section, the simulated interference point and the simulated interference source corresponding to the simulated reference pipe section, and moving the simulated interference pipe section, the simulated interference point and the simulated interference source to the length of the target pipe section and the positions of the monitoring interference point and the monitoring interference source to obtain the monitoring interference point and the monitoring interference source.

[0020] 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 will be... The test point with the largest absolute value is used as the monitoring interference point to extract the reference time. Reference potential at each test point Further pre-analysis steps are then performed;

[0021] Preliminary analysis: Calculate the current potential standard deviation at the monitoring interference point. and reference potential standard deviation Current potential standard deviation To monitor the interference point at the current time The standard deviation of all monitored energized potential data within the corresponding window period, and the standard deviation of the reference potential. To monitor interference points at the reference time Calculate the current potential standard deviation by taking the standard deviation of all monitored energized potential data within the corresponding window period. Subtract the standard deviation of the reference potential The difference is greater than the interference potential threshold. If the current interference is identified as non-steady-state interference, subsequent steps are stopped; if the difference is less than or equal to the interference potential threshold... Then proceed to the step of extracting the monitoring reference pipe section.

[0022] In some embodiments, during the pre-analysis step, if the difference is less than or equal to the interference potential threshold... Further steps are needed to determine if the standards are met.

[0023] 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.

[0024] In some embodiments, during the analysis and judgment step, an electrically continuous pipe segment is selected as the target pipe segment.

[0025] In some embodiments, the correlation coefficient It is greater than or equal to 0.5 and less than or equal to 0.8.

[0026] In some of these embodiments, 0 < ≤10.

[0027] In some embodiments, N is a natural number greater than or equal to 10.

[0028] In some of these embodiments, 0 < ≤10V.

[0029] Based on the above technical scheme, the embodiment of the present application utilizes the inherent potential distribution characteristics of steady-state direct current interference, first simulates the potential waveform composed of the energized potential along the pipeline generated by the different interference points at different distances from the interference source on the pipeline by using numerical simulation calculation software, extracts and intercepts the part with no obvious characteristics in the potential waveform by extracting the reference pipeline section, records the current potential waveform when the target pipeline section appears abnormal interference, extracts and intercepts the part with no obvious characteristics in the potential waveform by monitoring the reference pipeline section, sequentially standardizes the potential waveform at the time of abnormality with the simulated potential waveform, and then calculates the correlation coefficient, determines whether the current abnormal interference is steady-state direct current interference through the similarity of the potential waveform with characteristics at the time of abnormality and the simulated characteristic potential waveform, realizes the identification of steady-state direct current interference, enables the staff to quickly target the steady-state direct current interference, and adjust the potentiostat accordingly, so that the pipeline can be more efficiently adjusted to the best state of cathodic protection, and the problem that the steady-state direct current interference cannot be effectively identified at present is solved. DETAILED DESCRIPTION

[0030] The terms "first", "second", "third", are only used for descriptive purposes and should not be construed as indicating or implying relative importance or a specific number of the technical features indicated. Therefore, the features defined as "first", "second", "third" can explicitly or implicitly include one or more of the features.

[0031] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected, it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] In an illustrative embodiment of the present application, the uncertain single interference source steady-state direct current interference analysis method includes simulation parameter setting, simulation calculation, extraction of simulation reference pipeline section, establishment of reference array set, entry of analysis and judgment, extraction of monitoring reference pipeline section, establishment of monitoring potential curve, establishment of monitoring array set, correlation calculation and correlation determination.

[0033] The simulation parameter setting is performed, the pipeline parameters of the simulation interference pipeline section are set, the soil environment parameters are set, and the length of the simulation interference pipeline section is set A plurality of simulation interference points are set on the simulation interference pipe section, a plurality of simulation interference sources are set along the vertical direction of each simulation interference point, and the interference intensity of the simulation interference source is set. The simulation interference point is a point on the simulation interference pipe section closest to the simulation interference source.

[0034] Simulation calculation is performed, and a numerical simulation calculation software is used to calculate the energized potential curve formed by each simulation interference source on the simulation interference pipe section. The potential distribution of the steady-state direct current interference has certain characteristics, that is, the energized potential curve formed by the steady-state direct current interference on the pipeline has certain waveform characteristics. The absolute value of the potential at the position of the interference point in the curve is the largest, 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, one trough (or peak) is formed on the side of the interference point; when the interference point is not at the end of the pipe section, one trough (or peak) is formed on both sides of the interference point, and the curve further extends to a section away from the interference point beyond the trough (or peak), and the waveform gradually flattens. The most characteristic part of the curve is the section from the trough (or peak) on one side of the interference point to the trough (or peak) on the other side of the interference point. According to the potential distribution characteristics of the steady-state direct current interference, parameters are set in the numerical simulation calculation software, and the energized potential curve generated by a simulation interference source on the simulation interference pipe section can be simulated. Since a plurality of simulation interference sources are set at different distances from each simulation interference point, the energized potential curves generated by simulation interference sources at different positions and distances on the simulation interference pipe section can be obtained. The numerical simulation calculation software calculates the energized potential curve formed by the simulation interference source on the simulation interference pipe section, which is prior art and not the point of the present application. The energized potential curve of a simulation interference source simulated by simulation calculation has a horizontal axis from the beginning to the end of the simulation interference pipe section and a vertical axis of energized potential.

[0035] A simulation reference pipe section is extracted, and a portion of the beginning and end of the simulation interference pipe section corresponding to a simulation interference source is cut off to obtain a preliminary processing simulation pipe section. The cut-off lengths of the beginning and end of the simulation interference pipe section are a first cut-off length and a second cut-off length, respectively. The first cut-off length is , and the second cut-off length is , that is, the simulation interference pipe section is divided into two parts by the simulation interference point, and a portion of each part is cut off Between the beginning of the simulated pipe segment of the initial processing of the simulated interference source and the simulated interference point, the point with the largest absolute value of the potential difference between the two points is extracted and recorded as the reference starting point. The reference starting point is one of the simulated interference points, thus finding the peak or trough of the potential curve on one side of the simulated interference point. Similarly, between the end of the simulated pipe segment of the initial processing of the simulated interference source and the simulated interference point, the point with the largest absolute value of the potential difference between the two points is extracted and recorded as the reference ending point. The reference ending point is one of the simulated interference points, thus finding the peak or trough of the potential curve on the other side of the simulated interference point. The initial processing simulated pipe segment between the reference starting point and the reference ending point is used as the simulated reference pipe segment for this interference source. Following the aforementioned method, the simulated reference pipe segment for the next simulated interference source is extracted until all simulated interference sources have corresponding simulated reference pipe segments. This step essentially obtains the energizing potential curve of each simulated interference source on its corresponding simulated reference pipe section. Compared with the energizing potential curve on the simulated interference pipe section, this curve removes the gradually flattening part of the waveform 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.

[0036] A reference array set is established by setting N reference points at equal intervals from the reference start point to the reference end point on the simulated reference pipe segment for each simulated interference source. That is, the reference points are distributed at the reference start point, reference end point, and the pipe segment in between. Based on the energizing potential curves formed by each simulated interference source on the simulated reference pipe segment, the energizing potential of all reference points corresponding to each interference source is obtained. These potentials are then arranged sequentially from the reference start point to the reference end point to form a reference array. The reference arrays corresponding to each simulated interference source are combined into a reference array set. This step essentially obtains a dataset of the most characteristic parts of the energizing potential curves of simulated interference sources at different locations and distances along the simulated pipeline. In a reference array, the x-axis of each data point represents the position of the reference point, and the y-axis represents the energizing potential.

[0037] Enter the analysis and judgment, when the dynamic deviation potential of any test point on the target pipe section is detected. The absolute value is greater than the interference potential threshold. If the target pipe segment experiences abnormal interference, the current time will be determined as follows: The corresponding time is recorded as the reference time. The process then proceeds 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 stakes are located along the target pipe section, each serving as a test point. Each test stake monitors the on-state and off-state potentials of its corresponding test point within the target pipe section. , For the test point at the current time an average of all monitored energized potential data in the corresponding window period, a reference time an average of all monitored energized potential data in the corresponding window period, a reference time earlier than the current time Since the energized potential on the pipeline is not stable, with small fluctuations, taking the average value in a window period can truly reflect the size of the energized potential in that period. Comparing the average values of the energized potential in two time periods of the same length in real time can more accurately find the abnormal changes of the energized potential on the pipeline due to steady-state DC interference, so as to accurately find that the pipeline is disturbed by steady-state DC when the absolute value of the change exceeds the threshold.

[0038] extracting a monitoring reference pipe section, cutting off the first end and the end of the target pipe section to obtain a preliminary processing monitoring pipe section, the cutting off length of the first end and the end of the target pipe section is a third cutting off length and a fourth cutting off length, the third cutting off length is , the fourth cutting off length is , the detection interference point is the test point with the maximum absolute value of the average value of the energized potential data in the window period corresponding to the reference time on the target pipe section. Between the first end of the preliminary processing monitoring pipe section and the detection interference point, extract the point with the maximum absolute value of the energized potential difference with the detection interference point and mark it as the monitoring starting point, the monitoring starting point is one of the test points, so as to find the peak or valley of the energized potential curve on one side of the detection interference point; between the end of the preliminary processing monitoring pipe section and the detection interference point, extract the point with the maximum absolute value of the energized potential difference with the detection interference point and mark it as the monitoring ending point, the monitoring ending point is one of the test points, so as to find the peak or valley of the energized potential curve on the other side of the detection interference point, the preliminary processing monitoring pipe section between the monitoring starting point and the monitoring ending point is taken as the monitoring reference pipe section. This step essentially obtains the monitoring reference pipe section in the target pipe section, which removes the gradually flat parts on both sides of the energized potential curve on the whole target pipe section and retains the most characteristic part, including the part with the interference point and the peak or valley parts on both sides thereof.

[0039] establishing a monitoring potential curve, fitting the energized potential monitored by each test point in the monitoring reference pipe section at the reference time to the monitoring potential curve.

[0040] 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 simulated reference pipe section. The energizing 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 simulated reference pipe section, ensuring that the number and arrangement of data points are identical across both pipe sections for subsequent correlation coefficient calculations.

[0041] Correlation calculations were performed, and the Pearson correlation coefficient was calculated for each reference array in the monitoring array and reference array sets. More specifically, the monitoring array is compared with a reference array using the Pinnarson correlation coefficient. In the calculation, the monitoring reference pipe segment corresponding to the monitoring array and the simulated reference pipe segment corresponding to the reference 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, i.e., to calculate the Pinnarson correlation coefficient. Data points were set at the same locations on both sections of the pipeline. Pinnarson correlation coefficient. 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.

[0042] To determine the correlation, if the Pearson correlation coefficient... The largest absolute value in the correlation coefficient is greater than or equal to the correlation coefficient. That is, the Pearson correlation coefficient The one with the largest absolute value is greater than or equal to the correlation coefficient. If the current interference is a steady-state DC interference from a single source, then it is determined that the current interference is a steady-state DC interference from a single source; if the Pearson correlation coefficient is... The largest absolute value in the correlation coefficient is less than the correlation coefficient. That is, the Pearson correlation coefficient The one with the largest absolute value has the smallest correlation coefficient. If the current interference is determined to be a steady-state DC interference from a single source, and the Pearson correlation coefficient is [value missing], then the current interference is considered to be a steady-state DC interference from a single source. When the value is negative, it indicates that the energized potential curve of the monitoring reference pipe section is similar in shape to the energized potential curve of the corresponding simulated reference pipe section, but the waveforms of the two are opposite and negatively correlated. This indicates that the actual steady-state DC interference from a single interference source is opposite in direction to the interference simulated during the simulation calculation.

[0043] In the above exemplary embodiments, the uncertain steady-state direct current interference analysis method of the present application utilizes the potential distribution characteristics inherent to steady-state direct current interference, simulates the energized potential curves presented by single interference sources at different locations and distances along the length of the pipeline, and cuts off a portion of the simulated energized potential curves at the beginning and end, retaining the portion that is most characteristic of steady-state direct current interference. The actual measured energized potential curves of the target pipeline are also cut off at the beginning and end in a manner that retains the portion that is most characteristic of steady-state direct current interference. The two pipeline segments to be compared are standardized in length, and the point positions of the extracted data of the two pipeline segments are made the same. Finally, the correlation coefficient is calculated to determine the similarity of the two energized potential curves. When the similarity reaches a set threshold, the current interference is determined to be steady-state direct current interference from a single interference source, effectively identifying the interference type of steady-state direct current interference from a single interference source. After efficient identification, the subsequent constant potential instrument adjustment can be more timely and targeted, ensuring that the target pipeline segment to be protected can eliminate steady-state direct current interference and achieve the best state of cathodic protection, solving the problem of ineffective identification of steady-state direct current interference.

[0044] Before calculating the correlation coefficient, the simulation interference pipeline segment and the target pipeline segment are cut off, i.e., the simulation reference pipeline segment and the monitoring reference pipeline segment are extracted, both in a manner that retains the portion that is most characteristic of steady-state direct current interference. The first cut-off ensures that the non-characteristic portion of the waveform is removed, and then the portion before the start point and after the end point is cut off to ensure that the remaining portion fully reflects the most characteristic part from the wave peak (or trough) on one side of the interference point to the wave peak (or trough) on the other side of the interference point. This ensures that in the subsequent correlation coefficient calculation, the monitoring array generated by the target pipeline segment conforms to the characteristics of the corresponding reference array, ensuring that the monitoring array of the target pipeline segment conforms to the waveform characteristics of steady-state direct current interference when the correlation coefficient reaches the threshold, and ensuring the accuracy of the interference type confirmation. The simulation reference pipeline segment and the monitoring reference pipeline segment used in the correlation coefficient calculation use the same data point setting method and setting number, ensuring that the data brought into the correlation coefficient calculation accurately reflects the similarity of the two energized potential curves.

[0045] In some embodiments, when it is determined in the correlation judgment step that there is steady-state direct current interference from a single interference source, a result output step is further performed.

[0046] The result output step extracts the simulation reference pipeline segment corresponding to the maximum absolute value of the Pearson correlation coefficient Since each monitoring array is calculated with a corresponding reference array for the Pearson correlation coefficient , the simulation reference pipeline segment corresponding to the maximum absolute value of the Pearson correlation coefficient The absolute value of the largest one in the correlation coefficient calculation is extracted from the reference array, and the analog reference pipe segment of the reference array is further extracted, that is, the Pearson correlation coefficient is completed The extraction of the analog reference pipe segment corresponding to the absolute value of the largest one. The analog reference pipe segment is extracted, and the analog interference pipe segment, the analog interference point and the analog interference source corresponding to the analog reference pipe segment are further extracted. The analog interference pipe segment is stretched to the length of the target pipe segment, the analog interference pipe segment and the target pipe segment are standardized in length, and the positions of the analog interference point and the analog interference source are moved accordingly, so that the length-standardized analog interference pipe segment, the analog interference point and the analog interference source can reflect the position of the interference point and the distance between the interference source and the interference point when the target pipe segment is actually disturbed by the steady-state direct current interference, that is, the monitoring interference point and the monitoring interference source are obtained.

[0047] For example, if the length of the target pipe segment is 80 km, the length of the analog interference pipe segment is 100 km, the interference point is located at the 20th km of the analog interference pipe segment, and the interference source is 5 km away from the interference point. After the analog interference pipe segment is standardized in length to become 80 km, which is the same length as the target pipe segment, the interference point becomes located at the 16th km, and the interference source becomes 4 km away from the interference point. Therefore, the steady-state direct current interference on the target pipe segment, the monitoring interference point located at the 16th km of the target pipe segment, and the monitoring interference source located at a position 4 km vertically away from the monitoring interference point can be quickly found according to the positions of the monitoring interference point and the monitoring interference source, so that the steady-state direct current interference can be eliminated as soon as possible, and the target pipe can be restored to a good state.

[0048] In some embodiments, when it is determined in the analysis and judgment step that the target pipe segment has abnormal interference, the test point with the largest absolute value of the dynamic deviation potential is taken as the monitoring interference point, the reference time is extracted, and the baseline potential of each test point is further extracted for the pre-analysis step.

[0049] In the pre-analysis step, the current potential standard deviation and the reference potential standard deviation of the monitoring interference point are calculated. The current potential standard deviation is the standard deviation of all monitored energized potential data within the window period corresponding to the current time of the monitoring interference point, and the reference potential standard deviation is the standard deviation of all monitored energized potential data within the window period corresponding to the reference time of the monitoring interference point. The difference between the current potential standard deviation and the reference potential standard deviation is calculated, and if the difference is greater than the interference potential threshold , then the current interference is determined to be non-steady-state interference, and the subsequent steps are stopped; if the difference is less than or equal to the interference potential threshold , then the step of extracting a monitoring reference pipe section is entered.

[0050] Since the energized potential generated by the non-steady-state direct current interference on the target pipeline has a large fluctuation, this will make the standard deviation of the energized potential at the current time when the interference occurs high, and the standard deviation of the energized potential at the reference time when no interference occurs remains stable, thereby making the difference between the current potential standard deviation and the reference potential standard deviation large, and if the difference is greater than the threshold, it indicates that the current interference is not steady-state direct current interference, thereby stopping the subsequent steps, making the analysis complete quickly, and the overall process more efficient.

[0051] In some embodiments, in the pre-analysis step, if the difference is less than or equal to the interference potential threshold , the step of judging whether the target pipe section meets the standard is further performed.

[0052] The off potential of each test point of the target pipe section is compared with the standard potential range, if the off potential of all test points is within the standard potential range, the subsequent steps are stopped; if the off potential of any one of the test points is outside the standard potential range, the step of extracting a monitoring reference pipe section is entered.

[0053] If the interference is not steady-state direct current interference, but the off potential of the target pipe section meets the standard, the cathodic protection state is good, and there is no need to adjust the potentiostat, it is not meaningful to judge whether the interference type is steady-state direct current interference, at this time the subsequent steps are stopped, making the analysis complete quickly, and the overall process more efficient.

[0054] In some embodiments, in the analysis and judgment step, a section of electrically continuous pipe section is taken as the target pipe section. In order to prevent electrochemical corrosion, the pipeline is generally divided into multiple sections and connected through an insulating joint, and the pipelines on both sides of the insulating joint are connected through a wire, so that the current applied by the potentiostat can be transferred from one pipe section to the adjacent pipe section, so that the pipeline can reach the potential level that meets the overall cathodic protection effect. The wire for cross connection may fail, if the entire pipeline is taken as the target pipeline, the potential state on the target pipeline cannot accurately reflect the real potential state when the interference occurs, taking a section of electrically continuous pipe section as the target pipe section can ensure that the potential on the target pipe section can reflect the real potential state when the interference occurs, that is, when steady-state direct current interference occurs, the energized potential curve of the target pipe section can have the characteristics of steady-state direct current interference, ensuring that the steady-state direct current interference can be accurately identified.

[0055] In some embodiments, the correlation coefficient greater than or equal to 0.5 and less than or equal to 0.8. Due to the interference point and the interference source position set by the simulation calculation, it is difficult to ensure complete coincidence with the interference point and the interference source when the interference actually occurs. The similarity is 50% to 80%, the energized potential curve of the monitoring reference pipe segment is identified as being relatively similar to the energized potential curve of the corresponding simulation reference pipe segment, and the current interference can be accurately confirmed as single interference source steady-state direct current interference.

[0056] In some embodiments, 0 < N < 10. ≤10, that is, when the monitoring reference pipe segment and the simulation reference pipe segment are extracted, the interference point is decomposed, and the first and last parts are cut off within 10% first, which can ensure that the cut-off part is a relatively flat part of the waveform, and can also avoid cutting off the part that best reflects the steady-state direct current interference, thereby ensuring the accuracy of subsequent correlation coefficient calculation.

[0057] In some embodiments, N is a natural number greater than or equal to 10. The data points of the monitoring reference pipe segment and the extracted simulation reference pipe segment are at least 10, which can ensure that the data group arranged by the data points can reflect the potential curve characteristics of the steady-state direct current interference.

[0058] In some embodiments, 0 < N < 10. ≤10V. The potential difference within 10V can sensitively discover the occurrence of abnormal interference or sensitively judge the occurrence of non-steady-state interference.

[0059] Finally, it should be noted that: the embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts of each embodiment can be referred to.

[0060] The above embodiments are only used to illustrate the technical solutions of the present application rather than limit them. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalent ones without departing from the spirit of the present application. They should all be included in the technical solution range of the present application.

Claims

1. A method for analyzing steady-state direct current interference of an uncertain single interference source, characterized in that, The steps are as follows: Simulation parameter setting: set the pipeline parameters of the simulation interference pipe section, set the soil environment parameters, set the length of the simulation interference pipe section A plurality of simulation interference points are set on the simulation interference pipe section, a plurality of simulation interference sources are arranged along the vertical direction of each simulation interference point, and the interference intensity of the simulation interference sources is set; Simulation calculation: numerical simulation software is used to calculate the energized potential curve formed by each simulation interference source on the simulation interference pipe section; Extracting the analog reference tube section: the first end and the last end of the analog interference tube section corresponding to each analog interference source are cut off to obtain a preliminary processing analog tube section, the cutting-off length of the first end and the last end of the analog interference tube section is a first cutting-off length and a second cutting-off length respectively, the first cutting-off length is the distance between the analog interference point corresponding to the analog interference source and the first end of the analog interference tube section , and the second cutting-off length is the distance between the analog interference point corresponding to the analog interference source and the last end of the analog interference tube section ; a point with the largest absolute value of the energized potential difference from the analog interference point is extracted between the first end of the preliminary processing analog tube section of the analog interference source and the analog interference point and is recorded as a reference starting point, a point with the largest absolute value of the energized potential difference from the analog interference point is extracted between the last end of the preliminary processing analog tube section of the analog interference source and the analog interference point and is recorded as a reference ending point, and the preliminary processing analog tube section between the reference starting point and the reference ending point is taken as the analog reference tube section of the interference source; Reference array set is established: N reference points are set on the simulation reference pipe section of each simulation interference source from the reference starting point to the reference ending point at equal intervals, the energized potential of each reference point corresponding to each simulation interference source is obtained according to the energized potential curve formed by each simulation interference source on the simulation reference pipe section, and the reference array is arranged in order from the reference starting point to the reference ending point, and the reference arrays corresponding to each simulation interference source are combined into a reference array set; Entering the analysis and judgment phase: When the dynamic deviation potential at any test point on the target pipe section... The absolute value is greater than the interference potential threshold. If the target pipe segment experiences abnormal interference, the current time will be determined as follows: The corresponding time is recorded as the reference time. Proceed to the step of extracting the monitoring reference pipe section; among which, , For the test point at the current time The average value of all monitored energized potential data within the corresponding window period. For the test point at the reference time The average value of all monitored energized potential data within the corresponding window period, reference time. Earlier than the present moment ; Extracting the monitoring reference pipe section: cutting off the first end and the last end of the target pipe section to obtain a preliminary processing monitoring pipe section, the cutting off length of the first end and the last end of the target pipe section is the third cutting off length and the fourth cutting off length respectively, the third cutting off length is the distance between the monitoring interference point and the first end of the target pipe section , the fourth cutting off length is the distance between the monitoring interference point and the last end of the target pipe section ; extracting the point between the first end of the preliminary processing monitoring pipe section and the monitoring interference point and the monitoring interference point with the largest absolute value of energized potential difference and recording it as the monitoring starting point, extracting the point between the last end of the preliminary processing monitoring pipe section and the monitoring interference point and the monitoring interference point with the largest absolute value of energized potential difference and recording it as the monitoring ending point, taking the preliminary processing monitoring pipe section between the monitoring starting point and the monitoring ending point as the monitoring reference pipe section; Establishing the monitoring potential curve: the monitoring reference tube segment is divided into several test points at the reference time The monitored energized potential is fitted into the monitoring potential curve; Monitoring array is established: N monitoring points are set on the monitoring reference pipe section from the reference starting point to the reference ending point at equal intervals, the energized potential of each monitoring point is obtained according to the monitoring potential curve, and the monitoring array is arranged in order from the monitoring starting point to the monitoring ending point; Correlation calculation: Calculate the Pearson correlation coefficient of the monitoring array and each reference array in the set of reference arrays ; Correlation determination: if the maximum absolute value in the Pearson correlation coefficient is greater than or equal to the correlation coefficient , it is determined that the current interference is a single source of steady-state DC interference; if the maximum absolute value in the Pearson correlation coefficient is less than the correlation coefficient , it is determined that the current interference is not a single source of steady-state DC interference.

2. The unbalanced single disturbance source steady-state direct current disturbance analysis method according to claim 1, characterized in that, When it is determined in the correlation judgment step that there is a single interference source of steady-state direct current interference, the result output step is further performed; Result output: the Pearson correlation coefficient The simulation reference pipe section corresponding to the largest absolute value is extracted, and the simulation interference pipe section, simulation interference point and simulation interference source corresponding to the simulation reference pipe section are further extracted. The simulation interference pipe section is stretched or contracted to the length of the target pipe section, and the positions of the simulation interference point and the simulation interference source are moved accordingly to obtain the monitoring interference point and the monitoring interference source.

3. The unbalanced single disturbance source steady-state direct current disturbance analysis method 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 will be adjusted. The test point with the largest absolute value is used as the monitoring interference point to extract the reference time. Reference potential at each test point Further pre-analysis steps are then performed; Pre-analysis: calculate the current potential standard deviation of the monitoring interference point and the reference potential standard deviation , the current potential standard deviation is the standard deviation of all monitored energized potential data within the window period corresponding to the current time of the monitoring interference point , the reference potential standard deviation is the standard deviation of all monitored energized potential data within the window period corresponding to the reference time of the monitoring interference point , the current potential standard deviation is calculated by subtracting the reference potential standard deviation , if the difference is greater than the interference potential threshold , it is determined that the current interference is non-steady-state interference, and the subsequent steps are stopped; if the difference is less than or equal to the interference potential threshold , the step of extracting a monitoring reference pipe section is entered.

4. The method of claim 3, wherein, In the pre-analysis step, if the difference is less than or equal to the interference potential threshold value , a compliance judgment step is further performed. Standard judgment: the de-energized potential of each test point of the target pipe section is compared with the standard potential range, if the de-energized potential of all test points is located within the standard potential range, the subsequent steps are stopped; if the de-energized potential of any one of the test points is located outside the standard potential range, the extraction of the monitoring reference pipe section step is entered.

5. The unbalanced single disturbance source steady-state direct current disturbance analysis method according to claim 1, characterized in that, In the analysis judgment step, a continuously electrically connected pipe section is taken as a target pipe section.

6. The unbalanced single disturbance source steady-state direct current disturbance analysis method according to claim 1, characterized in that, the correlation coefficient greater than or equal to 0.5 and less than or equal to 0.

8.

7. The unbalanced single disturbance source steady-state direct current disturbance analysis method according to claim 1, characterized in that, 0＜ ≤10。 8. The method of claim 1, wherein, N is a natural number greater than or equal to 10.

9. The unbalanced single disturbance source steady-state direct current disturbance analysis method according to claim 1, characterized in that, 0< ≤10V。