Segmentally Adjustable DC Interference Mitigation Method and Device

Abstract

A segmented adjustable DC interference mitigation method and device. The method includes: potential monitoring, interference judgment, compliance judgment, jumper adjustment, jumper resistance, first adjustment of resistor, analysis of influence of first adjustment, potential state analysis, analysis of influence of second adjustment, second adjustment of resistor, and third adjustment of resistor. The device includes a jumper switch, an adjustable resistor, and a control switch; the upstream pipeline and the downstream pipeline are electrically connected through the jumper switch; one end of the adjustable resistor is electrically connected to one pipeline, and the other end is electrically connected to the other pipeline through the control switch. In the embodiments of the present invention, by means of the jumper resistance, the potential difference between the interference side and the non-interference side of the insulating joint is reduced, the influence of the DC stray current on the pipeline on the non-interference side of the insulating joint is alleviated, the influence range of the DC stray current interference is effectively reduced, and an adjustable resistance value resistor is adopted, which increases the flexibility of on-site adjustment to achieve a better effect of suppressing the DC stray current interference.

Description

Technical Field

[0001] The present invention belongs to the technical field of cathodic protection, and particularly relates to a method for mitigating DC interference with segmented adjustability. Background Art

[0002] DC stray current interference has a significant impact on the cathodic corrosion protection of pipelines. Common methods for eliminating DC stray current interference include passive drainage, active drainage, shielding, pipeline segmented insulation, etc.

[0003] Through pipeline segmented insulation, the interference section can be isolated from the non-interference section to reduce the intensity and influence range of interference. The insulating joints along the pipeline are equipped with jumper cables for maintaining electrical connection. When interference occurs, the pipeline can be segmented and insulated by disconnecting the jumper cables.

[0004] However, for strong DC interference, when using the segmented insulation method to mitigate interference, compared with before disconnecting the electrical connection, a greater potential deviation will occur at one or both ends of the insulating joint, and a large potential difference will be generated at both ends, which has a great adverse impact on the anti-corrosion of the pipeline near the insulating joint.

[0005] To solve this problem, the general method is to parallel a drainage ground bed at both ends of the insulating joint after disconnecting the jumper cable of the insulating joint. After paralleling the drainage ground bed, the interference current flows into the ground through the interference-side drainage ground bed, which can reduce the potential deviation on the interference side. Part of the interference current flowing into the ground flows into the pipeline through the non-interference-side drainage ground bed, which can also play a certain role in mitigating the potential deviation on the non-interference side. However, the disconnection and connection of the jumper cable can only achieve the on-off of the electrical connection at both ends of the insulating joint, and the drainage ground bed is also fixed. These methods do not have the ability to adjust and cannot reduce or eliminate the potential deviation caused by DC interference as needed, resulting in poor mitigation effect of DC interference. Summary of the Invention

[0006] In view of the deficiencies in the related art, the present invention provides a method and device for mitigating DC interference with segmented adjustability to solve the problems of non-adjustability and poor mitigation effect in the current method for eliminating DC interference by segmented insulation.

[0007] The present invention provides a method for mitigating DC interference with segmented adjustability, including the following steps:

[0008] Potential monitoring: Continuously measure the on-potential V on_up and off-potential V off_up of the upstream pipeline, as well as the on-potential V on_down and off-potential V off_down of the downstream pipeline;

[0009] Interference judgment: Calculate the absolute value ΔV of the difference between the on-potential V on_up and the normal on-potentialup If ΔV up is greater than or equal to the set threshold A, then perform the compliance judgment step;

[0010] Compliance judgment: Compare the power-off potential V off_up with the compliance potential range. If the power-off potential V off_up is outside the compliance potential range, then perform the bridging adjustment step;

[0011] Bridging adjustment: Disconnect the bridging switch K1 connecting the upstream pipeline and the downstream pipeline, and compare both the power-off potential V off_up and the power-off potential V off_down with the compliance potential range. If the power-off potential V off_up or the power-off potential V off_down is in a non-compliant state, then perform the bridging resistance step;

[0012] Bridging resistance: Connect the adjustable resistor, which has been adjusted to the maximum resistance value, across the upstream pipeline and the downstream pipeline. Then compare both the power-off potential V off_up and the power-off potential V off_down with the compliance potential range. If one of the power-off potential V off_up and the power-off potential V off_down is in an under-protected state and the other is in an over-protected state, then perform the first resistor adjustment step; If one of the power-off potential V off_up and the power-off potential V off_down is in a compliant state and the other is in a non-compliant state, and the power-off potential in the compliant state is at the boundary of the compliance potential range, then perform the potential state analysis step; If one of the power-off potential V off_up and the power-off potential V off_down is in a compliant state and the other is in a non-compliant state, and the power-off potential in the compliant state is not at the boundary of the compliance potential range, then perform the second resistor adjustment step;

[0013] First resistor adjustment: Compare the power-off potential V off_up before the bridging adjustment step with the compliance potential range. If the power-off potential V off_up before the bridging adjustment is in an over-protected state, then gradually reduce the resistance value of the adjustable resistor until the power-off potential in the under-protected state in the bridging resistance step reaches the upper limit value of the compliance potential range, and perform the first adjustment impact analysis step; If the power-off potential V off_up before the bridging adjustment is not in an over-protected state, then gradually reduce the resistance value of the adjustable resistor until the power-off potential in the over-protected state in the bridging resistance step reaches the lower limit value of the compliance potential range, and perform the first adjustment impact analysis step;

[0014] First adjustment impact analysis: Compare the power-off potential V after the first adjustment step of the resistor off_up and the power-off potential V off_down with the qualified potential range. If the power-off potential V off_up or the power-off potential V off_down is in a non-compliant state, and the current potential value of the non-compliant side's power-off potential is closer to the qualified potential range than its potential value after the cross-connected resistor step, then perform the third adjustment step of the resistor; if the power-off potential V off_up or the power-off potential V off_down is in a non-compliant state, and the current potential value of the non-compliant side's power-off potential is farther from the qualified potential range than its potential value after the cross-connected resistor step, then maintain the status quo;

[0015] Potential state analysis: Compare the power-off potential V before the cross-connected adjustment step off_up with the qualified potential range. If the power-off potential V before the cross-connected adjustment off_up is in an over-protected state and the qualified side's power-off potential is at the upper limit value of the qualified potential protection range, then perform the second adjustment impact analysis step; if the power-off potential V before the cross-connected adjustment off_up is not in an over-protected state and the qualified side's power-off potential is at the lower limit value of the qualified potential protection range, then perform the second adjustment impact analysis step; if the power-off potential V before the cross-connected adjustment off_up is in an over-protected state and the qualified side's power-off potential is not at the upper limit value of the qualified potential protection range or the power-off potential V before the cross-connected adjustment off_up is not in an over-protected state and the qualified side's power-off potential is not at the lower limit value of the qualified potential protection range, then maintain the status quo;

[0016] Second adjustment impact analysis: Compare the current potential value of the non-compliant side's power-off potential with its potential value after the cross-connected resistor step. If the current potential value of the non-compliant side's power-off potential is closer to the qualified potential range, then perform the third adjustment step of the resistor; if the current potential value of the non-compliant side's power-off potential is farther from the qualified potential range, then maintain the status quo;

[0017] Resistor second adjustment: Gradually reduce the resistance value of the adjustable resistor until the qualified side's power-off potential reaches the boundary of the qualified potential range or the non-compliant side's power-off potential reaches within the qualified potential range or the potential change direction of the non-compliant side's power-off potential turns away from the qualified potential range, and then maintain the status quo;

[0018] Resistor third adjustment: Gradually reduce the resistance value of the adjustable resistor until the qualified side's power-off potential reaches the boundary on the other side of the qualified potential range or the non-compliant side's power-off potential reaches within the qualified potential range or the potential change direction of the non-compliant side's power-off potential turns away from the qualified potential range, and then maintain the status quo.

[0019] In some of these embodiments, in the second resistor adjustment step, the resistance value of the adjustable resistor is adjusted according to a set adjustment step size;

[0020] If, after the adjustable resistor is adjusted, the off-state potential of the non-compliant side is further away from the compliant potential range or the off-state potential of the compliant side becomes non-compliant compared to before the adjustment, then the resistance value of the adjustable resistor is restored to the value before the adjustment, the adjustment step size is decreased, and the resistance value of the adjustable resistor is re-adjusted starting from the decreased adjustment step size; if the adjustment step size is less than or equal to the minimum step size after the decrease, then maintain the current state;

[0021] If, after the adjustable resistor is adjusted, the off-state potential of the non-compliant side is closer to the compliant potential range and the off-state potential of the compliant side remains in the compliant state compared to before the adjustment, then both the off-state potential of the non-compliant side and the off-state potential of the compliant side after the adjustment of the adjustable resistor are compared with the compliant potential range;

[0022] If the off-state potential of the non-compliant side is still in the non-compliant state and the off-state potential of the compliant side is not at the boundary of the compliant potential range, then the resistance value of the adjustable resistor is adjusted again according to the set adjustment step size; if the off-state potential of the non-compliant side is in the compliant state, or the off-state potential of the compliant side is at the boundary of the compliant potential range, then maintain the current state.

[0023] In some of these embodiments, in the third resistor adjustment step, the resistance value of the adjustable resistor is adjusted according to a set adjustment step size;

[0024] If, after the adjustable resistor is adjusted, the off-state potential of the non-compliant side is further away from the compliant potential range or the off-state potential of the compliant side becomes non-compliant compared to before the adjustment, then the resistance value of the adjustable resistor is restored to the value before the adjustment, the adjustment step size is decreased, and the resistance value of the adjustable resistor is re-adjusted starting from the decreased adjustment step size; if the adjustment step size is less than or equal to the minimum step size after the decrease, then maintain the current state;

[0025] If, after the adjustable resistor is adjusted, the off-state potential of the non-compliant side is closer to the compliant potential range and the off-state potential of the compliant side remains in the compliant state compared to before the adjustment, then both the off-state potential of the non-compliant side and the off-state potential of the compliant side after the adjustment of the adjustable resistor are compared with the compliant potential range;

[0026] If the off-state potential of the non-compliant side is still in the non-compliant state and the off-state potential of the compliant side does not move from one boundary of the compliant potential range to the other boundary, then the resistance value of the adjustable resistor is adjusted again according to the set adjustment step size; if the off-state potential of the non-compliant side is in the compliant state, or the off-state potential of the compliant side moves from one boundary of the compliant potential range to the other boundary, then maintain the current state.

[0027] In some of these embodiments, one end of the adjustable resistor is electrically connected to one of the upstream pipeline and the downstream pipeline, and the other end of the adjustable resistor is electrically connected to the other of the upstream pipeline and the downstream pipeline through the control switch K2;

[0028] In the step of connecting the resistor across, by adjusting the resistance value of the adjustable resistor to the maximum value and closing the control switch K2, the resistance value of the adjustable resistor connected across between the upstream pipeline and the downstream pipeline is in the maximum state.

[0029] In some of these embodiments, the set threshold A is greater than or equal to 0.5V.

[0030] In some of these embodiments, the minimum resistance value of the adjustable resistor is 0Ω.

[0031] In some of these embodiments, after maintaining the current situation, the reaching-standard reset step is carried out;

[0032] Reaching-standard reset: Continuously monitor the energized potential V on_up and the energized potential V on_down , calculate the absolute value ΔV of the difference between the energized potential V on_up and the normal energized potential up as well as the absolute value ΔV of the difference between the energized potential V on_down and the normal energized potential down , if either ΔV up or ΔV down is less than the set threshold A, remove the connection of the adjustable resistor across the upstream pipeline and the downstream pipeline, and close the cross-connection switch K1, then return to the potential monitoring step.

[0033] In some of these embodiments, the normal energized potential is the average value of the energized potential on the pipeline within a set time period before the current moment.

[0034] In some of these embodiments, the set time period is the whole day before the current moment.

[0035] The present invention also provides a segmented adjustable DC interference mitigation device, which is applied to a pipeline configured with an insulating joint and includes a cross-connection switch, an adjustable resistor, and a control switch;

[0036] There are two pipelines, which are the upstream pipeline and the downstream pipeline respectively;

[0037] Both ends of the insulating joint are respectively connected to the upstream pipeline and the downstream pipeline;

[0038] The upstream pipeline and the downstream pipeline are electrically connected through the cross-connection switch;

[0039] One end of the adjustable resistor is electrically connected to one pipeline, and the other end is electrically connected to the other pipeline through the control switch.

[0040] Based on the above technical solution, in the embodiment of the present invention, by means of connecting a shunt resistor, the longitudinal resistance of the pipeline is increased, the potential difference between the interference side and the non-interference side of the insulating joint is reduced, the influence of the DC stray current on the pipeline on the non-interference side of the insulating joint is alleviated, the intensity of the DC stray current is reduced, the influence range of the DC stray current interference is effectively reduced, and a resistor with adjustable resistance value is adopted, which increases the flexibility of on-site adjustment, so as to achieve a better effect of suppressing the DC stray current interference, maximize the achievement of the qualified power-off potential, and solve the problems of non-adjustability and poor mitigation effect existing in the current method for eliminating segmented insulation DC interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings described herein are used to provide a further understanding of the present invention and form a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0042] Figure 1 is the operation flow chart of the method for mitigating segmented adjustable DC interference of the present invention;

[0043] Figure 2 is the operation flow chart of the second adjustment step of the resistor in the method for mitigating segmented adjustable DC interference of the present invention;

[0044] Figure 3 is the operation flow chart of the third adjustment step of the resistor in the method for mitigating segmented adjustable DC interference of the present invention;

[0045] Figure 4 is the structural schematic diagram of the device for mitigating segmented adjustable DC interference of the present invention;

[0046] In the figure:

[0047] 1, insulating joint; 2, shunt switch; 3, adjustable resistor; 4, control switch; 5, upstream pipeline; 6, downstream pipeline. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0048] Next, the technical solutions in the embodiments will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0049] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present invention.

[0050] The terms "first", "second", "third" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", "third" may explicitly or implicitly include one or more of such features.

[0051] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] As Figure 1 shown, in a schematic embodiment of the segmented adjustable DC interference mitigation method of the present invention, the segmented adjustable DC interference mitigation method includes potential monitoring, interference judgment, compliance judgment, jumper adjustment, jumper resistance, first resistor adjustment, first adjustment impact analysis, potential state analysis, second adjustment impact analysis, second resistor adjustment, and third resistor adjustment.

[0053] Two sections of pipelines are connected by an insulating joint. The pipeline upstream of the insulating joint is the upstream pipeline, and the pipeline downstream of the insulating joint is the downstream pipeline. The upstream pipeline and the downstream pipeline are electrically connected to each other through a closed jumper switch K1, so that both the upstream pipeline and the downstream pipeline can effectively obtain cathodic protection and anti-corrosion.

[0054] Potential monitoring, continuously measuring the on-potential V on_up and off-potential V off_up of the upstream pipeline through a sensor, on_down as well as the on-potential V off_down and off-potential V

[0055] of the downstream pipeline. on_up Performing interference judgment, calculating the absolute value ΔV up of the difference between the on-potential V upCompare with the set threshold A. If ΔV up is greater than or equal to the set threshold A, then perform the compliance judgment step.

[0056] Perform the compliance judgment. Compare the off-potential V off_up with the compliance potential range. If the off-potential V off_up is outside the compliance potential range, then perform the bridging adjustment step. The compliance potential range is the potential range that can provide effective protection in the cathodic protection anti-corrosion technical standard, which is prior art.

[0057] Perform the bridging adjustment. Disconnect the bridging switch K1 connecting the upstream pipeline and the downstream pipeline, and then compare the measured off-potential V off_up and the off-potential V off_down both with the compliance potential range. If the off-potential V off_up or the off-potential V off_down is in a non-compliant state, that is, either one of the upstream and downstream off-potentials is outside the compliance potential range, then perform the bridging resistance step.

[0058] Perform the bridging resistance. Connect the adjustable resistor adjusted to the maximum resistance value across the upstream pipeline and the downstream pipeline, and then compare the measured off-potential V off_up and the off-potential V off_down both with the compliance potential range. At this time, the off-potential V off_up and the off-potential V off_down compared are the data measured after the adjustable resistor is bridged. If the off-potential V off_up and the off-potential V off_down show that one is in an under-protected state and the other is in an over-protected state, then perform the first resistor value adjustment step; if the off-potential V off_up and the off-potential V off_down show that one is in a compliant state and the other is in a non-compliant state, and the off-potential in the compliant state is at the boundary of the compliance potential range, then perform the potential state analysis step, that is, whether the connection of the adjustable resistor makes the off-potential on one side just compliant, and whether the off-potential on the other side can be adjusted to be compliant or approach compliance by adjusting the resistance value of the adjustable resistor still needs to be further analyzed through the potential state analysis step; if the off-potential V off_up and the off-potential V off_down show that one is in a compliant state and the other is in a non-compliant state, and the off-potential in the compliant state is not at the boundary of the compliance potential range, then perform the second resistor adjustment step, that is, the connection of the adjustable resistor makes the off-potential on one side compliant, and the adjustment of the resistance value of the adjustable resistor enables the off-potential on that side to change within the compliance potential range and maintain the compliant state, so that the off-potential on the other side can be adjusted to the compliant state or approach compliance through the second resistor adjustment step.

[0059] The under-protection state means that the off-state potential is positive within the qualified potential range, and the over-protection state means that the off-state potential is negative within the qualified potential range. The boundaries of the qualified potential range are the critical values at both ends of the qualified potential range. If the qualified potential range is -1.2V to -0.85V, then the boundaries of the qualified range are -1.2V and -0.85V, -0.85V is the upper limit value of the qualified potential range, and -1.2V is the lower limit value of the qualified potential range.

[0060] Perform the first resistance value adjustment of the resistor, and compare the off-state potential V before the cross-connection adjustment step off_up with the qualified potential range. If the off-state potential V before the cross-connection adjustment off_up is in the over-protection state, gradually reduce the resistance value of the adjustable resistor until the off-state potential in the under-protection state during the cross-connection resistance step reaches the upper limit value of the qualified potential range, and perform the first adjustment impact analysis step; if the off-state potential V before the cross-connection adjustment off_up is not in the over-protection state, gradually reduce the resistance value of the adjustable resistor until the off-state potential in the over-protection state during the cross-connection resistance step reaches the lower limit value of the qualified potential range, and perform the first adjustment impact analysis step.

[0061] Since before the first resistance value adjustment step of the resistor, the off-state potentials of the upstream and downstream are in a state of one over-protection and one under-protection. After the first resistance value adjustment of the resistor, one of the off-state potentials of the upstream and downstream pipelines reaches the boundary of the qualified potential range and is in a qualified state. Therefore, the side of the upstream and downstream pipelines with the off-state potential in the qualified state is taken as the qualified side; while the other of the off-state potentials of the upstream and downstream is still in an unqualified state. Therefore, the side of the upstream and downstream pipelines with the off-state potential in the unqualified state is taken as the unqualified side.

[0062] Perform the first adjustment impact analysis step, and compare the off-state potential V measured after the first adjustment step of the resistor off_up and the off-state potential V off_down both with the qualified potential range. If the off-state potential V off_up or the off-state potential V off_down is in an unqualified state, and the current potential value of the off-state potential on the unqualified side is closer to the qualified potential range compared to its potential value after the cross-connection resistance step, then perform the third adjustment step of the resistor. That is, the adjustment of the resistance value of the adjustable resistor not only makes one side of the off-state potential qualified, but also reduces the degree of unqualified of the off-state potential on the other side. There is further room for adjustment of the resistance value of the adjustable resistor. Through the third adjustment step of the resistor, while keeping one side of the off-state potential qualified, adjust the off-state potential on the other side to be qualified or approach qualification; if the off-state potential V off_up or the off-state potential V off_downIf it is in a non-compliant state and the current potential value of the off-state potential on the non-compliant side is further away from the compliant potential range compared to its potential value after the cross-connection resistance step, then maintain the status quo. That is, the adjustment of the adjustable resistor's resistance not only makes the off-state potential on one side compliant, but also increases the degree of non-compliance of the off-state potential on the other side. This indicates that the resistance of the adjustable resistor cannot be further adjusted. If the resistance of the adjustable resistor is further decreased, the degree of non-compliance of the off-state potential on the other side will be further increased. Maintaining the status quo can achieve the best state that the off-state potentials of the upstream and downstream pipelines can reach currently.

[0063] During the cross-connection resistance step, if the off-state potential V off_up and the off-state potential V off_down show that one is in a compliant state and the other is in a non-compliant state, then the side with the off-state potential in the compliant state in the upstream and downstream pipelines is taken as the compliant side, and the other side is taken as the non-compliant side.

[0064] Conduct a potential state analysis. Compare the off-state potential V off_up before the cross-connection adjustment step with the compliant potential range. If the off-state potential V off_up before the cross-connection adjustment is in an over-protected state and the off-state potential of the compliant side is at the upper limit value of the compliant potential protection range, then perform the second adjustment impact analysis step. That is, although the connection of the adjustable resistor makes the off-state potential on one side compliant at the critical value, whether adjusting the resistance of the adjustable resistor will cause the off-state potential on this side to move out of the compliant potential range, and whether adjusting the resistance of the adjustable resistor will cause an increase in the degree of non-compliance on the other side need to be determined through the second adjustment impact analysis step; if the off-state potential V off_up before the cross-connection adjustment is not in an over-protected state and the off-state potential of the compliant side is at the lower limit value of the compliant potential protection range, then perform the second adjustment impact analysis step. That is, although the connection of the adjustable resistor makes the off-state potential on one side compliant at the critical value, whether adjusting the resistance of the adjustable resistor will cause the off-state potential on this side to move out of the compliant potential range, and whether adjusting the resistance of the adjustable resistor will cause an increase in the degree of non-compliance on the other side need to be determined through the second adjustment impact analysis step; if the off-state potential V off_up before the cross-connection adjustment is in an over-protected state and the off-state potential of the compliant side is not at the upper limit value of the compliant potential protection range or the off-state potential V off_up before the cross-connection adjustment is not in an over-protected state and the off-state potential of the compliant side is not at the lower limit value of the compliant potential protection range, then maintain the status quo. That is, although the connection of the adjustable resistor makes the off-state potential on one side compliant at the critical value, adjusting the resistance of the adjustable resistor will cause the off-state potential on this side to move out of the compliant potential range. Maintaining the status quo can keep the off-state potential on one side compliant and achieve the best state of the off-state potentials of the upstream and downstream pipelines in the current situation.

[0065] Conduct the second adjustment impact analysis by comparing the current potential value of the de-energized potential on the non-compliant side with its potential value after the cross-connection resistance step. If the current potential value of the de-energized potential on the non-compliant side is closer to the compliant potential range, perform the third resistor adjustment step, that is, adjust the resistance value of the adjustable resistor so that the de-energized potential on the compliant side does not move out of the compliant potential range, and the connection of the adjustable resistor enables the de-energized potential on the non-compliant side to approach compliance. Further adjust the resistance value of the adjustable resistor through the third resistor adjustment step, which can adjust the de-energized potential on the non-compliant side to compliance or approach compliance, achieving the best upstream and downstream pipeline de-energized potential state under the current situation. If the current potential value of the de-energized potential on the non-compliant side is farther from the compliant potential range, maintain the current situation, that is, although adjusting the resistance value of the adjustable resistor can make the de-energized potential on the compliant side not move out of the compliant potential range, the connection of the adjustable resistor makes the non-compliance degree of the de-energized potential on the non-compliant side more serious. Maintaining the current situation can achieve the best upstream and downstream pipeline de-energized potential state under the current situation.

[0066] Conduct the second resistor adjustment, gradually reduce the resistance value of the adjustable resistor until the de-energized potential on the compliant side reaches the boundary of the compliant potential range or the de-energized potential on the non-compliant side reaches within the compliant potential range or the potential change direction of the de-energized potential on the non-compliant side turns away from the compliant potential range. Then maintain the current situation, that is, adjust the resistance value of the adjustable resistor to keep the de-energized potential on the compliant side in a compliant state, adjust the de-energized potential on the non-compliant side to compliance or adjust the de-energized potential on the non-compliant side to be closer to the compliant potential range, so that the upstream and downstream de-energized potentials are both compliant or the degree of non-compliance on one side and compliance on the other side is reduced, ultimately achieving the best upstream and downstream pipeline de-energized potential state.

[0067] Conduct the third resistor adjustment, gradually reduce the resistance value of the adjustable resistor until the de-energized potential on the compliant side reaches the boundary on the other side of the compliant potential range or the de-energized potential on the non-compliant side reaches within the compliant potential range or the potential change direction of the de-energized potential on the non-compliant side turns away from the compliant potential range. Then maintain the current situation. That is, adjust the resistance value of the adjustable resistor to keep the de-energized potential on the compliant side in a compliant state, adjust the de-energized potential on the non-compliant side to compliance or adjust the de-energized potential on the non-compliant side to be closer to the compliant potential range, so that the upstream and downstream de-energized potentials are both compliant or the degree of non-compliance on one side and compliance on the other side is reduced, ultimately achieving the best upstream and downstream pipeline de-energized potential state.

[0068] In the above-described exemplary embodiment, by means of a shunt resistor, the longitudinal resistance of the pipeline is increased, the potential difference between the interference side and the non-interference side of the insulating joint is reduced, the influence of the DC stray current on the pipeline on the non-interference side of the insulating joint is alleviated, the intensity of the DC stray current is reduced, and the influence range of the DC stray current interference is effectively reduced; an adjustable resistor is adopted, which increases the flexibility of on-site adjustment to achieve a better effect of suppressing the DC stray current interference, maximizes the achievement of the off-state potential compliance, and solves the problems of non-adjustability and poor mitigation effect existing in the current method for eliminating the DC interference of segmented insulation.

[0069] After the first resistance value adjustment step of the resistor, the first adjustment influence analysis step is carried out. Thus, after adjusting the resistance value of the adjustable resistor to make one side of the upstream and downstream pipelines reach the compliance state, if the other side of the upstream and downstream pipelines is in a non-compliance state, it is determined whether there is still room for further adjustment of the resistance value of the adjustable resistor to make the off-state potential of the upstream and downstream pipelines reach the optimal state. When the first adjustment influence analysis step determines that there is still room for further adjustment of the adjustable resistor, in the third adjustment step of the resistor, the resistance value of the adjustable resistor is further lowered. Under the condition that the off-state potential of the compliance side remains compliant, the off-state potential of the non-compliance side is adjusted to the compliance state or the off-state potential of the non-compliance side is adjusted to be closer to the compliance potential range, so that the off-state potentials of the upstream and downstream pipelines are both compliant or the degree of one side being compliant and the other side being non-compliant is reduced, and finally the optimal off-state potential state of the upstream and downstream pipelines is achieved.

[0070] After the shunt resistor step, if one side potential is at the critical compliance state and the other side is non-compliant, it is determined whether there is still room for further adjustment of the resistance value of the adjustable resistor through the potential state analysis step to make the off-state potential of the upstream and downstream pipelines reach the optimal state. When the potential state analysis step determines that there is still room for further adjustment of the adjustable resistor, in the third adjustment step of the resistor, the resistance value of the adjustable resistor is further lowered. Under the condition that the off-state potential of the compliance side remains compliant, the off-state potential of the non-compliance side is adjusted to the compliance state or the off-state potential of the non-compliance side is adjusted to be closer to the compliance potential range, so that the off-state potentials of the upstream and downstream pipelines are both compliant or the degree of one side being compliant and the other side being non-compliant is reduced, and finally the optimal off-state potential state of the upstream and downstream pipelines is achieved.

[0071] After the shunt resistor step, if one side potential is compliant but not at the critical state and the other side is non-compliant, in the second adjustment step of the resistor, the resistance value of the adjustable resistor is further lowered. Under the condition that the off-state potential of the compliance side remains compliant, the off-state potential of the non-compliance side is adjusted to the compliance state or the off-state potential of the non-compliance side is adjusted to be closer to the compliance potential range, so that the off-state potentials of the upstream and downstream pipelines are both compliant or the degree of one side being compliant and the other side being non-compliant is reduced, and finally the optimal off-state potential state of the upstream and downstream pipelines is achieved.

[0072] In the interference judgment and compliance judgment steps, since the jumper switch K1 is in the closed state, the energized potential and de-energized potential of the upstream and downstream pipelines are the same at this time. For the calculation of the absolute value of the potential difference and the comparison of the de-energized potential, the energized potential V of the downstream pipeline can also be used. on_down and the de-energized potential V off_down .

[0073] In the interference judgment step, if ΔV up is less than the set threshold A, no subsequent steps are performed, and it returns to the potential monitoring step; in the compliance judgment step, if the de-energized potential V off_up is within the compliance potential range, no subsequent steps are performed, and it returns to the potential monitoring step.

[0074] During the DC interference mitigation process, even if the energized potential does not meet the standard and the absolute value of the difference between it and the normal energized potential is greater than the set threshold A, but when the upstream and downstream de-energized potentials meet the standard, the status quo is maintained, and it returns to the potential monitoring step without performing subsequent steps. Whether the upstream and downstream de-energized potentials do not meet the standard is used as the benchmark for subsequent adjustment steps in DC interference mitigation, avoiding the de-energized potential not meeting the standard due to adjustment, so as to ensure the cathodic protection effect of the upstream and downstream pipelines to the greatest extent.

[0075] In some embodiments, as Figure 2 shown, in the second resistor adjustment step, first adjust the resistance value of the adjustable resistor, and the resistance value of the adjustable resistor is adjusted according to the set adjustment step size.

[0076] If after the adjustment of the adjustable resistor, the de-energized potential on the non-compliant side is further away from the compliance potential range compared to before the adjustment or the de-energized potential on the compliant side becomes non-compliant, it means that the adjustment of the resistance value of the adjustable resistor this time has an unfavorable impact on the upstream and downstream pipeline de-energized potentials. Restore the resistance value of the adjustable resistor to before the adjustment, reduce the adjustment step size, return to the adjustment of the adjustable resistor, and start adjusting the resistance value of the adjustable resistor again according to the reduced adjustment step size. If the adjustment step size is reduced and is less than or equal to the minimum step size, it means that there is no adjustable space for the adjustable resistor, and the status quo is maintained, that is, the best upstream and downstream pipeline de-energized potential state under the current situation is achieved. Among them, the minimum step size is a manually set value.

[0077] If after the adjustment of the adjustable resistor, the de-energized potential on the non-compliant side is closer to the compliance potential range compared to before the adjustment and the de-energized potential on the compliant side remains in the compliant state, it means that the adjustment of the resistance value of the adjustable resistor this time has a favorable impact on the upstream and downstream pipeline de-energized potentials. Compare both the de-energized potential on the non-compliant side and the de-energized potential on the compliant side after the adjustment of the adjustable resistor with the compliance potential range.

[0078] If the off - power potential of the non - compliant side remains in a non - compliant state and the off - power potential of the compliant side is not at the boundary of the compliant potential range, it indicates that the adjustable resistor still has room for adjustment. Return to the adjustment of the adjustable resistor, and adjust the resistance value of the adjustable resistor again according to the set adjustment step size. After adjusting the adjustable resistor again, the off - power potential of the compliant side will not move out of the compliant potential range, while the off - power potential of the non - compliant side can reach compliance or approach compliance, ultimately achieving the optimal state of the off - power potentials of the upstream and downstream pipelines in the current state.

[0079] If the off - power potential of the non - compliant side is in a compliant state, or the off - power potential of the compliant side is at the boundary of the compliant potential range, it indicates that the adjustment of the adjustable resistor has reached the optimal state where the off - power potentials of both the upstream and downstream pipelines are compliant, or the off - power potential of the non - compliant side remains non - compliant but further adjusting the resistance value of the adjustable resistor will cause the off - power potential of the compliant side to move out of the compliant potential range. Maintaining the current state can achieve the optimal state of the off - power potentials of the upstream and downstream pipelines in the current state.

[0080] In some embodiments, as Figure 3 shown, in the third adjustment step of the resistor, first adjust the resistance value of the adjustable resistor, and the resistance value of the adjustable resistor is adjusted according to the set adjustment step size.

[0081] If, after adjusting the adjustable resistor, the off - power potential of the non - compliant side is further away from the compliant potential range compared to before the adjustment, or the off - power potential of the compliant side becomes non - compliant, it indicates that the adjustment of the resistance value of the adjustable resistor this time has an adverse effect on the off - power potentials of the upstream and downstream pipelines. Restore the resistance value of the adjustable resistor to its value before adjustment, reduce the adjustment step size, and restart the adjustment of the resistance value of the adjustable resistor according to the reduced adjustment step size; if the adjustment step size is less than or equal to the minimum step size after reduction, it indicates that the adjustable resistor has no more room for adjustment. Maintaining the current state will achieve the optimal state of the off - power potentials of the upstream and downstream pipelines in the current situation. Here, the minimum step size is a manually set value.

[0082] If, after adjusting the adjustable resistor, the off - power potential of the non - compliant side is closer to the compliant potential range compared to before the adjustment and the off - power potential of the compliant side remains in a compliant state, it indicates that the adjustment of the resistance value of the adjustable resistor this time has a beneficial effect on the off - power potentials of the upstream and downstream pipelines. Compare both the off - power potential of the non - compliant side and the off - power potential of the compliant side after adjusting the adjustable resistor with the compliant potential range.

[0083] If the off - power potential on the non - compliant side remains in a non - compliant state, and the off - power potential on the compliant side does not move from one boundary to the other within the compliant potential range, it indicates that the adjustable resistor still has room for adjustment. Return to the adjustment of the adjustable resistor, and adjust the resistance value of the adjustable resistor again according to the set adjustment step. After adjusting the adjustable resistor again, the off - power potential on the compliant side will not move out of the compliant potential range, and the off - power potential on the non - compliant side can reach compliance or approach compliance, ultimately achieving the optimal state of the off - power potentials of the upstream and downstream pipelines in the current state.

[0084] If the off - power potential on the non - compliant side is in a compliant state, or the off - power potential on the compliant side moves from one boundary to the other within the compliant potential range, it indicates that the adjustment of the adjustable resistor has reached the optimal state where the off - power potentials of both the upstream and downstream pipelines are compliant. Or, if the off - power potential on the non - compliant side remains non - compliant but further adjusting the resistance value of the adjustable resistor will cause the off - power potential on the compliant side to move out of the compliant potential range, then maintain the current status, and the optimal state of the off - power potentials of the upstream and downstream pipelines in the current state can be achieved.

[0085] In some embodiments, one end of the adjustable resistor is electrically connected to one of the upstream pipeline and the downstream pipeline, and the other end of the adjustable resistor is electrically connected to the other of the upstream pipeline and the downstream pipeline through a control switch K2.

[0086] In the step of bridging the resistor, by adjusting the resistance value of the adjustable resistor to the maximum value and closing the control switch K2, it is realized that the resistance value of the adjustable resistor bridged between the upstream pipeline and the downstream pipeline is in the maximum state.

[0087] The adjustable resistor is pre - connected to the pipelines upstream and downstream of the insulating joint through wires. By closing and opening the control switch K2, the operation of bridging or not bridging the adjustable resistor can be performed, improving the convenience of the operation in the step of bridging the resistor.

[0088] In some embodiments, the set threshold A is greater than or equal to 0.5V. Since the energized potential will continuously fluctuate, even without being affected by DC interference, it cannot continuously match the normal energized potential, and there will be a potential difference between the energized potential and the normal energized potential due to the fluctuation. Setting the threshold A greater than or equal to 0.5V can avoid triggering subsequent adjustment steps due to slight fluctuations in the energized potential, preventing frequent and ineffective interference mitigation operations.

[0089] In some embodiments, the minimum resistance value of the adjustable resistor is 0Ω, ensuring that the adjustable resistor can eliminate the non - compliant state deflection generated after bridging the resistor.

[0090] In some embodiments, after maintaining the current status, a compliance reset step is performed.

[0091] Compliance reset, continuously monitor the energized potential V on_up and the energized potential V on_down, calculate the energized potential V on_up the absolute value ΔV of the difference between the energized potential and the normal energized potential up and the energized potential V on_down the absolute value ΔV of the difference between the energized potential and the normal energized potential down , if ΔV up and ΔV down are both less than the set threshold A, then remove the jumper connection of the adjustable resistor to the upstream pipeline and the downstream pipeline, close the jumper switch K1, and return to the potential monitoring step.

[0092] The compliance reset step enables the upstream pipeline and the downstream pipeline of the segmented insulation node to resume the jumper connection and both the upstream pipeline and the downstream pipeline can return to the state of effectively obtaining cathodic protection and anti-corrosion after the DC interference disappears and the off - energized potential meets the standard or the deviation of the energized potential is less than the set threshold.

[0093] In some embodiments, the normal energized potential is the average value of the energized potentials on the pipeline within a set period of time before the current moment when the interference is judged. Taking the average value of the energized potentials in an earlier period of time as the normal energized potential can more accurately reflect the normal state of the energized potential on the pipeline when no DC interference occurs.

[0094] In some embodiments, the set period is the whole day before the current moment, that is, 24 hours of the whole day before the moment when the interference is judged. Since DC interference is usually randomly generated, selecting the average energized potential of the whole previous day can make the normal energized potential more accurately reflect the normal state of the energized potential on the pipeline without interference.

[0095] In some embodiments, if the minimum resistance value of the selected adjustable resistor is greater than 0Ω or the adjustable resistor fails, in the resistance adjustment step, if the resistance value of the adjustable resistor is adjusted to the lowest value and still cannot make the off - energized potential meet the standard, an alarm is issued to remind the maintenance personnel to conduct manual fault troubleshooting, so as to timely discover problems and restore the good cathodic protection state of the upstream and downstream pipelines.

[0096] Based on the above - mentioned segmented adjustable DC interference mitigation method, as Figure 4 shown, the present invention also provides a segmented adjustable DC interference mitigation device, which is applied to a pipeline configured with insulating joints. The segmented adjustable DC interference mitigation device includes a jumper switch 2, an adjustable resistor 3, and a control switch 4.

[0097] There are two pipelines, namely an upstream pipeline 5 and a downstream pipeline 6. Both ends of the insulating joint 1 are respectively connected to the upstream pipeline 5 and the downstream pipeline 6. The upstream pipeline 5 and the downstream pipeline 6 are electrically connected through the jumper switch 2. One end of the adjustable resistor 3 is electrically connected to one pipeline, and the other end is electrically connected to the other pipeline through the control switch 4.

[0098] By opening and closing the bridging switch 2, the control of the bridging connection and disconnection between the upstream pipeline 5 and the downstream pipeline 6 is realized. By controlling the opening and closing of the switch 4, the control of whether to bridge a resistor between the upstream pipeline 5 and the downstream pipeline 6 is realized.

[0099] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

[0100] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: still modifications can be made to the specific implementation manners of the present invention or equivalent replacements can be made to some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A segmented adjustable DC interference mitigation method, characterized in that It includes the following steps: Potential monitoring: Continuously measure the applied potential V of the upstream pipeline on_up and the off-potential V off_up as well as the applied potential V of the downstream pipeline on_down and the off-potential V off_down ; Interference judgment: Calculate the energized potential V on_up The absolute value ΔV of the difference from the normal energized potential up , if ΔV up is greater than or equal to the set threshold A, then perform the compliance judgment step; Reach standard judgment: Compare the power-off potential V off_up with the reach standard potential range. If the power-off potential V off_up is outside the reach standard potential range, then perform the bridging adjustment step; Cross-connection adjustment: Disconnect the cross-connection switch K1 that connects the upstream pipeline and the downstream pipeline, and take the power-off potential V off_up and the power-off potential V off_down are both compared with the qualified potential range. If the power-off potential V off_up or the power-off potential V off_down is in a non-compliant state, then perform the cross-connection resistance step; Bypass resistor: An adjustable resistor adjusted to its maximum resistance value is bypassed between the upstream pipeline and the downstream pipeline, and then the off-state potential V off_up and the off-state potential V off_down are both compared with the qualified potential range. At this time, the off-state potential V off_up and the off-state potential V off_down are the data measured after the adjustable resistor is bypassed. If one of the off-state potential V off_up and the off-state potential V off_down is in the under-protection state and the other is in the over-protection state, the first resistor adjustment step is carried out; if one of the off-state potential V off_up and the off-state potential V off_down is in the qualified state and the other is in the unqualified state, and the off-state potential in the qualified state is at the boundary of the qualified potential range, the potential state analysis step is carried out; if one of the off-state potential V off_up and the off-state potential V off_down is in the qualified state and the other is in the unqualified state, and the off-state potential in the qualified state is not at the boundary of the qualified potential range, the second resistor adjustment step is carried out; First adjustment of resistor: The power-off potential V before the bridging adjustment step off_up is compared with the qualified potential range. If the power-off potential V before the bridging adjustment off_up is in an over-protection state, gradually reduce the resistance value of the adjustable resistor until the power-off potential in the under-protection state in the bridging resistance step reaches the upper limit value of the qualified potential range, and perform the first adjustment impact analysis step; If the power-off potential V before the bridging adjustment off_up is not in an over-protection state, gradually reduce the resistance value of the adjustable resistor until the power-off potential in the over-protection state in the bridging resistance step reaches the lower limit value of the qualified potential range, and perform the first adjustment impact analysis step; First adjustment impact analysis: The off-state potential V after the first adjustment step of the resistor off_up and the off-state potential V off_down are both compared with the qualified potential range. If the off-state potential V off_up or the off-state potential V off_down is in a non-qualified state, and the current potential value of the off-state potential on the non-qualified side is closer to the qualified potential range compared to its potential value after the bridging resistor step, then the third adjustment step of the resistor is carried out; if the off-state potential V off_up or the off-state potential V off_down is in a non-qualified state, and the current potential value of the off-state potential on the non-qualified side is farther from the qualified potential range compared to its potential value after the bridging resistor step, then keep the status quo; Potential state analysis: Compare the power-off potential V before the bridging adjustment step off_up with the qualified potential range. If the power-off potential V before the bridging adjustment off_up is in an over-protected state and the power-off potential on the qualified side is at the upper limit of the qualified potential protection range, then perform the second adjustment impact analysis step; if the power-off potential V before the bridging adjustment off_up is not in an over-protected state and the power-off potential on the qualified side is at the lower limit of the qualified potential protection range, then perform the second adjustment impact analysis step; if the power-off potential V before the bridging adjustment off_up is in an over-protected state and the power-off potential on the qualified side is not at the upper limit of the qualified potential protection range or the power-off potential V before the bridging adjustment off_up is not in an over-protected state and the power-off potential on the qualified side is not at the lower limit of the qualified potential protection range, then maintain the status quo; Second adjustment impact analysis: Compare the current potential value of the off - power potential on the non - compliant side with its potential value after the cross - connection resistance step. If the current potential value of the off - power potential on the non - compliant side is closer to the compliant potential range, perform the third resistor adjustment step; if the current potential value of the off - power potential on the non - compliant side is farther from the compliant potential range, maintain the status quo; Second resistor adjustment: Gradually reduce the resistance value of the adjustable resistor until the off - power potential on the compliant side reaches the boundary of the compliant potential range, or the off - power potential on the non - compliant side reaches within the compliant potential range, or the potential change direction of the off - power potential on the non - compliant side turns away from the compliant potential range, and then maintain the status quo; Third resistor adjustment: Gradually reduce the resistance value of the adjustable resistor until the off - power potential on the compliant side reaches the boundary on the other side of the compliant potential range, or the off - power potential on the non - compliant side reaches within the compliant potential range, or the potential change direction of the off - power potential on the non - compliant side turns away from the compliant potential range, and then maintain the status quo.

2. The segmented adjustable DC interference mitigation method according to claim 1, wherein In the second resistor adjustment step, the resistance value of the adjustable resistor is adjusted according to the set adjustment step size; If, after the adjustment of the adjustable resistor, the off - power potential on the non - compliant side is farther from the compliant potential range than before the adjustment, or the off - power potential on the compliant side becomes non - compliant, then restore the resistance value of the adjustable resistor to the value before the adjustment, reduce the adjustment step size, and restart the adjustment of the resistance value of the adjustable resistor according to the reduced adjustment step size; if the adjustment step size is less than or equal to the minimum step size after reduction, maintain the status quo; If, after the adjustment of the adjustable resistor, the off - power potential on the non - compliant side is closer to the compliant potential range than before the adjustment and the off - power potential on the compliant side remains in the compliant state, then compare both the off - power potential on the non - compliant side and the off - power potential on the compliant side after the adjustment of the adjustable resistor with the compliant potential range; If the off - power potential on the non - compliant side is still in the non - compliant state and the off - power potential on the compliant side is not at the boundary of the compliant potential range, then adjust the resistance value of the adjustable resistor again according to the set adjustment step size; If the off - power potential on the non - compliant side is in the compliant state, or the off - power potential on the compliant side is at the boundary of the compliant potential range, then maintain the status quo.

3. The segmented adjustable DC interference mitigation method according to claim 1, wherein In the third resistor adjustment step, the resistance value of the adjustable resistor is adjusted according to the set adjustment step size; If, after the adjustment of the adjustable resistor, the off - power potential on the non - compliant side is farther from the compliant potential range than before the adjustment, or the off - power potential on the compliant side becomes non - compliant, then restore the resistance value of the adjustable resistor to the value before the adjustment, reduce the adjustment step size, and restart the adjustment of the resistance value of the adjustable resistor according to the reduced adjustment step size; if the adjustment step size is less than or equal to the minimum step size after reduction, maintain the status quo; If, after the adjustment of the adjustable resistor, the off - power potential on the non - compliant side is closer to the compliant potential range than before the adjustment and the off - power potential on the compliant side remains in the compliant state, then compare both the off - power potential on the non - compliant side and the off - power potential on the compliant side after the adjustment of the adjustable resistor with the compliant potential range; If the off - power potential on the non - compliant side remains in a non - compliant state and the off - power potential on the compliant side does not move from one boundary to the other within the compliant potential range, then adjust the resistance value of the adjustable resistor again according to the set adjustment step; if the off - power potential on the non - compliant side is in a compliant state, or the off - power potential on the compliant side moves from one boundary to the other within the compliant potential range, then maintain the current situation.

4. The segmented adjustable DC interference mitigation method according to claim 1, characterized in that, One end of the adjustable resistor is electrically connected to one of the upstream pipeline and the downstream pipeline, and the other end of the adjustable resistor is electrically connected to the other of the upstream pipeline and the downstream pipeline through the control switch K2; In the step of bridging the resistor, by adjusting the resistance value of the adjustable resistor to the maximum value and closing the control switch K2, an adjustable resistor with the maximum resistance value is bridged between the upstream pipeline and the downstream pipeline.

5. The segmented adjustable DC interference mitigation method according to claim 1, characterized in that The set threshold A is greater than or equal to 0.5V.

6. The segmented adjustable DC interference mitigation method according to claim 1, wherein The minimum resistance value of the adjustable resistor is 0Ω.

7. The segmented adjustable DC interference mitigation method according to claim 1, characterized in that, After maintaining the current situation, perform the compliance reset step; Reach the standard and reset: Continuously monitor the energized potential V on_up and the energized potential V on_down , calculate the energized potential V on_up and the absolute value of the difference ΔV between the energized potential V up and the energized potential V on_down and the absolute value of the difference ΔV between the energized potential V down . If both ΔV up and ΔV down are less than the set threshold A, remove the shunt connection of the adjustable resistor to the upstream pipeline and the downstream pipeline, close the shunt switch K1, and return to the potential monitoring step.

8. The segmented adjustable DC interference mitigation method according to claim 1, characterized in that, The normal power - on potential is the average value of the power - on potentials on the pipeline within the set time period before the current moment.

9. The segmented adjustable DC interference mitigation method according to claim 8, characterized in that, The set time period is the whole day before the current moment.

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