Multi-path adjustable output cathode protection system balance adjusting method

Abstract

The invention particularly relates to a balance adjusting method for a multi-path adjustable output cathode protection system. The balance adjusting method comprises the following steps: determining a function of a potential changing along with an adjustable resistor; utilizing an annealing algorithm to find out an adjustable resistor matrix corresponding to the most uniform potential matrix and outputting the adjustable resistor matrix; the adjustable resistance value of each path of anode is manually adjusted according to the output adjustable resistance matrix; adjusting the output current of the trunk to obtain a proper potential matrix; and after the trunk output current is determined, the constant potential rectifier is converted into constant potential operation, and the cathode protection system debugging is completed. According to the invention, the problem of balance adjustment of the protection current and the protection potential of the cathode protection system in a regional multi-path output state is solved.

Description

Technical Field

[0001] The invention relates to the technical field of cathode protection, and in particular to a balancing method for a cathode protection system with multiple adjustable outputs. Background Art

[0002] In complex regional buried pipeline cathodic protection systems such as stations, pipelines at different locations require different protection currents to achieve the same or similar protection levels due to differences in pipeline characteristics such as material and coating damage, as well as environmental parameters such as environmental pH, water content and salinity. For example, when large areas of pipeline coating are damaged, a higher protection current density is required to achieve the desired protection potential; changes in soil pH, water content and salinity will also affect the current density required for the pipeline to reach the desired protection potential.

[0003] In order to obtain a relatively appropriate protection current for the pipeline and thus obtain an effective protection level, multiple auxiliary anodes need to be buried on site. Due to the different soil environments in which the auxiliary anodes are located, their grounding resistances are also different, which in turn affects the output current of the auxiliary anodes. Therefore, it is necessary to add an adjustable resistor to the loop of each auxiliary anode to adjust the output of each circuit. This requires the cathodic protection system to be debugged and optimized to ensure that the protected pipelines receive better protection effects.

[0004] For cathodic protection systems with a large number of auxiliary anodes, changing the output of one auxiliary anode through an adjustable resistor will affect the potential of the surrounding protected pipelines and the output current of other circuits. The debugging process aims to make the potential of all protected pipelines as evenly distributed as possible. However, the workload is huge and the efficiency is extremely low if the potential distribution of the measuring points on the surface of the protected pipeline is observed only by manual irregular adjustment and testing. It is difficult to achieve a protective effect due to direct interference between the two. Summary of the invention

[0005] The object of the present invention is to provide a balancing method for a multi-channel adjustable output cathode protection system to solve the problem of balancing the protection current and protection potential of the cathode protection system under the regional multi-channel output state.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for balancing a multi-channel adjustable output cathode protection system comprises the following steps:

[0008] Step 1: When all anodes are disconnected from the constant potential instrument, the natural potential value of each potential measuring point of the pipeline is recorded to obtain a natural potential matrix;

[0009] Step 2: Only one anode is connected to the constant potential instrument at a time, and the other anodes are disconnected from the constant potential instrument. When the anode current is in a constant value state, the test potential value of each potential measuring point of the pipeline is recorded to obtain a test potential matrix;

[0010] Step 3, determine the coefficient matrix of the influence of electric potential on electric current;

[0011] Step 4, restore the connection between each anode branch and the constant potential instrument, and set the constant potential instrument to constant current operation;

[0012] Step 5, recording the initial adjustable resistance value and initial current value of each anode and the initial potential value of each potential measuring point of the pipeline, and obtaining an initial adjustable resistance matrix, an initial current matrix and an initial potential matrix;

[0013] Step 6, only changing the adjustable resistance value of one anode each time, while keeping the adjustable resistance values ​​of other anodes unchanged, recording the changed adjustable resistance value of each anode, the changed current value of each anode and the changed potential value of each potential measuring point of the pipeline, and then resetting the adjustable resistance to obtain the changed adjustable resistance matrix, the changed current matrix and the changed potential matrix;

[0014] Step 7, determine the function of the potential changing with the adjustable resistance;

[0015] Step 8: Using the annealing algorithm, find out the adjustable resistance matrix corresponding to the most uniform potential matrix and output it; manually adjust the adjustable resistance value of each anode according to the output adjustable resistance matrix;

[0016] Step 9: Adjust the main output current to obtain a suitable potential matrix; after determining the main output current, switch the constant potential instrument to constant potential operation to complete the cathodic protection system debugging.

[0017] In the present invention, the cathodic protection system includes a constant potential instrument with a multi-channel output function and m anodes connected to the constant potential instrument; one anode includes an adjustable resistor and an anode resistor connected in series; and there are n potential measuring points on the pipeline surface.

[0018] In the present invention, in step 1, when each anode is disconnected from the constant potential instrument, the natural potential value of each potential measuring point k of the pipeline is recorded. Get the natural potential matrix Wherein, k represents the number of the pipeline potential measuring point, k∈1, 2, 3,…, n.

[0019] In the present invention, in step 2, only one anode i is connected to the constant potential instrument at a time, and the remaining anodes are disconnected from the constant potential instrument, and the anode current is a constant value I test In this state, record the test potential value of each potential measuring point k in the pipeline Get the test potential matrix

[0020] Among them, k represents the number of the pipeline potential measuring point, and i represents the number of the anode path; k∈1, 2, 3,…, n; i∈1, 2, 3,…, m.

[0021] In the present invention, in step 3, determining the coefficient matrix of the influence of electric potential on electric current comprises the following steps:

[0022] Step 3.1: Determine the coefficient K of the potential at the potential measuring point k affected by the current of anode i k.i for:

[0023]

[0024] Step 3.2: Determine the coefficient matrix K of the influence of current on potential:

[0025]

[0026] Among them, k represents the number of the pipeline potential measuring point, and i represents the number of the anode path; k∈1, 2, 3,…, n; i∈1, 2, 3,…, m.

[0027] In the present invention, in step 5, the initial adjustable resistance value R of each anode i is recorded. i,0 , get the initial adjustable resistance matrix R0 = [R 1,0 ,R 2,0 ,R 3,0 ,......,R m,0 ];

[0028] Record the initial current value I of each anode i i,0 , and the initial current matrix I0=[I 1,0 ,I 2,0 ,I 3,0 ,......,I m,0 ];

[0029] Record the initial potential value E of each potential measuring point k in the pipeline k,0 , and the initial potential matrix E0 = [E 1,0 ,E 2,0 ,E 3,0 ,…E n,0 ] T ;

[0030] Among them, k represents the number of the potential measuring point, and i represents the number of the anode path; k∈1, 2, 3, ..., n; i∈1, 2, 3, ..., m.

[0031] In the present invention, in step 6, only the adjustable resistance value of one anode is changed each time, and the adjustable resistance values ​​of the other anodes remain unchanged, and the adjustable resistance value R of each anode i after the jth change of the adjustable resistance is recorded. i,j , and the adjustable resistance matrix R after the change is obtained = [R 1,1 ,R 2,2 ,R 3,3 ,......,R m,m ];

[0032] Each time, only the adjustable resistance value of one anode is changed, and the adjustable resistance values ​​of the other anodes remain unchanged. The current value I of each anode i after the jth change of the adjustable resistance is recorded. i,j , get the current matrix after the change

[0033]

[0034] Each time, only the adjustable resistance value of one anode is changed, and the adjustable resistance values ​​of the other anodes remain unchanged. The potential value E of each potential measuring point k in the pipeline after the jth change of the adjustable resistance is recorded. k,j , and obtain the potential matrix after the change

[0035] Among them, k represents the number of the potential measuring point, j represents the number of times the adjustable resistance is changed; i represents the number of anode paths; k∈1, 2, 3,…, n; i∈1, 2, 3,…, m; j∈1, 2, 3,…, m.

[0036] In the present invention, step 7, determining the function of potential changing with adjustable resistance, comprises the following steps:

[0037] Step 7.1, determining the adjustable resistance change matrix ΔR and the current change matrix ΔI;

[0038] ΔR=R-R0=[R 1,1 -R 1,0 ,R 2,2 -R 2,0 ,R 3,3 -R 3,0 ,......,R m,m -R m,0 ] T ;

[0039]

[0040] Step 7.2: Determine the current changing matrix with adjustable resistance for:

[0041]

[0042] Step 7.3: Determine the current matrix ΔR'=R'-R0, R' is the adjustable resistance matrix, R'=[R1,R2,R3,......,R m ];

[0043] The relationship between the potential change matrix ΔE' and the current matrix I' is determined as: Where, ΔE'=E'-E k,0 ; E' is the potential matrix, E'=[E1,E2,E3,......,E n ] T ;

[0044] Step 7.4, determine the function of potential changing with adjustable resistance:

[0045]

[0046] Among them, I sys is the output current of the potentiostat in step 4, I end is the main output current; R′ is the independent variable and E′ is the dependent variable.

[0047] In the present invention, in step 8, the potential-adjustable-resistance function is combined with the annealing algorithm to set the domain of the adjustable resistance matrix R', and the output current I of the constant potential meter is given. sys , given the number of effective digits of the adjustable resistance matrix R', the annealing algorithm outputs the adjustable resistance matrix corresponding to the most uniform potential matrix;

[0048] The most uniform potential matrix is ​​the potential matrix with the smallest variance between the potential values ​​of each potential measuring point on the pipeline and the assumed sample potential mean. The solution process is:

[0049]

[0050] Among them, E k E is the potential of the potential measuring point; ave is the assumed sample potential mean of the potential measurement point, equal to

[0051] In the present invention, in step 9, according to the function of the potential changing with the adjustable resistance, the potential matrix E' and the trunk output current I are calculated when other parameters remain unchanged. end is a linear relationship; adjust the main output current I end Get the appropriate potential matrix; determine the main output current I end Finally, switch the constant potential instrument to constant potential operation to complete the cathodic protection system debugging.

[0052] Beneficial technical effects of the present invention:

[0053] The balancing method for a multi-channel adjustable output cathode protection system of the present invention finds out the law of the change of potential with the adjustable resistance value, and uses an annealing algorithm to find out the optimal solution of the function under set conditions, which greatly improves the efficiency of balancing the cathode protection system. The method is suitable for the initial installation and commissioning of the multi-channel adjustable output cathode protection system and the balancing during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A flow chart of an embodiment of a method for balancing a multi-channel adjustable output cathode protection system of the present invention;

[0055] Figure 2 The figure is an equivalent circuit diagram of an embodiment of the pipeline multi-channel adjustable output cathode protection system of the present invention. DETAILED DESCRIPTION

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0057] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0058] The technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings and specific embodiments.

[0059] refer to Figure 1 This embodiment provides a method for balancing a multi-channel adjustable output cathode protection system, comprising the following steps:

[0060] Step 1: When all anodes are disconnected from the constant potential instrument, the natural potential value of each potential measuring point of the pipeline is recorded to obtain a natural potential matrix;

[0061] Step 2, each time only one anode is connected to the constant potential instrument, and the other anodes are disconnected from the constant potential instrument. When the anode output current is in a constant value state, the test potential value of each potential measuring point of the pipeline is recorded to obtain a test potential matrix;

[0062] Step 3, determine the coefficient matrix of the potential affected by the current;

[0063] Step 4, restore the connection between each anode branch and the constant potential instrument, and set the constant potential instrument to constant current operation;

[0064] Step 5, recording the initial adjustable resistance value and initial current value of each anode and the initial potential value of each potential measuring point of the pipeline, and obtaining an initial adjustable resistance matrix, an initial current matrix and an initial potential matrix;

[0065] Step 6, only changing the adjustable resistance value of one anode each time, while keeping the adjustable resistance values ​​of other anodes unchanged, recording the changed adjustable resistance value of each anode, the changed current value of each anode and the changed potential value of each potential measuring point of the pipeline, and then resetting the adjustable resistance to obtain the changed adjustable resistance matrix, the changed current matrix and the changed potential matrix;

[0066] Step 7, determine the function of the potential changing with the adjustable resistance;

[0067] Step 8: Using the annealing algorithm, find out the adjustable resistance matrix corresponding to the most uniform potential matrix and output it; manually adjust the adjustable resistance value of each anode according to the output adjustable resistance matrix;

[0068] Step 9: Adjust the output current of the cathodic protection system to obtain a suitable potential matrix; after determining the output current of the cathodic protection system, switch the constant potential instrument to constant potential operation to complete the debugging of the cathodic protection system.

[0069] refer to Figure 2 In this embodiment, the cathodic protection system is a cathodic protection system for a steel pipeline in the soil, including a constant potentiostat, an adjustable resistor, an anode resistor, an environmental resistor, a pipeline self-corrosion potential and a metal resistor; wherein the constant potentiostat is a constant 1A DC power supply; the adjustable resistors R1, R2 and R3 are all adjustable resistors with an adjustment range of (0-10)Ω and an adjustment accuracy of 1Ω; the anode resistor R Y1 , R Y2 , R Y3 They are 3Ω, 4Ω, and 5Ω respectively; the adjustable resistor R1 and the anode resistor R Y1 Form an anode, adjustable resistor R2 and anode resistor R Y2 Form an anode, adjustable resistor R3 and anode resistor R Y3 Form an anode; environmental resistance R H1 , R H2 The self-corrosion potential of the pipeline is 0.6V, and the DC power supply E Z1 、E Z2 、E Z3 Instead of; polarization resistance R J1 , R J2 , R J3 They are 5Ω, 7Ω, and 9Ω respectively; the metal resistance RS1 , R S2 They are 0.2Ω and 0.4Ω respectively.

[0070] In this embodiment, there are three potential measuring points on the pipeline surface.

[0071] In this embodiment, in step 1, when each anode is disconnected from the constant potential instrument, the natural potential value of each potential measuring point k of the pipeline is recorded. Get the natural potential matrix E z =[0.6,0.6,0.6]; where k represents the number of the pipeline potential measurement point, k∈1, 2, 3;

[0072] In this embodiment, in step 2, only one anode is connected to the constant potential instrument at a time, and the remaining anodes are disconnected from the constant potential instrument. When the anode current is 1A, the test potential value of each potential measuring point k of the pipeline is recorded. Get the test potential matrix

[0073] Among them, k represents the number of the pipeline potential measuring point, and i represents the number of the anode path; k∈1,2,3; i∈1,2,3.

[0074] In this embodiment, in step 3, determining the coefficient matrix of potential affected by current includes the following steps:

[0075] Step 3.1: Determine the coefficient K of the potential at the potential measuring point k affected by the current of anode i k.i for:

[0076]

[0077] Step 3.2: Determine the coefficient matrix K of the influence of current on potential:

[0078]

[0079] Among them, k represents the number of the pipeline potential measuring point, and i represents the number of the anode path; k∈1, 2, 3,…, n; i∈1, 2, 3,…, m.

[0080] In this embodiment, in step 5, the initial adjustable resistance value R of each anode i is recorded. i,0 , get the initial adjustable resistance matrix R0 = [R 1,0 ,R 2,0 ,R 3,0 ]=[0,0,0];

[0081] Record the initial current value I of each anode i i,0 , and the initial current matrix I0=[I 1,0 ,I2,0 ,I 3,0 ]=[0.432,0.322,0.247];

[0082] Record the initial potential value E of each potential measuring point k in the pipeline k,0 , and the initial potential matrix E0 = [E 1,0 ,E 2,0 ,E 3,0 ] T =[-0.276,-2.86,-2.81];

[0083] Among them, k represents the number of the potential measuring point, and i represents the number of the anode path; k∈1,2,3; i∈1,2,3.

[0084] In this embodiment, in step 6, only the adjustable resistance value of one anode is changed each time, and the adjustable resistance values ​​of the other anodes remain unchanged. The adjustable resistance value R of each anode i after the jth change of the adjustable resistance is recorded. i,j , and the adjustable resistance matrix R after the change is obtained = [R 1,1 ,R 2,2 ,R 3,3 ]=[5,5,5];

[0085] Each time, only the adjustable resistance value of one anode is changed, and the adjustable resistance values ​​of the other anodes remain unchanged. The current value I of each anode i after the jth change of the adjustable resistance is recorded. i,j , get the current matrix after the change

[0086]

[0087] Each time, only the adjustable resistance value of one anode is changed, and the adjustable resistance values ​​of the other anodes remain unchanged. The potential value E of each potential measuring point k in the pipeline after the jth change of the adjustable resistance is recorded. k,j , and obtain the potential matrix after the change

[0088] Among them, k represents the number of the potential measuring point, j represents the number of times the adjustable resistance is changed; i represents the number of anode paths; k∈1,2,3; i∈1,2,3; j∈1,2,3.

[0089] In this embodiment, step 7, determining the function of potential changing with adjustable resistance, includes the following steps:

[0090] Step 7.1, determining the adjustable resistance change matrix ΔR and the current change matrix ΔI;

[0091] ΔR=R-R0=[R 1,1 -R 1,0 ,R 2,2 -R 2,0,R 3,3 -R 3,0 ] T =[5,5,5] T ;

[0092]

[0093] Step 7.2: Determine the current changing matrix with adjustable resistance for:

[0094]

[0095] Step 7.3 ΔR'=R'-R0=[ΔR1, ΔR2, ΔR3]=[R1-R 1,0 ,R2-R 2,0 ,R3-R 3,0 ], R' is the adjustable resistance matrix;

[0096] The relationship between the potential change matrix ΔE' and the current matrix I' is determined as: Where, ΔE'=E'-E k,0 ; E' is the potential matrix, E'=[E1,E2,E3] T ;

[0097] Step 7.4, determine the function of potential changing with adjustable resistance:

[0098]

[0099] Among them, I sys is the current output by the potentiostat in step 4, I end is the main output current; R′ is the independent variable and E′ is the dependent variable.

[0100] In this embodiment, in step 8, the potential variation function with the adjustable resistance is combined with the annealing algorithm to set the domain of the adjustable resistance matrix R', and the output current I of the constant potential meter is given. sys =1A, given the number of effective digits of the adjustable resistance matrix R', the annealing algorithm outputs the adjustable resistance matrix corresponding to the most uniform potential matrix;

[0101] The most uniform potential matrix is ​​the potential matrix with the smallest variance between the potential values ​​of each potential measuring point on the pipeline and the assumed sample potential mean. The solution process is:

[0102]

[0103] Among them, E k is the potential of the potential measuring point; the minimum variance is 0.000867, and the adjustable resistance matrix output by the annealing algorithm is [0, 1, 0].

[0104] When the adjustable resistance matrix is ​​[0, 1, 0], the corresponding potential matrix is ​​[-2.80, -2.78, -2.85], and the potential matrix calculated by the annealing algorithm is [-2.81, -2.76, -2.86], with a relative error of [0.36%, 0.72%, 0.35%]. The relative error is completely acceptable for engineering applications.

[0105] In this embodiment, in step 9, according to the function of the potential changing with the adjustable resistance, the potential matrix E' and the trunk output current I are calculated when other parameters remain unchanged. end It is a linear relationship;

[0106] Assuming the optimal potential range is (-0.85~-1.2)V, adjust the main output current I end , and obtain the potential matrix E'=[-1.15, -1.15, -1.16];

[0107] Determine the main output current I end Finally, switch the constant potential instrument to constant potential operation to complete the cathodic protection system debugging.

[0108] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for balancing a multi-channel adjustable output cathodic protection system, characterized in that: The steps include: Step 1: When all anodes are disconnected from the constant potential instrument, the natural potential value of each potential measuring point of the pipeline is recorded to obtain a natural potential matrix; Step 2: Only one anode is connected to the constant potential instrument at a time, and the other anodes are disconnected from the constant potential instrument. When the anode current is in a constant value state, the test potential value of each potential measuring point of the pipeline is recorded to obtain a test potential matrix; Step 3, determine the coefficient matrix of the influence of electric potential on electric current; Step 4, restore the connection between each anode branch and the constant potential instrument, and set the constant potential instrument to constant current operation; Step 5, recording the initial adjustable resistance value and initial current value of each anode and the initial potential value of each potential measuring point of the pipeline, and obtaining an initial adjustable resistance matrix, an initial current matrix and an initial potential matrix; Step 6, only changing the adjustable resistance value of one anode each time, while keeping the adjustable resistance values ​​of other anodes unchanged, recording the changed adjustable resistance value of each anode, the changed current value of each anode and the changed potential value of each potential measuring point of the pipeline, and then resetting the adjustable resistance to obtain the changed adjustable resistance matrix, the changed current matrix and the changed potential matrix; Step 7, determining the function of the potential changing with the adjustable resistance; Step 8: Using the annealing algorithm, find out the adjustable resistance matrix corresponding to the most uniform potential matrix and output it; manually adjust the adjustable resistance value of each anode according to the output adjustable resistance matrix; Step 9: Adjust the main output current to obtain a suitable potential matrix; after determining the main output current, switch the constant potential instrument to constant potential operation to complete the cathodic protection system debugging.

2. The method for adjusting balance of a multi-channel adjustable output cathode protection system according to claim 1, characterized in that: The cathodic protection system includes a constant potential instrument with a multi-channel output function and m anodes connected to the constant potential instrument; one anode includes an adjustable resistor and an anode resistor connected in series; and there are n potential measuring points on the pipeline surface.

3. The method for balancing a multi-channel adjustable output cathode protection system according to claim 2, characterized in that: In step 1, when all anodes are disconnected from the constant potential instrument, record the natural potential value of each potential measuring point k in the pipeline. Get the natural potential matrix Wherein, k represents the number of the pipeline potential measuring point, k∈1, 2, 3,…, n.

4. The method for balancing a multi-channel adjustable output cathode protection system according to claim 3, characterized in that: In step 2, only one anode i is connected to the constant potential instrument at a time, and the remaining anodes are disconnected from the constant potential instrument. The anode current is a constant value I test In this state, record the test potential value of each potential measuring point k in the pipeline Get the test potential matrix Wherein, i represents the number of the anode path; i∈1, 2, 3, ..., m.

5. The method for balancing a multi-channel adjustable output cathode protection system according to claim 4, characterized in that: In step 3, determining the coefficient matrix of the influence of the potential on the current includes the following steps: Step 3.1: Determine the coefficient K of the potential at the potential measuring point k affected by the current of anode i k.i for: Step 3.2: Determine the coefficient matrix K of the influence of current on potential:

6. The method for balancing a multi-channel adjustable output cathode protection system according to claim 5, characterized in that: In step 5, record the initial adjustable resistance value R of each anode i i,0 , get the initial adjustable resistance matrix R0 = [R 1,0 ,R 2,0 ,R 3,0 ,......,R m,0 ]; Record the initial current value I of each anode i i,0 , and the initial current matrix I0=[I 1,0 ,I 2,0 ,I 3,0 ,......,I m,0 ]; Record the initial potential value E of each potential measuring point k in the pipeline k,0 , and the initial potential matrix E0 = [E 1,0 ,E 2,0 ,E 3,0 ,…E n,0 ] T .

7. The method for balancing a multi-channel adjustable output cathode protection system according to claim 6, characterized in that: In step 6, only the adjustable resistance value of one anode is changed each time, and the adjustable resistance values ​​of the other anodes remain unchanged. The adjustable resistance value R of each anode i after the jth change of the adjustable resistance is recorded. i,j , and the adjustable resistance matrix R after the change is obtained = [R 1,1 ,R 2,2 ,R 3,3 ,......,R m,m ]; Each time, only the adjustable resistance value of one anode is changed, and the adjustable resistance values ​​of the other anodes remain unchanged. The current value I of each anode i after the jth change of the adjustable resistance is recorded. i,j , get the current matrix after the change Each time, only the adjustable resistance value of one anode is changed, and the adjustable resistance values ​​of the other anodes remain unchanged. The potential value E of each potential measuring point k in the pipeline after the jth change of the adjustable resistance is recorded. k,j , and the potential matrix after the change is obtained Wherein, j represents the number of times the adjustable resistance is changed; j∈1, 2, 3, ..., m.

8. The method for balancing a multi-channel adjustable output cathode protection system according to claim 7, characterized in that: Step 7, determining the function of the potential changing with the adjustable resistance, comprises the following steps: Step 7.1, determining the adjustable resistance change matrix ΔR and the current change matrix ΔI; ΔR=R-R0=[R 1,1 -R 1,0 ,R 2,2 -R 2,0 ,R 3,3 -R 3,0 ,......,R m,m -R m,0 ] T ; Step 7.2: Determine the current changing matrix with adjustable resistance for: Step 7.3: Determine the current matrix ΔR'=R'-R0, R' is the adjustable resistance matrix, R'=[R1,R2,R3,......,R m ]; The relationship between the potential change matrix ΔE' and the current matrix I' is determined as: Where, ΔE'=E'-E k,0 ; E' is the potential matrix, E'=[E1,E2,E3,......,E n ] T ; Step 7.4, determine the function of potential changing with adjustable resistance: Among them, I sys is the output current of the potentiostat in step 4, I end is the main output current; R′ is the independent variable and E′ is the dependent variable.

9. The method for adjusting balance of a multi-channel adjustable output cathode protection system according to claim 8, characterized in that: Combine the function of potential changing with adjustable resistance with the annealing algorithm, set the domain and number of effective digits of the adjustable resistance matrix R', and give the output current I of the constant potential instrument. sys , the annealing algorithm outputs the adjustable resistance matrix corresponding to the most uniform potential matrix; The most uniform potential matrix is ​​the potential matrix with the smallest variance between the potential values ​​of each potential measuring point on the pipeline and the assumed sample potential mean. The solution process is: Among them, E k E is the potential of the potential measuring point; ave is the assumed sample potential mean of the potential measurement points.

10. The method for balancing a multi-channel adjustable output cathode protection system according to claim 9, characterized in that: In step 9, according to the function of potential changing with adjustable resistance, when other parameters remain unchanged, the potential matrix E' and the main output current I end is a linear relationship; adjust the main output current I end Get the appropriate potential matrix; Determine the main output current I end Finally, switch the constant potential instrument to constant potential operation to complete the cathodic protection system debugging.

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