Conversion method for simulating interference of actual power transmission line on buried pipeline

Abstract

The invention discloses a conversion method for simulating interference of an actual power transmission line on a buried pipeline. The method comprises the following steps: selecting actual working condition coordinates, voltage and current excitation values and scaling model coordinates; calculating a coating induced voltage value; calculating an induced electromotive force and a current excitation value required by the scaling power transmission line; calculating a coating induced voltage value generated by the scaling power transmission line model for each infinitesimal element of the buried pipeline to obtain an analog current excitation value or an optimized analog current excitation value; and constructing an experimental device by using the simulation current excitation value or the optimization simulation current excitation value and the scaling model. According to the correlation between the power transmission line and the buried pipeline model, the simulation of the power transmission line model under the actual working condition is realized by using the scaling power transmission line and the scaling pipeline model to adjust the magnitude of the simulation current, so that the experimental research is more credible and more convincing, and a reference is provided for subsequently constructing similar experimental devices.

Description

Technical Field

[0001] The invention belongs to the field of pipeline transportation, and in particular relates to a conversion method for simulating the interference of an actual power transmission line on a buried pipeline. Background Art

[0002] With the development of energy transportation and electric power industry, the cases where transmission lines and buried pipelines cross or even share corridors are increasing. The electromagnetic interference caused by transmission lines on buried pipelines is becoming more and more common, and the research on stray currents of transmission lines is receiving more and more attention.

[0003] At present, the research on the interference of stray current of transmission lines on buried pipelines is mainly carried out through simulation calculation and theoretical analysis. Experimental research has better credibility and value, but because it is necessary to directly apply interference current to the buried pipeline, this method is out of the interference mode of electromagnetic induction of transmission lines on buried pipelines; in addition, the overhead height of actual working transmission lines is usually above 10m, and the working voltage is usually above 10kV. It is difficult to carry out experimental operations on actual transmission lines and there are safety hazards; in the laboratory, the scaled-down model is used for testing. The experiment cannot verify the interference effect of actual transmission lines at hundreds of kilovolts and the overhead height of phase lines exceeding 10m on buried pipelines, so the expected experimental effect cannot be achieved. Therefore, a conversion method is needed to enable the interference of buried pipelines in the scaled-down model to achieve the interference effect of actual transmission lines. Summary of the invention

[0004] In order to solve the above problems, the object of the present invention is to provide a conversion method for simulating the interference of actual power transmission lines on buried pipelines.

[0005] In order to achieve the above object, the conversion method for simulating the interference of actual power transmission lines on buried pipelines provided by the present invention comprises the following steps performed in sequence:

[0006] 1) Selecting the three-dimensional spatial coordinates of the actual transmission line, the three-dimensional spatial coordinates of the actual buried pipeline, and the voltage and current excitation values ​​on the transmission line under actual working conditions, and selecting the three-dimensional coordinates of the scaled-down transmission line model and the three-dimensional coordinates of the scaled-down buried pipeline model required to simulate the actual working conditions;

[0007] 2) Substituting the three-dimensional spatial coordinates of the actual transmission line selected in step 1), the three-dimensional spatial coordinates of the actual buried pipeline, and the voltage and current excitation values ​​on the transmission line under actual working conditions into the electromagnetic simulation calculation software CDEGS, and obtaining the coating induced voltage value generated by the transmission line on each point of the buried pipeline under actual working conditions after modeling and simulation calculation;

[0008] 3) The scaled-down buried pipeline model is processed into microelement segments, and the coating induced voltage value calculated in step 2) is substituted into the transmission line theory equation to reversely calculate the induced electromotive force received by each microelement of the scaled-down buried pipeline model, and then the three-dimensional coordinates of the scaled-down transmission line model selected in step 1), the three-dimensional coordinates of the scaled-down buried pipeline and the induced electromotive force value are substituted into the electromagnetic induction calculation formula to reversely calculate the current excitation value required for the scaled-down transmission line, which is the value required to simulate the coating induced excitation voltage generated by the transmission line under actual working conditions;

[0009] 4) Substitute the current excitation value calculated in step 3) into the electromagnetic simulation calculation software CDEGS, calculate the coating induced voltage value generated by the scaled-down transmission line model for each microelement of the buried pipeline, and then compare the coating induced voltage value with the coating induced voltage value calculated in step 2) for each microelement and calculate the error value. If the error value is less than 10%, the current excitation value calculated in step 3) is used as the simulated current excitation value. If the error value is greater than 10%, the current excitation value calculated in step 3) is increased by the error value to obtain the optimized simulated current excitation value;

[0010] 5) Using the simulated current excitation value obtained in step 4 or the optimized simulated current excitation value and the scaled-down transmission line model and scaled-down buried pipeline model selected in step 1) to build an experimental device.

[0011] In step 3), the transmission line theory equation is:

[0012]

[0013] Where U and I are the induced voltage and current along the buried pipeline, respectively; Z is the impedance per unit length of the equivalent transmission line model circuit of the buried pipeline; Y is the admittance per unit length of the equivalent transmission line model circuit of the buried pipeline; and e is the induced electromotive force generated by the interference of the transmission line on the buried pipeline per unit length.

[0014] In step 3), the electromagnetic induction calculation formula is:

[0015]

[0016] Where ω is the angular frequency of the signal on the transmission line; It is the magnetic vector form of a certain point on the transmission line to a certain point on the buried pipeline; is the unit vector along the buried pipeline; Γ c is the closed area of ​​the interference area of ​​a certain point of the conductor; the expression of the magnetic vector formula is:

[0017]

[0018] Where r is the induction path of the transmission line interference to the buried pipeline, which is affected by the coordinates of the transmission line and the buried pipeline; I sk is the current excitation value required to simulate the actual working condition.

[0019] The conversion method for simulating the interference of actual power transmission lines on buried pipelines provided by the present invention has the following beneficial effects:

[0020] According to the correlation between the transmission line and the buried pipeline model, the simulation of the actual working condition transmission line model is realized by using the scaled-down transmission line and scaled-down pipeline model to adjust the simulated current size. The constructed experimental device can effectively simulate the changes in the interference of the actual transmission line on the pipeline when measuring variables such as soil resistivity and pipeline anti-corrosion layer that do not change the spatial position of the transmission line and the buried pipeline during operation, making the experimental research more credible and convincing, and providing a reference for the subsequent construction of similar experimental devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flow chart of a conversion method for simulating the interference of actual power transmission lines on buried pipelines provided by the present invention.

[0022] Figure 2 It is a schematic diagram of a conversion method provided by the present invention for simulating the interference of an actual power transmission line on a buried pipeline.

[0023] Figure 3 It is a distribution diagram of coating induced voltage caused by the interference of the transmission line on the buried pipeline under actual working conditions calculated by the electromagnetic simulation software CDEGS in the present invention.

[0024] Figure 4 It is a comparison diagram of the pipeline coating induced voltage obtained by simulating current in the present invention and the induced voltage obtained under actual working conditions. DETAILED DESCRIPTION

[0025] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] like Figure 1 , Figure 2 As shown, the conversion method for simulating the interference of actual power transmission lines on buried pipelines provided by the present invention comprises the following steps performed in sequence:

[0027] 1) Selecting the three-dimensional spatial coordinates of the actual transmission line, the three-dimensional spatial coordinates of the actual buried pipeline, and the voltage and current excitation values ​​on the transmission line under actual working conditions, and selecting the three-dimensional coordinates of the scaled-down transmission line model and the three-dimensional coordinates of the scaled-down buried pipeline model required to simulate the actual working conditions;

[0028] 2) Substituting the three-dimensional spatial coordinates of the actual transmission line selected in step 1), the three-dimensional spatial coordinates of the actual buried pipeline, and the voltage and current excitation values ​​on the transmission line under actual working conditions into the electromagnetic simulation calculation software CDEGS, and obtaining the coating induced voltage value generated by the transmission line on each point of the buried pipeline under actual working conditions after modeling and simulation calculation;

[0029] 3) The scaled-down buried pipeline model is processed into microelement segments, and the coating induced voltage value calculated in step 2) is substituted into the transmission line theory equation to reversely calculate the induced electromotive force received by each microelement of the scaled-down buried pipeline model, and then the three-dimensional coordinates of the scaled-down transmission line model selected in step 1), the three-dimensional coordinates of the scaled-down buried pipeline and the induced electromotive force value are substituted into the electromagnetic induction calculation formula to reversely calculate the current excitation value required for the scaled-down transmission line, which is the value required to simulate the coating induced excitation voltage generated by the transmission line under actual working conditions;

[0030] The transmission line theory equation is:

[0031]

[0032] In the formula, U and I are the induced voltage and current along the buried pipeline, respectively, Z is the impedance per unit length of the buried pipeline equivalent transmission line model circuit, Y is the admittance per unit length of the buried pipeline equivalent transmission line model circuit, and e is the induced electromotive force generated by the interference of the transmission line on the buried pipeline per unit length. The electromagnetic induction calculation formula is:

[0033]

[0034] Where ω is the angular frequency of the signal on the transmission line; It is the magnetic vector form of a certain point on the transmission line to a certain point on the buried pipeline; is the unit vector along the buried pipeline; Γ c is the closed area of ​​the interference area of ​​a certain point of the conductor; the expression of the magnetic vector formula is:

[0035]

[0036] Where r is the induction path of the transmission line interference to the buried pipeline, which is affected by the coordinates of the transmission line and the buried pipeline; I sk is the current excitation value required to simulate the actual working condition.

[0037] 4) Substitute the current excitation value calculated in step 3) into the electromagnetic simulation calculation software CDEGS, calculate the coating induced voltage value generated by the scaled-down transmission line model for each microelement of the buried pipeline, and then compare the coating induced voltage value with the coating induced voltage value calculated in step 2) for each microelement and calculate the error value. If the error value is less than 10%, the current excitation value calculated in step 3) is used as the simulated current excitation value. If the error value is greater than 10%, the current excitation value calculated in step 3) is increased by the error value to obtain the optimized simulated current excitation value;

[0038] 5) Using the simulated current excitation value obtained in step 4 or the optimized simulated current excitation value and the scaled-down transmission line model and scaled-down buried pipeline model selected in step 1) to build an experimental device.

[0039] In the present invention, the voltage and current values ​​of the actual transmission line are selected to be 750kV and 2000A respectively, and the height of the actual transmission line from the ground is 25 meters; the voltage of the scaled-down transmission line model is selected to be 220V, and the height of the scaled-down transmission line model from the ground is 2m; the length of the buried pipeline and the actual transmission line model and the scaled-down transmission line model are both selected to be 60m, the diameter of the actual buried pipeline is selected to be 508mm, and the diameter of the scaled-down buried pipeline model is selected to be 400mm. The voltage value of each point on the buried pipeline can be obtained by calculation using the electromagnetic simulation software CDEGS, such as Figure 3 As shown. The coating induced voltage values ​​corresponding to each point on the buried pipeline are reversely substituted into the scaled-down transmission line and scaled-down buried pipeline models, and the simulated current excitation value is calculated by software. The electromagnetic simulation software CDEGS is used to calculate the coating induced voltage value generated by the scaled-down transmission line model on the buried pipeline under simulated current conditions and compare it with the interference of the transmission line on the buried pipeline under actual working conditions. Figure 4 It can be seen that the interference of the scaled-down model on the buried pipeline is basically consistent with the actual working transmission line.

Claims

1. A conversion method for simulating the interference of actual power transmission lines on buried pipelines, characterized in that: The conversion method comprises the following steps performed in sequence: 1) Selecting the three-dimensional spatial coordinates of the actual transmission line, the three-dimensional spatial coordinates of the actual buried pipeline, and the voltage and current excitation values ​​on the transmission line under actual working conditions, and selecting the three-dimensional coordinates of the scaled-down transmission line model and the three-dimensional coordinates of the scaled-down buried pipeline model required to simulate the actual working conditions; 2) Substituting the three-dimensional spatial coordinates of the actual transmission line selected in step 1), the three-dimensional spatial coordinates of the actual buried pipeline, and the voltage and current excitation values ​​on the transmission line under actual working conditions into the electromagnetic simulation calculation software CDEGS, and obtaining the coating induced voltage value generated by the transmission line on each point of the buried pipeline under actual working conditions after modeling and simulation calculation; 3) The scaled-down buried pipeline model is processed into microelement segments, and the coating induced voltage value calculated in step 2) is substituted into the transmission line theory equation to reversely calculate the induced electromotive force received by each microelement of the scaled-down buried pipeline model, and then the three-dimensional coordinates of the scaled-down transmission line model selected in step 1), the three-dimensional coordinates of the scaled-down buried pipeline and the induced electromotive force value are substituted into the electromagnetic induction calculation formula to reversely calculate the current excitation value required for the scaled-down transmission line, which is the value required to simulate the coating induced excitation voltage generated by the transmission line under actual working conditions; 4) Substitute the current excitation value calculated in step 3) into the electromagnetic simulation calculation software CDEGS, calculate the coating induced voltage value generated by the scaled-down transmission line model for each microelement of the buried pipeline, and then compare the coating induced voltage value with the coating induced voltage value calculated in step 2) for each microelement and calculate the error value. If the error value is less than 10%, the current excitation value calculated in step 3) is used as the simulated current excitation value. If the error value is greater than 10%, the current excitation value calculated in step 3) is increased by the error value to obtain the optimized simulated current excitation value; 5) Using the simulated current excitation value obtained in step 4) or the optimized simulated current excitation value and the scaled-down transmission line model and scaled-down buried pipeline model selected in step 1) to build an experimental device.

2. The conversion method for simulating the interference of actual power transmission lines on buried pipelines according to claim 1 is characterized in that: In step 3), the transmission line theory equation is: Where U and I are the induced voltage and current along the buried pipeline, respectively; Z is the impedance per unit length of the equivalent transmission line model circuit of the buried pipeline; Y is the admittance per unit length of the equivalent transmission line model circuit of the buried pipeline; and e is the induced electromotive force generated by the interference of the transmission line on the buried pipeline per unit length.

3. The conversion method for simulating the interference of actual power transmission lines on buried pipelines according to claim 1 is characterized in that: In step 3), the electromagnetic induction calculation formula is: Where ω is the angular frequency of the signal on the transmission line; It is the magnetic vector form of a certain point on the transmission line to a certain point on the buried pipeline; is the unit vector along the buried pipeline; Γ c It is the closed area of ​​the interference area at a certain point of the conductor; The expression of magnetic vector is: Where r is the induction path of the transmission line interference to the buried pipeline, which is affected by the coordinates of the transmission line and the buried pipeline; I sk is the current excitation value required to simulate the actual working condition.

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