Power transmission line aging degree quantitative evaluation method

Abstract

The invention relates to a power transmission line aging degree quantitative evaluation method. The method comprises the following steps: collecting line operation information; according to the collected line operation information, carrying out field one-by-one and one-by-one technical element troubleshooting; evaluating the hidden danger of each element, and calculating to obtain a corresponding risk value; determining a total score deduction value of the whole section according to the score deduction value and the weight value of each technical element so as to determine a corresponding risk level; and finally, making a corresponding treatment strategy according to the risk level. The method can scientifically identify the risk factors affecting the safe operation of the old overhead transmission line, improves the accuracy of the risk assessment of the old overhead transmission line by quantifying the risk assessment result of each technical element, guides an operation and maintenance unit to orderly carry out the line hidden danger treatment work according to the order, prevents the occurrence of tower falling, line breaking and string breaking events, and improves the safety of the old overhead transmission line. The safety management level of old power transmission lines is improved, and safe and reliable operation of the lines is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of power grid operation assessment, and in particular to a method for quantitatively assessing the aging degree of a power transmission line. Background Art

[0002] With the continuous development of power grid construction, the lines in the corridors are becoming more and more dense, and there are more and more crossings between the lines. Overhead transmission lines have been in the wild for a long time, facing harsh and complex environments. Under the conditions of natural environment and external force damage, there are huge safety hazards in the transmission lines. Old overhead transmission lines that have been in operation for more than 40 years are more prone to failures. If failures such as tower collapse and line breakage occur in important transmission lines or "three-span" lines, it will have a huge impact on the safe and stable operation of the power grid. Therefore, it is necessary to carry out risk assessments on old overhead transmission lines, strengthen the operation and maintenance management and safety protection of old overhead transmission lines, improve the level of safety management, prevent problems before they occur, and improve the reliability of the operation of old overhead transmission lines. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and propose a quantitative assessment method for the degree of obsolescence of transmission lines, which can scientifically identify the risk factors that affect the safe operation of old overhead transmission lines, and improve the accuracy of risk assessment of old overhead transmission lines by quantifying the risk assessment results of various technical elements, so as to guide the operation and maintenance units to carry out the work of line hidden danger management in an orderly manner according to the importance of the risks, prevent the occurrence of tower collapse, line breakage and string breakage, improve the safety management level of old transmission lines, and ensure the safe and reliable operation of the lines.

[0004] The present invention solves the technical problem by adopting the following technical solutions:

[0005] A method for quantitatively evaluating the ageing degree of a transmission line comprises the following steps:

[0006] Step 1: Collect line operation information;

[0007] Step 2: Based on the line operation information collected in step 1, conduct on-site technical element inspections one by one;

[0008] Step 3: Evaluate the hidden dangers of each factor and calculate the corresponding risk value;

[0009] Step 4: Determine the total deduction value for the entire section based on the deduction value and weight value of each technical factor, thereby determining the corresponding risk level;

[0010] Step 5: Develop corresponding governance strategies based on risk levels.

[0011] Moreover, the technical elements in step 2 include: channel environment, foundation, pole tower, ground wire, hardware and insulators.

[0012] Moreover, the specific implementation method of step 3 is:

[0013] R=L×E×C×K

[0014] Among them, the risk level of the technical factor is determined according to the R value, where R<30 is level I risk, 30≤R<70 is level II risk, 70≤R<200 is level III risk, and 200≤R is level IV risk.

[0015] Moreover, the specific implementation method of step 4 is: assign weights to the six technical factors of channel environment, foundation, pole tower, ground wire, hardware and insulator through the AHP-entropy weight method, evaluate the hidden dangers of each factor based on the improved LEC method, and calculate the corresponding risk value.

[0016] Furthermore, the method of assigning weights to the six technical elements of channel environment, foundation, tower, ground wire, hardware and insulator by AHP-entropy weight method includes the following steps:

[0017] Step 4.1, construct a relative importance matrix; obtain the maximum eigenvalue and the corresponding eigenvector respectively, and determine the weight vector through consistency test;

[0018] Step 4.2, determine the weight matrix C based on the weight vector x;

[0019]

[0020] Step 4.3, calculate the weight vector correlation coefficient matrix D:

[0021]

[0022] And d ii =1,d ij =d ji ;

[0023] Step 4.4: Remove weights with large deviations:

[0024]

[0025] Among them, d i represents the sum of the similarities between the i-th expert’s weighted opinion and other experts’ weighted opinions, d i The smaller it is, the greater the deviation;

[0026] Step 4.5: Get the average value of the column vector of the weight matrix after screening Get the weight value of each indicator;

[0027] Step 4.6: Combine the subjective weight with the objective weight and introduce the entropy value variable. The final weight value is

[0028]

[0029] in, represents the weight value determined by the AHP method, represents the weight value determined by the entropy weight method, H j It represents the entropy value of the evaluation index.

[0030] The advantages and positive effects of the present invention are:

[0031] The present invention collects line operation information; conducts on-site base-by-base and item-by-item technical element inspections based on the collected line operation information; evaluates the hidden dangers of each element and calculates the corresponding risk value; determines the total deduction value of the entire section based on the deduction value and weight value of each technical element, thereby determining the corresponding risk level; and finally formulates a corresponding governance strategy based on the risk level. The present invention can scientifically identify the dangerous factors that affect the safe operation of old overhead transmission lines, and improve the accuracy of risk assessment of old overhead transmission lines by quantifying the risk assessment results of each technical element, guiding the operation and maintenance units to carry out line hidden danger governance work in an orderly manner according to the importance, preventing tower collapse, line breakage and string breakage events, improving the safety management level of old transmission lines, and ensuring safe and reliable operation of the lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a flow chart of the present invention;

[0033] Figure 2 The technical elements for risk assessment of old overhead transmission lines of the present invention;

[0034] Figure 3 This is the principle diagram of the AHP-entropy weighting method. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below with reference to the accompanying drawings.

[0036] The construction idea of ​​the present invention is: the risk assessment and management workflow of old overhead transmission lines includes information collection, technical factor investigation, technical factor deduction summary, section risk status summary, assessment conclusion, management strategy, etc.

[0037] By evaluating the old overhead transmission lines one by one and one by one, the superimposed influence of the technical elements of the line channel environment, foundation, tower, ground wire, hardware and insulator is considered. The AHP-entropy weight method is introduced to give certain weights to the six technical elements of channel environment, foundation, tower, ground wire, hardware and insulator. The hidden dangers of each element are evaluated based on the improved LEC method, and the corresponding risk value is calculated. According to the deduction value and weight value of each technical element, the total deduction value of the entire section is determined, so as to determine the corresponding risk level, and then determine the risk level of each section of the entire line.

[0038] A quantitative assessment method for the ageing of transmission lines, such as Figure 1 As shown, the following steps are included:

[0039] Step 1: Collect line operation information.

[0040] Step 2: Based on the line operation information collected in Step 1, conduct on-site technical element inspections one by one.

[0041] Technical elements include: channel environment, foundation, poles and towers, ground wires, hardware and insulators.

[0042] Step 3: Evaluate the hidden dangers of each factor and calculate the corresponding risk value.

[0043] Risk assessment of old overhead transmission lines requires the investigation of hidden dangers in six technical elements, such as the channel environment and foundation, and the specific risk value is obtained according to the severity of the consequences, the frequency of hazardous events, and the possibility of the consequences. According to the content of the hidden dangers and certain parameter value rules, the L, E, and C values ​​are determined respectively, and the risk adjustment coefficient K is in the range of 0.5 to 2, and the technical element risk value R is obtained.

[0044] R=L×E×C×K

[0045] The risk level of the technical factor is determined according to the R value, where R<30 is Level I risk, with a deduction of 2 points; 30≤R<70 is Level II risk, with a deduction of 4 points; 70≤R<200 is Level III risk, with a deduction of 8 points; and 200≤R is Level IV risk, with a deduction of 10 points, as shown in Table 1.

[0046] Table 1 Risk level of technical factors

[0047]

[0048] Step 4: Determine the total deduction value for the entire section based on the deduction value and weight value of each technical factor, and thus determine the corresponding risk level.

[0049] The above six technical factors have different impacts on the risk assessment results of old overhead transmission lines, so they need to be given appropriate weights. On the basis of the AHP method, the entropy weight method is added, the entropy value variable is introduced, the subjective weight and the objective weight are reasonably combined, and the AHP-entropy weight method weighting method is constructed, which includes the following steps:

[0050] Step 4.1, construct a relative importance matrix; obtain the maximum eigenvalue and the corresponding eigenvector respectively, and determine the weight vector through consistency test;

[0051] Step 4.2, determine the weight matrix C based on the weight vector x;

[0052]

[0053] Step 4.3, calculate the weight vector correlation coefficient matrix D:

[0054]

[0055] And d ii =1,d ij =d ji ;

[0056] Step 4.4: Remove weights with large deviations:

[0057]

[0058] Among them, d i represents the sum of the similarities between the i-th expert’s weighted opinion and other experts’ weighted opinions, d i The smaller it is, the greater the deviation;

[0059] Step 4.5: Get the average value of the column vector of the weight matrix after screening Get the weight value of each indicator;

[0060] Step 4.6: Combine the subjective weight with the objective weight and introduce the entropy value variable. The final weight value is

[0061]

[0062] in, represents the weight value determined by the AHP method, represents the weight value determined by the entropy weight method, H j It represents the entropy value of the evaluation index.

[0063] The weight values ​​of each technical factor are obtained based on the AHP-entropy weight method. The larger the value, the more likely it is to cause the failure and shutdown of the old overhead transmission line. The weight coefficients of each technical factor are shown in Table 2.

[0064] Table 2 Weight coefficients of technical factors

[0065]

[0066] For continuous tower sections, when the hidden dangers of the same technical elements are the same, they can be evaluated as a line section. The deduction value of the technical elements of the line section = weight score × corresponding basic deduction value, as shown in Table 3.

[0067] Table 3 Deduction value calculation table

[0068]

[0069]

[0070] Determine the risk status of the line section:

[0071] The sum of the deduction points of each technical factor in the line section is calculated. The risk status of the line section is determined by the maximum deduction value R of any single technical factor. 单 And the total deduction value R 总 Joint decision, divided into 4 states, as shown in Table 4.

[0072] (1) When R 单 ≤10, and R 总 <30, the line section is in normal condition.

[0073] (2) When 11≤R 单 ≤24, and 30≤R 总 When ≤60, the line section is in a low-risk state.

[0074] (3) When 25≤R 单 ≤32, or 61≤R 总 When ≤89, the line section is in medium risk status.

[0075] (4) When 32 <R 单 , or 90≤R 总 When , the line section is in a high-risk state.

[0076] Table 4 Evaluation criteria

[0077]

[0078] Step 5: Develop corresponding governance strategies based on risk levels.

[0079] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive. Therefore, the present invention includes but is not limited to the embodiments described in the specific implementation manner. Any other implementation manners derived by those skilled in the art based on the technical solution of the present invention also fall within the scope of protection of the present invention.

Claims

1. A method for quantitatively evaluating the obsolescence of a transmission line, characterized by: The following steps are involved: Step 1: Collect line operation information; Step 2: Based on the line operation information collected in step 1, conduct on-site technical element inspections one by one; Step 3: Evaluate the hidden dangers of each factor and calculate the corresponding risk value; Step 4: Determine the total deduction value for the entire section based on the deduction value and weight value of each technical factor, thereby determining the corresponding risk level; Step 5: Develop corresponding governance strategies based on risk levels.

2. A method for quantitatively assessing the aging degree of a power transmission line according to claim 1, characterized in that: The technical elements in step 2 include: channel environment, foundation, pole tower, ground wire, hardware and insulators.

3. A method for quantitatively assessing the aging degree of a power transmission line according to claim 1, characterized in that: The specific implementation method of step 3 is: R=L×E×C×K Among them, the risk level of the technical factor is determined according to the R value, where R<30 is level I risk, 30≤R<70 is level II risk, 70≤R<200 is level III risk, and 200≤R is level IV risk.

4. A method for quantitatively assessing the aging degree of a power transmission line according to claim 1, characterized in that: The specific implementation method of step 4 is: assign weights to the six technical factors of channel environment, foundation, pole tower, ground wire, hardware and insulator through the AHP-entropy weight method, evaluate the hidden dangers of each factor based on the improved LEC method, and calculate the corresponding risk value.

5. The method for quantitatively evaluating the aging degree of a power transmission line according to claim 1, characterized in that: The method of assigning weights to the six technical elements of channel environment, foundation, tower, ground wire, hardware and insulator by AHP-entropy weight method includes the following steps: Step 4.1, construct a relative importance matrix; obtain the maximum eigenvalue and the corresponding eigenvector respectively, and determine the weight vector through consistency test; Step 4.2, determine the weight matrix C based on the weight vector x; Step 4.3, calculate the weight vector correlation coefficient matrix D: And d ii =1,d ij =d ji ; Step 4.4: Remove weights with large deviations: Among them, d i represents the sum of the similarities between the i-th expert’s weighted opinion and other experts’ weighted opinions, d i The smaller it is, the greater the deviation; Step 4.5: Get the average value of the column vector of the weight matrix after screening Get the weight value of each indicator; Step 4.6: Combine the subjective weight with the objective weight and introduce the entropy value variable. The final weight value is in, represents the weight value determined by the AHP method, represents the weight value determined by the entropy weight method, H j It represents the entropy value of the evaluation index.

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