Power transmission tower typhoon rainstorm flood disaster assessment method based on analytic hierarchy process

Abstract

The invention discloses a transmission tower typhoon, rainstorm and flood disaster assessment method based on an analytic hierarchy process. The method comprises the following steps: establishing a risk factor assessment index system under the transmission tower typhoon, rainstorm and flood disasters; performing subjective weight calculation on each risk factor in the risk factor evaluation index system under the typhoon, rainstorm and flood disasters of the transmission tower based on an analytic hierarchy process to obtain a relative weight of each risk factor in the rating index system; and constructing a score deduction standard table of each risk factor, performing risk assessment on the transmission tower according to the risk factor evaluation index system under the typhoon, rainstorm and flood disasters of the transmission tower, and dividing risk grades. The method comprehensively considers the risk assessment of the transmission tower under the combined action of typhoon, rainstorm and flood disasters, and can provide auxiliary decisions for the power grid before disasters.

Description

Technical Field

[0001] The invention belongs to the technical field of disaster prevention and reduction of power systems, and specifically relates to a method for evaluating typhoon, rainstorm and flood disasters of power transmission towers based on a hierarchical analysis method. Background Art

[0002] The high-speed and strong winds brought by typhoons may cause risks such as line flashover, transmission tower collapse, and insulator damage, which poses a great safety hazard to the transmission and distribution network. Therefore, it is urgent to study the evaluation method of typhoon disasters on the power grid in order to provide a theoretical basis for the defense and recovery strategy of the power grid.

[0003] Typhoons are often accompanied by heavy rains when they land, leading to floods. In this disaster chain, various disaster events interact with each other, forming a complex disaster system, and each link may lead to serious consequences and impacts on power grid equipment. Summary of the invention

[0004] The purpose of the present invention is to provide a method for evaluating typhoon, rainstorm and flood disasters of transmission towers based on hierarchical analysis method, which makes up for the problem that the current risk assessment of transmission towers pays more attention to strong winds and pays less attention to rainstorms and flood disasters caused by typhoons.

[0005] In order to solve the above technical problems, the technical solution of the present invention is: a method for evaluating typhoon, rainstorm and flood disasters of transmission towers based on analytic hierarchy process, comprising the following steps:

[0006] S1. Establish a risk factor evaluation index system for transmission towers under typhoon, rainstorm and flood disasters;

[0007] S2. Based on the analytic hierarchy process, the subjective weight of each risk factor in the risk factor evaluation index system of transmission tower typhoon, rainstorm and flood disasters is calculated to obtain the relative weight of each risk factor in the rating index system;

[0008] S3. Construct a standard table for deduction of each risk factor, conduct risk assessment on transmission towers according to the risk factor evaluation index system under typhoon, rainstorm and flood disasters of transmission towers, and divide the risk levels.

[0009] S1 is specifically:

[0010] S1.1. Construct risk factors for evaluating the potential failures of transmission towers themselves;

[0011] S1.2. Construct risk factors for disaster prevention and mitigation to evaluate the impact of natural disasters on power grid operations through a series of measures and means, and to ensure safe and stable operation of the power grid and the reliability of power supply;

[0012] S1.3. Construct climate change risk factors for evaluating the impact of climate on transmission towers;

[0013] S1.4. Combine the risk factors of potential fault hazards, disaster prevention and mitigation, and climate change to form a risk factor evaluation index system for transmission towers under typhoon, rainstorm and flood disasters.

[0014] S2 is specifically:

[0015] S2.1. Construct judgment matrices corresponding to the system criteria, risk factors for potential faults, risk factors for disaster prevention and mitigation, and risk factors for climate change in the risk factor evaluation index system for transmission towers under typhoon, rainstorm and flood disasters, including the criteria layer, potential fault layer, disaster prevention and mitigation capability layer, and climate change layer;

[0016] S2.2. According to the judgment matrix, the subjective weight of each risk factor in the risk factor evaluation index system of transmission tower typhoon, rainstorm and flood disasters is calculated to obtain the relative weight of each risk factor in the rating index system;

[0017] S2.3. Test the consistency of the judgment matrix according to the analytic hierarchy process.

[0018] S3 is specifically:

[0019] S3.1. Construct a standard table for deduction of each risk factor to quantitatively assess the degree of typhoon, rainstorm and flood disasters faced by transmission towers;

[0020] S3.2. Calculate the total score based on the deduction standard table of all risk factors, and obtain the calculation result of the typhoon, rainstorm and flood disaster risk assessment of the transmission tower;

[0021] S3.3. Based on the calculation results, the risk level of typhoon, rainstorm and flood disasters faced by transmission towers is divided into risk levels.

[0022] Risk factors for potential fault hazards include at least wind deviation tripping, line breakage or string drop failure, pole tower deformation failure and pole tower tilt failure; risk factors for disaster prevention and mitigation include at least technical equipment level, operation and maintenance management and emergency response capabilities; risk factors for climate change include at least wind speed, rainfall, disaster duration and temperature.

[0023] The calculation method for calculating the subjective weight of each risk factor in the risk factor evaluation index system for transmission tower typhoon, rainstorm and flood disasters based on the judgment matrix in S2.2 is:

[0024]

[0025] W iNormalize the vector so that the sum of all elements in the vector is equal to 1, which is the sorting weight vector, denoted by W, then W = (W 1 , W 2 ...Wn) T , expressed as:

[0026]

[0027] The maximum eigenvalue of the judgment matrix is ​​expressed as:

[0028]

[0029] Where n is the order of the judgment matrix; λ max is the maximum characteristic root of the judgment matrix; W is the corresponding λ max The normalized eigenvector of i is the component of W, is the weight of the sub-factor; a ij It is the score obtained by comparing the importance of indicator i and indicator j.

[0030] The method for testing the consistency of the judgment matrix according to the hierarchical analysis method in S2.3 is:

[0031]

[0032] Among them, C is the consistency index, the smaller C is, the greater the consistency is; λ max is the maximum eigenvalue of the judgment matrix; n is the order of the judgment matrix.

[0033] The calculation method for the calculation results in S3.2 is:

[0034] S=A 1 +A 2 +A 3

[0035] Among them, S is the total deduction value of the target tower score; A 1 The final deduction value for the target tower failure potential; A 2 The final deduction value for the target tower’s disaster prevention and mitigation capabilities; A 3 This is the final deduction value for climate change of the target tower.

[0036] A 1 , A 2 , A 3 The calculation method is as follows:

[0037]

[0038] Where: ij is the risk weight obtained through the hierarchical analysis method; is the deduction value of factor i; is the deduction value of factor j; n is the number of factors in aspect i.

[0039] A computer-readable storage medium is also provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of any of the above methods are implemented.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention takes transmission towers as the research object, constructs a series of risk indicators for typhoon, rainstorm and flood disasters of transmission towers, divides them into hierarchical structures, calculates the weight proportion of each factor through the judgment matrix, and obtains the risk level of the transmission tower based on the actual status of each factor and the risk factor deduction table. The present invention comprehensively considers the risk assessment of transmission towers under the combined effects of typhoons, rainstorms and floods, and can provide auxiliary decision-making for the power grid before disasters. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of a flow chart of an embodiment of the present invention;

[0043] Figure 2 Schematic diagram of the hierarchical structure of risk factors of transmission towers under typhoon, rainstorm and flood disasters in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0045] The technical solution of the present invention is: a method for evaluating typhoon, rainstorm and flood disasters of transmission towers based on the analytic hierarchy process, such as Figure 1 As shown, the following steps are included:

[0046] S1. Establish a risk factor evaluation index system for transmission towers under typhoon, rainstorm and flood disasters;

[0047] S2. Based on the analytic hierarchy process, the subjective weight of each risk factor in the risk factor evaluation index system of transmission tower typhoon, rainstorm and flood disasters is calculated to obtain the relative weight of each risk factor in the rating index system;

[0048] S3. Construct a standard table for deduction of each risk factor, conduct risk assessment on transmission towers according to the risk factor evaluation index system under typhoon, rainstorm and flood disasters of transmission towers, and divide the risk levels.

[0049] In July 2023, Typhoon Tali entered Guangdong Province, and four transmission towers of the Guangdong Power Grid were damaged, which can be used to verify the risk assessment. A line tripped, and the daily statistics of the line were queried. This embodiment conducted a risk assessment analysis on the No. 23 tower of this line.

[0050] like Figure 2 As shown, S1.1: Risk factors for potential failures:

[0051] The hidden faults in the transmission towers themselves are one of the disaster-causing factors of typhoons, rainstorms and floods. The main hidden faults include wind deviation tripping, line breakage or string drop failure, tower deformation failure, tower tilt failure, etc.

[0052] S1.2: Risk factors for disaster prevention and mitigation:

[0053] The disaster prevention and mitigation capability of power grid refers to the ability of power grid to minimize the impact of disasters on power grid operation and ensure the safe and stable operation of power grid and the reliability of power supply through a series of measures and means when facing natural disasters. It mainly includes: technical equipment level, operation and maintenance management and emergency response capabilities.

[0054] S1.3: Risk factors for climate change:

[0055] In the risk assessment of typhoon, rainstorm and flood of transmission tower, we mainly analyzed four types of meteorological disaster factors, including: wind speed, rainfall, disaster duration and temperature. The influence of wind speed on transmission tower is significant. Strong wind will impose additional mechanical load on the transmission tower, especially the lateral wind force will cause the tower to bend and sway. Continuous rainfall may cause flooding of tower foundation and underground facilities. Long-term accumulation of water may cause the foundation soil to become loose, affecting the stability of the tower. The longer the duration of typhoon, rainstorm and flood, the more serious the damage to transmission tower and line. Changes in temperature will affect the physical properties of the materials used for tower, such as elastic modulus, yield strength, etc. In high temperature environment, some materials may become fragile, and fatigue cracks may be caused under long-term action.

[0056] S2.1: Construct a judgment matrix of criteria layer, fault potential layer, disaster prevention and mitigation capability layer, and climate change layer. The specific relative importance assessment method is shown in Table 1:

[0057] Table 1

[0058]

[0059] It was assessed that:

[0060] Criteria layer A judgment matrix:

[0061]

[0062] Judgment matrix of fault potential layer B1:

[0063]

[0064] Disaster prevention and mitigation capability layer B2 judgment matrix:

[0065]

[0066] Climate change layer B3 judgment matrix:

[0067]

[0068] S2.2: Calculate the relative weights of risk factors based on the judgment matrix. The specific calculation method is shown in Table 2:

[0069] Table 2

[0070]

[0071]

[0072] Where n is the order of the judgment matrix; λ max is the maximum characteristic root of the judgment matrix; W is the corresponding λ max The normalized eigenvector of i is the component of W, which refers to the weight of the sub-factor; a ij It is the score obtained by comparing the importance of indicator i and indicator j.

[0073] It is calculated that:

[0074] The relative weights of the criterion layer and the target layer are shown in Table 3:

[0075] Table 3

[0076]

[0077] The relative weights of each sub-factor of fault potential B1 are shown in Table 4:

[0078] Table 4

[0079]

[0080] The relative weights of each sub-factor of the power grid disaster prevention and mitigation capability B2 are shown in Table 5:

[0081] Table 5

[0082]

[0083] The relative weights of each sub-factor of climate change B3 are shown in Table 6:

[0084] Table 6

[0085]

[0086]

[0087] The final weights of each sub-factor are shown in Table 7:

[0088] Table 7

[0089]

[0090] S2.3: Check the consistency of the judgment matrix. In the hierarchical analysis method, C is used to check the consistency index of the judgment matrix. C = 0 means that the judgment matrix is ​​completely consistent. The larger the C, the more serious the inconsistency of the judgment matrix. The specific expression is:

[0091]

[0092] Among them, C is the consistency index, the smaller C is, the greater the consistency is; λ max is the maximum eigenvalue of the judgment matrix; n is the order of the judgment matrix.

[0093] The feasibility ratio calculated according to the formula is shown in Table 8:

[0094] Table 8

[0095]

[0096] According to the matrix feasibility calculation, all feasibility ratios are less than 0.1, which means that the matrix feasibility requirements are met.

[0097] S3.1: Construct a deduction table for each risk factor. In order to assess the risk level of transmission towers suffering from typhoon, rainstorm and flood disasters, it is necessary to systematically analyze and classify the potential factors that may cause failures. When constructing the typhoon, rainstorm and flood disaster assessment model, a method of deducting points item by item is adopted to record and classify the various potential fault hazards identified in the transmission towers. Whenever a certain type of fault listed in the table is found in the line, points are deducted according to the deduction standard corresponding to the fault type. In this way, the total deduction points of the transmission tower can be accumulated and calculated, and then the degree of typhoon, rainstorm and flood disasters faced by it can be quantitatively assessed.

[0098] The deduction standards for potential fault hazards are shown in Table 9:

[0099] Table 9

[0100]

[0101] Deduction criteria for disaster prevention and mitigation capabilities:

[0102] The technical equipment level of transmission towers has a significant impact on the grid's disaster prevention and mitigation capabilities. The deduction standards are as follows: 1 point will be deducted if the necessary remote monitoring and automation equipment is lacking; 1.0 point will be deducted if the tower design does not meet local wind and flood resistance standards; 1 point will be deducted if the fault location and isolation system is not installed or is poorly maintained.

[0103] Grid operation and maintenance management is a key link to ensure the safe, stable and efficient operation of the grid, involving the monitoring, maintenance, inspection and troubleshooting of grid facilities. The penalty standards are as follows: 1 point will be deducted for lack of regular line inspection and maintenance; 1 point will be deducted for failure to formulate or implement disaster emergency plans; 1 point will be deducted for lack of disaster risk assessment and hidden danger investigation.

[0104] The power grid emergency response capability refers to the ability of the power grid to take prompt and effective measures to minimize the impact and losses on users when faced with emergencies such as large-scale power outages caused by natural disasters, external damage, power safety accidents, etc. The deduction criteria are as follows: 1 point will be deducted if the emergency material reserves are insufficient or not updated in time; 1 point will be deducted if the emergency repair team is insufficient or not trained; 1 point will be deducted if the emergency communication and command system is not sound.

[0105] Deduction criteria for climate change: In the typhoon, rainstorm and flood risk assessment of transmission towers, we mainly analyzed four types of meteorological disaster factors, including: wind speed, rainfall, disaster duration and temperature.

[0106] The wind speed risk factor deduction standards are shown in Table 10:

[0107] Table 10

[0108]

[0109] The deduction standard for rainfall risk factor is shown in Table 11:

[0110] Table 11

[0111]

[0112]

[0113] The deduction standard for disaster duration risk factor is shown in Table 12:

[0114] Table 12

[0115]

[0116] The deduction standard for temperature risk factor is shown in Table 13:

[0117] Table 13

[0118]

[0119] The deduction standards are summarized in Table 14:

[0120] Table 14

[0121]

[0122]

[0123]

[0124] S3.2: The total score is calculated by comprehensive multi-factor calculation to obtain the results of the typhoon, rainstorm and flood disaster risk assessment of transmission towers. The evaluation calculation method is as follows:

[0125] S=A 1 +A 2 +A 3

[0126] Among them, S is the total deduction value of the target tower score; A 1 The final deduction value for the target tower failure potential; A 2 The final deduction value for the target tower’s disaster prevention and mitigation capabilities; A 3 The final deduction value for climate change of the target tower;

[0127] A 1 , A 2 , A 3 The calculation method is as follows:

[0128]

[0129] Where: ij is the risk weight obtained through the hierarchical analysis method; is the deduction value of factor i; is the deduction value of factor j; n is the number of factors in aspect i.

[0130] It is known that the tower has a record of wind deflection tripping, no broken wires or dropped strings, no tower deformation or tilting faults, lacks necessary remote monitoring and automation equipment, and the tower design meets local wind and flood control standards, but does not have a fault location system and wind-resistant reinforcement. There are no deductions in operation and maintenance and power grid disaster response and repair capabilities. The wind speed on that day was 10-12, the cumulative rainfall within 24 hours was more than 200mm, the typhoon disaster lasted less than 5 days, the temperature was 26°C, and the depth of accumulated water was less than 15cm. Combining the typhoon rainstorm flood disaster risk factor deduction table and the final weight of the typhoon rainstorm flood disaster risk factor, the calculation is:

[0131] Deduction for potential fault hazards: B1 = 0.0742

[0132] Disaster prevention and mitigation capability deduction: B2 = 0.2310

[0133] Deduction for climate change: B3 = 0.5623

[0134] Total deduction value: S = 0.8675

[0135] S3.3: The target tower risk value is obtained according to the evaluation calculation formula, and the evaluation results are divided into four levels: normal, caution, abnormal and severe. The evaluation risk level classification is shown in Table 15:

[0136] Table 15

[0137]

[0138] The final deduction value of the No. 23 pole tower of the line is 0.8675. According to the typhoon rainstorm and flood disaster risk status table, it can be seen that the pole tower is in an abnormal state. The tower status record during this period was queried. Due to the typhoon rainstorm weather, the pole body had multiple serious cracks, which was consistent with the assessment results. The present invention makes up for the problem that the current risk assessment of transmission towers pays more attention to strong winds and less attention to rainstorms and floods caused by typhoons.

[0139] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for evaluating typhoon, rainstorm and flood disasters of transmission towers based on analytic hierarchy process, characterized in that: The following steps are involved: S1. Establish a risk factor evaluation index system for transmission towers under typhoon, rainstorm and flood disasters; S2. Based on the analytic hierarchy process, the subjective weight of each risk factor in the risk factor evaluation index system of transmission tower typhoon, rainstorm and flood disasters is calculated to obtain the relative weight of each risk factor in the rating index system; S3. Construct a standard table for deduction of each risk factor, conduct risk assessment on transmission towers according to the risk factor evaluation index system under typhoon, rainstorm and flood disasters of transmission towers, and divide the risk levels.

2. The method for evaluating typhoon, rainstorm and flood disasters of power transmission towers based on analytic hierarchy process according to claim 1 is characterized in that: S1 is specifically: S1.

1. Construct risk factors for evaluating the potential failures of transmission towers themselves; S1.

2. Construct risk factors for disaster prevention and mitigation to evaluate the impact of natural disasters on power grid operations through a series of measures and means, and to ensure safe and stable operation of the power grid and the reliability of power supply; S1.

3. Construct climate change risk factors for evaluating the impact of climate on transmission towers; S1.

4. Combine the risk factors of potential fault hazards, disaster prevention and mitigation, and climate change to form a risk factor evaluation index system for transmission towers under typhoon, rainstorm and flood disasters.

3. The method for evaluating typhoon, rainstorm and flood disasters of power transmission towers based on analytic hierarchy process according to claim 1 is characterized in that: S2 is specifically: S2.

1. Construct judgment matrices corresponding to the system criteria, risk factors for potential faults, risk factors for disaster prevention and mitigation, and risk factors for climate change in the risk factor evaluation index system for transmission towers under typhoon, rainstorm and flood disasters, including the criteria layer, potential fault layer, disaster prevention and mitigation capability layer, and climate change layer; S2.

2. According to the judgment matrix, the subjective weight of each risk factor in the risk factor evaluation index system of transmission tower typhoon, rainstorm and flood disasters is calculated to obtain the relative weight of each risk factor in the rating index system; S2.

3. Test the consistency of the judgment matrix according to the hierarchical analysis method.

4. The method for evaluating typhoon, rainstorm and flood disasters of power transmission towers based on analytic hierarchy process according to claim 1 is characterized in that: S3 is specifically: S3.

1. Construct a standard table for deduction of each risk factor to quantitatively assess the extent of typhoon, rainstorm and flood disasters faced by transmission towers; S3.

2. The total score is calculated based on the deduction results of the deduction standard table for all risk factors, and the calculation results of the typhoon, rainstorm and flood disaster risk assessment of the transmission tower are obtained; S3.

3. Based on the calculation results, the risk level of typhoon, rainstorm and flood disasters faced by transmission towers is divided into risk levels.

5. The method for evaluating typhoon, rainstorm and flood disasters of power transmission towers based on analytic hierarchy process according to claim 2 is characterized in that: Risk factors for potential fault hazards include at least wind deviation tripping, line breakage or string drop failure, pole tower deformation failure and pole tower tilt failure; risk factors for disaster prevention and mitigation include at least technical equipment level, operation and maintenance management and emergency response capabilities; risk factors for climate change include at least wind speed, rainfall, disaster duration and temperature.

6. The method for evaluating typhoon, rainstorm and flood disasters of power transmission towers based on analytic hierarchy process according to claim 3 is characterized in that: The calculation method for calculating the subjective weight of each risk factor in the risk factor evaluation index system for transmission tower typhoon, rainstorm and flood disasters based on the judgment matrix in S2.2 is: W i Normalize the vector so that the sum of the elements is equal to 1, which is the sorting weight vector, denoted by W, then W = (W1, W2...Wn) T , expressed as: The maximum eigenvalue of the judgment matrix is ​​expressed as: Where n is the order of the judgment matrix; λ max is the maximum characteristic root of the judgment matrix; W is the corresponding λ max The normalized eigenvector of i is the component of W, is the weight of the sub-factor; a ij It is the score obtained by comparing the importance of indicator i and indicator j.

7. The method for evaluating typhoon, rainstorm and flood disasters of power transmission towers based on analytic hierarchy process according to claim 6 is characterized in that: The method for testing the consistency of the judgment matrix according to the hierarchical analysis method in S2.3 is: Among them, C is the consistency index, the smaller C is, the greater the consistency is; λ max is the maximum eigenvalue of the judgment matrix; n is the order of the judgment matrix.

8. The method for evaluating typhoon, rainstorm and flood disasters of power transmission towers based on analytic hierarchy process according to claim 4 is characterized in that: The calculation method for the calculation results in S3.2 is: S=A1+A2+A3 Among them, S is the total deduction value of the target tower score; A1 is the final deduction value for the target tower failure potential; A2 is the final deduction value for the target tower disaster prevention and mitigation capabilities; A3 is the final deduction value for the target tower climate change.

9. The method for evaluating typhoon, rainstorm and flood disasters of power transmission towers based on analytic hierarchy process according to claim 8 is characterized in that: The calculation methods of A1, A2 and A3 are as follows: Where: ij is the risk weight obtained through the hierarchical analysis method; is the deduction value of factor i; is the deduction value of factor j; n is the number of factors in aspect i.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

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