Screening method, system and equipment for vulnerable power transmission tower

Abstract

The invention discloses a method, a system and equipment for screening vulnerable power transmission towers, and relates to the technical field of power transmission line monitoring and early warning. Establishing a finite element model of the power transmission line according to the fluctuating wind load time history data; performing time domain analysis on the finite element model, layering the power transmission tower in the power transmission line, and calculating the damage index of each layer of the power transmission tower to obtain the overall damage index of the power transmission tower; and judging the power transmission tower of which the overall damage index is greater than a preset threshold value as a vulnerable power transmission tower. By adopting the embodiment of the invention, the structural resistance of the power transmission line can be fully considered, the wind-induced response condition of the power transmission line is calculated and analyzed according to the power transmission line finite element model, the vulnerable power transmission tower is screened out from the power transmission line, and a basis is provided for monitoring and early warning work of the power transmission line.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission line monitoring and early warning, and in particular to a screening method, system and equipment for vulnerable power transmission towers. Background Art

[0002] In recent years, as severe weather has become more frequent, it is necessary to evaluate the possible failures and even structural damage of transmission lines in severe weather, so as to provide a basis for rapid response to severe weather and post-disaster repair. In the monitoring and early warning of transmission lines, the assessment of line safety often directly depends on the meteorological data of the monitoring equipment and the acceleration data of the main body monitoring, and uses the common line wind disaster conditions. When the wind speed, wind direction, and line vibration reach a certain level, it is considered that a line fault has occurred.

[0003] However, the existing technology has at least the following problems: different transmission lines exhibit different structural resistances when facing wind effects, resulting in low warning accuracy. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method, system and equipment for screening vulnerable transmission towers, which can fully consider the structural resistance of the transmission line, calculate and analyze the wind-induced response of the transmission line according to the finite element model of the transmission line, and screen out vulnerable transmission towers from the transmission line, so as to provide a basis for the monitoring and early warning of the transmission line.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a method for screening vulnerable transmission towers, comprising:

[0006] Obtain the time history data of the fluctuating wind load of the transmission line;

[0007] Establishing a finite element model of the transmission line according to the pulsating wind load time history data;

[0008] Performing time domain analysis on the finite element model, stratifying the transmission towers in the transmission line and calculating the damage index of each layer of the transmission towers to obtain an overall damage index of the transmission towers;

[0009] A transmission tower whose overall damage index is greater than a preset threshold is determined as a vulnerable transmission tower.

[0010] As an improvement of the above solution, the step of obtaining the time history data of the fluctuating wind load of the transmission line includes:

[0011] Get the average wind speed time history of the transmission line;

[0012] Use linear filtering method to simulate and calculate the fluctuating wind speed time history of transmission lines;

[0013] The average wind speed time history and the pulsating wind speed time history are added together to obtain the overall wind speed time history. The pulsating wind load time history data of the transmission line is calculated based on the overall wind speed time history.

[0014] As an improvement of the above solution, the finite element model of the transmission line is established according to the pulsating wind load time history data, including:

[0015] Using finite element software and combining the transmission line structure design data, a finite element model of the transmission tower is established;

[0016] According to the pulsating wind load time history data, the pulsating wind load time history data is loaded at different heights of the transmission tower finite element model to obtain a finite element model of the transmission line.

[0017] As an improvement of the above solution, the finite element model is subjected to time domain analysis, the transmission towers in the transmission line are layered and the damage index between each layer of the transmission towers is calculated to obtain the overall damage index of the transmission towers, including:

[0018] Performing time domain analysis on the finite element model to obtain stress and strain information of all rods of the transmission tower;

[0019] According to the stress-strain information, the plastic strain information of the rod is obtained, and the damage degree of each rod is calculated;

[0020] According to the location of each node of the main material of the transmission tower, the transmission tower is divided into several layers in the horizontal direction;

[0021] Calculating the damage index between each layer of the transmission tower in the transmission line according to the damage degree of each rod;

[0022] The overall damage index of the transmission tower is calculated based on the damage indexes between the layers.

[0023] As an improvement of the above solution, obtaining the plastic strain information of the rod according to the stress-strain information and calculating the damage degree of each rod include:

[0024] According to the stress-strain information, the maximum plastic strain and the ultimate plastic strain of the rod under the wind load time history are obtained;

[0025] pass Calculate the damage degree of each member; where θ is the preset weight value; ε max is the maximum plastic strain of the member under the time history of wind load; ext is the ultimate plastic strain; ε iis the strain value reaching plastic strain in the i-th cycle; 0≤i≤d, d is the total number of cycles. As an improvement of the above scheme, the damage index between each layer of the transmission tower in the transmission line is calculated according to the damage degree of each rod, including:

[0026] pass Calculate the interlaminar damage index of the i-th section;

[0027] Where n is the total number of internode components in the i-th segment; D j is the damage degree of the jth member in the ith interval; w j is the weight coefficient of the j-th member in the ith interval.

[0028] As an improvement of the above solution, the overall damage index of the transmission tower is calculated based on the damage index of each layer, including:

[0029] Calculating the weight coefficients of the layers according to the interlayer damage index;

[0030] The overall damage index of the transmission tower is calculated by combining the weight coefficient and the interlayer damage index.

[0031] The embodiment of the present invention further provides a screening system for vulnerable transmission towers, comprising:

[0032] A time history data acquisition module is used to acquire the time history data of the pulsating wind load of the transmission line;

[0033] A finite element model building module, used to build a finite element model of the transmission line according to the pulsating wind load time history data;

[0034] An overall damage index calculation module is used to perform time domain analysis on the finite element model, layer the transmission towers in the transmission line and calculate the damage index between each layer of the transmission tower to obtain the overall damage index of the transmission tower;

[0035] The vulnerable transmission tower determination module is used to determine the transmission tower whose overall damage index is greater than a preset threshold as a vulnerable transmission tower.

[0036] As an improvement in the above solution, the overall damage index calculation module is specifically used to:

[0037] Performing time domain analysis on the finite element model to obtain stress and strain information of all rods of the transmission tower;

[0038] According to the stress-strain information, the plastic strain information of the rod is obtained, and the damage degree of each rod is calculated;

[0039] According to the location of each node of the main material of the transmission tower, the transmission tower is divided into several layers in the horizontal direction;

[0040] Calculating the damage index between each layer of the transmission tower in the transmission line according to the damage degree of each rod;

[0041] The overall damage index of the transmission tower is calculated based on the damage indexes between the layers.

[0042] An embodiment of the present invention also provides a screening device for vulnerable transmission towers, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the screening method for vulnerable transmission towers as described in any one of the above items is implemented.

[0043] Compared with the prior art, the present invention discloses a method, system and device for screening vulnerable transmission towers, which obtains the pulsating wind load time history data of the transmission line; establishes a finite element model of the transmission line according to the pulsating wind load time history data; performs time domain analysis on the finite element model, layers the transmission towers in the transmission line and calculates the damage index between each layer of the transmission tower to obtain the overall damage index of the transmission tower; and determines the transmission tower with the overall damage index greater than a preset threshold as a vulnerable transmission tower. By adopting the embodiments of the present invention, the structural resistance of the transmission line can be fully considered, the wind-induced response of the transmission line can be calculated and analyzed according to the finite element model of the transmission line, and vulnerable transmission towers can be screened out from the transmission line, providing a basis for the monitoring and early warning of the transmission line. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic flow chart of the steps of a method for screening vulnerable transmission towers provided by an embodiment of the present invention;

[0045] Figure 2 It is a structural schematic diagram of a screening system for vulnerable transmission towers provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] In the description of the specification and claims, it is to be understood that the terms first, second, etc. in the specification and claims are only used for the purpose of describing the same technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated, nor necessarily describing the order or time sequence. The terms are interchangeable where appropriate. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0048] See also Figure 1 The embodiment of the present invention provides a method for screening vulnerable transmission towers. In this embodiment, the method for screening vulnerable transmission towers is specifically performed through steps S1 to S4:

[0049] S1. Obtain the time history data of the pulsating wind load of the transmission line.

[0050] S2. Establishing a finite element model of the transmission line according to the pulsating wind load time history data.

[0051] Exemplarily, in an embodiment of the present invention, when establishing a finite element model, it is necessary to set the spatial dimensions of the transmission tower, the interface form of the rods, the material and specifications of the rods, and the settings need to completely correspond to the actual design data of the transmission line.

[0052] S3. Performing time domain analysis on the finite element model, stratifying the transmission towers in the transmission line and calculating the damage index of each layer of the transmission towers to obtain an overall damage index of the transmission towers.

[0053] It should be noted that, since the wind loads at different heights of the transmission towers are not the same, the wind disaster conditions at different heights of the transmission towers will be different. By using the embodiment of the present invention to layer the transmission towers in the transmission line, the structural characteristics of the transmission towers themselves can be carefully considered to more accurately determine the collapse damage of the transmission line.

[0054] S4. Determine the transmission tower whose overall damage index is greater than a preset threshold as a vulnerable transmission tower.

[0055] Exemplarily, in a preferred embodiment of the present invention, the preset threshold is 0.6. That is, when the calculated overall damage index of the transmission tower is greater than 0.6, the transmission tower is determined to be a vulnerable transmission tower.

[0056] In traditional transmission line monitoring and early warning work, field meteorological monitoring and line status monitoring devices are arranged at the transmission line, and then the meteorological data and line characteristics obtained by the monitoring devices are used to determine whether the line will fail. When the transmission line is subjected to strong winds, even if the wind speed reaches the design wind speed, it will not necessarily cause a failure or even a tower collapse. Only considering the wind speed for line early warning will result in low warning accuracy.

[0057] In the above scheme, by establishing a finite element model of the transmission line, the transmission towers in the transmission line are layered and the damage index between the layers of the transmission towers is calculated. This can take into account the impact of the structural characteristics of the transmission line itself on the wind disaster situation, and then screen out vulnerable transmission towers based on the overall damage index, providing a basis for the operation and maintenance of the transmission line.

[0058] As a preferred implementation, step S1, obtaining the time history data of the fluctuating wind load of the transmission line, includes:

[0059] Get the average wind speed time history of the transmission line;

[0060] Use linear filtering method to simulate and calculate the fluctuating wind speed time history of transmission lines;

[0061] The average wind speed time history and the pulsating wind speed time history are added together to obtain the overall wind speed time history. The pulsating wind load time history data of the transmission line is calculated based on the overall wind speed time history.

[0062] It should be noted that, after the overall wind speed time history is obtained, the wind load time history borne by the transmission tower structure, that is, the pulsating wind load time history data of the transmission line, can be determined according to the relevant specifications for overhead transmission line loads.

[0063] Further, preferably, the use of a linear filtering method to simulate and calculate the pulsating wind speed time history of a transmission line comprises:

[0064] pass Calculate the pulsating wind speed time history of the transmission line; where p is the order of the high-order regression filter method; is the autoregressive coefficient; Δt is the time interval; N(t) is a Gaussian random process with mean 0 and given covariance.

[0065] Furthermore, through Determine the autoregressive coefficients Gaussian random process N(t) = L·n(t); where L is given by the covariance matrix R N Decompose and determine, R N =L·L T .

[0066] Exemplarily, in the embodiment of the present invention, the time interval Δt is 0.01 s; and the order p of the high-order regression filtering method is 5.

[0067] In the above scheme, the pulsating wind speed time history of the transmission line is simulated and calculated by the linear filtering method, and then combined with the average wind speed time history, the pulsating wind load time history data of the transmission line can be obtained. The pulsating wind load time history data reflects the impact of meteorological data on the damage of the transmission line.

[0068] Preferably, step S2, establishing a finite element model of the transmission line according to the pulsating wind load time history data, comprises:

[0069] Using finite element software and combining the transmission line structure design data, a finite element model of the transmission tower is established;

[0070] According to the pulsating wind load time history data, the pulsating wind load time history data is loaded at different heights of the transmission tower finite element model to obtain a finite element model of the transmission line.

[0071] Further, as a preferred implementation, the pulsating wind load time history data is loaded at different heights of the transmission tower finite element model to obtain a finite element model of the transmission line, including:

[0072] By W s =W0μ s μ z β z BA s Calculate wind loads on transmission towers;

[0073] By W x =W0μ sc μ z dL p β c Bsin 2 θCalculate the wind load on the conductors of the transmission tower;

[0074] Where W0 is the basic wind pressure; μ s is the transmission tower pole shape coefficient; μ z is the height coefficient; β z is the wind vibration coefficient of the tower at height z; B is the wind load increase coefficient of the transmission tower; A s is the projected area of ​​the windward surface; μ sc is the conductor shape coefficient; d is the conductor diameter; L p is the length of the conductor segment; θ is the angle between the wind direction and the conductor;

[0075] The tower wind load and the conductor wind load are loaded at different heights of the transmission tower finite element model to obtain a finite element model of the transmission line.

[0076] Exemplarily, in one embodiment of the present invention, the transmission line structure design data includes the rod interface form, rod material, specification and transmission tower space size information; the rods include main rods and diagonal rods.

[0077] In the above scheme, the response of the transmission tower to the pulsating wind load at different heights can be understood, which is helpful for evaluating the safety of the transmission tower.

[0078] As a preferred implementation, step S3, performing time domain analysis on the finite element model, stratifying the transmission towers in the transmission line and calculating the damage index of each layer of the transmission towers to obtain the overall damage index of the transmission towers, is specifically performed through steps S31 to S35:

[0079] S31. Perform time domain analysis on the finite element model to obtain stress and strain information of all rods of the transmission tower.

[0080] S32. Obtain plastic strain information of the rods according to the stress-strain information, and calculate the damage degree of each rod.

[0081] It should be noted that rods will deform when subjected to loads, and when their strain reaches a certain level, they will enter the plastic stage. At this time, even if the load is removed, the rods cannot completely return to the unloaded state. Therefore, once the rods of the transmission tower enter the plastic stage, the transmission tower may be damaged. By obtaining the plastic strain information of the rods, it can be used to evaluate the safety and stability of the structure.

[0082] S33. Divide the transmission tower into several layers in the horizontal direction according to the position of each node of the main material of the transmission tower.

[0083] It should be noted that transmission towers are usually composed of a variety of materials. Under one classification standard, transmission towers mainly include the main tower body, insulators and ground wires. The node position of the main material of the transmission tower is the node or connection point of the transmission tower used to connect different materials and components. Generally, the node position will be marked in the structural design drawings and relevant specifications of the transmission tower. Since the material and component structure of the node connection part may be different, the wind load and tower body characteristics are also different. By dividing the transmission tower into several layers, it is helpful to conduct safety analysis of the transmission tower structure.

[0084] S34. Calculate the damage index between each layer of the transmission tower in the transmission line according to the damage degree of each rod.

[0085] S35. Calculate the overall damage index of the transmission tower according to the damage indexes between the layers.

[0086] In the above scheme, by dividing the transmission tower into several layers in the horizontal direction, the influence of different wind loads and tower body characteristics on the damage of the transmission line under different materials and component structures can be considered; combined with the damage degree of the rod obtained through the plastic strain information of the rod, the damage of the transmission line can be further and more accurately evaluated, and the overall damage index of the transmission tower can be calculated.

[0087] Further, preferably, step S32, obtaining plastic strain information of the rod according to the stress-strain information, and calculating the damage degree of each rod, includes:

[0088] According to the stress-strain information, the maximum plastic strain and the ultimate plastic strain of the rod under the wind load time history are obtained;

[0089] pass Calculate the damage degree of each member; where θ is the preset weight value; ε max is the maximum plastic strain of the member under the time history of wind load; ext is the ultimate plastic strain; ε i is the strain value reaching plastic strain in the i-th cycle; 0≤i≤d, d is the total number of cycles. Exemplarily, in a preferred embodiment of the present invention, θ is 0.03.

[0090] As a preferred implementation, step S34, calculating the damage index between each layer of the transmission tower in the transmission line according to the damage degree of each rod, includes:

[0091] pass Calculate the interlaminar damage index of the i-th section;

[0092] Where n is the total number of internode components in the i-th segment; D j is the damage degree of the jth member in the ith interval; w j is the weight coefficient of the j-th member in the ith interval.

[0093] As a preferred implementation, step S35, calculating the overall damage index of the transmission tower according to the damage indexes between the layers, includes:

[0094] Calculating the weight coefficients of the layers according to the interlayer damage index;

[0095] The overall damage index of the transmission tower is calculated by combining the weight coefficient and the interlayer damage index.

[0096] Preferably, the calculating the weight coefficient between each layer according to the interlayer damage index includes:

[0097] pass Calculate the weight coefficient of the i-th section; where SFDi is the interlaminar damage index of the ith interlayer.

[0098] Further, preferably, the combining the weight coefficient and the interlayer damage index to calculate the overall damage index of the transmission tower includes:

[0099] pass The overall damage index of the transmission tower is calculated; where β i is the weight coefficient of the i-th section, SFD i is the interlaminar damage index of the ith interlayer.

[0100] As a preferred implementation, multiple simulation analyses may be performed, and the vulnerability probability may be calculated according to the simulation results, specifically:

[0101] Under the average wind speed obtained by meteorological monitoring, the above method is used to screen vulnerable transmission towers multiple times to obtain several overall damage indexes of transmission towers;

[0102] Count the frequencies of the plurality of overall damage indices reaching the preset thresholds, and Calculate the probability of tower vulnerability at this wind speed; where, is the average wind speed; x is the average wind speed obtained by meteorological monitoring; AFD is the overall damage index; Z is the preset threshold.

[0103] Exemplarily, in a preferred embodiment of the present invention, Z=0.6.

[0104] It should be noted that, in the transmission line monitoring and early warning work, by adopting the vulnerability probability calculated by the embodiment of the present invention, it is possible to screen out the transmission line areas prone to failure from the transmission line, thereby providing a basis for the operation and maintenance of the transmission line.

[0105] A method for screening vulnerable transmission towers provided in an embodiment of the present invention is adopted. By establishing a finite element model of the transmission line, the transmission towers in the transmission line are layered and the damage index between each layer of the transmission tower is calculated. The influence of the structural characteristics of the transmission line itself on the wind disaster situation can be taken into account, and then the vulnerable transmission towers are screened according to the overall damage index, providing a basis for the operation and maintenance of the transmission line.

[0106] See also Figure 2 The embodiment of the present invention also provides a screening system for vulnerable transmission towers. The screening system for vulnerable transmission towers includes a time history data acquisition module 11, a finite element model establishment module 12, an overall damage index calculation module 13 and a vulnerable transmission tower determination module 14, wherein:

[0107] A time history data acquisition module 11 is used to acquire the time history data of the pulsating wind load of the transmission line;

[0108] A finite element model building module 12, used to build a finite element model of the transmission line according to the pulsating wind load time history data;

[0109] An overall damage index calculation module 13 is used to perform time domain analysis on the finite element model, layer the transmission towers in the transmission line and calculate the damage index between each layer of the transmission towers to obtain an overall damage index of the transmission towers;

[0110] The vulnerable transmission tower determination module 14 is used to determine the transmission tower whose overall damage index is greater than a preset threshold as a vulnerable transmission tower.

[0111] In traditional transmission line monitoring and early warning work, field meteorological monitoring and line status monitoring devices are arranged at the transmission line, and then the meteorological data and line characteristics obtained by the monitoring devices are used to determine whether the line will fail. When the transmission line is subjected to strong winds, even if the wind speed reaches the design wind speed, it will not necessarily cause a failure or even a tower collapse. Only considering the wind speed for line early warning will result in low warning accuracy.

[0112] In the above scheme, by establishing a finite element model of the transmission line, the transmission towers in the transmission line are layered and the damage index between the layers of the transmission towers is calculated. This can take into account the impact of the structural characteristics of the transmission line itself on the wind disaster situation, and then screen out vulnerable transmission towers based on the overall damage index, providing a basis for the operation and maintenance of the transmission line.

[0113] As a preferred implementation, the time course data acquisition module 11 is specifically used for:

[0114] Get the average wind speed time history of the transmission line;

[0115] Use linear filtering method to simulate and calculate the fluctuating wind speed time history of transmission lines;

[0116] The average wind speed time history and the pulsating wind speed time history are added together to obtain the overall wind speed time history. The pulsating wind load time history data of the transmission line is calculated based on the overall wind speed time history.

[0117] Further, preferably, the use of a linear filtering method to simulate and calculate the pulsating wind speed time history of a transmission line comprises:

[0118] pass Calculate the pulsating wind speed time history of the transmission line; where p is the order of the high-order regression filter method; is the autoregressive coefficient; Δt is the time interval; N(t) is a Gaussian random process with mean 0 and given covariance.

[0119] Furthermore, through Determine the autoregressive coefficients Gaussian random process N(t) = L·n(t); where L is given by the covariance matrix R N Decompose and determine, R N =L·L T .

[0120] In the above scheme, the pulsating wind speed time history of the transmission line is simulated and calculated by the linear filtering method, and then combined with the average wind speed time history, the pulsating wind load time history data of the transmission line can be obtained. The pulsating wind load time history data reflects the impact of meteorological data on the damage of the transmission line.

[0121] Preferably, the finite element model building module 12 is specifically used for:

[0122] Using finite element software and combining the transmission line structure design data, a finite element model of the transmission tower is established;

[0123] According to the pulsating wind load time history data, the pulsating wind load time history data is loaded at different heights of the transmission tower finite element model to obtain a finite element model of the transmission line.

[0124] As a preferred implementation, the overall damage index calculation module 13 is specifically used for:

[0125] The finite element model is analyzed in the time domain to obtain stress and strain information of all the rods of the transmission tower.

[0126] According to the stress-strain information, the plastic strain information of the rod is obtained, and the damage degree of each rod is calculated.

[0127] According to the location of each node of the main material of the transmission tower, the transmission tower is divided into several layers in the horizontal direction.

[0128] The damage index between each layer of the transmission tower in the transmission line is calculated according to the damage degree of each rod.

[0129] The overall damage index of the transmission tower is calculated based on the damage indexes between the layers.

[0130] It should be noted that transmission towers are usually composed of a variety of materials. Under one classification standard, transmission towers mainly include the main tower body, insulators and ground wires. The node position of the main material of the transmission tower is the node or connection point of the transmission tower used to connect different materials and components. Generally, the node position will be marked in the structural design drawings and relevant specifications of the transmission tower. Since the material and component structure of the node connection part may be different, the wind load and tower body characteristics are also different. By dividing the transmission tower into several layers, it is helpful to conduct safety analysis of the transmission tower structure.

[0131] In the above scheme, by dividing the transmission tower into several layers in the horizontal direction, the influence of different wind loads and tower body characteristics on the damage of the transmission line under different materials and component structures can be considered; combined with the damage degree of the rod obtained through the plastic strain information of the rod, the damage of the transmission line can be further and more accurately evaluated, and the overall damage index of the transmission tower can be calculated.

[0132] Further, preferably, obtaining the plastic strain information of the rod according to the stress-strain information and calculating the damage degree of each rod includes:

[0133] According to the stress-strain information, the maximum plastic strain and the ultimate plastic strain of the rod under the wind load time history are obtained;

[0134] pass Calculate the damage degree of each member; where θ is the preset weight value; ε max is the maximum plastic strain of the member under the time history of wind load; ext is the ultimate plastic strain; ε i is the strain value reaching plastic strain in the i-th cycle; 0≤i≤d, d is the total number of cycles. As a preferred embodiment, the damage index between each layer of the transmission tower in the transmission line is calculated according to the damage degree of each rod, including:

[0135] pass Calculate the interlaminar damage index of the i-th section;

[0136] Where n is the total number of internode components in the i-th segment; D j is the damage degree of the jth member in the ith interval; w j is the weight coefficient of the j-th member in the ith interval.

[0137] As a preferred implementation manner, the overall damage index of the transmission tower is calculated according to the damage indexes between the layers, including:

[0138] Calculating the weight coefficients of the layers according to the interlayer damage index;

[0139] The overall damage index of the transmission tower is calculated by combining the weight coefficient and the interlayer damage index.

[0140] Preferably, the calculating the weight coefficient between each layer according to the interlayer damage index includes:

[0141] pass Calculate the weight coefficient of the i-th section; where SFD i is the interlaminar damage index of the ith interlayer.

[0142] Further, preferably, the combining the weight coefficient and the interlayer damage index to calculate the overall damage index of the transmission tower includes:

[0143] pass The overall damage index of the transmission tower is calculated; where β i is the weight coefficient of the i-th section, SFD i is the interlaminar damage index of the ith interlayer.

[0144] As a preferred implementation, the screening system for vulnerable transmission towers further includes a vulnerability probability calculation module; the vulnerability probability calculation module is used to:

[0145] Under the average wind speed obtained by meteorological monitoring, the screening results of vulnerable transmission towers under multiple simulations are obtained, and several overall damage indexes of the transmission towers are obtained;

[0146] Count the frequencies of the plurality of overall damage indices reaching the preset thresholds, and Calculate the probability of tower vulnerability at this wind speed; where, is the average wind speed; x is the average wind speed obtained by meteorological monitoring; AFD is the overall damage index; Z is the preset threshold.

[0147] It should be noted that, in the transmission line monitoring and early warning work, by adopting the vulnerability probability calculated by the embodiment of the present invention, it is possible to screen out the transmission line areas prone to failure from the transmission line, thereby providing a basis for the operation and maintenance of the transmission line.

[0148] A system for screening vulnerable transmission towers provided in an embodiment of the present invention is used. By establishing a finite element model of a transmission line, the transmission towers in the transmission line are layered and the damage index between the layers of the transmission towers is calculated. This can take into account the impact of the structural characteristics of the transmission line itself on the wind disaster situation, and then screen out vulnerable transmission towers based on the overall damage index, providing a basis for the operation and maintenance of the transmission line.

[0149] An embodiment of the present invention also provides a screening device for vulnerable transmission towers, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, a screening method for vulnerable transmission towers as described above is implemented. The working principles and beneficial effects of the two correspond one to one, and thus will not be described in detail.

[0150] The present invention may take the form of a computer program product implemented on one or more storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing program code. Computer-readable storage media include permanent and non-permanent, removable and non-removable media, and information storage can be achieved by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include but are not limited to: phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.

[0151] It should be understood that the embodiments of the present application are not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the embodiments of the present application is limited only by the appended claims.

[0152] The above-mentioned embodiments only express several implementation methods of the embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. 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 embodiments of the present application, and these all belong to the protection scope of the embodiments of the present application.

Claims

1. A method for screening vulnerable transmission towers, characterized in that: include: Obtain the time history data of the fluctuating wind load of the transmission line; Establishing a finite element model of the transmission line according to the pulsating wind load time history data; Performing time domain analysis on the finite element model, stratifying the transmission towers in the transmission line and calculating the damage index of each layer of the transmission towers to obtain an overall damage index of the transmission towers; A transmission tower whose overall damage index is greater than a preset threshold is determined as a vulnerable transmission tower.

2. A method for screening vulnerable transmission towers according to claim 1, characterized in that: The obtaining of the time history data of the fluctuating wind load of the transmission line comprises: Get the average wind speed time history of the transmission line; Use linear filtering method to simulate and calculate the fluctuating wind speed time history of transmission lines; The average wind speed time history and the pulsating wind speed time history are added together to obtain the overall wind speed time history. The pulsating wind load time history data of the transmission line is calculated based on the overall wind speed time history.

3. A method for screening vulnerable transmission towers as described in claim 1, characterized in that: The step of establishing a finite element model of a transmission line according to the pulsating wind load time history data comprises: Using finite element software and combining the transmission line structure design data, a finite element model of the transmission tower is established; According to the pulsating wind load time history data, the pulsating wind load time history data is loaded at different heights of the transmission tower finite element model to obtain a finite element model of the transmission line.

4. A method for screening vulnerable transmission towers according to claim 1, characterized in that: The time domain analysis of the finite element model is performed, the transmission towers in the transmission line are layered and the damage index between each layer of the transmission tower is calculated to obtain the overall damage index of the transmission tower, including: Performing time domain analysis on the finite element model to obtain stress and strain information of all rods of the transmission tower; According to the stress-strain information, the plastic strain information of the rod is obtained, and the damage degree of each rod is calculated; According to the location of each node of the main material of the transmission tower, the transmission tower is divided into several layers in the horizontal direction; Calculating the damage index between each layer of the transmission tower in the transmission line according to the damage degree of each rod; The overall damage index of the transmission tower is calculated based on the damage indexes between the layers.

5. A method for screening vulnerable transmission towers as claimed in claim 4, characterized in that: The step of obtaining the plastic strain information of the rod according to the stress-strain information and calculating the damage degree of each rod comprises: According to the stress-strain information, the maximum plastic strain and the ultimate plastic strain of the rod under the wind load time history are obtained; pass Calculate the damage degree of each member; where θ is the preset weight value; ε max is the maximum plastic strain of the member under the time history of wind load; ext is the ultimate plastic strain; ε i is the strain value that reaches plastic strain in the i-th cycle; 0≤i≤d, d is the total number of cycles.

6. A method for screening vulnerable transmission towers as claimed in claim 4, characterized in that: The calculating the damage index between each layer of the transmission tower in the transmission line according to the damage degree of each rod comprises: pass Calculate the interlaminar damage index of the i-th section; Where n is the total number of internode components in the i-th segment; D j is the damage degree of the jth member in the ith interval; w j is the weight coefficient of the j-th member in the ith interval.

7. A method for screening vulnerable transmission towers as claimed in claim 4, characterized in that: The overall damage index of the transmission tower is calculated based on the damage indexes between the layers, including: Calculating the weight coefficients of the layers according to the interlayer damage index; The overall damage index of the transmission tower is calculated by combining the weight coefficient and the interlayer damage index.

8. A screening system for vulnerable transmission towers, characterized in that: include: A time history data acquisition module is used to acquire the time history data of the pulsating wind load of the transmission line; A finite element model building module, used to build a finite element model of the transmission line according to the pulsating wind load time history data; An overall damage index calculation module is used to perform time domain analysis on the finite element model, layer the transmission towers in the transmission line and calculate the damage index between each layer of the transmission tower to obtain the overall damage index of the transmission tower; The vulnerable transmission tower determination module is used to determine the transmission tower whose overall damage index is greater than a preset threshold as a vulnerable transmission tower.

9. A screening system for vulnerable transmission towers as claimed in claim 8, characterized in that: The overall damage index calculation module is specifically used for: Performing time domain analysis on the finite element model to obtain stress and strain information of all rods of the transmission tower; According to the stress-strain information, the plastic strain information of the rod is obtained, and the damage degree of each rod is calculated; According to the location of each node of the main material of the transmission tower, the transmission tower is divided into several layers in the horizontal direction; Calculating the damage index between each layer of the transmission tower in the transmission line according to the damage degree of each rod; The overall damage index of the transmission tower is calculated based on the damage indexes between the layers.

10. A screening device for vulnerable transmission towers, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the method for screening vulnerable transmission towers according to any one of claims 1 to 7 is implemented.

Images