Power transmission line tower structure safety assessment method and system based on measured data

Abstract

The invention relates to the field of disaster prevention and reduction of electric power engineering, in particular to a power transmission line tower structure safety assessment method and system based on measured data. The method comprises the following steps of: obtaining measurement data of differential settlement, foundation inclination, tower body inclination and suspension insulator string deflection of a running power transmission line tower structure foundation; solving a component stress ratio according to a rigidity balance equation, and establishing a skewness calculation model of the suspension insulator string; obtaining evaluation results of deformation characteristics and stress safety of the tower structure; establishing a safety evaluation standard; and the safety evaluation of the transmission line tower structure is realized. According to the tower structure safety assessment method and system established by the invention, a plurality of deformation characteristics such as foundation settlement, tower body inclination and suspension insulator chain deflection are fused, the stress safety of the tower structure is considered, and the assessment result provides a scientific basis for determining the operation and maintenance management priority. According to the method, the current standard blank is filled, and the refinement level of power transmission line safety management is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of disaster prevention and reduction in power engineering, and particularly to a method and system for evaluating the structural safety of transmission line towers based on measured data. Background Art

[0002] As a typical tall structure, a transmission line tower has the structural characteristics of a small base and a high tower body, and is extremely sensitive to foundation deformation. When uneven settlement occurs in the foundation, the center of gravity of the tower shifts, and additional bending moments are likely to be generated under the action of its own weight and wire tension, resulting in tower body deformation, component instability, and even overall collapse. At the same time, the imbalance of wire tension on both sides of a straight tower will force the suspension insulator string to deflect, shortening its electrical distance from the tower, increasing the risk of flashover, and threatening the safe operation of the power grid. At present, although industry regulations have set limits for parameters such as tower inclination and insulator string deflection, there is still a lack of a systematic standard for on-site measured safety evaluation methods for operating lines, making it difficult to provide accurate basis for operation and maintenance decisions.

[0003] In the prior art, the safety assessment of transmission lines is mainly carried out through manual inspection or single-parameter monitoring, which has obvious deficiencies: First, the assessment dimension is single, only focusing on tower inclination or insulator deflection, without comprehensively considering the coupling effects of multiple factors such as foundation settlement, structural stress, and electrical performance; Second, there is a lack of collaborative analysis of global and local coordinate systems, making it difficult to quantify the mechanical effects of foundation deformation on the upper structure; Third, the standard adaptability is poor. Existing regulations do not clarify the basis for dividing different safety levels and cannot guide differential operation and maintenance.

[0004] At present, there is not enough research work on the evaluation of the structural safety level of transmission line towers, and there is no specific method for evaluating the structural safety of operating transmission line towers based on measured data. Summary of the Invention

[0005] Aiming at the defects in the prior art, the present invention provides a method and system for evaluating the structural safety of transmission line towers based on measured data.

[0006] In a first aspect, a method for safety assessment of the structure of a transmission line tower based on measured data provided by the present invention includes the following steps: obtaining measurement data of various deformation characteristics of the tower structure of an operating transmission line, including foundation differential settlement, foundation inclination, tower body inclination, and suspension insulator string deflection; based on the data, obtaining evaluation results of various deformation characteristics and force-bearing safety of the tower structure; according to the evaluation results, establishing a safety assessment standard; and through the safety assessment standard, realizing the safety assessment of the tower structure of the operating transmission line. The present invention integrates data on foundation differential settlement, foundation inclination, tower body inclination, and suspension insulator string deflection of the tower structure, realizes a comprehensive quantitative assessment of the tower structure state, and significantly improves the accuracy and reliability of the assessment data; by analyzing the evaluation results of various deformation characteristics and the calculation results of the structural stress ratio, breaks through the limitations of existing theoretical calculations, and can more accurately identify potential risk points of the tower structure; by establishing a multi-dimensional safety assessment standard, dynamically correlates key indicators such as foundation settlement, tower body inclination, and internal force of the structure, and forms a scientific and systematic tower health state evaluation system; by obtaining a variety of measured data, realizes multi-angle dynamic diagnosis of the safety of the tower structure; through a standardized assessment process, greatly reduces the error of human experience judgment, and improves the intelligent level of transmission line operation and maintenance management; by directly guiding operation and maintenance decisions with the safety assessment results, realizes a closed-loop management from data collection to risk control, and effectively prevents the occurrence of major accidents such as tower collapse and insulator fracture.

[0007] Optionally, the data acquisition of the differential settlement of the foundation, the foundation inclination, the tower body inclination, and the deflection of the suspension insulator string of the operating transmission line tower structure includes: selecting the measurement control points of the foundation elevation, the tower body inclination, and the deflection of the suspension insulator string of the operating transmission line tower structure; establishing a local coordinate system and a global coordinate system according to the measurement control points; acquiring the data of the differential settlement of the foundation and the foundation inclination according to the local coordinate system; acquiring the data of the tower body inclination according to the local coordinate system; acquiring the data of the deflection of the suspension insulator string according to the local coordinate system. By selecting the key measurement control points of the foundation elevation, the tower body inclination, and the deflection of the suspension insulator string, the present invention realizes the precise monitoring of the key parts of the tower structure, significantly improves the pertinence and effectiveness of data acquisition; by establishing a dual reference system of the local coordinate system and the global coordinate system, it improves the systematicness and coordination of data processing; by calculating the differential settlement and inclination of the foundation, it eliminates the interference of the external environment on the foundation deformation measurement, and enhances the accuracy of the foundation stability assessment; by acquiring the tower body inclination in the local coordinate system, it realizes the independent analysis of the deformation of the main body of the tower, and more accurately reflects the safety state of the tower body structure; by using the local coordinate system to acquire the deflection of the suspension insulator string, it uniformly evaluates the spatial offset of the insulator string, effectively avoiding the perspective error caused by the global coordinate system; by synergistically applying the local coordinate system and the global coordinate system, it realizes the spatial association of the data of the foundation, the tower body, and the suspension insulator string, forming a three-dimensional evaluation system for the overall safety state of the tower structure; by standardizing the setting of the measurement control points and the coordinate system, it ensures the consistency and comparability of the measurement data of different towers, and improves the continuity and engineering application value of the long-term monitoring data.

[0008] Optionally, the acquisition of the data of the differential settlement of the foundation and the foundation inclination according to the local coordinate system includes: acquiring the elevation of the measurement control point according to the local coordinate system; acquiring the data of the differential settlement of the foundation based on the elevation of the measurement control point; acquiring the data of the foundation inclination based on the elevation of the measurement control point. By acquiring the elevation of the measurement control point, the present invention realizes the precise positioning and acquisition of the elevation data of the tower foundation, effectively avoiding the distortion of the elevation data caused by the ranging error under the global coordinate system; by calculating the differential settlement of the foundation using the elevation of the measurement control point, it converts the elevation change at different time points into settlement amount data, realizing the quantitative evaluation of the uneven settlement of the tower foundation; by calculating the foundation inclination using the elevation of the measurement control point, it improves the accuracy of the determination of the foundation inclination state; by uniformly processing the elevation data in the local coordinate system, it eliminates the calculation error caused by the external coordinate conversion, ensuring the reliability and consistency of the foundation deformation data; by synchronously calculating the differential settlement and inclination of the foundation, it realizes the double verification of the stability of the tower foundation, and enhances the comprehensiveness and scientificity of the foundation safety assessment.

[0009] Optionally, the step of obtaining the foundation inclination data based on the elevation of the measurement control points includes: establishing a foundation inclination model based on the elevation of the measurement control points, and the foundation inclination model satisfies the following expression: , where, and are the inclinations of the foundation along the direction and direction of the local coordinate system respectively, , , , are the measured elevation values of four measurement control points, , are the spans of the foundation along the direction and direction of the local coordinate system respectively; the foundation inclination data is obtained through the foundation inclination model. By establishing a foundation inclination model, the present invention converts discrete elevation data into accurate inclination indicators, realizing the scientific quantitative characterization of the inclination state of the tower foundation; by adopting a two-way independent calculation mode, the inclination degrees of the foundation along two orthogonal directions are respectively evaluated, breaking through the limitation that the existing measurement methods are difficult to reflect the overall inclination characteristics; by introducing span parameters, the influence of different tower sizes on the inclination calculation is eliminated, making the evaluation data comparable across projects; by using the elevation difference averaging algorithm, the interference of individual measurement point errors on the overall result is effectively suppressed, significantly improving the anti-interference ability and reliability of the inclination calculation.

[0010] Optionally, the step of obtaining the tower body inclination data according to the local coordinate system includes: establishing a tower body inclination model according to the local coordinate system, and the tower body inclination model satisfies the following expression: , where, and are the tower body inclinations along the direction and direction of the local coordinate system respectively, , are respectively the center points of the th tower structure component relative to the center point of the foundation along the direction and The offset in the direction; through the tower inclination model, the data of the tower inclination is obtained. By establishing the tower inclination model, the present invention realizes the accurate calculation of the offset of the center point of the pole tower structural component, significantly improving the accuracy and reliability of the tower deformation detection; by adopting a two-way independent calculation mode, the inclination degrees of the tower along two orthogonal directions are respectively evaluated, overcoming the defect that the existing measurement methods cannot comprehensively reflect the inclination characteristics of the tower; by calculating the offsets of the center points of multiple components, the overall inclination of the tower is comprehensively grasped, realizing the refined evaluation of the safety state of the pole tower structure.

[0011] Optionally, the obtaining the data of the suspension insulator string skewness according to the local coordinate system includes: obtaining the suspension insulator string vector in the global coordinate system; establishing a calculation model of the suspension insulator string vector in the local coordinate system according to the conversion relationship between the global coordinate system and the local coordinate system; establishing a calculation model of the skewness angle of the suspension insulator string in the line direction based on the calculation model of the suspension insulator string vector in the local coordinate system; establishing a calculation model of the skewness value of the suspension insulator string in the line direction based on the calculation model of the skewness angle of the suspension insulator string in the line direction; obtaining the skewness angle of the suspension insulator string in the line direction in the local coordinate system through the calculation model of the skewness angle of the suspension insulator string in the line direction; obtaining the skewness value of the suspension insulator string in the line direction in the local coordinate system through the calculation model of the skewness value of the suspension insulator string in the line direction; obtaining the data of the suspension insulator string skewness through the skewness angle and skewness value of the suspension insulator string in the line direction in the local coordinate system. By obtaining the suspension insulator string vector in the global coordinate system, the present invention realizes the accurate mathematical characterization of the spatial skewness of the insulator, breaking through the limitation that the traditional two-dimensional observation cannot reflect the three-dimensional skewness state; by constructing the conversion relationship between the local coordinate system and the global coordinate system, the complex spatial vector is transformed into local parameters that can be quantitatively analyzed, significantly improving the engineering applicability of the insulator skewness detection; by establishing a calculation model of the suspension insulator string vector in the local coordinate system, the accurate calculation of the spatial position of the insulator string is realized, eliminating the problem of cumulative measurement error caused by a single coordinate system; by developing a calculation model of the skewness angle in the line direction, the spatial vector is transformed into an intuitive angle parameter, realizing the scientific quantitative evaluation of the skewness degree of the insulator; by establishing a calculation model of the skewness value, a dual evaluation system of angle and displacement is formed, enhancing the comprehensiveness and reliability of the insulator state diagnosis; by synergistically analyzing the skewness angle and skewness value in the local coordinate system, the spatial offset characteristics of the insulator string are accurately reflected, providing key data support for the safe operation of the line.

[0012] Optionally, the calculation model of the suspension insulator string vector satisfies the following relational expression:

[0013] Wherein, is the vector of the suspension insulator string in the local coordinate system, is the rotation angle between the local coordinate system and the global coordinate system, 、 、 are the spatial coordinates of the vector of the suspension insulator string in the global coordinate system; the calculation model of the deflection angle of the suspension insulator string in the line direction satisfies the following expression:

[0014] where, is the rotation angle between the local coordinate system and the global coordinate system, 、 、 are the spatial coordinates of the vector of the suspension insulator string in the global coordinate system, 、 、 are the spatial coordinates of the unit vector in the direction of the large tower in the line direction in the local coordinate system, is the deflection angle of the suspension insulator string in the line direction in the local coordinate system, satisfying the following conditions: when , the deflection direction of the suspension insulator string in the local coordinate system is towards the small tower direction; when , the deflection direction of the suspension insulator string in the local coordinate system is towards the large tower direction; when , the deflection angle of the deflection direction of the suspension insulator string in the local coordinate system is 0; the calculation model of the deflection value of the suspension insulator string in the line direction satisfies the following relational expression:

[0015] where, is the deflection value of the suspension insulator string in the line direction in the local coordinate system, 、 、 are the spatial coordinates of the unit vector in the direction of the large tower in the line direction in the local coordinate system, 、 、 are the spatial coordinates of the vector of the suspension insulator string in the global coordinate system, is the rotation angle between the local coordinate system and the global coordinate system. By establishing a calculation model for the vector of the suspension insulator string based on coordinate rotation transformation, the present invention realizes the accurate mapping of spatial vectors in the global and local coordinate systems, significantly improving the accuracy of the description of the spatial skew degree of the insulator; by introducing the rotation angle, the complex spatial coordinate transformation is simplified into a computable mathematical relationship, enhancing the applicability of the model under different line alignment conditions; by establishing a skew angle calculation model, the three-dimensional spatial vector is transformed into an intuitive skew angle, realizing the accurate discrimination of the skew direction of the insulator. By setting the positive and negative discrimination conditions for the skew angle, a direct correspondence between the skew direction and the angle value is established, making the judgment of the skew state of the insulator have a clear physical meaning; by constructing a skew value calculation model, the quantitative evaluation of the spatial offset of the insulator is realized, providing accurate data support for the grading of the skew degree; by integrating the global coordinate system to participate in the parameters of the local coordinate system, the limitation of single coordinate system analysis is overcome, and a more comprehensive insulator state evaluation system is formed.

[0016] Optionally, obtaining the evaluation result of the mechanical safety of the tower structure based on the data includes: based on the data, establishing a tower structure balance equation, and the form of the tower structure balance equation is as follows:

[0017] Wherein, , , , are stiffness matrix parameters, is the unknown nodal displacement, is the known tower foot nodal displacement, is the known nodal load, is the unknown nodal force corresponding to the tower foot node. According to the balance equation of the tower structure and in combination with the magnitude of the differential settlement of the tower foundation, the determination results of the unknown nodal displacement and the unknown nodal force are obtained; according to the known nodal displacement and the determined unknown nodal displacement, the internal force of the components of the tower structure is solved; according to the internal force of the components, the stress ratios of each component are solved; based on the stress ratios of each component, an evaluation method for the force-bearing safety of the components of the tower structure is determined, and the evaluation method includes: if the stress ratios of the components of the tower structure are all not greater than 1, the components of the tower structure are safe in force-bearing; if there are components of the tower with a stress ratio greater than 1, the components of the tower structure are unsafe in force-bearing; according to the evaluation method, the evaluation result of the force-bearing safety of the components of the tower structure is obtained. By establishing the balance equation of the tower structure, the present invention systematically correlates the stiffness parameters, nodal displacements and loads, realizing the accurate mathematical characterization of the force-bearing state of the tower; by dividing the solution strategies of known displacements and unknown displacements and combining the differential settlement data of the foundation to invert the structural response, the present invention breaks through the limitation that the existing methods are difficult to reflect the influence of foundation deformation; by constructing the stiffness matrix and comprehensively considering the mechanical interaction of each component of the tower, the accuracy of structural analysis is significantly improved; by solving and calculating the unknown nodal force, the accurate evaluation of the tower foot reaction force is realized, providing key data for the checking of the bearing capacity of the foundation; by setting the safety criterion of the stress ratio and establishing a clear force-bearing safety standard, the structural strength evaluation has engineering operability.

[0018] Optionally, establishing a safety assessment standard according to the evaluation result includes: determining safety assessment content according to the evaluation result; determining a safety assessment level according to the safety assessment content; establishing a safety assessment standard through the safety assessment content and the safety assessment level. By determining the safety assessment content, the present invention realizes the full-dimensional coverage of the state of the tower structure; by establishing the mapping relationship between the assessment content and the safety level, the complex technical parameters are converted into intuitive risk levels, greatly improving the engineering readability and practicability of the assessment result; by standardizing the definition method of the assessment level, the risk judgment scales of different tower types are unified, realizing the horizontal comparability of towers across regions and voltage levels.

[0019] In a second aspect, a transmission line tower structure safety assessment system based on measured data provided by the present invention includes an input device, a processor, an output device, and a memory. The input device, the processor, the output device, and the memory are interconnected. Among them, the memory is used to store a computer program, the computer program includes program instructions, the processor is configured to call the program instructions, and the system uses the above-mentioned transmission line tower structure safety assessment method based on measured data. The system provided by the present invention has a high degree of integration, and the information transmission between components is smooth. By using measured data, a comprehensive assessment system for tower foundation settlement, tower body inclination, and insulator deflection is constructed, realizing a three-dimensional safety perception of the transmission line state from local to overall; by developing an algorithm for solving the tower structure stiffness balance equation, the coupled analysis of foundation deformation and upper structure response is realized, significantly improving the accuracy of the tower force state assessment; by constructing the conversion relationship between the local coordinate system and the global coordinate system, complex spatial vectors are transformed into local parameters that can be quantitatively analyzed, significantly improving the engineering applicability of insulator deflection detection; by designing the association rules between the stress ratio criterion and multi-level safety standards, complex mechanical analysis is transformed into an intuitive risk level, forming a scientific and complete tower safety assessment standard system; by establishing an intelligent matching mechanism between the assessment results and the operation and maintenance strategies, a closed-loop management system for monitoring, assessment, and disposal is formed, promoting the transmission line operation and maintenance into a new stage of intelligence. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flowchart of the transmission line tower structure safety assessment method based on measured data according to an embodiment of the present invention; Figure 2 It is a schematic plan view of the elevation measurement control points of the tower foundation according to an embodiment of the present invention; Figure 3 It is a schematic plan view of the measurement control points of the tower body according to an embodiment of the present invention; Figure 4 It is a simplified diagram of the spatial form analysis of the suspension insulator string according to an embodiment of the present invention; Figure 5 It is a schematic structural diagram of the transmission line tower structure safety assessment system based on measured data according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] Specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described here are only for illustrative purposes and are not intended to limit the present invention. In the following description, in order to provide a thorough understanding of the present invention, a large number of specific details are set forth. However, it will be apparent to those of ordinary skill in the art that: the present invention does not have to be practiced with these specific details. In other instances, well-known circuits, software, or methods have not been described in detail to avoid obscuring the present invention.

[0022] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or subcombination. In addition, it should be understood by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale.

[0023] See also Figure 1 The embodiment of the present invention provides a method for safety assessment of a transmission line tower structure based on measured data, the method comprising the following steps: S1. Obtain data on the foundation differential settlement, foundation inclination, tower inclination and suspension insulator string deflection of the tower structure in the operating transmission line.

[0024] In one embodiment, firstly, measurement control points of the foundation elevation, tower inclination and suspension insulator string deflection of the operating transmission line tower structure are selected.

[0025] Specifically, there are a total of 4 measurement control points for the tower foundation elevation, and each control point is selected at the outer point of the tower leg close to the top surface of the concrete foundation; there are a total of 16 measurement control points for the tower body inclination, and 4 measurement control points are selected on the lower cross-arm conductor suspension layer, the middle cross-arm conductor suspension layer, the upper cross-arm conductor suspension layer and the ground wire suspension layer respectively; there are a total of 2 measurement control points for the deflection of a single suspension insulator string, the upper control point is the insulator string suspension point, and the lower control point is the center of the suspension wire clamp.

[0026] Furthermore, the four basic elevation measurement control points of the tower are projected on a plane, such as Figure 2 As shown in the corner points, Figure 2 The direction of the large black arrow points to the direction of the large tower. Along the direction of the large tower, the lower left corner point is numbered as JC1, and the other three corner points are numbered as JC2, JC3, and JC4 in a clockwise direction.

[0027] Furthermore, in order to facilitate the analysis of the measurement data, Figure 2 Establish the local coordinate system of the tower , the local coordinate system axis, The axis directions are parallel to the two centerline directions of the tower foundation. The local coordinate system is named as the first local coordinate system.

[0028] Further, the elevations of the four corner points are obtained by using the basic elevation measurement control points.

[0029] Further, the basic differential settlement is calculated to obtain the data of the basic differential settlement. The basic differential settlement is the elevation difference between the basic elevation measurement control points, including the elevation differences between corner points JC1 and JC2, JC2 and JC3, JC3 and JC4, JC4 and JC1, JC1 and JC3, and JC2 and JC4. Therefore, there are multiple groups of basic differential settlement values. Among them, the calculation of the basic differential settlement between corner points JC1 and JC2 is as follows:

[0030] Wherein, is the basic differential settlement of the measurement control points JC1 and JC2, unit: , and are the measured elevations of the measurement control points JC1 and JC2 respectively, unit: .

[0031] Further, according to the first local coordinate system, a basic inclination model is established, and the basic inclination model satisfies the following expression:

[0032] Wherein, and are the inclinations of the foundation along the direction and the direction of the local coordinate system respectively, , , , are the measured elevation values of the four measurement control points, unit: , and are the spans of the foundation along the direction and the direction of the local coordinate system respectively, unit: . The inclination is positive when it tends to the positive direction of the corresponding local coordinate axis.

[0033] Further, the data of the basic inclination is obtained by using the basic inclination model.

[0034] Further, taking the angle steel tower of a certain 220 kV double-circuit line on the same tower as an example, the tower body measurement control points of the tower are projected on the basis of the basic elevation measurement control points of Figure 2 , and then a plane projection is carried out, as shown by the corner points other than the basic elevation measurement control points in Figure 3 , Figure 3HDX1 to HDX4, HDS1 to HDS4, HDZ1 to HDZ4, and DX1 to DX4 are the measurement control points for the lower cross-arm, middle cross-arm, upper cross-arm, and ground wire suspension layer respectively, and JC1 to JC4 are the measurement control points for the foundation elevation.

[0035] Further, according to the local coordinate system, a tower inclination model is established, and the tower inclination model satisfies the following expression:

[0036] Where, 、 are the tower inclinations along the directions of the local coordinate system and respectively, 、 are the offsets of the center point of the th type of tower structure component relative to the center point of the foundation along the directions of the local coordinate system and respectively, with the unit: ; is the height of the center point of the th type of tower structure component, with the unit: ; When , the tower structure component is the lower cross-arm; When , the tower structure component is the middle cross-arm; When , the tower structure component is the upper cross-arm; When , the tower structure component is the ground wire suspension layer.

[0037] It should be noted that the center point of the tower structure component is the diagonal intersection point of the measurement control points of the tower structure component, and the center point of the foundation is the diagonal intersection point of the measurement control points of the foundation elevation.

[0038] Further, through the tower inclination model, the data of the tower inclination is obtained.

[0039] Further, based on the spatial coordinates of the upper and lower two control points of a single suspension insulator string, the deflection angle and deflection value of the suspension insulator string in the line direction are obtained.

[0040] Specifically, please refer to Figure 4 , Figure 4 is a simplified diagram for the spatial form analysis of the suspension insulator string. Figure 4 In 、 are the deflection angle and deflection value of the suspension insulator string perpendicular to the line direction respectively, is the local coordinate system of the pole tower, is the global coordinate system, also known as the measurement coordinate system, 、 、 、 are the corner points taken in the global coordinate system, 、 、 、 are the corner points taken in the local coordinate system, Point and Points are the upper and lower control points of the suspension insulator string in the global coordinate system. According to the Point and The spatial coordinates of the points are used to obtain the vector of the suspension insulator string , is the rotation angle corresponding to the local coordinate system obtained by rotating the global coordinate system counterclockwise around the positive direction of the axis, is Point and The length between the points, is The corresponding point of the point after rotation in the local coordinate system, is located on the axis, such that is perpendicular to the axis, 、 are the deflection angle and deflection value of the suspension insulator string in the line direction respectively, is Point and The distance between the points, is the unit vector in the direction of the large tower in the line direction in the local system, denoted as , 、 、 are constants, Figure 4 In, 。

[0041] Furthermore, through the vector of the suspension insulator string and the local coordinate system, a calculation model of the vector of the suspension insulator string in the local coordinate system is established. The calculation model of the vector of the suspension insulator string satisfies the following relationship:

[0042] Wherein, is the vector of the suspension insulator string in the local coordinate system, is the rotation angle between the local coordinate system and the global coordinate system, 、 、 are the spatial coordinates of the vector of the suspension insulator string in the global coordinate system.

[0043] Further, based on the suspension insulator string vector calculation model, a calculation model for the deflection angle of the suspension insulator string in the line direction is established. The calculation model for the deflection angle of the suspension insulator string in the line direction satisfies the following expression:

[0044] wherein, is the rotation angle between the local coordinate system and the global coordinate system, , , are the spatial coordinates of the suspension insulator string vector in the global coordinate system, , , are the spatial coordinates of the unit vector in the direction of the large tower in the line direction in the local coordinate system, is the deflection angle of the suspension insulator string in the line direction in the local coordinate system, and satisfies the following conditions: When , the deflection direction of the suspension insulator string in the local coordinate system is towards the small tower direction; When , the deflection direction of the suspension insulator string in the local coordinate system is towards the large tower direction; When , the deflection angle of the deflection direction of the suspension insulator string in the local coordinate system is 0.

[0045] Further, based on the deflection angle of the suspension insulator string in the line direction, a calculation model for the deflection value of the suspension insulator string in the line direction is established. The calculation model for the deflection value of the suspension insulator string in the line direction satisfies the following relational expression:

[0046] wherein, is the deflection value of the suspension insulator string in the line direction in the local coordinate system, , , are the spatial coordinates of the unit vector in the direction of the large tower in the line direction in the local coordinate system, , , are the spatial coordinates of the suspension insulator string vector in the global coordinate system, is the rotation angle between the local coordinate system and the global coordinate system.

[0047] Further, through the calculation model for the deflection value of the suspension insulator string in the line direction, the deflection value of the suspension insulator string in the line direction in the local coordinate system is obtained; Further, substitute the deflection angle and deflection value of the suspension insulator string in the local coordinate system in the line direction into the calculation expression of the deflection degree of the suspension insulator string to obtain the data of the deflection degree of the suspension insulator string. The calculation expression is as follows:

[0048] Wherein, represents the deflection degree of the suspension insulator string in the line direction, represents the deflection angle of the suspension insulator string in the line direction, represents the deflection value of the suspension insulator string in the line direction, represents the length of the suspension insulator string.

[0049] It should be noted that the greater the difference in wire tension on both sides of the tower, the greater the horizontal additional force borne by the tower structure, which is not conducive to the structural safety of the tower. The deflection degree of the suspension insulator string of the tower in the line direction can reflect the magnitude of the wire tension difference on both sides.

[0050] S2. Based on the above data, obtain the evaluation results of the deformation characteristics and force-bearing safety of the tower structure.

[0051] In one embodiment, input the measured differential settlement of the tower foundation as the tower foot displacement load into the tower structure calculation model, calculate the internal forces of the tower structure components according to the typical load combinations under different load conditions given by relevant specifications, and judge the section strength and stability of the components. The tower structure calculation model includes the tower structure balance equation.

[0052] Specifically, when the tower foot node displacement is known, establish the tower structure balance equation, and the form of the tower structure balance equation is as follows:

[0053] Wherein, , , , are stiffness matrix parameters, is the unknown node displacement, is the known tower foot node displacement, is the known node load, is the unknown node force corresponding to the tower foot node, referring to the internal force at the node, and the distribution intensity of the internal force in the local area of the node is the stress.

[0054] Further, when the differential settlement of the tower foundation is small, the geometric nonlinearity caused by the known displacement can be ignored, and it is considered that the overall stiffness matrix of the structure is a constant. After expanding the above formula, we can get:

[0055]

[0056] Furthermore, based on the above expansion, the displacements of the unknown nodes are obtained. and the forces at the tower foot nodes .

[0057] Furthermore, when the differential settlement of the tower foundation is large, the geometric nonlinearity caused by the displacement of the tower foot needs to be considered, and the overall stiffness matrix and node displacements of the structure need to be further determined through iterative calculations.

[0058] For each structural element, based on the element node displacements (already solved) and the element stiffness , the element node forces can be solved, as shown in the following equation:

[0059] Based on the internal forces of the components obtained from the calculation, combined with the component cross-sections and material properties, the stress ratios of the structural components can be obtained according to the relevant specifications. The evaluation results of the mechanical safety of the tower structure include: If the structural calculation results show that the stress ratios of all components of the tower are not greater than 1, it indicates that there is a certain redundancy in the strength and stability of the tower structural components and it is relatively safe; If there are components with stress ratios greater than 1, it indicates that the cross-sectional strength or stability redundancy of these components does not meet the requirements of the relevant specifications.

[0060] Furthermore, for the evaluation of the differential settlement of the tower foundation.

[0061] Specifically, the differential settlement of the tower foundation is obtained through on-site measurement. Considering the measurement error and the influence of construction error during line construction, the maximum differential settlement of the foundation obtained from the measurement is divided into three grades: When , the differential settlement of the foundation is large, which is the high-level grade; When , the differential settlement of the foundation is relatively large, which is the medium-level grade; When , the differential settlement of the foundation is small, which is the low-level grade.

[0062] Furthermore, for the evaluation of the tower inclination.

[0063] Specifically, the "Operation Regulations for Overhead Transmission Lines" (DL / T 741-2019) (hereinafter referred to as the "Operation Regulations") stipulate the basic requirements and technical (operation) standards for the operation of overhead transmission lines. For example, the maximum allowable value of the inclination (including deflection) of steel towers with a height angle below 50m is 1.0%; according to the "Operation Regulations", the inclination of the pole tower is evaluated, and the evaluation is divided into two types: "meeting the operation regulations" and "not meeting the operation regulations".

[0064] Furthermore, for the evaluation of the relationship between the foundation inclination direction and the pole tower inclination direction.

[0065] Specifically, when the foundation inclination direction and the pole tower inclination direction are basically the same, it indicates that the correlation between the pole tower inclination and the foundation inclination is relatively high, and the calculation result obtained by inputting the tower foot displacement as a load into the pole tower structure calculation model can more truly reflect the current safety status of the operating pole tower structure; evaluate the relationship between the foundation differential settlement and the foundation safety for the foundation inclination direction and the pole tower inclination direction, and the evaluation is divided into two types: "basically the same" and "not the same".

[0066] Furthermore, for the evaluation of the calculation results of the internal forces of the pole tower structure.

[0067] Specifically, the member stress ratio can reflect the section strength and stability redundancy of the member. For members with a stress ratio greater than 1, the section strength or stability redundancy does not meet the requirements of relevant specifications. According to the number of members with excessive stress ratios, the evaluation of the calculation results of the internal forces of the pole tower structure is divided into three types: "many members with excessive stress ratios" (no less than 10 groups of members with excessive stress ratios), "few members with excessive stress ratios" (less than 10 groups and more than 1 group of members with excessive stress ratios), and "no members with excessive stress ratios".

[0068] Furthermore, for the evaluation of the inclination of the suspension insulator string.

[0069] Specifically, for straight-line pole towers, the tension difference between the two sides of the conductor is unfavorable to the force on the pole tower structure and the insulator string. Therefore, the evaluation of the inclination of the suspension insulator string is added. The inclination of the suspension insulator string includes the inclination angle and the inclination value. Article 5.3.10 of the "Operation Regulations for Overhead Transmission Lines" (DL / T 741-2019) stipulates that the inclination angle of the insulator string of a straight-line pole tower in the line direction (except for the pre-inclination required by the design) should not be greater than 7.5 degrees, or the maximum offset should not be greater than 300mm. Evaluate the inclination of the suspension insulator string of a straight-line pole tower according to the "Operation Regulations", and the evaluation is divided into two types: "meeting the operation regulations" and "not meeting the operation regulations".

[0070] S3. According to the evaluation results, establish a safety assessment standard.

[0071] In one embodiment, according to the evaluation results, a set of safety assessment criteria for the operating transmission line tower structure, also known as the tower grading criteria, are established as follows: Grade I tower: A tower with a large differential settlement of the foundation, the tower inclination not meeting the requirements of the "Operating Regulations", the foundation inclination direction being close to the tower inclination direction, and many members with stress ratio exceeding the limit; Grade II tower: A tower with a relatively large differential settlement of the foundation, the tower inclination not meeting the requirements of the "Operating Regulations", and the foundation inclination direction being close to the tower inclination direction; or a straight tower with a tower body inclination not meeting the requirements of the "Operating Regulations" and a suspension insulator string with a deflection not meeting the requirements of the "Operating Regulations", and not belonging to Grade I tower; Grade III tower: Except for Grade I and Grade II, a tower with a tower inclination not meeting the requirements of the "Operating Regulations"; or a tower with a relatively large differential settlement of the foundation, many members with stress ratio exceeding the limit, and the foundation inclination direction being close to the tower inclination direction; Grade IV tower: A tower other than Grade I, Grade II, and Grade III towers.

[0072] Furthermore, the treatment methods for different grade towers are as follows: For towers with a safety grade of Grade I, promptly entrust an agency with corresponding qualifications to conduct technical treatment on them, such as strengthening the foundation and then jacking and leveling; For the tower structures with a safety grade of Grade II and Grade III, monitor their deformations during use and conduct technical treatment when necessary; For the tower structures with a safety grade of Grade IV, no measures need to be taken temporarily, and strengthen the observation during the operation of the transmission line.

[0073] S4. Through the safety assessment criteria, the safety assessment of the operating transmission line tower structure is realized.

[0074] In one embodiment, in combination with the safety assessment criteria in step S3, the safety grade of the operating transmission line tower structure is determined step by step, thereby realizing the safety assessment of the operating transmission line tower structure.

[0075] Please refer to Figure 5 , Figure 5 , which is a schematic structural diagram of a safety assessment system for a transmission line tower structure based on measured data in an embodiment of the present invention. The system includes an input device, a processor, an output device, and a memory. The input device, the processor, the output device, and the memory are interconnected. Among them, the memory is used to store computer programs, the computer programs include program instructions, the processor is configured to call the program instructions, and the system uses the above-mentioned safety assessment method for a transmission line tower structure based on measured data.

[0076] In this embodiment, the input device includes a data acquisition device and a user input device.

[0077] Specifically, the data acquisition device is used to collect data on the elevation of the tower foundation in real time; the user input device is used to input relevant data on the tower structure. The input device obtains data on tower foundation settlement, tower body inclination, and insulator skew in real time, converts the data into a standardized format in the global / local coordinate system, and transmits it to the processor for safety analysis.

[0078] Furthermore, the processor includes a data preprocessing module, a mechanical calculation module, and a safety assessment module.

[0079] Specifically, the data preprocessing module is used for coordinate transformation and data filtering; the mechanical calculation module is used for solving the stiffness matrix equilibrium equation and calculating the stress ratio; the safety assessment module performs risk grading based on safety assessment criteria. The processor calculates the foundation inclination, tower body deformation, and insulator skew based on the local / global coordinate system; solves the tower structure equilibrium equation, analyzes the force safety and deformation characteristics; and combines the assessment criteria to output the tower safety level.

[0080] Furthermore, the output device includes a visual monitoring large screen, an early warning terminal, and a report generation module.

[0081] Specifically, the visual monitoring large screen is used to display the three-dimensional tower model and deformation animation; the early warning terminal is used for audible and visual alarms of safety risks; the report generation module is used to generate a safety assessment report. The output device intuitively displays the tower deformation, force state, and safety level; automatically triggers an early warning for high-risk towers and pushes it to the operation and maintenance personnel; generates a detailed assessment report to support comparative analysis of historical data.

[0082] Furthermore, the memory uses a high-speed solid-state drive, which has the characteristics of fast read and write speed, large capacity, and high reliability. It is mainly used to store the data input by the input device and the result data processed by the processor, and can meet the storage requirements of large amounts of data.

[0083] In summary, the present invention establishes an all-round assessment system by integrating data on foundation settlement, tower body inclination, insulator skew, and structural stress ratio; combines the stiffness matrix equilibrium equation with the skew angle calculation model to quantify the correlation between deformation and force, and accurately identifies risks; matches the safety level according to the measured data, facilitating relevant parties to understand the urgency of the event, and can be used as a basis for the owner unit to determine the technical processing priority of the event. This method fills the current standard gap and significantly improves the refinement level of transmission line safety management.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention, and they should all be covered by the scope of the claims and the description of the present invention.

Claims

1. A transmission line tower structure safety assessment method based on measured data, characterized in that: The method comprises the following steps: Obtain data on the differential settlement of the tower structure foundation, foundation inclination, tower body inclination and suspension insulator string deflection of the operating transmission line; Based on the data, obtaining evaluation results of deformation characteristics and stress safety of the tower structure; Establishing safety assessment standards based on the evaluation results; Through the safety assessment standard, the safety assessment of the tower structure of the transmission line in operation is achieved.

2. A transmission line tower structure safety assessment method based on measured data according to claim 1, characterized in that: The data of obtaining the foundation differential settlement, foundation inclination, tower body inclination and suspension insulator string deflection of the tower structure in the operating transmission line includes: Select the measurement control points of the foundation elevation, tower inclination and suspension insulator string deflection of the operating transmission line tower structure; Establishing a local coordinate system according to the measurement control points; According to the local coordinate system, data of foundation differential settlement and foundation inclination are obtained; According to the local coordinate system, obtaining data on the inclination of the tower body; According to the local coordinate system, data on the skewness of the suspension insulator string is obtained.

3. A transmission line tower structure safety assessment method based on measured data according to claim 2, characterized in that: The step of obtaining data of foundation differential settlement and foundation inclination according to the local coordinate system includes: According to the local coordinate system, obtaining the elevation of the measurement control point; Based on the elevation of the measurement control point, obtaining data of foundation differential settlement; Based on the elevation of the measured control point, basic inclination data is obtained.

4. A transmission line tower structure safety assessment method based on measured data according to claim 3, characterized in that: The obtaining of the data of the basic inclination based on the elevation of the measurement control point comprises: Based on the elevation of the measured control point, a basic inclination model is established, and the basic inclination model satisfies the following expression: ， in, , The basis along the local coordinate system Direction and The tilt of the direction, , , , is the measured elevation value of the four survey control points, , The basis along the local coordinate system Direction and span of direction; The basic inclination data is obtained through the basic inclination model.

5. A transmission line tower structure safety assessment method based on measured data according to claim 2, characterized in that: The step of obtaining the tower body inclination data according to the local coordinate system includes: According to the local coordinate system, a tower body inclination model is established, and the tower body inclination model satisfies the following expression: ， in, , Along the local coordinate system Direction and The inclination of the tower in the direction , Respectively The center point of the tower structure component is relative to the center point of the foundation in the local coordinate system. Direction and Direction offset; The tower body inclination data is obtained through the tower body inclination model.

6. A transmission line tower structure safety assessment method based on measured data according to claim 2, characterized in that: The step of obtaining the data of the skewness of the suspension insulator string according to the local coordinate system comprises: Get the suspension insulator string vector in the global coordinate system; By using the suspension insulator string vector, a suspension insulator string vector calculation model in the local coordinate system is established; Based on the vector calculation model of suspension insulator string, a calculation model of the skew angle of suspension insulator string along the line direction is established; Based on the calculation model of the deflection angle of the suspension insulator string along the line direction, a calculation model of the deflection value of the suspension insulator string along the line direction is established; Obtaining the deflection angle of the suspension insulator string along the line direction in the local coordinate system through the calculation model of the deflection angle of the suspension insulator string along the line direction; Obtaining the deflection value of the suspension insulator string along the line direction in the local coordinate system through the calculation model of the deflection value of the suspension insulator string along the line direction; The data of the deflection degree of the suspension insulator string are obtained through the deflection angle and deflection value of the suspension insulator string in the line direction in the local coordinate system.

7. A transmission line tower structure safety assessment method based on measured data according to claim 6, characterized in that: The suspension insulator string vector calculation model satisfies the following relationship: ， in, is the suspension insulator string vector in the local coordinate system, is the rotation angle between the local coordinate system and the global coordinate system, , , is the spatial coordinate of the suspension insulator string vector in the global coordinate system; the calculation model of the suspension insulator string deflection angle along the line direction satisfies the following expression: ， in, is the rotation angle between the local coordinate system and the global coordinate system, , , is the spatial coordinate of the suspension insulator string vector in the global coordinate system, , , is the unit vector space coordinate in the direction of the large tower along the line in the local coordinate system, is the skew angle of the suspension insulator string along the line direction in the local coordinate system, satisfying the following conditions: when When , the deflection direction of the suspension insulator string in the local coordinate system is the direction of the small tower; when When , the deflection direction of the suspension insulator string in the local coordinate system is the direction of the large tower; when When , the deflection angle of the suspension insulator string in the deflection direction in the local coordinate system is 0; The calculation model of the deflection value of the suspension insulator string along the line direction satisfies the following relationship: ， in, is the deflection value of the suspension insulator string along the line direction in the local coordinate system, , , is the unit vector space coordinate in the direction of the large tower along the line in the local coordinate system, , , is the spatial coordinate of the suspension insulator string vector in the global coordinate system, is the rotation angle between the local coordinate system and the global coordinate system.

8. The method for safety assessment of transmission line tower structure based on measured data according to claim 1, characterized in that: The obtaining of the evaluation result of the stress safety of the tower structure based on the data includes: Based on the data, a pole tower structure equilibrium equation is established, and the pole tower structure equilibrium equation is in the following form: ， in, , , , is the stiffness matrix parameter, is the unknown node displacement, is the known tower foot node displacement, is the known node load, is the unknown nodal force corresponding to the tower foot node; According to the tower structure equilibrium equation and in combination with the magnitude of the tower foundation differential settlement, the determination results of the unknown node displacement and the unknown node force are obtained; According to the known node displacements and the determined unknown node displacements, the internal forces of the components of the tower structure are obtained by solving; According to the internal force of the component, the stress ratio of each component is solved; Based on the stress ratios of the components, an evaluation method for the stress safety of the tower structure components is determined, wherein the evaluation method includes: if the stress ratios of the tower structure components are not greater than 1, the tower structure components are stress safe; if the stress ratio of a component of the tower is greater than 1, the tower structure components are stress unsafe; According to the evaluation method, an evaluation result of the stress safety of the tower structure component is obtained.

9. A transmission line tower structure safety assessment method based on measured data according to claim 1, characterized in that: The establishment of safety assessment standards based on the evaluation results includes: Determine the content of the safety assessment based on the evaluation results; Determine the safety assessment level according to the safety assessment content; A security assessment standard is established based on the security assessment content and the security assessment level.

10. A transmission line tower structure safety assessment system based on measured data, the system using a transmission line tower structure safety assessment method based on measured data according to any one of claims 1 to 9, characterized in that: The system includes an input device, a processor, an output device and a memory, wherein the input device, the processor, the output device and the memory are connected to each other, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions.

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