Transmission line tower structure safety evaluation method and system based on measured data

Abstract

The present application relates to the field of power engineering disaster prevention and mitigation, and particularly relates to a power transmission line tower structure safety evaluation method and system based on measured data. The method comprises the following steps: obtaining the measurement data of foundation differential settlement, foundation inclination, tower body inclination and suspension insulator string deflection of the running power transmission line tower structure; solving the component stress ratio according to the stiffness balance equation, and establishing a suspension insulator string deflection calculation model; obtaining the evaluation results of the deformation characteristics and stress safety of the tower structure; establishing a safety evaluation standard; and realizing the safety evaluation of the power transmission line tower structure. The tower structure safety evaluation method and system established by the present application integrates the deformation characteristics of foundation settlement, tower body inclination and suspension insulator string deflection, considers the stress safety of the tower structure, and provides a scientific basis for determining the operation and maintenance priority. The method fills the gap in the existing standards and significantly improves the fine level of power transmission line safety management.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power engineering disaster prevention and mitigation, and particularly relates to a power transmission line tower structure safety evaluation method and system based on measured data. BACKGROUND

[0002] As a typical high-rise structure, the power transmission line tower has the structural characteristics of small base and high tower body, and is extremely sensitive to foundation deformation. When uneven settlement of the foundation occurs, the center of gravity of the tower deviates, and additional bending moment is easily generated under the action of self-weight and conductor tension, resulting in tower body deformation, component instability, and even overall collapse. At the same time, the unbalanced tension of the conductors on both sides of the straight tower will force the suspension insulator string to deviate, shorten the electrical distance between the insulator string and the tower, increase the flashover risk, and threaten the safe operation of the power grid. At present, although the industry regulations have set limits for the inclination of the tower and the inclination of the insulator string, there is still a lack of systematic standards for on-site safety evaluation methods for running lines, making it difficult to provide accurate basis for operation and maintenance decisions.

[0003] In the prior art, the safety evaluation of the power transmission line is mainly carried out by manual inspection or single parameter monitoring, which has obvious deficiencies: first, the evaluation dimension is single, only the tower body inclination or the insulator inclination is concerned, and the influence of the foundation settlement, structural stress and electrical performance multi-factor coupling is not considered comprehensively; second, there is a lack of coordinated analysis of global and local coordinate systems, and it is difficult to quantify the mechanical influence of foundation deformation on the superstructure; third, the standard adaptability is poor, and the existing regulations do not clearly specify the basis for dividing different safety levels, which cannot guide differentiated operation and maintenance.

[0004] At present, there are not enough researches on the safety level evaluation of the power transmission line tower structure, and there is no specific safety evaluation method for the running power transmission line tower structure based on measured data. SUMMARY

[0005] In view of the defects in the prior art, the present application provides a power transmission line tower structure safety evaluation method and system based on measured data.

[0006] In a first aspect, the present application provides a kind of transmission line tower structure safety evaluation method based on measured data, comprising the following steps: obtaining the deformation characteristic measurement data of the tower structure of running transmission line, including foundation differential settlement, foundation inclination, tower body inclination and suspension insulator string deflection;Based on the data, obtain the evaluation result of each deformation characteristic and stress safety of the tower structure;According to the evaluation result, establish safety evaluation standard;Through the safety evaluation standard, realize the safety evaluation of the tower structure of running transmission line.The present application integrates the data of tower structure foundation differential settlement, foundation inclination, tower body inclination and suspension insulator string deflection, realizes the comprehensive quantitative evaluation of tower structure state, significantly improves the accuracy and reliability of evaluation data;Through the analysis of each deformation characteristic evaluation result and structure stress ratio calculation result, break through the limitation of existing theoretical calculation, can more accurately identify the potential risk point of tower structure;Through the establishment of multidimensional safety evaluation standard, dynamically correlate the key indexes such as foundation settlement, tower body inclination and structure internal force, form a set of scientific and systematic tower health state evaluation system;Through obtaining a variety of measured data, realize the multi-angle dynamic diagnosis of tower structure safety;Through standardized evaluation process, the error of human experience judgment is greatly reduced, and the intelligent level of transmission line operation and maintenance management is improved;Through the safety evaluation result directly guiding operation and maintenance decision, realize the closed-loop management from data acquisition to risk control, effectively prevent the occurrence of tower collapse, insulator fracture major accident.

[0007] Optionally, the obtaining the data of the foundation differential settlement, the foundation inclination, the tower body inclination and the suspension insulator string deflection of the operating power transmission line tower structure comprises: selecting a measurement control point of the foundation elevation, the tower body inclination and the suspension insulator string deflection of the operating power transmission line tower structure; establishing a local coordinate system and a global coordinate system according to the measurement control point; obtaining the data of the foundation differential settlement and the foundation inclination according to the local coordinate system; obtaining the data of the tower body inclination according to the local coordinate system; and obtaining the data of the suspension insulator string deflection according to the local coordinate system. By selecting the key measurement control points of the foundation elevation, the tower body inclination and the suspension insulator string deflection, the application realizes accurate monitoring of the key parts of the tower structure, significantly improves the pertinence and effectiveness of data acquisition; by establishing the dual reference system of the local coordinate system and the global coordinate system, the systematization and coordination of data processing are improved; by calculating the foundation differential settlement and the inclination, the interference of the external environment on the foundation deformation measurement is eliminated, and the accuracy of the foundation stability evaluation is enhanced; by obtaining the tower body inclination in the local coordinate system, independent analysis of the tower body deformation is realized, and the safety state of the tower body structure is more accurately reflected; by obtaining the suspension insulator string deflection by using the local coordinate system, the spatial offset of the insulator string is uniformly evaluated, and the perspective error caused by the global coordinate system is effectively avoided; by the collaborative application of the local coordinate system and the global coordinate system, the spatial correlation of the foundation, the tower body and the suspension insulator string data is realized, and a stereoscopic evaluation system of the overall safety state of the tower structure is formed; by setting the standardized measurement control points and the coordinate system, the consistency and comparability of the measurement data of different towers are ensured, and the continuity and engineering application value of long-term monitoring data are improved.

[0008] Optionally, the obtaining the data of the foundation differential settlement and the foundation inclination according to the local coordinate system comprises: obtaining the elevation of the measurement control point according to the local coordinate system; obtaining the data of the foundation differential settlement based on the elevation of the measurement control point; and obtaining the data of the foundation inclination based on the elevation of the measurement control point. By obtaining the elevation of the measurement control point, the application realizes accurate positioning and acquisition of the tower foundation elevation data, effectively avoids the elevation data distortion problem caused by ranging error in the global coordinate system; by calculating the foundation differential settlement by using the elevation of the measurement control point, the elevation change at different time points is converted into settlement data, and quantitative evaluation of the uneven settlement of the tower foundation is realized; by calculating the foundation inclination by using the elevation of the measurement control point, the accuracy of the foundation inclination state determination is improved; by uniformly processing the elevation data in the local coordinate system, the calculation error caused by external coordinate conversion is eliminated, and the reliability and consistency of the foundation deformation data are ensured; by simultaneously calculating the foundation differential settlement and the inclination, double verification of the stability of the tower foundation is realized, and the comprehensiveness and scientificity of the foundation safety evaluation are enhanced.

[0009] Optionally, the obtaining of the data of the base inclination based on the measured control point elevations comprises: establishing a base inclination model based on the measured control point elevations, the base inclination model satisfying the following expression:

[0010] ,

[0011] wherein, 、 are respectively the inclinations of the base along the local coordinate system direction and direction, 、 、 、 are measured elevation values of the four control points, 、 are respectively the spans of the base along the local coordinate system direction and direction; and the data of the base inclination is obtained through the base inclination model. The present application converts discrete elevation data into accurate inclination indicators by establishing a base inclination model, thereby achieving scientific and quantitative characterization of the inclination state of the tower foundation; the two-way independent calculation mode is adopted to respectively evaluate the inclination of the base along two orthogonal directions, thereby breaking through the limitation of the existing measurement method that is difficult to reflect the overall inclination characteristics; the span parameter is introduced to eliminate the influence of size differences of different towers on the inclination calculation, so that the evaluation data has cross-project comparability; the elevation difference average algorithm effectively suppresses the interference of individual measurement point errors on the overall result, thereby significantly improving the anti-interference and reliability of the inclination calculation.

[0012] Optionally, the obtaining of the data of the tower body inclination based on the local coordinate system comprises: establishing a tower body inclination model based on the local coordinate system, the tower body inclination model satisfying the following expression:

[0013] ,

[0014] wherein, 、 are respectively the inclinations of the tower body along the local coordinate system direction and direction, 、 are respectively the distances of the center point of the first tower structure component from the center point of the base along the local coordinate system direction and The tower body inclination model is used to obtain data of the tower body inclination. The present application realizes the accurate calculation of the center point offset of the tower structure component by establishing the tower body inclination model, significantly improves the accuracy and reliability of the tower body deformation detection, evaluates the inclination degree of the tower body along two orthogonal directions by using the bidirectional independent calculation mode, overcomes the defects of the existing measurement methods that cannot comprehensively reflect the tower body inclination characteristics, comprehensively masters the overall inclination of the tower body by calculating the center point offset of multiple components, and realizes the fine evaluation of the safety state of the tower structure.

[0015] Optionally, the obtaining of the data of the inclination degree of the suspension insulator string according to the local coordinate system comprises: obtaining a suspension insulator string vector in a global coordinate system; establishing a suspension insulator string vector calculation model in the local coordinate system according to a conversion relationship between the global coordinate system and the local coordinate system; establishing a suspension insulator string line direction deflection angle calculation model based on the suspension insulator string vector calculation model; establishing a suspension insulator string line direction deflection value calculation model based on the suspension insulator string line direction deflection angle calculation model; obtaining a suspension insulator string line direction deflection angle in the local coordinate system through the suspension insulator string line direction deflection angle calculation model; obtaining a suspension insulator string line direction deflection value in the local coordinate system through the suspension insulator string line direction deflection value calculation model; and obtaining the data of the inclination degree of the suspension insulator string through the suspension insulator string line direction deflection angle and the deflection value in the local coordinate system. The present application realizes the accurate mathematical representation of the insulator space inclination degree by obtaining the suspension insulator string vector in the global coordinate system, breaks through the limitation of the traditional two-dimensional observation that cannot reflect the three-dimensional deflection state, converts the complex space vector into the local parameters that can be quantitatively analyzed by establishing the conversion relationship between the local coordinate system and the global coordinate system, significantly improves the engineering applicability of the insulator deflection detection, realizes the accurate calculation of the spatial position of the insulator string by establishing the suspension insulator string vector calculation model in the local coordinate system, eliminates the measurement error accumulation problem caused by a single coordinate system, converts the space vector into the intuitive angle parameter by developing the line direction deflection angle calculation model, realizes the scientific quantitative evaluation of the deflection degree of the insulator, forms the double evaluation system of the angle and the displacement by establishing the deflection value calculation model, and enhances the comprehensiveness and reliability of the insulator state diagnosis. The spatial deflection characteristics of the insulator string are accurately reflected by the cooperative analysis of the deflection angle and the deflection value in the local coordinate system, which provides key data support for the safe operation of the line.

[0016] Optionally, the suspension insulator string vector calculation model satisfies the following relationship:

[0017]

[0018] wherein, is a vector of the suspension insulator string in the local coordinate system, is a rotation angle of the local coordinate system and the global coordinate system, is a spatial coordinate of the vector of the suspension insulator string in the global coordinate system, and the inclination angle calculation model of the suspension insulator string in the line direction satisfies the following expression:

[0019]

[0020] wherein, is a rotation angle of the local coordinate system and the global coordinate system, is a spatial coordinate of the vector of the suspension insulator string in the global coordinate system, is a spatial coordinate of the unit vector in the line direction of the large tower in the local coordinate system, is an inclination angle of the suspension insulator string in the line direction in the local coordinate system, and satisfies the following conditions: when , the inclination direction of the suspension insulator string in the local coordinate system is a direction pointing to the small tower; when , the inclination direction of the suspension insulator string in the local coordinate system is a direction pointing to the large tower; when , the inclination angle of the inclination direction of the suspension insulator string in the local coordinate system is 0; and the inclination value calculation model of the suspension insulator string in the line direction satisfies the following relationship:

[0021]

[0022] wherein, is an inclination value of the suspension insulator string in the line direction in the local coordinate system, is a spatial coordinate of the unit vector in the line direction of the large tower in the local coordinate system, is a spatial coordinate of the vector of the suspension insulator string in the global coordinate system, ​​​​​​​​​​Rotation angles of the local coordinate system and the global coordinate system. The application realizes accurate mapping of space vectors in the global and local coordinate systems by establishing a vector calculation model of the suspension insulator string based on coordinate rotation conversion, significantly improves the accuracy of the description of the insulator space skewness, introduces rotation angles to simplify the complex space coordinate conversion into a calculable mathematical relationship, enhances the applicability of the model under different line directions, establishes a skew angle calculation model to convert the three-dimensional space vector into an intuitive skew angle, realizes accurate discrimination of the insulator skew direction, sets positive and negative discrimination conditions for the skew angle, establishes a direct correspondence between the skew direction and the angle value, makes the insulator skew state judgment have clear physical meaning, constructs a skew value calculation model to realize quantitative evaluation of the insulator space displacement, provides accurate data support for skew degree classification, and integrates the global coordinate system into the local coordinate system parameters to overcome the limitations of single coordinate system analysis, forming a more comprehensive insulator state evaluation system.

[0023] Optionally, the evaluation result of the tower structure stress safety is obtained based on the data, including: based on the data, a tower structure balance equation is established, and the tower structure balance equation is in the following form:

[0024]

[0025] wherein, , , , is a stiffness matrix parameter, is an unknown node displacement, is a known tower foot node displacement, is a known node load, The unknown node force corresponding to the tower foot node is obtained. According to the tower structure balance equation, combined with the size of the differential settlement of the tower foundation, the determination result of the unknown node displacement and the unknown node force is obtained; according to the known node displacement and the determined unknown node displacement, the member internal force of the tower structure is solved; according to the member internal force, the stress ratio of each member is solved; based on the stress ratio of each member, the evaluation method of the force safety of the tower structure member is determined, and the evaluation method comprises: if the stress ratio of the tower structure member is not greater than 1, the force safety of the tower structure member is safe; if the stress ratio of the tower structure member is greater than 1, the force safety of the tower structure member is unsafe; according to the evaluation method, the evaluation result of the force safety of the tower structure member is obtained. The present application realizes the accurate mathematical characterization of the force state of the tower by establishing the tower structure balance equation, systematically correlating the stiffness parameters, the node displacement and the load; by dividing the known displacement and the unknown displacement, the structure response is inversed combined with the foundation differential settlement data, which breaks through the limitation that the existing method cannot reflect the influence of the foundation deformation; by constructing the stiffness matrix, the mechanical interaction of each member of the tower is considered completely, which significantly improves the accuracy of the structure analysis; by solving the unknown node force, the accurate evaluation of the tower foot counterforce is realized, which provides key data for the foundation bearing capacity checking; by setting the safety criterion of the stress ratio, the clear force safety standard is established, so that the structure strength evaluation has engineering operability.

[0026] Optionally, the establishment of the safety evaluation standard according to the evaluation result comprises: determining the safety evaluation content according to the evaluation result; determining the safety evaluation level according to the safety evaluation content; and establishing the safety evaluation standard through the safety evaluation content and the safety evaluation level. The present application realizes the full-dimensional coverage of the tower structure state by determining the safety evaluation content; by establishing the mapping relationship between the evaluation content and the safety level, the complex technical parameters are converted into intuitive risk levels, which greatly improves the engineering readability and practicality of the evaluation result; by the definition method of the standardized evaluation level, the risk judgment scale of different tower types is unified, which realizes the horizontal comparability of the towers across regions and voltage levels.

[0027] Secondly, the present invention provides a transmission line tower structure safety assessment system based on measured data, comprising an input device, a processor, an output device, and a memory, wherein the input device, the processor, the output device, and the memory are interconnected, wherein 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 aforementioned transmission line tower structure safety assessment method based on measured data. The system provided by this invention boasts high integration and smooth information transmission between its components. By utilizing measured data, it constructs a comprehensive assessment system for tower foundation settlement, tower tilt, and insulator skew, achieving a three-dimensional safety perception of transmission line status from local to overall. Through the development of an algorithm based on the tower structure stiffness balance equation, it achieves coupled analysis of foundation deformation and superstructure response, significantly improving the accuracy of tower stress state assessment. By constructing a transformation relationship between local and global coordinate systems, it transforms complex spatial vectors into quantifiable local parameters, significantly enhancing the engineering applicability of insulator skew detection. By designing correlation rules between stress ratio criteria and multi-level safety standards, it transforms complex mechanical analysis into intuitive risk levels, forming a scientifically complete tower safety assessment standard system. Finally, by establishing an intelligent matching mechanism between assessment results and operation and maintenance strategies, it forms a closed-loop management system for monitoring, assessment, and handling, propelling transmission line operation and maintenance into a new intelligent stage. Attached Figure Description

[0028] Figure 1 This is a flowchart of the transmission line tower structure safety assessment method based on measured data according to an embodiment of the present invention;

[0029] Figure 2 This is a schematic planar projection of the control points for measuring the elevation of the tower foundation according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic planar projection of the tower body measurement control points according to an embodiment of the present invention;

[0031] Figure 4 This is a simplified diagram illustrating the spatial morphology analysis of the suspension insulator string according to an embodiment of the present invention.

[0032] Figure 5 This is a schematic diagram of the structure of the transmission line tower structure safety assessment system based on measured data, according to an embodiment of the present invention. Detailed Implementation

[0033] Specific embodiments of the present application will now be described in detail with reference to the drawings, which are provided by way of example and not limitation. A person of ordinary skill in the art will immediately appreciate that the application can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation, while the application contemplates all modifications and equivalents falling within the scope of the application. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, one of ordinary skill in the art will immediately appreciate that the application can be practiced without the specific details

[0034] Reference throughout this specification to "an embodiment", "embodiments", "one example", or "an example" means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the application. Thus, appearances of the phrases "in one embodiment", "in embodiments", "one example" or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics can be combined in any suitable

[0035] See Figure 1 The embodiments of the present application provide a method for safety evaluation of transmission line tower structure based on measured data, which comprises the following steps:

[0036] S1. Obtain the data of foundation differential settlement, foundation inclination, tower body inclination and suspension insulator string deflection of the tower structure of the running transmission line.

[0037] In one embodiment, first, the measurement control points of the foundation elevation, tower body inclination and suspension insulator string deflection of the tower structure of the running transmission line are selected.

[0038] Specifically, the measurement control points of the tower foundation elevation are a total of 4, and each control point is selected at the point close to the outer side of the tower leg on the top surface of the concrete foundation; the measurement control points of the tower body inclination are a total of 16, 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; the measurement control points of the single suspension insulator string deflection are a total of 2, and the upper control point is the suspension point of the insulator string, and the lower control point is the center of the suspension clamp.

[0039] Further, the 4 foundation elevation measurement control points of the tower are projected in the plane, as shown by the corner points in Figure 2 , the black arrow direction in Figure 2 points to the direction of the large tower, and along the direction of the large tower, the lower left corner point is numbered as JC1, and the other three corner points are numbered in sequence as JC2, JC3 and JC4 in clockwise direction.

[0040] Further, for the convenience of analyzing and measuring data, in Figure 2 A local coordinate system of the tower is established The direction of the axis and the axis of the local coordinate system is parallel to the direction of the two center lines of the tower foundation respectively. The local coordinate system is named as the first local coordinate system.

[0041] Further, the elevation of the four corner points is obtained by using the foundation elevation survey control points.

[0042] Further, the foundation differential settlement is calculated to obtain the data of the foundation differential settlement, which is the elevation difference of each foundation elevation survey control point, including the elevation difference of the corner points JC1 and JC2, JC2 and JC3, JC3 and JC4, JC4 and JC1, JC1 and JC3, and JC2 and JC4, so there are multiple sets of foundation differential settlement values. Among them, the foundation differential settlement of the corner points JC1 and JC2 is calculated as follows:

[0043]

[0044] Among them, is the foundation differential settlement of the JC1 and JC2 survey control points, with the unit of: , , are the measured elevations of the JC1 and JC2 survey control points respectively, with the unit of: .

[0045] Further, according to the first local coordinate system, a foundation inclination model is established, which satisfies the following expression:

[0046]

[0047] Among them, , are the inclinations of the foundation along the direction of the local coordinate system and the direction of respectively, , , , are the measured elevation values of the four survey control points, with the unit of: , , are the spans of the foundation along the direction of the local coordinate system and the direction of respectively, with the unit of: . The inclination is positive in the positive direction of the corresponding local coordinate axis.

[0048] Further, a basic inclination model is obtained according to the basic inclination data.

[0049] Further, taking a 220kV double circuit line angle steel tower as an example, the tower body measurement control points are projected on the basis of the elevation measurement control points of the foundation, and then are projected on the plane, as shown in the following figure: Figure 2 Figure 3 Figure 3 HDX1~ HDX4, HDS1~ HDS4, HDZ1~ HDZ4, DX1~ DX4 in the figure are measurement control points of the lower cross arm, the middle cross arm, the upper cross arm and the ground wire suspension layer respectively, and JC1~ JC4 are the elevation measurement control points of the foundation.

[0050] Further, a tower body inclination model is established according to the local coordinate system, and the tower body inclination model satisfies the following expression:

[0051]

[0052] wherein, , are the tower body inclinations along the direction of the local coordinate system and the direction of the local coordinate system respectively, , are the offset amounts of the center point of the first tower structure component relative to the center point of the foundation along the direction of the local coordinate system and the direction of the local coordinate system respectively, and the unit is: , is the height of the center point of the first tower structure component, and the unit is: ;

[0053] when , the tower structure component is the lower cross arm;

[0054] when , the tower structure component is the middle cross arm;

[0055] when , the tower structure component is the upper cross arm;

[0056] when , the tower structure component is the ground wire suspension layer.

[0057] It should be noted that the center point of the tower structure component is the intersection point of the control points of the tower structure component, and the center point of the foundation is the intersection point of the elevation measurement control points of the foundation.

[0058] ​​Further, the tower body inclination model is used to obtain data of the tower body inclination.

[0059] Further, the spatial coordinates of the upper and lower control points of the single suspension insulator string are used to obtain the line direction deflection angle and deflection value of the suspension insulator string.

[0060] Specifically, refer to Figure 4 , Figure 4 for the spatial form analysis diagram of the suspension insulator string. Figure 4 , are the line direction deflection angle and deflection value of the suspension insulator string respectively, is a local coordinate system of the tower, is a global coordinate system, also called a measurement coordinate system, , , , is an angle point in the global coordinate system, , , , is an angle point in the local coordinate system, and are the upper and lower control points of the suspension insulator string in the global coordinate system, and the line direction vector of the suspension insulator string is obtained according to the spatial coordinates of and , , is the rotation angle of the global coordinate system around the positive direction of the axis to obtain the local coordinate system, is the length between and , is the corresponding point of in the local coordinate system after rotation, is located on the axis, so that is perpendicular to the axis, , are the line direction deflection angle and deflection value of the suspension insulator string respectively, is the distance between and , is the unit vector of the line direction of the large tower in the local coordinate system, denoted as , , , are constants, Figure 4 , .

[0061] ​Further, a local coordinate system is established based on the insulator string vector and the global coordinate system, and a calculation model of the insulator string vector in the local coordinate system is established, and the calculation model of the insulator string vector in the local coordinate system satisfies the following relationship:

[0062]

[0063] wherein, is the insulator string vector in the local coordinate system, is a rotation angle of the local coordinate system and the global coordinate system, , , is a spatial coordinate of the insulator string vector in the global coordinate system.

[0064] Further, based on the calculation model of the insulator string vector, a calculation model of the insulator string direction skew angle along the line is established, and the calculation model of the insulator string direction skew angle along the line satisfies the following expression:

[0065]

[0066] wherein, is a rotation angle of the local coordinate system and the global coordinate system, , , is a spatial coordinate of the insulator string vector in the global coordinate system, , , is a unit vector spatial coordinate of the local coordinate system in the direction of the large tower along the line, is the insulator string direction skew angle along the line in the local coordinate system, and satisfies the following conditions:

[0067] when , the skew direction of the insulator string in the local coordinate system is in the direction of the small tower;

[0068] when , the skew direction of the insulator string in the local coordinate system is in the direction of the large tower;

[0069] when , the skew angle of the skew direction of the insulator string in the local coordinate system is 0.

[0070] Further, based on the insulator string direction skew angle along the line, a calculation model of the insulator string direction skew value along the line is established, and the calculation model of the insulator string direction skew value along the line satisfies the following relationship:

[0071]

[0072] wherein, is the line direction deflection value of the suspension insulator string in the local coordinate system, is the unit vector space coordinate of the line direction of the large tower in the local coordinate system, is the space coordinate of the suspension insulator string vector in the global coordinate system, is the rotation angle of the local coordinate system and the global coordinate system.

[0073] Further, the line direction deflection value of the suspension insulator string in the local coordinate system is obtained through the line direction deflection value calculation model of the suspension insulator string.

[0074] Further, the line direction deflection angle and the line direction deflection value of the suspension insulator string in the local coordinate system are substituted 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, and the calculation expression is as follows:

[0075]

[0076] wherein, represents the line direction deflection degree of the suspension insulator string, represents the line direction deflection angle of the suspension insulator string, represents the line direction deflection value of the suspension insulator string, represents the length of the suspension insulator string.

[0077] It should be noted that the greater the difference between the conductor 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 in the line direction can reflect the size of the tension difference between the conductors on both sides.

[0078] S2. Based on the data, the evaluation results of the deformation characteristics and the force safety of the tower structure are obtained.

[0079] In one embodiment, the measured differential settlement of the tower foundation is taken as the tower foot displacement load input into the tower structure calculation model. The member internal force of the tower structure is calculated according to the typical load combination under different load cases given in the relevant specification, and the member section strength and stability are judged. The tower structure calculation model includes tower structure balance equation.

[0080] Specifically, the tower foot node displacement is known, the tower structure balance equation is established, and the form of the tower structure balance equation is as follows: ​​​​

[0081]

[0082] wherein, , , , 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 node force corresponding to the tower foot node, which refers to the internal force at the node, and the distribution intensity of the internal force in the local area of the node is stress.

[0083] Further, when the differential settlement of the tower foundation is small, the geometric nonlinearity caused by the known displacement can be ignored, the overall stiffness matrix of the structure is considered as a constant, and the above formula is expanded to obtain:

[0084]

[0085]

[0086] Further, according to the above expansion formula, the unknown node displacement and the tower foot node force are obtained.

[0087] Further, when the differential settlement of the tower foundation is large, the geometric nonlinearity caused by the tower foot displacement needs to be considered, and the overall stiffness matrix of the structure and the node displacement need to be further determined through iterative calculation.

[0088] For each structural unit, according to the unit node displacement (solved) and the unit stiffness , the unit node force can be solved, as shown in the following formula:

[0089]

[0090] According to the calculated internal force of the member, combined with the member section and material properties, the stress ratio of the structural member can be obtained according to the relevant specifications. The evaluation results of the safety of the tower structure include:

[0091] If the structural calculation results show that the stress ratios of all members of the tower are not greater than 1, it means that the strength and stability of the structural members of the tower have a certain redundancy, and the tower structure is relatively safe.

[0092] If there is a member with a stress ratio greater than 1, it means that the sectional strength or stability redundancy of the part of the member does not meet the requirements of the relevant specifications.

[0093] Further, the evaluation of the size of the differential settlement of the tower foundation.

[0094] Specifically, the differential settlement amount of the tower foundation is obtained by field measurement, the maximum differential settlement amount obtained by measurement is considered in view of the measurement error and the construction error influence in the line construction, and the maximum differential settlement amount obtained by measurement is divided into three grades

[0095] When , the differential settlement amount of the foundation is large, and is in the high amount grade;

[0096] When , the differential settlement amount of the foundation is large, and is in the high amount grade;

[0097] When , the differential settlement amount of the foundation is small, and is in the low amount grade.

[0098] Further, the inclination of the tower is evaluated.

[0099] Specifically, the Overhead Transmission Line Operation Regulation (DL / T 741-2019) (hereinafter referred to as the “operation regulation”) stipulates the basic requirements and technical (operation) standards for the operation of overhead transmission lines, such as the maximum allowable value of the inclination (including deflection) of the angle steel tower below 50m height is 1.0%; the inclination of the tower is evaluated according to the “operation regulation”, and the evaluation is divided into “satisfying the operation regulation” and “not satisfying the operation regulation”.

[0100] Further, the relationship between the inclination direction of the foundation and the inclination direction of the tower is evaluated.

[0101] Specifically, when the inclination direction of the foundation and the inclination direction of the tower are basically consistent, it indicates that the correlation between the tower inclination and the foundation inclination is high, and the calculation result obtained by inputting the tower foot displacement as a load into the tower structure calculation model can more truly reflect the safety status of the running tower structure; the relationship between the foundation differential settlement foundation safety and the inclination direction of the foundation and the inclination direction of the tower is evaluated, and the evaluation is divided into “basically consistent” and “not consistent”.

[0102] Further, the evaluation of the internal force calculation result of the tower structure is performed.

[0103] Specifically, the member stress ratio can reflect the cross-section strength and stability redundancy of the member, and the cross-section strength or stability redundancy of the member with a stress ratio greater than 1 does not meet the relevant specification requirements, according to the number of stress ratio over-limit members, the internal force calculation result of the tower structure is evaluated into three kinds of “stress ratio over-limit members are more” (stress ratio over-limit members are not less than 10 groups), “stress ratio over-limit members are less” (stress ratio over-limit members are less than 10 groups, and more than 1 group) and “there is no stress ratio over-limit member”.

[0104] Further, the evaluation of the deflection of the suspension insulator string is performed. ​

[0105] Specifically, for straight-line towers, the tension difference of the two sides of the conductor is not conducive to the force of the tower structure and the insulator string, so the inclination of the suspension insulator string is evaluated. The inclination of the suspension insulator string includes the inclination angle and the inclination value. According to the “Overhead Transmission Line Operation Regulations” (DL / T 741-2019) 5.3.10, the inclination angle of the insulator string of the straight-line tower in the direction of the line (except for the pre-bias required by the design) should not be greater than 7.5 degrees, or the maximum deviation should not be greater than 300 mm. According to the “Operation Regulations”, the inclination of the suspension insulator string of the straight-line tower is evaluated, which is divided into “satisfying the operation regulations” and “not satisfying the operation regulations”.

[0106] S3. According to the evaluation results, a safety evaluation standard for the running transmission line tower structure is established, also known as the tower grade differentiation standard, which is as follows:

[0107] In one embodiment, according to the evaluation results, a set of safety evaluation standards for the running transmission line tower structure, also known as the tower grade differentiation standard, is established, which is as follows:

[0108] Class I tower: tower with large foundation differential settlement, tower tilt not meeting the requirements of the “Operation Regulations”, foundation tilt direction close to the tower tilt direction, and many stress ratio over-limit members;

[0109] Class II tower: tower with large foundation differential settlement, tower tilt not meeting the requirements of the “Operation Regulations”, foundation tilt direction close to the tower tilt direction; or tower body tilt not meeting the requirements of the “Operation Regulations”, and there are suspension insulator strings with inclination not meeting the requirements of the “Operation Regulations” and not belonging to Class I tower;

[0110] Class III tower: tower with tower tilt not meeting the requirements of the “Operation Regulations”; or tower with large foundation differential settlement, many stress ratio over-limit members, and foundation tilt direction close to the tower tilt direction;

[0111] Class IV tower: tower other than Class I, Class II, and Class III towers.

[0112] Further, the treatment methods for different grade towers are as follows:

[0113] For the tower with safety grade I, the corresponding qualified institution is commissioned as soon as possible to perform technical treatment, such as foundation reinforcement and then jacking and leveling;

[0114] For the tower structure with safety grade II and III, the deformation thereof is monitored during use, and technical treatment is performed if necessary;

[0115] For the tower structure with safety grade IV, no measures need to be taken, and observation is strengthened during the operation of the transmission line.

[0116] S4. Realize the safety evaluation of the transmission line tower structure in operation through the safety evaluation standard.

[0117] In one embodiment, the safety level of the transmission line tower structure in operation is determined step by step in combination with the safety evaluation standard in step S3, so as to realize the safety evaluation of the transmission line tower structure in operation.

[0118] Please refer to Figure 5 , Figure 5 The structural diagram of a kind of transmission line tower structure safety evaluation system based on measured data in the embodiment of the application. The system includes input device, processor, output device and memory, the input device, the processor, the output device and the memory are connected with each other, wherein the memory is used to store computer program, the computer program includes program instruction, the processor is configured to call the program instruction, the system uses the safety evaluation method of the one kind of transmission line tower structure based on measured data.

[0119] In the embodiment, the input device includes data acquisition device and user input device.

[0120] Specifically, the data acquisition device is used to collect the data of tower foundation elevation in real time; the user input device is used to input the related data of tower structure. The input device acquires the data of tower foundation settlement, tower body inclination and insulator deflection in real time, and converts the data into standardized format under global / local coordinate system, and transmits to the processor for safety analysis.

[0121] Further, the processor includes data preprocessing module, mechanics calculation module and safety evaluation module.

[0122] Specifically, the data preprocessing module is used for coordinate conversion and data filtering; the mechanics calculation module is used for stiffness matrix balance equation solving and stress ratio calculation; the safety evaluation module is used for risk classification based on safety evaluation standard. The processor calculates foundation inclination, tower body deformation and insulator deflection based on local / global coordinate system; solves tower structure balance equation, analyzes stress safety and deformation characteristics; in combination with evaluation standard, outputs tower safety level.

[0123] Further, the output device includes visual monitoring large screen, early warning terminal and report generation module.

[0124] Specifically, the visual monitoring large screen is used to display a three-dimensional tower model and a deformation animation; the early warning terminal is used for sound and light alarm of safety risks; and the report generation module is used to generate a safety evaluation report. The output device directly displays the tower deformation, stress state and safety level; automatically triggers the early warning of high-risk towers and pushes it to the operation and maintenance personnel; and generates a detailed evaluation report to support historical data comparison and analysis.

[0125] Further, the memory adopts a high-speed solid state disk, has the characteristics of fast read-write speed, large capacity and high reliability, is mainly used for storing data input by the input device and result data after being processed by the processor, and can meet the demand of large data storage.

[0126] To sum up, the application establishes a comprehensive evaluation system by fusing basic settlement, tower body inclination, insulator deflection and structure stress ratio data; quantifies the correlation between deformation and stress by combining the stiffness matrix balance equation and deflection angle calculation model, accurately identifies the risk; and matches the safety level according to the measured data, so that the relevant parties can understand the emergency degree of the event, which can be used as a basis for the owner to determine the technical processing priority of the event. This method fills the gap in the current standard, and significantly improves the fine level of transmission line safety management.

[0127] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application, and they should be covered in the scope of the claims and the specification of the application.

Claims

1. A method for safety evaluation of a transmission line tower structure based on measured data, characterized in that, The method comprises the following steps: Obtaining data of foundation differential settlement, foundation inclination, tower body inclination and suspension insulator string deflection of a tower structure of an operating power transmission line, comprising: Selecting measurement control points of foundation elevation, tower body inclination and suspension insulator string deflection of the tower structure of the operating power transmission line; Establishing a local coordinate system according to the measurement control points; Obtaining a suspension insulator string vector under a global coordinate system; Establishing a suspension insulator string vector calculation model under the local coordinate system through the suspension insulator string vector; Based on the suspension insulator string vector calculation model, a suspension insulator string line direction deflection angle calculation model is established; Based on the suspension insulator string line direction deflection angle calculation model, a suspension insulator string line direction deflection value calculation model is established; Through the suspension insulator string line direction deflection angle calculation model, a suspension insulator string line direction deflection angle under the local coordinate system is obtained; Through the suspension insulator string line direction deflection value calculation model, a suspension insulator string line direction deflection value under the local coordinate system is obtained; Through the suspension insulator string line direction deflection angle and deflection value under the local coordinate system, data of the suspension insulator string deflection is obtained; The suspension insulator string vector calculation model satisfies the following relationship: ， wherein, is the vector of the suspension insulator string in the local coordinate system, is the rotation angle of the local coordinate system and the global coordinate system, , , is the spatial coordinate of the vector of the suspension insulator string in the global coordinate system; the suspension insulator string order-of-line-direction deflection angle calculation model satisfies the following expression: ， wherein, is a rotation angle of the local coordinate system and the global coordinate system, , , is a spatial coordinate of the vector of the string of suspension insulators in the global coordinate system, , , is a spatial coordinate of the unit vector in the direction of the large tower along the line in the local coordinate system, is a deflection angle of the string of suspension insulators in the direction along the line in the local coordinate system, which satisfies the following condition: When the direction of the deflection of the overhang insulator string in the local coordinate system is the small tower direction; When the direction of the deflection of the overhang insulator string in the local coordinate system is the direction of the large tower. When the deflection angle of the deflection direction of the overhang insulator string in the local coordinate system is 0. The suspension insulator string line direction deflection value calculation model satisfies the following relationship: ， wherein, is the line direction deflection value of the overhang insulator string in the local coordinate system; Based on the data, evaluation results of each deformation feature and force safety of the tower structure are obtained; According to the evaluation results, a safety evaluation standard is established; Through the safety evaluation standard, safety evaluation of the tower structure of the operating power transmission line is realized.

2. The method for safety evaluation of transmission line tower structure based on measured data according to claim 1, characterized in that, The obtaining of the data of the foundation differential settlement, foundation inclination, tower body inclination and suspension insulator string deflection of the tower structure of the operating power transmission line comprises: According to the local coordinate system, data of the foundation differential settlement and foundation inclination are obtained; According to the local coordinate system, data of the tower body inclination are obtained; According to the local coordinate system, data of the suspension insulator string deflection are obtained.

3. The method for safety evaluation of transmission line tower structure based on measured data according to claim 2, characterized in that, The obtaining of the data of the foundation differential settlement and foundation inclination according to the local coordinate system comprises: According to the local coordinate system, measurement control point elevations are obtained; Based on the measurement control point elevations, data of the foundation differential settlement are obtained; Based on the measurement control point elevations, data of the foundation inclination are obtained.

4. The method for safety evaluation of transmission line tower structure based on measured data according to claim 3, characterized in that, The obtaining of the data of the foundation inclination based on the measurement control point elevations comprises: Based on the measurement control point elevations, a foundation inclination model is established, and the foundation inclination model satisfies the following expression: ， ， wherein , are the inclinations of the base along the local coordinate system direction and direction, respectively, , , , are the measured elevation values of the four measuring control points, , are the spans of the base along the local coordinate system direction and direction, respectively. Through the foundation inclination model, data of the foundation inclination are obtained.

5. The method for safety evaluation of transmission line tower structure based on measured data according to claim 2, characterized in that, The obtaining of the data of the tower body inclination according to the local coordinate system comprises: According to the local coordinate system, a tower body inclination model is established, and the tower body inclination model satisfies the following expression: ， ， wherein, , are the tower body inclinations along the local coordinate system direction and direction, respectively, , are the offsets of the center point of the th tower structure component relative to the center point of the foundation along the direction and direction in the local coordinate system, respectively, is the height of the center point of the th tower structure component; Through the tower body inclination model, data of the tower body inclination are obtained.

6. The method for safety evaluation of transmission line tower structure based on measured data according to claim 1, characterized in that, The obtaining of the evaluation results of the force safety of the tower structure based on the data comprises: Based on the data, a tower structure balance equation is established, and the tower structure balance equation is in the following form: wherein, , , , is a stiffness matrix parameter, is an unknown node displacement, is a known tower foot node displacement, is a known node load, is an unknown node force corresponding to the tower foot node; According to the tower structure balance equation, in combination with the size of the tower foundation differential settlement, the determination result of the unknown node displacement and the unknown node force is obtained; According to the known node displacement and the determined unknown node displacement, the member internal force of the tower structure is solved; According to the member internal force, the stress ratio of each member is solved; Based on the stress ratio of each member, the evaluation method of the force safety of the tower structure member is determined, and the evaluation method comprises: if the stress ratio of the tower structure member is not greater than 1, the force safety of the tower structure member is safe; if the stress ratio of the tower structure member is greater than 1, the force safety of the tower structure member is unsafe; According to the evaluation method, the evaluation result of the force safety of the tower structure member is obtained.

7. The method for safety evaluation of transmission line tower structure based on measured data according to claim 1, characterized in that, According to the evaluation result, the establishment of the safety evaluation standard comprises: According to the evaluation result, the safety evaluation content is determined; According to the safety evaluation content, the safety evaluation level is determined; Through the safety evaluation content and the safety evaluation level, the safety evaluation standard is established.

8. A system for safety evaluation of transmission line tower structure based on measured data, the system using a method for safety evaluation of transmission line tower structure based on measured data according to any one of claims 1 to 7, characterized in that, The system comprises an input device, a processor, an output device and a memory, and the input device, the processor, the output device and the memory are connected with each other, wherein the memory is used for storing a computer program, the computer program comprises program instructions, and the processor is configured to call the program instructions.

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