A method for cyclically judging the dynamic stability state of transmission tower poles

Abstract

The present invention discloses a method for cyclically judging the dynamic stability state of transmission tower rods, comprising: after respectively establishing numerical models of the transmission tower and the conductor ground wire, defining connection conditions and boundary constraints to form a numerical model of the transmission line, then automatically extracting sample values ​​of key variables in the numerical model through a programming script, forming a characteristic parameter database, a stress state database, etc. as basic data, forming a dynamic instability zone database, an excitation coefficient database, etc. as judgment data, cyclically judging the dynamic stability state of each key rod, and outputting a rod state set S and a dynamic stability state state of the transmission tower; the present invention has strong universality and can simulate transmission lines with different tower types and different spans; it can establish the dynamic instability zone of the key rod and judge the dynamic stability of the rod, and is more in line with engineering practice than the static stability state judgment method.

Description

Technical Field

[0001] The present invention relates to the technical field of wind resistance of power transmission lines, and in particular to a method for cyclically judging the dynamic stability state of power transmission tower poles. Background Art

[0002] The safe operation of power grids provides crucial support for the normal lives of residents and the smooth operation of various industries. If a transmission line is damaged, the time-consuming restoration and reconstruction process often results in prolonged power outages in localized areas, causing significant economic losses. Therefore, analysis and research on transmission line safety is crucial.

[0003] In the study of wind-induced vibration of transmission lines, researchers both domestically and internationally have conducted numerous wind tunnel tests on tower-line systems to analyze the wind-induced response characteristics of transmission lines under various operating conditions. However, this method is costly and technically challenging, making it suitable only as a supplementary tool. Current research on wind-resistant transmission lines still primarily relies on numerical simulations. Transmission towers are characterized by a large number of members and complex stress states. In wind-induced tower collapse accidents, member failure is often caused by instability. Therefore, developing a reasonable method for determining the dynamic stability state of members is crucial for reliability analysis and the normal operation of transmission lines. Current research on transmission lines often uses nonlinear static pushover analysis to investigate the bearing capacity, failure characteristics, and collapse mechanisms of existing transmission towers under wind loads, or employs incremental dynamic analysis and explicit time integration methods to analyze the collapse of transmission tower numerical models. For determining member stability, existing common techniques often rely on elastic stability theory, consider the correlation of components during buckling, and calculate the stability state from a static stability perspective. However, in the study of wind-induced damage to transmission towers, only considering the static effect of wind load on the tower cannot meet the increasingly stringent engineering requirements. Summary of the Invention

[0004] In order to solve at least one technical problem existing in the above background technology, the present invention provides a method for cyclically determining the dynamic stability state of a transmission tower pole.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] A method for cyclically determining the dynamic stability state of a transmission tower member, the method comprising:

[0007] Based on the actual transmission tower construction drawings of the transmission line, the spatial coordinates of key nodes are determined, and the spatial configuration of the numerical model of each member is determined to construct the spatial configuration of the transmission tower numerical model. The parameters of the member are then assigned to the spatial configuration of the transmission tower numerical model.

[0008] According to the span and sag of the actual transmission line, the spatial coordinates of the conductor ground wire numerical model in the state without internal force are determined, the spatial configuration of the conductor ground wire in the state without internal force is established, and then the conductor ground wire parameters are assigned to the spatial configuration of the conductor ground wire numerical model in the state without internal force;

[0009] Based on the tower-line connection method of the actual transmission line, the connector between the transmission tower numerical model and the internal force-free state space configuration of the conductor ground wire numerical model is defined; based on the boundary conditions of the actual line, all degrees of freedom of the tower leg of the transmission tower numerical model and the ground contact point are constrained, and the corresponding degrees of freedom of the internal force-free state space configuration of the conductor ground wire numerical model at the end without the transmission tower numerical model are constrained to form the overall transmission line numerical model and determine the number N of key members;

[0010] Establish characteristic parameter database and stress state database;

[0011] Establish a dynamic instability zone database, where the dynamic instability zone data is calculated from the variables in the database in steps 4 and 5;

[0012] Establish an excitation coefficient database, including the minimum excitation coefficient and actual excitation coefficient of each key member. Combined with the key member dynamic instability zone database, the dynamic stability state of each key member is cyclically judged, and the member state set S and the transmission tower dynamic stability state state are output.

[0013] Furthermore, the parameters of the rod include material properties, including density, elastic modulus, and yield strength; the parameters of the conductor ground wire include material properties, including density, elastic modulus, and linear expansion coefficient.

[0014] Furthermore, the parabola method or the catenary method is used to determine the spatial coordinates of the conductor ground wire numerical model in a state without internal force.

[0015] Furthermore, the characteristic parameter database includes cross-sectional dimensions, actual length, slenderness ratio, and stable bearing capacity variables.

[0016] Furthermore, the stress state database includes axial force time history data, axial force static component and dynamic component, and excitation characteristic frequency variables.

[0017] Furthermore, a programming script is used to automatically extract characteristic parameter data from the transmission tower numerical model and form a characteristic parameter database, integrating key pole geometry information data as the basic data for dynamic stability judgment.

[0018] The stress state database of key members in the transmission tower numerical model is automatically extracted through programming scripts to integrate the stress state data of key members as the basic data for dynamic stability judgment.

[0019] Furthermore, the required variable sample values ​​are automatically extracted from the characteristic parameter database and the stress state database through programming scripts, and the upper and lower boundaries of the dynamic instability zone of the rod are automatically calculated using the extracted variable sample values ​​to form a dynamic instability zone database as the criterion data for dynamic stability judgment.

[0020] Furthermore, the required variable sample values ​​are automatically extracted from the characteristic parameter database and the stress state database through programming scripts, and the minimum excitation coefficient and actual excitation coefficient of the rod are automatically calculated using the extracted variable sample values ​​to form an excitation coefficient database as the criterion data for dynamic stability judgment.

[0021] Furthermore, the required variable sample values ​​are automatically extracted from the dynamic instability zone database and the excitation coefficient database through programming scripts, and the dynamic stability state of the pole is automatically evaluated using the extracted variable sample values. After looping through all key poles, the pole state set S and the dynamic stability state state of the transmission tower are formed.

[0022] Furthermore, the rod types of the transmission tower numerical model include angle steel components, circular tube components, and T-shaped composite components, Y-shaped composite components, cross-shaped composite components, and double L-shaped composite components commonly used in in-situ reinforcement schemes.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The method for cyclically judging the dynamic stability state of transmission tower poles of the present invention determines the dynamic stability state of transmission tower poles by establishing a characteristic parameter database, a stress state database, a dynamic instability zone database, and an excitation coefficient database; and can simulate transmission lines with different tower types and different spans.

[0025] This solution is highly universal and can simulate transmission lines with different tower types and different spans. It can establish the dynamic instability zone of key pole members and judge the dynamic stability of the pole members, which is more in line with engineering practice than the static stability state judgment method. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A flowchart of the steps of a method for cyclically determining the dynamic stability state of a transmission tower pole provided by an embodiment of the present invention;

[0027] Figure 2 Schematic diagram of the numerical model of a transmission tower and key data extraction points according to an embodiment of the present invention;

[0028] Figure 3 A simplified diagram of the initial configuration of the conductor ground wire according to an embodiment of the present invention;

[0029] Figure 4Schematic diagram of a numerical model of a power transmission line according to an embodiment of the present invention;

[0030] Figure 5 This is a schematic diagram of the dynamic instability region and the excitation coefficient state according to an embodiment of the present invention;

[0031] The meanings of the reference numerals in the figure are: 1. Numerical model of transmission tower; 2. Numerical model of conductor and ground wire; 3. Articulated connection; 4. Articulated connection with insulator; 5. Fully constrained boundary; 6. Limitedly constrained boundary. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0033] Example:

[0034] See Figure 1 As shown, the method for cyclically determining the dynamic stability state of a transmission tower pole provided in this embodiment mainly includes the following steps:

[0035] Step 1: According to the actual transmission tower construction drawing of the transmission line, determine the spatial coordinates of the key nodes, and determine the spatial configuration of the numerical model of each rod to construct the spatial configuration of the transmission tower numerical model 1; assign the material properties of the rod, including density, elastic modulus, yield strength and other parameters, to the spatial configuration of the transmission tower numerical model 1 to form the following: Figure 2 The numerical model of the transmission tower and key data extraction points shown, including but not limited to Figure 2 The marked points in ;

[0036] Step 2: According to the actual transmission line span and sag, Figure 3 The force diagram of the conductor ground wire's initial configuration is shown. The parabola method or catenary method is used to determine the spatial coordinates of the conductor ground wire numerical model 2 in the state without internal forces. The spatial configuration of the conductor ground wire's state without internal forces is established through the input file import method. The material properties of the conductor ground wire, including parameters such as density, elastic modulus, and linear expansion coefficient, are assigned to the spatial configuration of the conductor ground wire numerical model in the state without internal forces.

[0037] Step 3: According to the tower-line connection mode of the actual transmission line, define the connector between the transmission tower numerical model and the internal force-free state space configuration of the conductor ground wire numerical model; according to the boundary conditions of the actual line, constrain all degrees of freedom of the tower leg and ground contact point of the transmission tower numerical model, and constrain the corresponding degrees of freedom of the internal force-free state space configuration of the conductor ground wire numerical model at the end where the transmission tower numerical model is not arranged, forming the following Figure 4The overall transmission line numerical model shown includes a transmission tower numerical model 1, a conductor and ground wire numerical model 2, an articulated connection 3, an articulated connection with an insulator 4, a fully constrained boundary 5, a finitely constrained boundary 6, and determines the number N of key members;

[0038] Step 4: Establish a characteristic parameter database, including variables such as cross-sectional dimensions, actual length, slenderness ratio, and stable bearing capacity;

[0039] Step 5: Establish a stress state database, including variables such as axial force time history data, axial force static and dynamic components, and excitation characteristic frequency;

[0040] Step 6: Establish a database of dynamic instability zones. The data of dynamic instability zones are calculated from the variables in the database of steps 4 and 5. The upper and lower boundaries of the dynamic instability zones of the members are shown in the following diagram: Figure 5 As shown;

[0041] Step 7: Establish an excitation coefficient database, including the minimum excitation coefficient and actual excitation coefficient of each key member. Combined with the database of dynamic instability zones of key members, the dynamic stability state of each key member is cyclically determined, and the member state set S and the dynamic stability state of the transmission tower are output.

[0042] Preferably, to complete step seven, it is necessary to establish random wind field time history data that conforms to the topographical characteristics and wind field characteristics of the transmission line location;

[0043] Preferably, to complete the step seven, it is necessary to calculate the response characteristics of the transmission line finite element model under the action of the random wind field using the established random wind field data;

[0044] In a specific embodiment, the required variable sample values ​​are automatically extracted from the characteristic parameter database and the stress state database by a programming script, and the upper and lower boundaries of the dynamic instability zone of the rod are automatically calculated using the extracted variable sample values, forming a dynamic instability zone database as the criterion data for dynamic stability judgment. The required variable sample values ​​are automatically extracted from the characteristic parameter database and the stress state database by a programming script, and the minimum excitation coefficient and actual excitation coefficient of the rod are automatically calculated using the extracted variable sample values, forming an excitation coefficient database as the criterion data for dynamic stability judgment. The required variable sample values ​​are automatically extracted from the dynamic instability zone database and the excitation coefficient database by a programming script, and the dynamic stability state of the rod is automatically evaluated using the extracted variable sample values. After looping through all key rods, a rod state set S and a transmission tower dynamic stability state state are formed.

[0045] In a specific embodiment, the transmission tower numerical model and the conductor ground wire numerical model are the main structures of this solution, and there is no limit on the number and tower type; the tower type includes but is not limited to the multi-rod space tower of the dry-shaped tower, cat-head tower, wine glass tower and other types;

[0046] In a specific embodiment, the numerical model of the conductor ground wire considers the deformation under the action of gravity; the method of establishing the initial conductor ground wire finite element model includes but is not limited to the parabolic coordinate positioning method, the catenary coordinate positioning method, etc.;

[0047] In a specific embodiment, the types of rods in the transmission tower numerical model include but are not limited to angle steel members, round tube members, and T-shaped composite members, Y-shaped composite members, cross-shaped composite members, double L-shaped composite members, etc. commonly used in in-situ reinforcement schemes;

[0048] In a specific embodiment, there is no limit to the number of transmission tower numerical models, including but not limited to the common single-tower two-span line model, three-tower two-span line model, three-tower five-span line model, five-tower four-span line model, etc.

[0049] In a specific embodiment: the conductor ground wire numerical model includes but is not limited to a ground wire numerical model and a conductor numerical model; the conductor numerical model includes but is not limited to a commonly used double-split conductor model, a four-split conductor model, an eight-split conductor model, etc.;

[0050] In a specific embodiment, the connection scheme between the transmission tower numerical model and the conductor ground wire finite element model includes but is not limited to a multi-point articulated connector connection, an insulator numerical model connection, etc.

[0051] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made based on the essence of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A method for cyclically determining the dynamic stability state of a transmission tower member, characterized in that: The method comprises: Based on the actual transmission tower construction drawings of the transmission line, the spatial coordinates of key nodes are determined, and the spatial configuration of the numerical model of each member is determined to construct the spatial configuration of the transmission tower numerical model. The parameters of the member are then assigned to the spatial configuration of the transmission tower numerical model. According to the span and sag of the actual transmission line, the spatial coordinates of the conductor ground wire numerical model in the state without internal force are determined, the spatial configuration of the conductor ground wire in the state without internal force is established, and then the conductor ground wire parameters are assigned to the spatial configuration of the conductor ground wire numerical model in the state without internal force; According to the tower-line connection mode of the actual transmission line, the connector between the transmission tower numerical model and the internal force-free state space configuration of the conductor ground wire numerical model is defined; according to the boundary conditions of the actual line, all degrees of freedom of the tower leg of the transmission tower numerical model and the ground contact point are constrained, and the corresponding degrees of freedom of the internal force-free state space configuration of the conductor ground wire numerical model at the end where the transmission tower numerical model is not arranged are constrained to form the overall transmission line numerical model and determine the number of key rods. N ; Establish characteristic parameter database and stress state database; Establish a dynamic instability zone database, where the dynamic instability zone data is calculated from the variables in the characteristic parameter database and the stress state database; Establish an excitation coefficient database, including the minimum excitation coefficient and actual excitation coefficient of each key member, combine it with the key member dynamic instability zone database, cyclically judge the dynamic stability state of each key member, and output the member state set S and the transmission tower dynamic stability state ; The required variable sample values ​​are automatically extracted from the characteristic parameter database and the stress state database through programming scripts, and the upper and lower boundaries of the dynamic instability zone of the member are automatically calculated using the extracted variable sample values ​​to form a dynamic instability zone database as the criterion data for dynamic stability judgment; The required variable sample values ​​are automatically extracted from the characteristic parameter database and the stress state database through programming scripts, and the minimum excitation coefficient and actual excitation coefficient of the rod are automatically calculated using the extracted variable sample values ​​to form an excitation coefficient database as the criterion data for dynamic stability judgment; The required variable sample values ​​are automatically extracted from the dynamic instability zone database and the excitation coefficient database through programming scripts, and the dynamic stability state of the rod is automatically evaluated using the extracted variable sample values. After looping through all key rods, a rod state set is formed. S and the transmission tower dynamic stability state.

2. The method for cyclically judging the dynamic stability state of a transmission tower pole according to claim 1, characterized in that: The parameters of the rod include material properties, including density, elastic modulus, and yield strength; the parameters of the conductor ground wire include material properties, including density, elastic modulus, and linear expansion coefficient.

3. The method for cyclically judging the dynamic stability state of a transmission tower pole according to claim 1, wherein: The parabola method or catenary method is used to determine the spatial coordinates of the conductor ground wire numerical model under the state without internal force.

4. The method for cyclically determining the dynamic stability state of a transmission tower pole according to claim 1, wherein: The characteristic parameter database includes cross-sectional dimensions, actual length, slenderness ratio, and stable bearing capacity variables.

5. The method for cyclically judging the dynamic stability state of a transmission tower pole according to claim 4, characterized in that: The stress state database includes axial force time history data, axial force static component and dynamic component, and excitation characteristic frequency variables.

6. The method for cyclically judging the dynamic stability state of a transmission tower pole according to claim 1 or 4, characterized in that: Automatically extract characteristic parameter data from the transmission tower numerical model through programming scripts and form a characteristic parameter database, integrating key pole geometry information data as the basic data for dynamic stability judgment; The stress state database of key members in the transmission tower numerical model is automatically extracted through programming scripts, and the stress state data of key members are integrated as the basic data for dynamic stability judgment.

7. The method for cyclically determining the dynamic stability state of a transmission tower member according to claim 1, wherein: The rod types of the transmission tower numerical model include angle steel components, circular tube components, and T-shaped composite components, Y-shaped composite components, cross-shaped composite components, and double L-shaped composite components commonly used in in-situ reinforcement schemes.

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