scholarly journals Shaking Table Array Tests of an Ultra-High-Voltage Cup-Type Transmission Tower-Line System

2019 ◽  
Vol 2019 ◽  
pp. 1-20 ◽  
Author(s):  
Fei Wang ◽  
Ke Du ◽  
Jingjiang Sun ◽  
Fuyun Huang ◽  
Zhenghui Xiong
Keyword(s):  
Ground Motion ◽  
Transmission Lines ◽  
Shaking Table ◽  
Transmission Tower ◽  
Acceleration Response ◽  
Lumped Mass ◽  
Line System ◽  
Transmission Towers ◽  
Tower Model ◽  
Line Coupling

Ultra-high-voltage (UHV) cup-type transmission towers supported with long-span transmission lines are unavoidably subjected to the coupling action between the towers and the transmission lines. Therefore, investigating how tower-line coupling affects UHV cup-type transmission towers is important. In this study, three shaking table array tests of an UHV cup-type transmission tower-line system were carried out to investigate the dynamic characteristics of the coupling action between the towers and transmission lines based on the following four comparative models: a single-tower model, a single-tower model with suspended lumped masses, a three-tower-two-line model, and a five-tower-four-line model. The test results demonstrated that the tower-line coupling interaction had a significant effect on the dynamic characteristics and seismic responses, as the suspended conductor line and the suspended lumped mass decreased the frequency of the transmission tower. Under longitudinal ground motion, the model with the suspended lumped mass had the lowest peak acceleration response and the largest peak displacement response. Under the same ground motion, the four models had similar peak strains in the longitudinal direction. Under transverse-the-line ground motion, the model with the suspended lumped mass had the lowest peak acceleration response and the smallest peak responses for displacement and strain in the transverse direction; therefore, this model is inappropriate for the simulation and seismic evaluation of transmission tower-line systems.

scholarly journals Collapse Analysis of a Transmission Tower-Line System Induced by Ice Shedding

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiaxiang Li ◽  
Biao Wang ◽  
Jian Sun ◽  
Shuhong Wang ◽  
Xiaohong Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
Transmission Lines ◽  
Progressive Collapse ◽  
Element Model ◽  
Transmission Tower ◽  
Line System ◽  
Finite Element Software ◽  
Transmission Towers ◽  
Ice Shedding ◽  
The Impact

Ice shedding causes transmission lines to vibrate violently, which induces a sharp increase in the longitudinal unbalanced tension of the lines, even resulting in the progressive collapse of transmission towers in serious cases, which is a common ice-based disaster for transmission tower-line systems. Based on the actual engineering characteristics of a 500 kV transmission line taken as the research object, a finite element model of a two-tower, three-line system is established by commercial ANSYS finite element software. In the modeling process, the uniform mode method is used to introduce the initial defects, and the collapse caused by ice shedding and its influencing parameters are systematically studied. The results show that the higher the ice-shedding height is, the greater the threat of ice shedding to the system; furthermore, the greater the span is, the shorter the insulator length and the greater the dynamic response of the line; the impact of ice shedding should be considered in the design of transmission towers.

Study on Simplified Models for Coupled Transmission Tower-Line System to Seismic Excitations

2004 ◽  
Author(s):  
Hong-Nan Li ◽  
Wen-Long Shi ◽  
Guo-Xin Wang
Keyword(s):  
Transmission Lines ◽  
Computational Models ◽  
Equations Of Motion ◽  
Coupled System ◽  
Shaking Table ◽  
Analysis Method ◽  
Transmission Tower ◽  
Seismic Excitations ◽  
Line System ◽  
Out Of Plane

The simplified computational models of high-voltage transmission tower-line system under out-of-plane and in-plane vibrations are presented due to seismic excitations in this paper. The equations of motion are derived and the computer program is compiled to obtain the earthquake responses of the coupled system. To verify the rationality of the proposed approaches, the shaking-table experiments of the coupled system of transmission lines and their supporting towers are carried out and the results indicate that the errors of theoretical and testing results of systemic seismic responses are within the acceptable arrange in engineering area. Based on these studies, a simplified analysis method is proposed to make the seismic response calculation of coupled tower-conductor system faster and more effective.

Galloping of Transmission Tower-Line System and Anti-Galloping Research

2010 ◽  
Vol 44-47 ◽  
pp. 2666-2670
Author(s):  
Li Li ◽  
Wei Jiang ◽  
Hua Jin Cao
Keyword(s):  
Element Model ◽  
Nonlinear Finite Element ◽  
Control Measures ◽  
Transmission Tower ◽  
Line System ◽  
Transmission Towers ◽  
Coupling System ◽  
Internal Forces ◽  
Nonlinear Finite Element Model ◽  
Line Coupling

A nonlinear finite element model of transmission tower-line coupling system including transmissions, towers and insulators is established based on ANSYS in this paper. The restarting technology is proposed to solve the vertical, horizontal and torsional galloping of the transmission conductors. Under the condition of different wind velocity, galloping of tower line system is performed to get amplitude of the transmissions and internal forces of the transmission towers. Based on the typical case, the galloping control measures of using interphase spacers and multi-point weighting are performed. Various layouts projects of the galloping control measures are carried out and the effective ones are attained.

Gust Response Factor of a Transmission Tower Under Typhoon

2020 ◽  
pp. 2150001
Author(s):  
Xing Fu ◽  
Wen-Long Du ◽  
Hong-Nan Li ◽  
Wen-Ping Xie ◽  
Kai Xiao ◽  
...  
Keyword(s):  
Wind Speed ◽  
Field Measurements ◽  
Element Model ◽  
Structural Safety ◽  
Transmission Tower ◽  
Response Factors ◽  
Line System ◽  
Transmission Towers ◽  
Synoptic Wind ◽  
Gust Response

The gust response factors (GRFs) of transmission towers in current standards are reviewed for synoptic winds. The collapse of most transmission towers has occurred under the high-intensity wind (HIW) caused by events such as typhoons, hurricanes, and downbursts. Thus, this paper studies the GRF of a transmission tower under the typhoon. First, the definition of GRF and its extended form for the transmission towers are developed. Then the wind speed simulation of a typhoon event is introduced. Based on the structural health monitoring (SHM) system installed on tower #32, the measured GRFs under the super typhoon Mangkhut are calculated. Then the finite element model (FEM) of the transmission tower-line system is established to simulate the dynamic response to further calculate the GRFs, which agrees well with the field measurements. Both the field measurement and simulation results show that the GRFs under the typhoon are larger than those under the synoptic wind and that the recommended GRFs in the Chinese standard underestimate the peak responses. Finally, a parametric analysis is performed, which demonstrates that the turbulence intensity, wind speed, and power-law exponent all have great effects on the GRFs of transmission towers. In the HIW-prone areas, it is recommended that the characteristics of the HIW can be considered in improving the GRF values to guarantee the structural safety of transmission towers.

scholarly journals Nonlinear Seismic Behavior of Different Boundary Conditions of Transmission Line Systems under Earthquake Loading

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Li Tian ◽  
Xia Gai
Keyword(s):  
Boundary Conditions ◽  
Transmission Line ◽  
Transmission Lines ◽  
Seismic Analysis ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Earthquake Loading ◽  
Transmission Tower ◽  
Line System ◽  
Different Boundary Conditions

Nonlinear seismic behaviors of different boundary conditions of transmission line system under earthquake loading are investigated in this paper. The transmission lines are modeled by cable element accounting for the nonlinearity of the cable. For the suspension type, three towers and two span lines with spring model (Model 1) and three towers and four span lines’ model (Model 2) are established, respectively. For the tension type, three towers and two span lines’ model (Model 3) and three towers and four span lines’ model (Model 4) are created, respectively. The frequencies of the transmission towers and transmission lines of the suspension type and tension type are calculated, respectively. The responses of the suspension type and tension type are investigated using nonlinear time history analysis method, respectively. The results show that the responses of the transmission tower and transmission line of the two models of the suspension type are slightly different. However, the responses of transmission tower and transmission line of the two models of the tension type are significantly different. Therefore, in order to obtain accurate results, a reasonable model should be considered. The results could provide a reference for the seismic analysis of the transmission tower-line system.

Analysis on Wind-Induced Vibration Dynamic Responses of Transmission Tower-Line System

2013 ◽  
Vol 327 ◽  
pp. 284-289
Author(s):  
Xiao Guang Hu ◽  
Jing Bo Yang ◽  
Feng Li Yang
Keyword(s):  
Random Vibration ◽  
Coupling Effect ◽  
Dynamic Responses ◽  
Building Structures ◽  
Transmission Tower ◽  
Line System ◽  
Vibration Theory ◽  
Random Vibration Theory ◽  
Wind Induced Vibration ◽  
Line Coupling

Tower-line system of overhead transmission line are sensitive to wind. Therefore, dynamic effect of wind load should be taken into consideration, for instance, wind-induced vibration coefficient. There might be some errors in the calculation of the coefficient in accordance with ‘Load code for the design of building structures’, for its ignoring the irregular figure, scattered masses and coupling effect of tower-line system. Tower-line system is set up in virtual environment, with tower-line coupling considered, and research wind-induced vibration dynamic responses under Davenport wind speed spectrum. Random vibration theory was applied to calculate the coefficient. Whole tower was divided by hight, and calculated segment’s the wind-induced vibration coefficient seprately. Compare the coefficient from Load Code and random vibration theory, the latter with tower-line coupling effect and tower figure considered, is close to the actual.

scholarly journals 3D HIGH-EFFICIENCY AND HIGH-PRECISION MODEL-DRIVEN MODELLING FOR POWER TRANSMISSION TOWER

2020 ◽  
Vol XLIV-4/W3-2020 ◽  
pp. 421-426
Author(s):  
Z. Wu ◽  
H. Wang ◽  
W. Yu ◽  
J. Xi ◽  
W. Lei ◽  
...  
Keyword(s):  
High Efficiency ◽  
Power Transmission ◽  
Principal Direction ◽  
Point Clouds ◽  
Model Matching ◽  
Transmission Tower ◽  
Model Driven ◽  
Transmission Towers ◽  
Key Points ◽  
Tower Model

Abstract. Constructing the transmission tower from LiDAR point clouds is a fundamental step for smart grid. However, currently the transmission tower construction method relies heavily on manual editing, which is far from the practical industrial application. This paper proposes a model-driven based method to realize 3D construction of transmission tower fast and accurately. This method first generates different types of 3D tower models. Then, it calculates the direction characteristic of point clouds distribution using the obtained transmission towers point clouds. While finding the principal direction of transmission towers, the local coordinates of the transmission towers are settled. And then the key points are captured in a semi-automatically way. According to these key points, the transmission tower model that best matches the point clouds is selected using the model matching algorithm. Comparing with the existing traditional manual editing methods, the method proposed in this paper can ensure the integrity and accuracy of the reconstructed tower model using the model-driven based strategy. The proposed method makes a trade-off between manual editing and efficiency, which guarantees the quality of tower modelling. And the feasibility and practicability of the proposed method are verified by the experiments on real-world point clouds data.

scholarly journals Performance Evaluation on Transmission Tower-Line System with Passive Friction Dampers Subjected to Wind Excitations

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Bo Chen ◽  
Xiang Xiao ◽  
Peng-yun Li ◽  
Wan-li Zhong
Keyword(s):  
Performance Evaluation ◽  
Axial Stiffness ◽  
Parameter Study ◽  
Fe Model ◽  
Optimal Parameters ◽  
Friction Damper ◽  
Transmission Tower ◽  
Lumped Mass ◽  
Line System ◽  
Friction Dampers

The vibration control and performance evaluation on a transmission-tower line system by using friction dampers subjected to wind excitations are carried out in this study. The three-dimensional finite element (FE) model of a transmission tower is firstly constructed. A two-dimensional lumped mass model of a transmission tower is developed for dynamic analysis. The analytical model of transmission tower-line system is proposed by taking the dynamic interaction between the tower and the transmission lines into consideration. The mechanical model of passive friction damper is presented by involving the effects of damper axial stiffness. The equation of motion of the transmission tower-line system incorporated with the friction dampers disturbed by wind excitations is established. A real transmission tower-line system is taken as an example to examine the feasibility and reliability of the proposed control approach. An extensive parameter study is carried out to find the optimal parameters of friction damper and to assess the effects of slipping force axial stiffness and hysteresis loop on control performance. The work on an example structure indicates that the application of friction dampers with optimal parameters could significantly reduce wind-induced responses of the transmission tower-line system.

Effects of Tower-Line Coupling on Seismic Vibration Control of Large Crossing Transmission Tower-Line System with TMD

2011 ◽  
Vol 243-249 ◽  
pp. 4005-4008
Author(s):  
Gang Wu ◽  
Chang Hai Zhai ◽  
Shuang Li
Keyword(s):  
Vibration Control ◽  
Seismic Vibration ◽  
Transmission Tower ◽  
Fem Model ◽  
Line System ◽  
Dynamic Character ◽  
Line Coupling

At present, the effect of tower-line coupling is neglected in seismic vibration control with TMD for transmission tower-line system. However, for large crossing transmission tower-line system(LCTL), the neglect can affect the performance of TMD. In this study, a typical FEM model of LCTL is established. The effect of tower-line coupling on dynamic character of LCTL is analyzed. Then, the performance of TMD considering the tower-line coupling is compared with TMD neglecting the tower-line coupling. It is concluded that tower-line coupling affect the performance of TMD significantly for LCTL.

scholarly journals Effect of Unbalanced Force Loading on the Safety of Transmission Tower

2021 ◽  
Vol 898 (1) ◽  
pp. 012011
Author(s):  
Hongji Zhang
Keyword(s):  
Transmission Lines ◽  
Simulation Analysis ◽  
Practical Importance ◽  
Element Model ◽  
Transmission Tower ◽  
Maximum Displacement ◽  
Force Loading ◽  
Finite Element Software ◽  
Unbalanced Force ◽  
Transmission Towers

Abstract High-voltage transmission towers, as support points for overhead transmission lines, are often under the condition of unbalanced force loading. Transmission towers can collapse because of the unbalanced forces, leading to the power outage. Therefore, it is of practical importance to set a research on the effect of unbalanced force loading on the safety of transmission tower. In this paper, based on the prototype of 500kV transmission tower, the integral beam element model is established by ABAQUS finite element software for simulation analysis. Static load mode and unbalanced force loading were considered in this simulation model. Through the comparative analysis of the maximum displacement and stress in transmission tower, the safety of the 500kV transmission tower was analyzed. The variations of maximum displacement and Mises stress with the increasing unbalanced force were obtained. The limit of unbalanced force the 500kV transmission tower can sustain was given by comparing the simulated results.

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