Line Tower Research Articles

Tower and power line segmentation method based on RandLA-Net

Abstract The scale of the power grid of China has gradually expanded, and the number of long-distance and high-level transmission lines has also increased. However, it is very hard to detect the power infrastructure transmission lines because of the complex laying environment and various ground features. Lines and towers in the power system are important components of power transmission, and their safety directly affects the operation of the entire power system. Reasonable management of lines and towers can reduce the occurrence of faults and system safety risks. At present, both manual inspection efficiency and visual inspection processing accuracy are low. An airborne LiDAR point cloud has become a key means for monitoring towers and power lines. In response to the above problems, we propose a tower and power line segmentation algorithm based on RandLA-Net. Experimental results demonstrate that the proposed method gets precise detection of power poles and lines, and enhances the efficiency in identifying hazardous areas along power lines. The highest Mean Intersection over Union (mloU) recorded is 95.34%, establishing a clear correlation between power towers and lines. Power line data holds significant importance for the power sector, facilitating the monitoring and management of transmission lines.

Numerička analiza titrajnog odziva dalekovoda velikog raspona prijenosnih vodova izazvanog vjetrom

Based on the engineering background related to ±800 kV ultra-high voltage (UHV) transmission lines spanning the Yellow River, finite element models were developed for single-tower and transmission tower-line systems, with their wind-induced responses under wind loads were simulated and analysed. In addition, the coupling effect in a large-span transmission tower line system was investigated. The results showed that the natural vibration frequency of the tower-line system was slightly lower than that of a single tower and that the torsional natural frequency was the most significantly reduced. The transmission tower-line system has a maximum displacement of 1.92 times that of a single tower when the wind angle is 0°. The maximum axial force and stress in the tower-line system are 1.6 times and 1.37 times higher than those in a single tower. The interaction between the tower and wires significantly affects the wind-induced response of the tower body. Hence, considering the dynamic coupling effect of the tower-line transmission system is important when designing a tower.

Experimental and Finite Element Analyses of Adjustable Foundation Bolts in Transmission Towers

Uneven settlement of transmission tower foundations can result in catastrophic events, such as tower collapse and line failures, disrupting power transmission operations. To address the challenging repairs caused by uneven foundation settlement of transmission towers, we propose an adjustable foundation bolt (AFB). This paper provides a detailed theoretical analysis of the AFB’s stability and load-bearing capacity, including critical buckling force formulas and maximum normal stress expressions. Finite element simulations confirm the precision of our theoretical formulations. Additionally, we introduce a method using baffles to enhance its load-bearing capacity, analyzing the impact of different numbers of baffles through numerical simulations. The experimental results validate the effectiveness of baffles in enhancing structural load-bearing capacity. The device brings convenience and efficiency to the maintenance of transmission towers.

An efficient active learning Kriging approach for expected fatigue damage assessment applied to wind turbine structures

Estimating fatigue damage in wind turbine structures over their lifetime is a time-demanding task, necessitating simulations encompassing all the wind and wave conditions. Typically, this involves expending several thousand hours in simulation efforts. Given formidable computational demand, this study proposes an efficient active learning Kriging approach named ALK-EFDA for estimating expected fatigue damage in wind turbines. The ALK-EFDA framework leverages a Kriging surrogate model to predict fatigue damage levels across various wind-wave scenarios, and a learning function is designed to reduce Kriging prediction error in the high probability of occurrences of wind-wave cases. An active learning approach is proposed to estimate the expected fatigue damage efficiently. To validate the effectiveness of this approach, we applied it to a 15 MW Semi-submersible floating wind turbine model. The proposed approach estimates the expected short-term fatigue damage of the wind turbine tower and mooring lines. Our findings demonstrate that the ALK-EFDA method efficiently and accurately estimates fatigue damage in wind turbine structures. Compared to simulation methods, the proposed ALK-EFDA approach significantly reduces computational expenses by over 30 times. Furthermore, the absolute error, when compared to simulated results, remains at approximately 1%. This method will be a useful tool for offshore wind turbine designers.

Research on ice shedding and broken conductor in tower-line system based on CR method

In cold climates, the damage to the transmission tower-line system is usually caused by ice shedding, broken conductors, and broken ground wires. To replicate the ice shedding and broken conductor scenarios more accurately and expeditiously within the transmission tower-line system, we have engineered a finite element computational program leveraging the co-rotational theory method, utilizing the C++ programming language. Additionally, we have orchestrated its visualization interface utilizing the QT and Visualization Toolkit (VTK) platforms. This program can accurately and rapidly simulate large displacement geometric nonlinear problems. An ice detachment criterion considering the resultant acceleration is proposed. Compared with previous judgment criteria, the criterion proposed in this article can adapt to the previous prediction accuracy and is more efficient in calculation. A finite element method for disconnection simulation of “node failure” was proposed, and its accuracy and computational efficiency were verified by comparison with experiments. By analyzing the coupling effect of disconnection and deicing in the tower line system, it is concluded that ground wires often have a stronger deicing effect than conductors. Although broken conductor will cause large-scale ice shedding from the span, the impact on the most dangerous point of the tower will be very small, this providing a theoretical basis for ice-covered broken conductor in the tower-line system. The simulation method proposed in this article also provides a new research idea for the simulation of ice shedding and broken conductor of tower-line systems.

Coupled Dynamic Characteristics of a Spar-Type Offshore Floating Two-Bladed Wind Turbine with a Flexible Hub Connection

To reduce manufacturing, transportation, lifting and maintenance costs of increasingly larger and larger floating wind turbines, a Spar-type floating two-bladed wind turbine based on the 5 MW OC3-Hywind floating wind turbine model from the National Renewable Energy Laboratory (NREL) is studied in this paper. The two-bladed wind turbine can cause serious problems with large dynamic loads, so a flexible hub connection was introduced between the hub mount and nacelle carrier to alleviate the dynamic effect. The paper focuses on studying the dynamic responses of the proposed Spar-type floating two-bladed wind turbine with a flexible hub connection at rated and extreme environmental conditions. Fully coupled time-domain simulations are carried out by integrating aerodynamic loads on blades, hydrodynamic loads on the spar, structural dynamics of the tower, blades and mooring lines, control system and flexible hub connection. The analysis results show that the application of a flexible hub connection between the hub mount and nacelle carrier can make a contribution to enable the Spar-type floating two-bladed wind turbine to effectively dampen the motion of the floating platform, while significantly reducing the tower load and blade deflection.

RCDAM-Net: A Foreign Object Detection Algorithm for Transmission Tower Lines Based on RevCol Network

As an important part of the power system, it is necessary to ensure the safe and stable operation of transmission lines. Due to long-term exposure to the outdoors, the lines face many insecurity factors, and foreign object intrusion is one of them. Traditional foreign object (bird’s nest, kite, balloon, trash bag) detection algorithms suffer from low efficiency, poor accuracy, and small coverage, etc. To address the above problems, this paper introduces the RCDAM-Net. In order to prevent feature loss or useful feature compression, the RevCol (Reversible Column Networks) is used as the backbone network to ensure that the total information remains unchanged during feature decoupling. DySnakeConv (Dynamic Snake Convolution) is adopted and embedded into the C2f structure, which is named C2D and integrates low-level features and high-level features. Compared to the original BottleNeck structure of C2f, the DySnakeConv enhances the feature extraction ability for elongated and weak targets. In addition, MPDIoU (Maximum Performance Diagonal Intersection over Union) is used to improve the regression performance of model bounding boxes, solving the problem of predicted bounding boxes having the same aspect ratio as true bounding boxes, but with different values. Further, we adopt Decoupled Head for detection and add additional auxiliary training heads to improve the detection accuracy of the model. The experimental results show that the model achieves mAP50, Precision, and Recall of 97.98%, 98.15%, and 95.16% on the transmission tower line foreign object dataset, which is better to existing multi-target detection algorithms.

Transmission Tower and Power Line Detection Based on Improved Solov2

Transmission Tower and Power Line Detection Based on Improved Solov2

Application of BPNN Optimized by Fireworks Algorithm on Structural Bearing Capacity Analysis of Transmission Tower under Icing Conditions

With the increasing power demand in city development, the construction and application of transmission towers need to meet higher requirements. Icing is an extreme meteorological condition in the world, and icing disasters cause various accidents such as tower collapse and line disconnection of large-area lines every year. Therefore, it is of great significance to study the ultimate bearing capacity of transmission towers under icing conditions. The structural bearing capacity under icing is greatly affected by meteorological conditions and environmental factors, which has strong randomness and complexity, and brings a series of urgent problems to the structural stability of transmission towers. In the paper, the ultimate bearing capacity analysis and failure path research are conducted on the 500 kV linear cathead tower structure, and a structural bearing capacity prediction model based on the fireworks algorithm (FWA) is established. In order to accurately predict the structural bearing capacity, reduce the adverse effects of line icing, and ensure the structural stability of the transmission tower, the FWA is introduced into the neural network model. The self-adjusting mechanism of the local search ability and global search ability of the FWA is used to optimize the optimization process of weights and thresholds in the neural network, and a structural bearing capacity prediction model based on the FWA improved backpropagation neural network (BPNN) is proposed. Through the analysis and calculation of the measured data of the transmission tower in a certain area, and the comparative study with the traditional BPNN and the BPNN optimized by other common algorithms, the analysis and calculation results of the FWA-BPNN model used in this paper are closer to the actual value, the multiple indicators are more superior, and the model is more stable, which can realize the rapid and accurate analysis of the axial stress of tower members and maximum displacement between member nodes of the transmission tower under the icing condition.

In-situ live jacking technology of corner transmission tower

Aiming at the current situation that the foundation of the corner transmission tower is corroded, sunken, or the height of the tower line is insufficient, innovative low-cost technology is proposed to upgrade the foundation in-situ based on no power outages, and the analysis of the whole process of the in-situ live jacking construction of the transmission tower is studied in this paper. Firstly, through elastic mechanical equilibrium relationship, two form-finding methods of numerical analysis are derived and the results of several form-finding methods are analyzed and compared by a project example, among which the result error of the finite element method and the catenary method is negligible, while the error of the parabolic method is about 2% compared with the first two methods, but it can meet the engineering requirements. Secondly, the relevant laws of internal force and deformation of the lifting process are summarized, and a comparative analysis of theoretical and measured results verified the reliability and safety of the technology. Through the calculation program of the self-compiled parabolic method, the laws of tower line changes during the lifting process of the transmission tower are summarized, providing technical support for engineering practice and reference for related research.

Research on electromagnetic scattering characteristics of high voltage transmission lines considering rough surface

With the continuous construction of the UHV power grid in China, the electromagnetic scattering of electromagnetic waves from random rough surfaces will have a certain impact on the passive interference of high-voltage transmission lines. To solve the problem of solving the propagation law of electromagnetic scattering in the electromagnetic interference of high-voltage transmission lines to radio stations, this paper is based on the approximation method and moment method of electromagnetic scattering, This paper explores the influence of lossless rough surface and lossy rough surface on the passive interference of high-voltage tower line, focusing on the influence of sea level and dielectric constant of seawater on the electromagnetic scattering characteristics of the target under the sea background, and obtains the general law.

Study of the Prevention Method of ±800 kV Transmission Tower Foundation Deviation

The stability of transmission tower bases is key to ensuring the safe operation of power lines. This paper proposes a joint displacement-control technique for foundation-inclined piles and prestressed foundation tie beams to address the problem of tower base displacement and durability degradation caused by environmental factors. A finite element model of an exposed-pile transmission tower conforming to the structural characteristics of the actual line tower was established based on the current situation of Tower 292 of the ±800 kV Tianzhong line in Xinjiang, China. Three different displacement-control schemes were analyzed under the combined effects of tower line load, ice-cover load, and wind load, including changing exposed pile height, changing inclined pile tilt angle, and increasing the prestressed foundation tie beam. The analysis shows that the combined displacement-control technology of foundation-inclined piles and prestressed foundation tie beams can reduce the horizontal displacement of EHV tower foundations by more than 50%, which greatly reduces safety problems caused by tower displacement and effectively improves tower durability.

Shape Memory Alloy-Spring Pendulum for Vibration Suppression of Wind-Induced Transmission Tower-Line Systems

Wind-induced vibration suppression of transmission line structures is critical for structural reliability and serviceability. In this study, a shape memory alloy-spring pendulum (SMA-SP) is proposed for a wind-induced tower-line system to improve the reliability and serviceability of the control unit. A numerical calculation method of the transmission tower line structure coupled with the SMA-SP is established with special emphasis on the solid elements of the damper. Furthermore, the effectiveness and reliability of vibration suppression on wind-induced transmission line structures are evaluated and parametric analyses are conducted; the results reveal the influences of key parameters on the performance of SMA-SP and provide design recommendations for applications. In this study, it is demonstrated that the SMA-SP provides more stable control effects on the wind-induced vibration of transmission line structures than a conventional spring pendulum (SP), and the proposed numerical method effectively demonstrates the nonlinear mechanism of the damper. The parametric analyses show that SMA-SP exhibits low sensitivity levels to variations in the tuning frequency ratio and achieves optimal reduction effects after satisfying the internal resonance condition.

Seismic response study of a steel lattice transmission tower considering the hysteresis characteristics of bolt joint slippage

Ignorance of the influences of bolt slippage effects on transmission towers will lead to the underestimation of the deformations of the transmission towers. Therefore, the responses of transmission towers under different load scenarios cannot be accurately predicted. This will result in an incorrect estimation of the ultimate load-bearing capacity and the failure mode of transmission towers. Recently, studies of the influences of bolt slippage effects on transmission towers have been limited to static analysis only. This paper presents a dynamic response study of transmission towers considering bolt slippage. This paper first presents the test results of the mechanical properties of typical bolt joints in transmission towers under cyclic and monotonic loads. The numerical models of typical joints and the hysteresis curves of each joint under cyclic loads are then proposed, and the numerical models of hysteresis curves are validated through laboratory tests. From the various simulation results on the different types of joints, the hysteretic curves of each joint are obtained, and the skeleton curves are extracted. The numerical models of the slippage effect of transmission tower joints are then integrated into the tower–line system model for seismic analysis. The numerical simulation results indicate that neglecting the dynamic effect of bolt slippage will underestimate the seismic response of transmission towers, which will directly lead to an overestimation of the dynamic resistance capacity of the transmission towers. Furthermore, the higher the earthquake magnitude is, the more serious the influence.

Seismic responses of transmission tower-line system under multi-component ground motions

In this study, shaking table tests, theoretical research, and finite element modeling analysis were conducted on seismic responses of a transmission tower-line system under multi-component ground motions. The rocking component of ground motion was determined from the original seismic record by the wavelet analysis. The shaking table tests for scale models (single tower and tower-line system) that satisfy the similarity ratio of an actual tower-line system, were performed under multiple directions of motion. Dynamic equations under multi-component (horizontal, coupled horizontal, and tilting (CHT), and coupled vertical, horizontal, and tilting (CVHT)) ground motions were first derived in theoretical studies. The finite element model based on the actual transmission tower line system was built, and the response of the system under the identical working condition was calculated. It is found that the rotational component of the ground motion cannot be overlooked and significantly impacts the seismic response of the tower-line system, which is reflected especially as the vertical motion is coupled. The tilting ground motion, the additional second-order effect, and the foundation tilting jointly cause the increase in the response amplitude and significant asymmetric displacement effect. Since this effect of tilting ground motions, the weakening effect of the transmission line to reduce the responses for the displacement and acceleration of the tower-line system is also weakened. It is, therefore, essential to consider the adverse effects of multi-component ground motions on the designing of transmission tower systems in high-intensity areas.

Paradigm of Numerical Simulation of Spatial Wind Field for Disaster Prevention of Transmission Tower Lines

Paradigm of Numerical Simulation of Spatial Wind Field for Disaster Prevention of Transmission Tower Lines

Fully coupled aero-hydrodynamic analysis of a biomimetic fractal semi-submersible floating offshore wind turbine under wind-wave excitation conditions

With wind energy utilization shifting to the deep sea, floating offshore wind turbines (FOWTs) have huge potential to improve the competitiveness of offshore wind energy generation. However, traditional FOWT systems are often in force imbalance due to the unique swaying characteristics caused by the unfixed foundation and high center of mass of the platform. Therefore, a novel bionic semi-submersible floating platform based on Victoria Amazonia (with random fractal structure) is proposed to increase the hydrodynamic stability of FOWT. A regular fractal structure with similar number of perforations and perforated area is also implemented to verify the effectiveness of the bionic FOWT. In this study, the unsteady computational fluid dynamic approach is adopted to simulate the aerodynamic and hydrodynamic response. More specifically, the dynamic fluid-body interaction module integrated in STAR-CCM+ is employed to establish a FOWT numerical model with rotating blades, tower, and mooring line system. Furthermore, the volume of fluid model in conjunction with the 6-DOF solver was used to efficiently solve the fluid-induced dynamic motion of FOWT in a multi-phase flow composed of air and water. Finally, the fully coupled calculation of the fractal structure FOWT was performed using the established reliable numerical model. The maximum average thrust and power of 736.43 kN and 5294.04 kW are obtained by random fractal FOWT in aerodynamic responses, while in hydrodynamic amplitude responses, the maximum decreases of 19.16% are obtained by both random fractal and regular fractal structures. As for amplitude responses in heave and surge, the random fractal FOWT of 12.91% and 5.05% decreases performs relatively better than the regular one (11.48% and 4.09% decreases). In addition, the visualization of unsteady flow fields and vortices in fractal structures is investigated in detail. Compared with the regular fractal structure, vortices within random fractal structure interact adequately with the pontoon walls, resulting in higher energy absorption effect and stability.

Research on Grid Information Model (GIM) Technology of Transmission Line Based on Full-area Feature Weight Template Matching Recognition

Aiming at the problems of low efficiency, poor spatial location and incomplete attribute information in current transmission line modeling methods, a refined modeling method for transmission lines based on full area feature weighted template matching is proposed. First, collect the point cloud of the scary line, and extract the point cloud data of the tower and power line; Secondly, statistical outlier filter is used to denoise point cloud data; Finally, the GIM model of the transmission line is constructed by using the whole region feature weighted template matching method, which realizes the integrity and lightweight of the geometric, appearance and semantic information of the three-dimensional model of the transmission line, improves the efficiency of the transmission line modeling, and is verified by taking a 500kV transmission line as an example.

Numerical Simulation of Galloping Characteristics of Multi-Span Iced Eight-Bundle Conductors Tower Line System

The galloping condition of an iced eight-bundle conductor tower line system, under different parameters, is studied by using a finite element model of a multi-span iced eight-bundle conductor tower line system. The galloping frequency, amplitude, traces of multi-span iced eight-bundle conductors under different wind velocities, span lengths, and initial angles of wind attack are discussed. The different tower line connection methods are compared, based on existing research on the relationship between the aerodynamic characteristics of the conductor and galloping conditions. The results show that the galloping situation of a multi-span iced eight-bundle conductor tower line system varies greatly depending on the conditions, which has a significant impact on the tower line.

Research on transient response of tower-line system under wind field based on finite element simulation

Most of the transmission poles and towers are built in the wild, and are often subjected to various loads such as wind, rain, ice and snow, especially the collapse of the tower caused by wind disasters. In order to study the response characteristics and disaster risk of towers under the wind field, this paper takes a 110kV transmission line as an example, and builds a “three towers and two lines” model based on ANSYS. Relevant specification parameters are calculated for the tower and conductor loads in this wind field, and the wind pressure time history is generated; based on the ANSYS transient analysis, the load wind pressure time history is used to analyze the dynamic response of the tower line, and the model is obtained in the static and dynamic wind field. Under the stress and displacement results, the response characteristics were analyzed. The research results can provide reference for tower design and line disaster prevention and mitigation.