Overhead Power Transmission Lines Research Articles

Achieving Superior Strength‐ductility‐conductivity Combination in TiB2p/6201 Composites via Particle Rotation and Sub‐grain Refinement

The key factor in the material design of overhead power transmission lines is to obtain a desired balance among strength, ductility and electrical conductivity. In this study, TiB2 particulate reinforced aluminum matrix composites were prepared to find a way out of the intrinsic dilemma behind this balance by tailoring the sub‐grain refinement. The interaction in the form of inhomogeneous deformation induced by the flexibility discrepancy between the rigid particles and soft matrix was studied. On the one hand, the hexagonal plate‐like TiB2 particles rotate with the inhomogeneous deformation, forcing the biggest exposed plane ((0001) basal plane) parallel to the plastic flow direction, which is beneficial for the dislocation multiplication and hindrance of dislocation slipping. On the other hand, inhomogeneous deformation generates plentiful geometry necessary dislocations, and divides the microstructure into two types: in the particle‐rich region ultrafine grains are formed, and in the particle‐free region significant sub‐grains refinement is observed. The sub‐grains with 3 wt.% TiB2 is refined from ∽897 nm to ∽248 nm. Thanks to these microstructural benefits, the composites achieve the following strength‐ductility‐conductivity combination: ultimate tensile strength is 370 MPa, elongation after fracture is 11.2%, and electrical conductivity is 51.79% IACS. Besides, the elastic modulus reaches 75.43 GPa.This article is protected by copyright. All rights reserved.

Novel lossy compression method of noisy time series data with anomalies: Application to partial discharge monitoring in overhead power lines

In overhead power transmission lines, particularly in regions like natural parks where establishing a safe zone is difficult, the adoption of cross-linked polyethylene insulated covered conductors (CCs) helps prevent outages due to vegetation contact. However, these CCs are susceptible to partial discharge (PD) activity, which can degrade insulation and lead to system failures. Detecting and analyzing PD are essential for maintaining power system reliability and safety. A key challenge in PD monitoring is transmitting the large volumes of PD signal data over unreliable 2G networks, as existing compression methods either compromise on data integrity or are ineffective. This paper introduces a novel lossy compression technique utilizing an autoencoder with skip connections and correction data to address this issue. Unlike previous algorithms that struggle with noisy time series data and fail to preserve crucial anomaly information, our method reconstructs the signal without anomalies, which are subsequently restored using correction data. Achieving a compression factor of about 25 (reducing data to 4.1% of its original size), this approach maintains essential PD signal features for analysis. The effectiveness of our method is validated by three classification algorithms, showing promise for future fault detection, diagnosis, and memory space reduction. This innovative compression solution marks a significant advancement in PD data processing, offering a balanced trade-off between compression efficiency and data fidelity, and paving the way for enhanced remote monitoring in power transmission systems.

Study of operation of a polymer insulator under uniform and non-uniform contamination

RELEVANCE. Suspended insulators, the technical condition of which largely determines the reliability of power supply to consumers of different categories, are one of the most damaged elements of overhead power transmission lines [1-2]. This is primarily due to the fact that during their operation, insulators are exposed to various climatic conditions that have a direct impact on their insulating properties. Moreover, precipitation, such as rain, fog or dew, has the greatest impact precisely in combination with various solid, liquid and gaseous particles deposited on the insulator surface from the air, and forming a layer of surface contamination. Wetting this layer increases the electrical conductivity of the entire overhead line insulation structure and reduces its insulating capacity. Study of influence of dampening of contaminated surface of suspended insulation on their discharge characteristics is an urgent scientific task. The solution of this task enables to develop the existing understanding of the mechanisms of formation and development of discharges on the contaminated and wetted surface of insulation and to formulate the appropriate diagnostic attributes applicable to control the condition of the overhead power line insulators. OBJECTIVE. To carry out laboratory research aimed at studying the behavior of suspended high-voltage polymer insulators of overhead power lines when they are moistened. To formulate appropriate diagnostic attributes applicable for control of condition of suspended insulators of overhead power lines during their operation. METHODS. At the solution of the posed problem experimental methods of research, consisting in simulation of work of the contaminated polymeric insulator in the atmosphere of a pure fog with application of the special experimental installation developed by the authors of this article were applied. RESULTS. As a result of laboratory research, by continuous registration of leakage current values, as well as signals coming from the remote sensor, characteristic features of contaminated insulator humidification were revealed, which can be used as diagnostic signs in the process of their operation.

Fault detection through discrete wavelet transform in overhead power transmission lines

AbstractTransmission lines are a very important and vulnerable part of the power system. Power supply to the consumers depends on the fault‐free status of transmission lines. If the normal working condition of the power system is disturbed due to faults, the persisting fault of long duration results in financial and economic losses. The fault analysis has an important association with the selection of protective devices and reliability assessment of high‐voltage transmission lines. It is imperative to devise a suitable feature extraction tool for accurate fault detection and classification in transmission lines. Several feature extraction techniques have been used in the past but due to their limitations, that is, for use in stationary signals, limited space in localizing nonstationary signals, and less robustness in case of variations in normal operation conditions. Not suitable for real‐time applications and large calculation time and memory requirements. This research presents a discrete wavelet transform (DWT)‐based novel fault detection technique at different parameters, that is, fault inception and fault resistance with proper selection of mother wavelet. In this study, the feasibility of DWT using MATLAB software has been investigated. It has been concluded from the simulated data that wavelet transform together with an effective classification algorithm can be implemented as an effective tool for real‐time monitoring and accurate fault detection and classification in the transmission lines.

Examination of Gas Active Arc Extinguishing and Lightning Protection for Transmission Lines

The study investigated the gas active arc extinguishing and lightning protection for transmission lines. Lightning is one of the most significant sources of over voltages in overhead transmission lines. The lightning over voltages could lead to failure of the devices connected to the transmission line. Fundamental constraint on the reliability of an electrical power transmission system is the effectiveness of its protective system. The role of the protective system is to safeguard transmission system components from the effects of electrical overstress. Shield wire and surge arresters are an important means of lightning protection in transmission and distribution systems. Therefore, it is necessary to analyze the influence of over voltages caused due to lighting. The requirements of system security for lightning protection technology reach the high standard that lightning strike tripping and wire breakage are not allowed. Both the power supply side and the demand side have very high requirements for lightning protection of transmission lines, but the lightning accident rate remains high. This situation poses a great threat to the reliability and safety of power network, it is urgent to solve this problem. The gas active interrupter principle is put forward. From two latitudes of lightning overvoltage and power frequency over current, the effective control of lightning accident rate caused by large probability and multiple lightning strike is realized. This paper is aimed at evaluation of protection level of transmission line by using gas active arc extinguishing, shield wire and line surge arresters against lightning overvoltage. When lightning strikes, the internal short gap of the main body and the air gap break down, and the lightning arc enters the arc-extinguishing body through the breakdown channel. Arc is compressed by force to form internal and external gradients temperature in order to produce jet airflow. Jet airflow acts on the subsequent power frequency follow current arc, a model coupling an arc and a compressed jet airflow in a multi-fracture compression airflow arc-extinguishing structure is established and simulated. The increase in voltage due to lightning are investigated by using the MATLAB software. Direct and induced, types of lightning strokes are considered. The model of a 33kV three-phase overhead power transmission line is developed considering the RL circuit. The simulations are performed based on time domain analysis. Also, numerical analysis is made for 133kV tower structure transmitting power over 220km from 132 KV Sub-transmission Lines in port Harcourt region. Based on the simulation study this research study gas active arc extinguishing and lightning protection for transmission lines, are very important in computer application like Electromagnetic Transient Propagation (EMTP) and Power System Computer Aided Design (PSCAD) which are used in future study. These soft wares provide an alternative way to bring the precise result in study of lightning protection level of high voltage transmission line.

Многофакторное автоматизированное исследование методов определения места повреждения на модели воздушной линии электропередачи 500 кВ

Fault location is one of the main means of automation of electric power on overhead power lines. Well-timed elimination and organization of maintenance and repair work to put power lines into operation require high accuracy of fault location. Fault location methods based on the parameters of emergency mode using data of electronic (digital or optical) instrument transformers have been developed in Ivanovo State Power Engineering University (ISPU). The use of electronic transformers makes it possible to reduce the instrumental error of fault location due to accurate measurements of electrical quantities during short circuit, including the measurement of the derivative of the primary current. The aim of the study of fault location methods developed by the ISPU team is to evaluate the errors of these methods with a variation of many factors affecting the calculation of fault location in an automated mode using modern modeling tools. A multifactorial automated research of the fault location methods is carried out using a simulation model of an ultra-high voltage network in the Matlab + Simulink software package. One-sided and two-sided fault location methods based on the parameters of emergency mode developed in ISPU are chosen as the studied methods. In the research methodology presented in the article, the values of the factors affecting the measurement of fault location, including the parameters of the network element models, are changed using a program in the MATLAB language with parallel calculations performed on different processor cores. A technique for automated research of fault location methods has been developed including a model of an ultra-high voltage electrical network in Simulink and a simulation model control program in Matlab. More than 100,000 computational experiments have been carried out for each fault location method. According to the study, the influence of transient resistance is excluded, and the influence of the network frequency is practically absent in the two-sided method. The change in the parameters of power transmission lines and equivalent systems is less affected in comparison with the one-sided method. The Monte Carlo method of fault location algorithms has shown that the errors of one-sided method do not meet the requirements of PJSC «FGC UES» standards in less than 20% of cases, and the errors of the two-sided method under the same modeling conditions do not meet the requirements only in 1% of cases. The developed research methodology makes it possible to evaluate the accuracy of fault location methods when changing the set of factors influencing the measurement in an automated mode. The carried-out research of one-sided and two-sided fault location methods based on emergency mode parameters and data of electronic transformers has showed sufficient accuracy on the model of a 500 kV overhead power transmission line with changes in individual factors affecting the measurement of fault location and when randomly setting a set of parameters of the network model.

Newly Designed Identification Scheme for Monitoring Ice Thickness on Power Transmission Lines

Overhead power transmission line icing (PTLI) disasters are one of the most severe dangers to power grid safety. Automatic iced transmission line identification is critical in various fields. However, existing methods primarily focus on the linear characteristics of transmission lines, employing a two-step process involving edge and line detection for PTLI identification. Nonetheless, these traditional methods are often complicated when confronted with challenges such as background noise or variations in illumination, leading to incomplete identification of the target area, missed target regions, or misclassification of background pixels as foreground. This paper proposes a new iced transmission line identification scheme to overcome this limitation. In the initial stage, we integrate the image restoration method with image filter enhancement to restore the image’s color information. This combined approach effectively retains valuable information and preserves the original image quality, thereby mitigating the noise presented during the image acquisition. Subsequently, in the second stage, we introduce an enhanced multi-threshold algorithm to separate background and target pixels. After image segmentation, we enhance the image and obtain the region of interest (ROI) through connected component labeling modification and mathematical morphology operations, eliminating background regions. Our proposed scheme achieves an accuracy value of 97.72%, a precision value of 96.24%, a recall value of 86.22%, and a specificity value of 99.48% based on the average value of test images. Through object segmentation and location, the proposed method can avoid background interference, effectively solve the problem of transmission line icing identification, and achieve 90% measurement accuracy compared to manual measurement on the collected PTLI dataset.

A Novel Autonomous Landing Method for Flying–Walking Power Line Inspection Robots Based on Prior Structure Data

Hybrid inspection robots have been attracting increasing interest in recent years, and are suitable for inspecting long-distance overhead power transmission lines (OPTLs), combining the advantages of flying robots (e.g., UAVs) and climbing robots (e.g., multiple-arm robots). Due to the complex work conditions (e.g., power line slopes, complex backgrounds, wind interference), landing on OPTL is one of the most difficult challenges faced by hybrid inspection robots. To address this problem, this study proposes a novel autonomous landing method for a developed flying–walking power line inspection robot (FPLIR) based on prior structure data. The proposed method includes three main steps: (1) A color image of the target power line is segmented using a real-time semantic segmentation network, fusing the depth image to estimate the position of the power line. (2) The safe landing area (SLA) is determined using prior structure data, applying the trajectory planning method with geometric constraints to generate the dynamic landing trajectory. (3) The landing trajectory is tracked using real-time model predictive control (MPC), controlling FPLIR to land on the OPTL. The feasibility of the proposed method was verified in the ROS Gazebo environment. The RMSE values of the position along three axes were 0.1205,0.0976 and 0.0953, respectively, while the RMSE values of the velocity along these axes were 0.0426, 0.0345 and 0.0781. Additionally, experiments in a real environment using FPLIR were performed to verify the validity of the proposed method. The experimental results showed that the errors of position and velocity for the FPLIR landing on the lines were 6.18×10−2 m and 2.16×10−2 m/s. The simulation results as well as the experimental findings both satisfy the practical requirements. The proposed method provides a foundation for the intelligent inspection of OPTL in the future.

A Data Set of Signals from an Antenna for Detection of Partial Discharges in Overhead Insulated Power Line

We introduce a data set obtained via a contactless antenna method for detecting partial discharges in XLPE-covered conductors used in medium-voltage overhead power transmission lines. The data set consists of almost three years’ worth of data, collected every hour from 9 measuring stations in Czechia and Slovakia. Each sample in the data set represents a single signal gathered for 20 ms. The contactless method is deployed on the same stations as the galvanic contact method, which is used by power distributors and can provide ground truth. Also manually curated data by human expert are present. Successful detection of partial discharges can prevent electricity shutdowns and forest fires resulting from insulation failure due to vegetation contact. The data set is particularly relevant for covered conductors used in mountainous regions where establishing a safe zone is challenging. The contactless method offers advantages such as cheaper and easier installation. The data set has the potential to develop machine learning models to detect partial discharges and facilitate safer and cheaper use of covered conductors.

The Reduction Factor of Pultrude Glass Fibre-Reinforced Polyester Composite Cross-Arm: A Comparative Study on Mathematical Modelling for Life-Span Prediction.

This paper presents an experimental and numerical investigation of pultruded composite glass fibre-reinforced polymer (pGFRP) cross-arms subjected to flexural creep behaviour to assess their performance and sustainability in composite cross-arm structure applications. The primary objective of this study was to investigate the failure creep behaviour of pGFRP cross-arms with different stacking sequences. Specifically, the study aimed to understand the variations in strain rate exhibited during different stages of the creep process. Therefore, this study emphasizes a simplified approach within the experiment, numerical analysis, and mathematical modelling of three different pGFRP composites to estimate the stiffness reduction factors that determine the prediction of failure. The findings show that Findley's power law and the Burger model projected very different strains and diverged noticeably outside the testing period. Findley's model estimated a minimal increase in total strain over 50 years, while the Burger model anticipated PS-1 and PS-2 composites would fail within about 11 and 33 years, respectively. The Burger model's forecasts might be more reasonable due to the harsh environment the cross-arms are expected to withstand. The endurance and long-term performance of composite materials used in overhead power transmission lines may be predicted mathematically, and this insight into material property factors can help with design and maintenance.

Моделирование режима одностороннего включения линии электропередачи сверхвысокого напряжения с применением устройства синхронизации моментов включения контактов фаз выключателя

Simulating the switching on of an overhead power transmission line (PTL) of ultra-high voltage in a dead-end mode, containing a significant aperiodic current component, both from the switch control key and in the three-phase automatic reclosing (TARC) cycle, is performed using the MATLAB software package. The aim of modelling is to search and find the optimal modes of electrical transmission operation in terms of admitting the values of the aperiodic current component and assessing possible values of overvoltages in the phases of power transmission lines. The possibility of using phase-by-phase control of a high-voltage circuit breaker, which ensures closing the power contacts of the circuit breaker phase at the moment of the maximum value of the instantaneous voltage on these contacts, is checked as a measure that can significantly reduce the influence of the aperiodic current component on the possibility of damaging switching equipment and developing an emergency situation in the power system. The results obtained can be used to practically eliminate the influence of the aperiodic current component in all possible modes (dead-end mode of an overhead line (OL), in an unsuccessful automatic reclosing cycle (ARC) for all types of short circuits on a high-voltage power line) with shunt reactors put into operation and without putting them into operation.

Ant Colony Optimization based algorithm to determine the optimum route for overhead power transmission lines

Electrical power distribution networks present one of the most essential infrastructure projects. Despite of the vitality of this sector and the huge budgets of their projects, but it is still depends on traditional manual routing techniques which are slow, expensive and inefficient comparing with the current AI revolutionary techniques. Hence, this research presented a novel AI model for optimizing “overhead power transmitting lines” (OHPTL) routing using Ant Colony Optimization (ACO) technique. The proposed technique depends on the core routine (which can generate random and valid routes and estimate their total cost) and searching algorithm (which uses ACO technique to find the optimum route among the generated routes). As a prototype, the proposed technique was codes in “Visual Basic for Applications” VBA, while MS-EXCEL was used to handle the graphical inputs and outputs. The functionality of the technique was validated using three virtual case studies and its optimization capability was tested using a real-life case study. The results showed that the total cost of the optimized route is about 75% of the existing route.

Risk assessment models of power transmission lines undergoing heavy ice at mountain zones based on numerical model and machine learning

To deliver the cleaner energy, such as water, wind and solar power, from the remote mountainous areas to the power load areas, overhead power transmission lines are widely employed around the world. It is not an easy job to guarantee the safety of the long distance power transmission with hundreds or even thousands of kilometers of lines, especially crossing heavy ice zones at mountains. In this work, a numerical model to simulate the static and dynamic responses of transmission lines undergoing heavy ice is proposed and validated. Using the model, parameter study under different line sections depending on the mountain terrains, height difference and tension in conductors is carried out. It is obtained that the ice-induced dynamic characteristics of transmission lines at mountain zones are highly different with those of traditional design standard, with more complicated and dangerous. Therefore, to assess the risk level of transmission lines at mountain zones, the numerical model is used to gather the big dataset. Then, five machine learning-based models, including three tree-based and two artificial neural network (ANN)-based models, are developed and compared to find the optimal one. It is found that the multi-layer feed-forward deep ANN (MLF-DNN)-based model behaves optimal with the best evaluation scores. Based on the models, the predominant input parameters to affect the risk level are obtained and some suggestions to improve the ice resistance for the design and operation of transmission lines at mountain zones are proposed.

Effects of parameter adjustment on the electromagnetic field of an overhead power transmission line model

Studies have shown that high-voltage power transmission lines emit electromagnetic radiation, which has adverse effects on human health. This paper presents the effects of parameter adjustment on the electric and magnetic fields of an overhead power transmission line model at human height. A finite element software, COMSOL multiphysics, was used to simulate the electric and magnetic fields. The electric and magnetic fields generated by the 1200-kV and 220-kV overhead power transmission line models were first computed and the models were validated by comparing the simulation results with those of previous studies. Numbers of parameter were adjusted in order to investigate their effects on the electric and magnetic field distributions. Based on the results, the electric field intensity increases with an increase in the voltage of the conductors. The magnetic field density increases with an increase in the current carried by the conductors. A voltage of 700 kV results in an electricity field intensity that exceeds the residential safety limit (50 kV/m) set by the International Commission on Non-Ionizing Radiation Protection. Hence, a proper right-of-way is needed to ensure that residential areas are at a safe distance away from transmission towers.

New Approach to Evaluate the Energy Efficiency of Overhead Power Transmission Lines: Results of Theoretical and Experimental Research

This article describes a new approach to evaluating energy efficiency of overhead power transmission lines which is based on power transmission line losses calculation taking into account induction currents and heating in the supporting elements. We present the results of theoretical and experimental research of induction currents and heating evaluation in pylons of the overhead power transmission line. To find the flux linkage for induction currents, calculations using the Poisson equation for vector magnetic potential were carried out. The limiting values of induction currents and heating temperature are estimated using a graphical approach. The analysis of the power losses balance for a 500-kV power transmission line demonstrates considerable energy-saving benefits. The update of the previous conference paper is implying to compare energy efficiency of the overhead power transmission line for thermal and electric energy losses associated with induced currents and to conclude about their interchangeability. Additionally, it is resumed which using technical assumptions in the study. The research work might be of interest for design and modernization of overhead power transmission lines.

Имитационное моделирование воздушных линий электропередачи напряжением 610 кВ для исследования алгоритмов определения места возникновения однофазных замыканий на землю

As part of evolution of single phase to earth faults protection methods and tools in 6–10 kV networks the development of simulation study methods of these networks and their components becomes relevant. A significant direction in this area is upgrading of sensors installed directly on the wires and electrical transmission towers. These sensors are installed in the conditions of an electromagnetic field acting on them and dynamically changes both in time and space, especially during emergency modes including single phase to earth faults. Application of modern software offers a challenge for complex simulation study of electromagnetic fields distribution at the location of the measuring transducers in continuously variable electromagnetic environment. The above-noted statement determines the relevance of the research goal, which is the development of a simulation study method of 6–10 kV overhead power lines, the model of which is designed to study existing and create new single phase to earth fault location algorithms and devices. To solve the tasks set the methods of simulation study of overhead transmission lines and corresponding medium voltage networks in PSCAD and COMSOL Multiphysics software have been used. The general concept of design of a 6–10 kV network and an overhead transmission line simulation model is formulated. The geometrical parameters of the section of the model of an overhead power transmission line to simulate electromagnetic transients are selected, considering the frequency dependence of the line parameters (inductance and active resistance). The proposed model of the overhead transmission line is verified, and recommendations for its application are given. The developed “inductive” component of the proposed overhead transmission line model allows to provide high accuracy of calculation of transient components of currents and voltages during single phase to earth faults. It makes possible to use this model for the development and research of single phase to earth fault location algorithms. The developed approach to simulation study of an overhead transmission line is the field of interest for further research, as it makes it possible to calculate the components of the electric field which are observed during single phase to earth faults.

Особенности моделирования воздушных и кабельных участков линий электропередачи 110–750 кВ при использовании фазного координатного базиса

Power system steady state and transient analysis require correct modeling of overhead transmission lines and cables operating at 110–750 kV. The key difficulties to model sections of overhead and cable lines are caused by complex conductor geometry, their transposition, as well as grounding schemes of ground wires of overhead lines and screens of underground cables. The paper covers various aspects of 110–750 overhead line and cable modeling that must be taken into consideration to obtain a reliable mathematical model in a phase domain. Modern software does not provide a universal solution to determine line parameters. The 110–500 kV cable line modeling issues have not been worked out properly and require careful analysis of specialized foreign literature. Thus, the task to develop the algorithms of calculating the parameters of overhead and cable power lines is relevant, taking into account the various configuration options of these lines which are possible in operational practice. To derive overhead transmission line and cable line models, electric circuit theory and matrix algebra methods have been used. The ATP/ATPDraw and MATLAB/Simulink software environment has been used to investigate what tools are available to determine line parameters, as well as to verify some of the calculation results. Analysis has been carried out to reveal the options available in the ATP/ATPDraw and MATLAB/Simulink software to compute line parameters in a phase domain. An algorithm has been developed and verified to calculate overhead line parameters regardless of the number of parallel circuits. The key features of the calculation of the matrix of linear resistances of overhead power transmission lines are outlined. The main features of modern cable lines operating at 110–500 kV are also described. The paper presents various cable layouts possible in real-field conditions, as well as provides expressions that allow obtaining correct impedances and admittances for a system of cable line conductors. Study of the options of various software tools dedicated to overhead line parameter calculation in a phase domain has revealed that these tools cannot be deemed universal to represent an overhead line of whatever configuration. However, the developed algorithm is universal as it allows computing line parameters regardless the ground wire grounding approach. The expressions presented in this paper consider various layouts of 110–500 kV cable lines that could be encountered in the Russian power system.

The method of multi-objective parametric design of magnetic field active canceling robust system for residential multy-story buildings closed to double-circuit overhead power lines

Aim. Development the method of multi-objective parametric design for robust system of active canceling of magnetic field based on binary preference relations of local objective for multi-objective minimax optimization problem. Methodology. Spatial location coordinates of the compensating winding and the current in the shielding winding were determined during the preference-based multi-objective parametric design of systems of active canceling based on solution of the vector minimax optimization, in whith the vector objective function calculated based on Biot-Savart's law. The solution of this vector minimax optimization problem calculated based on nonlinear Archimedes algorithm. Components of Jacobi matrix and Hesse matrix calculated based on multi-swarm multi-agent optimization. Results. Theoretically and experimentally confirmed the effectiveness of reducing the level of the magnetic field in residential multy-storey old building of a double-circuit overhead power transmission lines with a barrel-type arrangement of wires by means of active shielding with two compensation winding. Originality. The method of multi-objective parametric design for robust system of active canceling of magnetic field based on binary preference relations of local objective for multi-objective minimax optimization problem is developed. Practical value. It is shown the possibility to reduce the level of magnetic field in residential multy-storey old building closed to double-circuit overhead power transmission lines with a barrel-type arrangement of wires by means of system of active canceling with two canceling winding to a level safe for the population with an induction of 0.5 μT.

Uncertainties Propagation and Global Sensitivity Analysis of the Aeolian Vibration of OPGW Cables

AbstractThis paper is devoted to evaluating the quantification of uncertainty involved in the study of Aeolian vibrations of optical ground wire (OPGW) cable systems installed on overhead power transmission lines. The energy balance method (EBM) is widely used to estimate the severity of steady-state Aeolian vibrations. Although the EBM requires some experimental characterization of system parameters (as indicated by international standards), it is necessary to mention that such a procedure is connected with uncertainties which makes it difficult for the proper homologation of the cable systems. In this article, the parametric probabilistic approach is employed to quantify the level of uncertainty associated with the EBM in the study of Aeolian vibrations of OPGW. The relevant parameters of the EBM (damper properties, cable self-damping, and the power imparted by the wind) are assumed as random variables whose distribution is deduced by means of the maximum entropy principle. Then a Monte Carlo simulation is performed, and the input and output uncertainties are contrasted. Finally, a global sensitivity analysis is conducted to identify the Sobol' indices. Results indicate that parameters related to self-damping and damper are the most influential on uncertainty and output variability. In this sense, the present framework constitutes a powerful tool in the robust design of damper systems for OPGW cables.

Path Planning of Unmanned Aerial Systems for Visual Inspection of Power Transmission Lines and Towers

The inspection of power transmission and distribution systems is performed visually by foot patrolling and helicopter methods. These methods have various disadvantages such as time-consuming, high operating cost, safety issues, and improper results. To overcome this issue, power utility companies are searching for the alternatives like Unmanned Aerial Systems (UAS) or drones. UAS are safe, cost effective, and requires less time for power transmission line inspection compared to the regular methods. In this manuscript, a decisive flight path planning for UAS to visually inspect a power transmission line and towers is explained. The objective of this paper is to maximize the performance of three functions such as coverage of transmission tower, quality of captured image, and flight time. Second, proposing an automated inspection strategy for UAS to follow the overhead power transmission lines. These objectives are achieved by formulating a cost function, to convert the path planning into a safe operation for UAS. The results of Particle Swarm Optimization (PSO) and Simulated Annealing (SA) are compared to find the best path for UAS. The experimental finding shows that PSO algorithm has higher efficiency and effectiveness compared to the SA algorithm and benefits the UAS with a safe flight path for the inspection of power transmission towers.