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This paper introduces a singular measurement infrastructure for real-time monitoring of transmission lines, applied to a 230 kV section of the Brazilian grid. The system aimed to expand the scope of monitoring variables using new concepts of optical sensing. Thus, variables are captured not only in the electrical domain but also in the mechanical, thermal, and environmental domains through optical technologies and meteorological measurement sensors strategically positioned along the transmission line. The system relies on new features, including a high-voltage polymeric insulator instrumentalized with optical fiber sensors to measure line electrical current, conductor temperature, mechanical strain, and an electro-optical signal processing unit fed by a solar system. The correlations between the monitored variables provide more complete information about what happens in the transmission line compared to the analysis of purely electrical quantities. For instance, the Spearman coefficient of 0.9909 highlights the strong correlation between anchoring force and ambient temperature. This new way of monitoring systems opens the doors to a multivariate power system analysis. [ABSTRACT FROM AUTHOR]

This article presents a novel scheme for matching real source impedance at uncorrelated dual frequencies to frequency-dependent complex loads (FDCLs). The series transmission line as an FDCL to complex conjugate load (CCL) transformer, which has been used in several earlier reported dual-band matching networks, can be used under limited load conditions. In the proposed scheme, instead of transforming the loads to two complex conjugate points on the Smith chart, the series transmission line is used to transform loads to two uncorrelated points on g = 1 circle, hence matching the real part of the admittance. The leftover susceptances are then cancelled using stubs. This enables dual-band impedance matching under all load conditions at any frequency ratio. Two structures have been presented utilizing the proposed scheme. The complete mathematical description with closed-form solutions for both the proposed structures are provided. Two prototype matching networks for frequency ratios 2.75 and 5.6 using structures I and II respectively are designed and implemented on ROGERS RO4003 substrate having a dielectric constant of 3.38 and a substrate height of 20 mils. The simulated and the measured results are in good accordance. [ABSTRACT FROM AUTHOR]

Existing fault situation frameworks conventionally use different ABC-domain or sequence network equivalent circuits for different fault types. The environmental conditions lead to changes in the parameters of the double-circuit transmission lines, and these incorrect parameters cause errors in the fault situation frameworks. The best tool for fault situation and protection of double-circuit transmission lines is the use of frameworks that work independently of the line parameters. In this article, fault situation for double-circuit transmission lines is implemented based on the measured voltage and current of each line, utilizing an Extreme Learning Machine capable of identifying nonlinear equations between measured values and fault situation. First, all types of faults were simulated at different distances in a power grid with a double-circuit transmission line. Then, the information obtained is utilized to train intelligent tools. Finally, the fault situations for different distances and resistances are estimated to assess the suggested method. To assess the superiority of the suggested framework over other intelligent frameworks, the outcomes of this article are compared with the outcomes obtained from two intelligent tools, artificial neural networks and support vector machines, which show more precision and reliability of the Extreme Learning Machine than other tools. [ABSTRACT FROM AUTHOR]

To investigate the force characteristics of phase spacers during ice-shedding galloping of transmission lines, a comprehensive finite element model for double-circuit lines on the same tower was developed. The analysis focused on the spacers' suppression effect on galloping and the variation in their axial force. A solid finite element model of phase spacers was constructed, incorporating suspension fittings, ball eye links, and composite insulators. By using the axial force time history under galloping as excitation, the deformation and stress distribution of phase spacers, as well as stress changes in their connection fittings, were studied. The results revealed that phase spacers significantly suppress galloping, with a more pronounced effect on middle-phase conductors. Axial force fluctuates sharply due to galloping, but stabilizes over time, approaching a limit value. The ice-shedding galloping phenomenon impacts stress distribution, with the ball eye link being more susceptible to fracture. Although the ball-and-socket connection at the composite insulator stem may experience high bending stress, the overall stress distribution meets safety requirements, ensuring safe and stable transmission line operation. [ABSTRACT FROM AUTHOR]

Transient analysis in power systems is essential for identifying deficiencies in the system, as well as for the protection and design of equipment. Transients can arise from natural events or network operations; in either case, they have the potential to cause significant damage to transmission lines, protection devices, generators, or transformers. This study examines a 20 kA, 1.2/50 µs lightning strike on a distributed-parameter transmission line connected to a power transformer. The voltage distributions across the winding sections on the neutral grounded high-voltage side of a disc-structured power transformer were obtained using the state-space method. An equivalent circuit for the state-space model was also developed in the Alternative Transients Program–Electromagnetic Transients Program (ATP-EMTP), and the results from both methods were compared. Both approaches revealed that the voltage waveforms in the transformer's winding sections were consistent, with the voltage distribution decreasing linearly. Additionally, the voltage–current waves reached the transformer with a specific delay, depending on the characteristics of the transmission line and the location of the lightning strike. The impact of an increase in the grounding resistance value on the high-voltage side of the transformer on voltage distribution and peak voltage levels was examined. The proposed method effectively captures the voltage–current behavior of the transmission line and transformer windings during transient conditions. It is concluded that the state-space method serves as a viable alternative for transient analysis in power systems and can enhance the design of protection equipment and winding insulation studies. [ABSTRACT FROM AUTHOR]

This article describes a novel method for locating and detecting triple line to ground (LLL-G) faults in 110 km of 132 kV transmission lines. To find the transmission line fault, the three phase system currents were first recorded at the appropriate sampling frequency. Then, the total harmonic distortion (THD) and direct current (DC) components were computed using the Fast Fourier transform (FFT). When compared to normal conditions, high values of THD and DC components have been seen in fault situations; fault has been identified as a result. The fault distance in the transmission line has been measured using spline extrapolation or linear interpolation. With this method, very encouraging outcomes have been obtained for fault assessment in transmission line. [ABSTRACT FROM AUTHOR]

During deicing operations on transmission lines, the cutting forces generated by the milling cutter of a deicing robot exert significant reaction forces on the robot body. Excessive cutting forces can compromise the robot's locomotion stability and deicing performance. This study introduces an optimization of the traditional straight-plate milling cutter by designing two new types of deicing milling cutters: oblique-cut and straight-cut milling cutters. The effects of cutter geometry, milling speed, and feed rate on cutting forces were systematically investigated using finite element simulations. A deicing test platform was constructed to validate the simulation results. The findings indicate that the cutting force hierarchy among the three designs is as follows: straight-plate > oblique-cut > straight-cut. Notably, the straight-cut milling cutter reduces cutting forces by 16–33% compared with the traditional straight-plate cutter. Furthermore, higher milling speeds and faster feed rates along the transmission line increase cutting forces. These studies provide valuable guidance for optimizing milling cutter designs in deicing robots. [ABSTRACT FROM AUTHOR]

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To maintain the reliability of power systems, routine inspections using drones equipped with advanced object detection algorithms are essential for preempting power-related issues. The increasing resolution of drone-captured images has posed a challenge for traditional target detection methods, especially in identifying small objects in high-resolution images. This study presents an enhanced object detection algorithm based on the Faster Region-based Convolutional Neural Network (Faster R-CNN) framework, specifically tailored for detecting small-scale electrical components like insulators, shock hammers, and screws in transmission line. The algorithm features an improved backbone network for Faster R-CNN, which significantly boosts the feature extraction network's ability to detect fine details. The Region Proposal Network is optimized using a method of guided feature refinement (GFR), which achieves a balance between accuracy and speed. The incorporation of Generalized Intersection over Union (GIOU) and Region of Interest (ROI) Align further refines the model's accuracy. Experimental results demonstrate a notable improvement in mean Average Precision, reaching 89.3%, an 11.1% increase compared to the standard Faster R-CNN. This highlights the effectiveness of the proposed algorithm in identifying electrical components in high-resolution aerial images. [ABSTRACT FROM AUTHOR]

Precise and rapid fault location on transmission lines is a cornerstone for enhancing the reliability and cost-efficiency of power systems. This paper proposes an innovative approach to a fault location by solving an optimization problem. The process relies on transmission line parameters, which can vary significantly under various operating conditions. Inaccurate parameters can severely affect fault location results. To address this issue, the paper proposes a parameter estimation process. Additionally, when faults occur near transmission line terminals, high fault currents can cause current transformer (CT) saturation and secondary current distortion, further impacting fault location accuracy. Instead of using currents distorted by CT saturation, this paper proposes to estimate the currents for inputting into the fault location procedure. To achieve accurate parameter and current estimation at both terminals of the transmission line, advanced artificial bee colony (ABC) algorithms such as Chaos ABC algorithm and Chaos particle swarm optimization (PSO)-ABC algorithm are employed. These are enhanced variants designed to improve exploitation ability, leading to better convergence values and reduced iteration requirements. The proposal is applied for locating three-line (L-L-L), three-line to-ground (L-L-L-G), two-line (L-L), two-line to-ground (L-L-G), and line-to-ground (L-G) faults on the transmission line with various locations. More specifically, the transmission line parameter variations and the CT saturation are considered to enhance the practicality of the fault location problem. Numerical results and comparisons confirm the proposal’s effectiveness, being better than the previous traditional fault location technique such as the impedance-based (IB) technique, as well as other meta-heuristic algorithms such as a grey wolf optimization (GWO) algorithm, a gravitational search (GS) algorithm, and an inclined planes optimization (IPO) algorithm. The error percentages of the fault location results are always less than 1.16%, 1.19%, 1.18%, 1.16%, and 1.04% in the L-L-L, L-L-L-G, L-L, L-L-G, and L-G fault location problems, respectively by using the Chaos PSO-ABC algorithm.

Abstract High voltage alternating current (HVAC) and high voltage direct current (HVDC) transmission systems have acted as the pillars for the transmission field in power networks. Thus, two types of circuit breakers (CBs) existed; HVDC-CB and HVAC-CB. This imposed a burden on manufacturers by requiring them to set up a separate production line for each type of them, increasing production time and overall cost. This paper proposes a solution for this problem by combing both types into a single universal frame termed as UHAD-CB that could be utilized in both systems. Achieving this aim would reduce the manufacturing obstacles and benefit the entire industry. The proposed UHAD-CB was based on the structure of HVDC-CB which utilizes SF6 interrupter equipped with shunt L-C branch. The UHAD-CB is tested in both HVDC and HVAC systems and the results proved its reliability in both systems. The evaluation analysis for the performance of UHAD-CB showed its ability to reduce the transient recovery voltage by 28% in comparison to conventional HVAC-CB. This increase in performance rates allowed the usage of SF6 interrupter with lower cooling power than that for HVAC-CB which compensates for the added cost for L-C branch. In addition, the overall reduction in cost from the manufacturing point of view would add to that benefit. Finally, the optimum L and C values were found to be in range of 0.1 mH and 50 µF respectively for the selected systems.

To address the difficulty in distinguishing different types of insulators in transmission lines and the need for intelligent identification of insulator defects, a real-time detection method for intelligent classification and defect identification of transmission line insulators based on a LightWeight-YOLOv8n network is proposed. This method is used to efficiently detect isolator defects in complex environments and to quickly identify isolator classes. The LightWeight network model MobileNetV3 is used as the backbone network and is based on the YOLOv8n model. The feature extraction ability of the model is enhanced, the redundancy of model parameters is reduced, and the detection speed is improved by adding the SimAM attention mechanism at the end of the backbone network. The LightWeight CSPPC module is used to enhance the feature fusion component of YOLOv8n, reducing the computation load and network complexity while maintaining the accuracy of the model. To further improve the performance of the algorithm, the WIoUv3 bounding box regression loss function is used to replace the original CIoU loss function, and the SlideLoss is used to replace ClsLoss as the category loss function. The experimental results show that the detection accuracy reaches 92.4%, the recall rate reaches 86.6%, and the mAP50 reaches 90.6%. Meanwhile, the training speed is increased by 40.54%, floating-point operation is reduced by 28.57%, and the model parameters are reduced by 34%. Heatmap visualization analysis also showed that the improved models exhibited greater concentration and confidence than the baseline models. Compared to other algorithms, LightWeight-YOLOv8n showed significant advantages in overall performance, accuracy, and real-time target detection. After a random test of 100 images from the test set, the LightWeight-YOLOv8n model exhibited the lowest detection speed and was able to achieve real-time detection. [ABSTRACT FROM AUTHOR]

Abstract Currently, a 2-port microwave transmission line with a glass window is usually used to transmit microwave energy to a pressure vessel while sealing the high-pressure gas. In this situation, the damage of the brittle glass window will inevitably result in disastrous accidents. In this paper, the idea of a “2+4”-port microwave transmission line is first proposed to solve this problem. A 4-port waveguide bridge structure is connected to the input port of a traditional 2-port structure, which can release the high-pressure gas safely when the glass window of the 2-port microwave transmitting structure fails. To test this idea, a “2+4”-port microwave transmission line at 2.45 GHz was designed and fabricated. The effectiveness of the whole system in microwave transmission was validated by both simulations and experiments. A high microwave transmittance of more than 97% in the simulation and 91% in the experiment was achieved. The long-time transmission of 15-kW microwave energy, 5 times higher than the previous work, was realized. Moreover, the effectiveness of the transmission line in releasing high-pressure gas (0.6 MPa) was validated by a series of fluid-structure interaction simulations. This research proposes a new transmission structure for transmitting microwave into a pressurized environment safely and efficiently, which can be promoted to a series of applications including vacuum electron devices, microwave ovens, and so on.

The failure of overhead transmission lines in the United States can lead to significant economic losses and widespread blackouts, affecting the lives of millions. This study focuses on analyzing the failure of transmission lines, specifically considering the effects of wind, ambient temperature, and current demands, incorporating minimal and significant pre-existing damage. We propose a multiphysics framework to analyze the transmission line failures across sensitive and affected states of the United States, integrating historical data on wind and ambient temperature. By combining numerical simulation with historical data analysis, our research assesses the impact of varying environmental conditions on the reliability of transmission lines. Our methodology begins with a deterministic approach to model temperature and damage evolution, using phase-field modeling for fatigue and damage coupled with electrical and thermal models. Later, we adopt the probability collocation method to investigate the stochastic behavior of the system, enhancing our understanding of uncertainties in model parameters, conducting sensitivity analysis to identify the most significant model parameters, and estimating the probability of failures over time. This approach allows for a comprehensive analysis of factors affecting transmission line reliability, contributing valuable insights into improving power line’s resilience against environmental conditions.

Objective To investigate the differences in anti-pull bearing characteristics between single anchor and group anchors foundations of transmission lines, Methods this study employs a combination of theoretical analysis and field experiments. First, based on the structural characteristics, the bearing mechanisms of singleand group anchors were analyzed in terms of force and deformation. The full-length bonded anchors, commonly used in transmission line projects, were selected as the research object, with the granite ground in Quanzhou selected as the test site. On-site full-scale tests were conducted on three single anchors and four group anchors. Displacement sensors were used to monitor foundation and ground deformation, while optical frequency domain reflectometry (OFDR) recorded the strain in the anchor rods. The load-displacement curve of the test foundation and the internal force distribution along the anchor interface were obtained. Finally, a comparative analysis of the deformation and failure mechanisms for both anchor types was performed. Results The results show that the load-displacement curve of a single anchor differs from that of group anchors, with plastic deformation being more pronounced in group anchors. In the initial stages of testing, anchor system displacement is primarily governed by the tension in the anchor bars, whereas at the end of the test, displacement is more influenced by slippage at the anchor-rock interface. The axial tension stress of the anchor rod decreases gradually with depth, reaching near-zero at depths of 2 to 3 m. The failure mode of a single anchor under tensile load is related to the saturated uniaxial compressive strength of rock, while the failure mode for group anchors is influenced by the number of single anchor. It is recommended that group anchors foundation tests be used to determine the bond strength at the anchor interface for design purposes in engineering applications. Conclusion The research findings can provide references for the selection and design of rock anchor foundations for transmission lines.

Currently, a 2-port microwave transmission line with a glass window is usually used to transmit microwave energy to a pressure vessel while sealing the high-pressure gas. In this situation, the damage of the brittle glass window will inevitably result in disastrous accidents. In this paper, the idea of a "2+4"-port microwave transmission line is first proposed to solve this problem. A 4-port waveguide bridge structure is connected to the input port of a traditional 2-port structure, which can release the high-pressure gas safely when the glass window of the 2-port microwave transmitting structure fails. To test this idea, a "2+4"-port microwave transmission line at 2.45 GHz was designed and fabricated. The effectiveness of the whole system in microwave transmission was validated by both simulations and experiments. A high microwave transmittance of more than 97% in the simulation and 91% in the experiment was achieved. The long-time transmission of 15-kW microwave energy, 5 times higher than the previous work, was realized. Moreover, the effectiveness of the transmission line in releasing high-pressure gas (0.6 MPa) was validated by a series of fluid-structure interaction simulations. This research proposes a new transmission structure for transmitting microwave into a pressurized environment safely and efficiently, which can be promoted to a series of applications including vacuum electron devices, microwave ovens, and so on. [ABSTRACT FROM AUTHOR]

This paper examines the modeling approaches used to analyze the electric field distribution in high-voltage direct-current gas-insulated systems (HVDC-GISs) used for the acceleration grid power supply (AGPS) of neutral beam injectors (NBIs). A key challenge in this context is the degradation of dielectric performance due to radiation-induced conductivity (RIC), a phenomenon specific to the harsh radioactive environments near fusion reactors. Traditional models for gas conductivity in HVDC-GISs often rely on constant or nonlinear conductivity formulations, which are based on experimental data but fail to capture the effects of external ionizing radiation that triggers RIC. To address this limitation, a more advanced approach, the drift–diffusion recombination (DDR) model, is used, as it more accurately represents gas ionization and the influence of radiation fields. However, this increased accuracy comes at the cost of higher computational complexity. This paper compares the different modeling strategies, discussing their strengths and weaknesses, with a focus on the capabilities in evaluating the charge accumulation and the RIC phenomenon. [ABSTRACT FROM AUTHOR]

Aviation warning balls should be installed on transmission lines that traverse the airport clearance area and airspace. However, the widespread installation of aviation warning balls may impact the flow field around the ground line, posing safety hazards to the stable operation of the transmission lines in the wind field. In this study, a three-dimensional flow field of the combined structure of the aviation warning ball and ground line, resembling a spherical-cylinder shape, was established using computational fluid dynamics(CFD)numerical simulation. This study investigates the influence of the aviation warning ball on the aerodynamic characteristics of the transmission lines at a Reynolds number of 10 000. The results show a significant impact of the warning ball on the aerodynamic characteristics of the surrounding ground line. Near the warning ball, the ground line segments experience pronounced negative wind pressure compared to the distant cylindrical sections, especially when the position angles of the cylindrical surface range from θ=60° to 90° and θ=270° to 300°. The presence of the warning ball significantly increases the average drag coefficient of the adjacent ground line, intensifying variations in both the drag coefficient and the lift coefficient. Its influence extends approximately 0.95 m around the warning ball. The warning ball interacts with the vortex of the nearby ground line during the shedding process, which leads to the irregular form of the ground line vortex shedding, and further affects the frequency of the vortex shedding and the Strouhal number. [ABSTRACT FROM AUTHOR]

Transmission line conventional current differential schemes are significantly impacted by the dynamic fault current features, transient behavior, and unpredictable power generation of large-scale doubly fed induction generator-based wind farms (DFIG-WFs). Further, combined effects of WFs and flexible alternating current transmission system (FACTS) controller have adverse effect on various unit protection schemes. Normal transmission lines have a current differential between the two ends that rises with line length. If the WFs power output is low, the capacitive charging current may match the load current. Conventional differential protection methods are facing difficulties in the presence of WFs. This research proposes a data-driven approach to determine the effects of several scenarios with significant offshore WFs coupled to transmission lines on differential relay characteristics. The per-phase differential current is calculated using the short-term matrix pencil method (STMPM) based signal reconstruction technique. The net change in the current magnitude is then determined by estimating the first- and second-order derivatives of this data. Lastly, a disturbance detection index (DDI) is derived from the Euclidean distance between these first and second derivative components. The PSCAD/EMTDC simulation studies that were carried out show that the suggested strategy functions satisfactorily for a variety of disturbances, such as internal and external faults, fault resistance, fluctuating fault position, WF penetration changes, and other types of non-fault switching events. [ABSTRACT FROM AUTHOR]

The failure of overhead transmission lines in the United States can lead to significant economic losses and widespread blackouts, affecting the lives of millions. This study focuses on analyzing the failure of transmission lines, specifically considering the effects of wind, ambient temperature, and current demands, incorporating minimal and significant pre-existing damage. We propose a multiphysics framework to analyze the transmission line failures across sensitive and affected states of the United States, integrating historical data on wind and ambient temperature. By combining numerical simulation with historical data analysis, our research assesses the impact of varying environmental conditions on the reliability of transmission lines. Our methodology begins with a deterministic approach to model temperature and damage evolution, using phase-field modeling for fatigue and damage coupled with electrical and thermal models. Later, we adopt the probability collocation method to investigate the stochastic behavior of the system, enhancing our understanding of uncertainties in model parameters, conducting sensitivity analysis to identify the most significant model parameters, and estimating the probability of failures over time. This approach allows for a comprehensive analysis of factors affecting transmission line reliability, contributing valuable insights into improving power line's resilience against environmental conditions. [ABSTRACT FROM AUTHOR]

Ice shedding and vibration of ice-covered transmission lines can pose a serious threat to the safe operation of power lines in heavy ice areas. However, the common preventative practice of installing anti-vibration hammers, spacers and other devices on the line has limited effects on the safe operation of transmission lines. This paper focused on the simulation and experimental study of the influence of orthogonal double pendulum damper, a new type of anti-vibration device for transmission lines, on the ice shedding and vibration reduction of transmission lines. The 3-DOF calculation model of the orthogonal double pendulum damper was established, and the influence of the parameters of orthogonal double pendulum damper on the ice shedding of the line was simulated and analysed. In addition, natural ice shedding tests of lines were carried out at Xuefeng Mountain National Field Station, and ice shedding and vibration displacement response of lines was measured after the installation of orthogonal double pendulum dampers. The results showed that The three main structural parameters of mass, pendulum length and arm length can affect the maximum amplitude of ice shedding and vibration of transmission lines. The mass of the hammerhead has an effect on the vibration in both vertical and horizontal directions; the pendulum length mainly affects the vibration of the line in the horizontal direction; the arm length mainly affects the vibration in the vertical direction. [ABSTRACT FROM AUTHOR]

Aerial photography using unmanned aerial vehicles (UAVs) to detect foreign objects is an important method to ensure the safety of transmission lines. However, existing detection algorithms often encounter challenges in complex environments, including limited recognition capability and high computational demands. To address these issues, this paper proposes YOLO-LAF, a lightweight foreign object detection algorithm that is based on YOLOv8n and incorporates an innovative adaptive weight pooling technique. The proposed method introduces a novel adaptive weight pooling module within the backbone network to enhance feature extraction for detecting foreign objects on transmission lines. Additionally, a multi-scale detection strategy is designed to integrate the FasterBlock and EMA modules. This combination enables the model to effectively capture both global and local image features through cross-channel interactions, thereby reducing misdetection and omission rates. Furthermore, a C2f-SCConv module is introduced in the neck network to streamline the model by eliminating redundant features, thus improving computational efficiency. Experimental results demonstrate that YOLO-LAF achieves average accuracies of 91.2% and 85.3% on the Southern Power Grid and RailFOD23 datasets, respectively, outperforming the original YOLOv8n algorithm by 2.6% and 1.8%. Moreover, YOLO-LAF reduces the number of parameters by 23.5% and 14.8% and the computational costs by 19.9% and 24.8%, respectively. These improvements demonstrate the superior detection performance of YOLO-LAF compared to other mainstream detection algorithms. [ABSTRACT FROM AUTHOR]

Guyed towers in high-voltage transmission lines consist of the tower body, guy wire system, and foundation. A well-designed guy wire system with optimized tension levels is essential to maintain the stability of the tower under wind loads and other external forces. In practical operation, to prevent excessive corrosion of the pinned metal components at the tower base, these connections are often encased in concrete, altering the base connection conditions and affecting the structural forces on the tower. This study develops a finite element analysis model based on two guyed tower structures from a high-voltage transmission line project. By measuring the actual tensions of the guy wire and testing the basic material performance, this model considers the effects of varying base connection conditions and different guy wire tension levels. Under designed ice load and extreme wind load conditions, the analysis focuses on changes in tower body stress, tower-top displacement and inclination, and guy wire forces. The results indicate that when the tower base is uniformly pinned or fixed, the initial guy wire tension has minimal impact on maximum tower stress but significantly affects maximum tower displacement and inclination when the tower was under the ice and wind load conditions. The base connection condition has a pronounced impact on the stress states of the tower and guy wire system, especially under the designed wind loads. In particular, when the base is fixed, the maximum base stress in Tower 1 under the wind loads is 270% higher than in a pinned condition. The initial guy wire tension level significantly affects the guy wire force under the ice and wind loads; for example, when Tower 1 is subjected to approximately 85% of the design level of high wind load, some guy wires reach full relaxation prematurely, presenting localized strength failure risks at the tower foot, potentially threatening the tower safety under extreme design loads. [ABSTRACT FROM AUTHOR]

Faults in transmission lines cause instability of power system and result in degrading end users sophisticated equipment. Therefore, in case of fault and for the quick restoration of problematic phases, reliable and accurate fault detection and classification techniques are required to categorize the faults in a minimum time. In this work, 500 kV transmission line (Jamshoro‐New Karachi), Sindh, Pakistan has been modeled in MATLAB. The discrete wavelet transform (DWT) has been used to extract features from the transient current signal for different faults in 500 kV transmission line under various parameters such as fault location, fault inception angle, ground resistance and fault resistance and time series data has been obtained for fault classification. Moreover, the temporal convolutional neural network (TCN) is used for fault classification in 500 kV transmission network due to its robust framework. From simulation results, it is found that faults in 500 kV transmission line are classified with 99.9% accuracy. Furthermore, the simulation results of the TCN model compared to bidirectional long short‐term memory (BiLSTM) and Gated Recurrent Unit (GRU) and it has been found that TCN model is capable of classifying faults in 500 kV transmission line with high accuracy due to its ability to handle long receptive field size, less memory requirement and parallel processing due to dilated causal convolutions. Through this work, the meantime to repair of 500 kV transmission line can be reduced. [ABSTRACT FROM AUTHOR]

Bird’s nest on power transmission lines pose a threat to the safe operation of power equipment and may even affect the stability of the entire power system. To address the challenge that traditional methods face in achieving accurate real-time detection in complex environments, this paper proposes the BN-YOLO bird’s nest detection method based on the YOLOv8s baseline model, enhancing its suitability for real-time applications in intricate settings. First, we replaced the original backbone network of YOLOv8s with a lightweight FasterNet module, thereby reducing computational burden and improving network performance. Second, the feature fusion network was redesigned, incorporating the efficient multi-scale attention module (EMA) to optimize feature fusion capabilities across different scales. Subsequently, we proposed a lighter and faster C2f structure by substituting the standard convolution in the C2f structure with partial convolution (PConv). Finally, Wise-IOUv3 was utilized as the regression loss function to mitigate the effects of low-quality annotations and accelerate network convergence. Experimental results demonstrate that on our self-constructed transmission line bird’s nest dataset, the bird’s nest detection method we proposed achieved a 97.73% score. Compared to the original YOLOv8s, the mean average precision (mAP) increased by 2.19%, and the detection speed improved from 61 FPS to 83 FPS. In addition, our method outperforms other mainstream object detection algorithms, such as SSD, DETR, and RT-DETR, providing higher detection efficiency while maintaining high accuracy. These results confirm that the proposed method can effectively detect bird’s nest targets in complex environments and fulfill the requirements for real-time inspection. This research not only enhances the accuracy and efficiency of bird’s nest detection in power transmission lines but also offers a novel solution for the safe operation and maintenance of smart grids, which holds significant practical application value. [ABSTRACT FROM AUTHOR]

The main objective of the work is to energize the wireless sensor network by using Radio Frequency energy harvesting. It has the potential to harvest the RF energy available in the surroundings. However, the available RF bands in the atmosphere are unpredictable. Therefore, a multiband harvester's design adds more power from the vast number of sub-operating bands. In this work, a multiband rectifier is designed to harvest energy from 1.28 GHz, 1.8 GHz, 2.44 GHz, 3.5 GHz, and 5 GHz frequency bands simultaneously. An enhanced impedance matching network is designed and validated. The purpose of this is to improve the performance of the rectifier. Multiband rectifier achieves higher conversion efficiency than the traditional single-band approach. The highest power conversion efficiency is measured at 89.08% at 0 dBm input power at 1.8 GHz operating band and 4.8 V DC power is received. This paper introduces a novel design structure as well as a simple circuit structure of a multiband rectifier. The proposed rectifier provides sufficient energy to power the sensors used in wireless sensor networks and many other low-power electronic devices in a series of potential applications. It also demonstrates the higher conversion efficiency with existing designs. [ABSTRACT FROM AUTHOR]

Capacitively coupled plasmas (CCPs) are widely used in plasma processing applications, where efficient power coupling between the radio frequency (RF) source and the plasma is crucial. In practical CCP systems, impedance matching networks (IMNs) are employed to minimize power reflection. However, the presence of coaxial cables can significantly impact plasma impedance and matching performance. We develop a comprehensive simulation framework for the IMN design of CCPs, fully considering the effects of RF coaxial cables. The model self-consistently couples a distributed transmission line (TL) model, a lumped-element circuit model, and an electrostatic particle-in-cell model. This coupled model is used to investigate the impact of coaxial cables on matching performance under various discharge conditions and cable configurations. The simulation results indicate that the optimal power transmission efficiency was achieved after 6 matching iterations. The power coupled to the CCP increased from 2.7 W before matching to 180.9 W, and the reflection coefficient ultimately decreased to 0.003. The results also reveal that neglecting the cables will lead to a decrease in the power dissipated in the CCP. The proposed method demonstrates effectiveness in achieving impedance matching for different gas pressures (75–300 mTorr) and cable lengths. It can be concluded that the matching speed is faster for an appropriate cable length. This work provides valuable insights into the role of TLs in CCP impedance matching and offers a practical tool for optimizing power delivery in realistic CCP systems with RF coaxial cables. [ABSTRACT FROM AUTHOR]

To solve the measuring problem of the hanger's position and attitude, an approach based on improved April Tag technology was proposed. The method adopted a special magnetic label fixing mode to reduce the difficulty and requirements of label installation. The position and attitude of the hanger were measured based on the spatial coordinate transformation theory, with the visual measuring results of the April Tag labels on the hanger and the key dimensions of the hanger. Meanwhile, the visual measuring results of the April Tag were screened based on the relative relationship between labels to enhance the accuracy. A positing and attitude measurement experiment was conducted on the hanger of the overhead transmission lines' tower assembled by floor-standing double boom derrick. The results show that the proposed approach can effectively and accurately measuring the spatial position and attitude of the hanger. [ABSTRACT FROM AUTHOR]

Conductor breakage with ice load is one of the major threats to the safe operation of transmission lines. The ice load increases the unbalanced longitudinal tension, leading to failure of tower members and even progressive collapse of the transmission line. This paper proposes an autotriggered anticollapse fusing hardware (AAFH), designed to reduce the unbalanced longitudinal tension caused by conductor breakage. When the longitudinal unbalanced tension of the transmission line exceeds the threshold of the AAFH, the fused part is destroyed, and the AAFH is elongated to reduce the longitudinal unbalanced tension. First, the construction and working mechanism of the device are introduced, and a numerical model of the transmission line–AAFH system is established to verify its effectiveness. Then, a parameter determination method for unbalanced tension in the tower‐line system subjected to conductor breakage is proposed. In addition, the control performance of the device is studied. The results show that AAFH can effectively reduce the unbalanced tension induced by conductor breakage. The proposed method can predict the unbalanced tension of transmission lines, with an error within 10%. The greater the length of vertical/horizontal elongation, the better the protective effect. From a safety perspective, the AAFH should be designed according to the actual transmission line parameters to achieve an ideal control effect. [ABSTRACT FROM AUTHOR]

Point cloud semantic segmentation is crucial for identifying and analyzing transmission lines. Due to the number of point clouds being huge, complex scenes, and unbalanced sample proportion, the mainstream machine learning methods of point cloud segmentation cannot provide high efficiency and accuracy when extending to transmission line scenes. This paper proposes a filter-assisted airborne point cloud semantic segmentation for transmission lines. First, a large number of ground point clouds is identified by introducing the well-developed cloth simulation filter to alleviate the impact of the imbalance of the target object proportion on the classifier's performance. The multi-dimensional features are then defined, and the classification model is trained to achieve the multi-element semantic segmentation of the transmission line scene. The experimental results and analysis indicate that the proposed filter-assisted algorithm can significantly improve the semantic segmentation performance of the transmission line point cloud, enhancing both the point cloud segmentation efficiency and accuracy by more than 25.46% and 3.15%, respectively. The filter-assisted point cloud semantic segmentation method reduces the volume of sample data, the number of sample classes, and the sample imbalance index in power line scenarios to a certain extent, thereby improving the classification accuracy of classifiers and reducing time consumption. This research holds significant theoretical reference value and engineering application potential for scene reconstruction and intelligent understanding of airborne laser point cloud transmission lines. [ABSTRACT FROM AUTHOR]

In order to investigate the characteristics and typical influential factors of wildfires caused by accidental faults in high-voltage transmission lines, a bespoke platform was constructed for the purpose of conducting simulation experiments. Discharge and ignition experiments were conducted on a variety of substrates, including kidney fern fragments, cedar needle fragments, poplar sawdust, and eucalyptus leaf fragments, to investigate the effects of different gaps on the initiation and propagation of wildfires. The results demonstrate that the discharge-inducing ignition stages can be succinctly summarized as "two phases and two points" (the discharge induction period, the gap breakdown point, the arc induction period and the fault removal point) when a suitable gap is maintained between the simulated falling lines and the vegetation surface. In the event of direct contact, the removal of the fault is not possible. The potential for ignition of the aforementioned vegetation types by the discharge is as follows: cedar needles > eucalyptus leaf fragments ≈ poplar sawdust > kidney fern fragments. As the water content increases, eucalyptus leaf fragments can still be ignited, and the breakdown voltages required for discharge-inducing ignitions gradually decrease. In the case of different forest ground vegetation types, when ignited by the discharge between the falling lines and the vegetation under conditions of proper gap and moisture content, the resulting ignition and sustained flames will promote the formation of streamer channels and further aggravate the discharges and burning processes, potentially leading to the ignition of a wildfire. [ABSTRACT FROM AUTHOR]