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This paper implements the stochastic filters for state and parameter estimation of nonuniform transmission lines (NTL). In general, transmission line (TL) problem is a continuous time and space problem. By taking the line loading noise into account, the TL equations become a stochastic partial differential equation (PDE) rather than a simple set of coupled finite stochastic differential equations (SDE). By transforming the spatial variables into the Fourier domain, the stochastic PDE can be transformed into an infinite sequence of SDE. After truncation to a finite set of Fourier series coefficients, it becomes a finite set of coupled linear SDE, which is the required domain in which extended Kalman filter (EKF) and unscented Kalman filter (UKF) can be applied. For state space equation of EKF and UKF, the voltage and current of periodic NTL are expanded into an infinite set of spatial harmonics. In this way, the voltage and current measurement of NTL become an eigenvalue problem. The NTL is considered as cascade of small infinite NTL and the four distributed primary parameters of the periodic NTL are expressed using Fourier series expansion. Finally, the Kalman filter (KF)-based state estimation and the EKF- and UKF-based parameter estimation have been compared with recursive least squares (RLS) method. The simulation results present the superiority of the method. [ABSTRACT FROM AUTHOR]

This paper presents a novel technique for matching complex loads to a real source concurrently at uncorrelated frequencies under any load conditions. In the proposed method, a branched stub adds susceptances to the load admittances such that the adjusted loads for all the frequencies can be shifted to g = 1 circle using a single series transmission line; hence matching the real part of the admittances. The left-over susceptance is cancelled through another branched stub. Its adaptability allows it to increase the number of bands by adding transmission lines to the branched stubs. The structure is not subject to any fabrication-related limitations because all the transmission lines used in the design have a characteristic impedance of 50 Ohms. The concept has been validated by designing a prototype matching network for N = 3 and extending it to N = 4, and N = 5 by adding elements to the branched stubs. All the structures are fabricated on ROGERS RO4003 substrate with a dielectric constant, er = 3.38 and height, h = 20 mils. The simulated and the measured results are in good accordance. [ABSTRACT FROM AUTHOR]

In this paper, we address the problem of developing a unified method for quantifying and improving the cyber resilience of large-scale cyber-physical systems (CPSs) against cyber-attacks targeting structural controllability. To this end, we provide necessary and sufficient conditions to extend the concept of structural controllability of single-layer systems to two-layer CPSs comprising of power network as the physical layer and communication network as the cyber layer. Next, in order to assess cyber resilience, we introduce the notion of $ R $ R -resilient CPS as the maximum number of cyber nodes that can be attacked by an adversary while preserving the structural controllability of the entire CPS. Furthermore, we provide an algorithm to find the optimal network reconfiguration matrix to increase the resilience level of CPS from $ R $ R -resilient to $ ({R + 1}) $ (R + 1) -resilient by adding a minimum number of transmission lines to the physical layer or communication links to the cyber layer, or both. Additionally, the proposed methodology is extended to achieve $ ({R + \alpha }) $ (R + α) -resilient CPS, where α>1. The effectiveness of the proposed method is verified through simulations of IEEE 14, IEEE 39, and IEEE 118 power networks with different cyber topologies, considering four scenarios of denial-of-service (DoS) attacks, including targeted and random node attacks. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In this paper, a novel Ultra-Wideband (UWB) Bandstop Filter (BSF) with five Transmission Zeros (TZ) and three Transmission Poles (TP) is presented. This filter is designed with a new type of resonator. Validation of the proposed filter with the lumped model is also investigated. Further, the transmission line circuit model of the filter is proposed, and consequently even and odd mode impedance is calculated analytically. Furthermore, a compact size of 16.8 mm × 14.98 mm (0.2λg × 0.18λg) is achieved by employing folded stubs. The proposed filter offers an Ultra-wide bandwidth of 7.5 GHz (2.9 –10.4 GHz) with a rejection depth of greater than 20 dB over the entire stopband. Moreover, the upper and lower skirt factors of 70 dB per GHz are achieved. A prototype of the proposed UWB BSF is fabricated and measured. Simulated and measured results are in good agreement, which validates the proposed design. [ABSTRACT FROM AUTHOR]

A novel technique for estimation of the wall's relative permittivity, thickness and conductivity from signals measured from the through-wall radar is presented in this paper. The retrieval process is built around an electromagnetic circuit model that represents the wall structure as a transmission line segment. The propagation of the radar signal through the wall is equivalently described as a pair of voltage and current waves that propagate along the transmission line, using analogies between the electrical parameters of the transmission line segment and the constituent parameters of the materials of the wall structure. The synthetic time domain signal obtained analytically and the real through wall imaging time domain signal were correlated to estimate the wall parameters of the layers that comprise the wall structure. The effectiveness of the proposed estimation technique has been demonstrated through simulation and experimentation on two actual building walls. A comparison with conventional methods revealed consistent results between the estimated wall parameters using the proposed technique and those obtained through traditional approaches. These findings highlight the potential of the proposed method in enhancing the accuracy of real-time target localization and tracking in through-wall imaging applications. [ABSTRACT FROM AUTHOR]

Far distant wind farms are integrated nowadays with the help of Voltage Source Converter (VSC)-based HVDC grids. Rapid fault current is very common in VSC-based HVDC grids and, therefore, quick fault detection and fast executing protection methods are critical for the existence of the HVDC grids. This paper proposes a rise time-based fault detection method using local measurement data and Travelling Wave (TW) characteristics of incoming fault TW. Dominating frequency of the primary wavefront is computed by the rise time of incoming fault TW. With the help of auto-updating transmission line parameters and the dominating frequency of incoming TW, the fault location is identified. The performance of the proposed method has been observed in PSCAD Simulation with a 4-Terminal HVDC test grid in multiple scenarios and compared with the existing fault detection methods on multiple levels. The results show that the proposed method is very fast, and accurate and can complete the whole Fault Location process within a few microseconds just after the Inception of the fault. [ABSTRACT FROM AUTHOR]

A novel low-profile, compact tri-band linearly and dual-sense circularly polarized (CP) antenna realized using via-less epsilon negative transmission line (ENG-TL) is investigated in this paper. The antenna miniaturization has been achieved by the zeroth-order resonance (ZOR) property of ENG-TL, which is actuated by connecting closed-loop octagonal ring radiator to an elliptical stub through a meandered-line structure. Circular polarization is accomplished by etching an L-shaped slot in the partial ground plane. The measured S11 result demonstrates that the proposed antenna features triple-band characteristics spanning from 2.42 to 2.50 GHz, 3.29 to 3.59 GHz and 5.43 to 5.55 GHz with centre frequencies of 2.46, 3.44, and 5.49 GHz, respectively. The antenna is offering linear polarization (LP) in the first and third bands while radiates left-handed CP in the + Z direction in the second band. An exceptional axial ratio (AR) of 0.062 dB has been achieved at 3.49 GHz with 3 dB axial ratio bandwidth (ARBW) extending from 3.35 to 3.67 GHz. This antenna offers an average simulated gain of 1.7 dBi across the CP band while 2.06, 1.75 and 3.67 dBi are acquired at 2.59, 3.53 and 5.62 GHz, respectively. Beside low-profile (0.013λ0 height) and miniaturized size (0.287λ0 × 0.205 λ0), intended antenna exhibits extended −10 dB impedance bandwidth, wide 3 dB AR bandwidth and reasonable radiation performance. It covers relevant frequency bands; therefore, it has the potential to be employed in 2.5 GHz LTE/UMTS, 3.5 GHz WiMAX, and 5.5 GHz WLAN applications. [ABSTRACT FROM AUTHOR]

Examines the characteristics of travelling waves along the non-linear transmission lines for monolithic integrated circuits. Analysis of slow-wave structures like MIS and Schottky-barrier strip lines; Examination of suitable equivalent circuits leading to characteristic wave equations; Parameters of the non-linearity, dispersion and dissipation and the boundary conditions of practical devices.

This article seeks to discuss the associations elaborated by riverine interlocutors between infrastructures and the landscape in which they occur, within the context of climate change in the Brazilian state of Amazonas. Here, we debate the relational character of infrastructures, and how they act as important markers of river seasonality, landscape, people's existence, and practices from the perspective of the accessed riverine people. This paper's discussion is supported by qualitative data from semi-structured interviews and field notes from two riverine communities in the Amazonas state: Tumbira and Lago do Catalão. Inspired by authors who dialogue with Social Studies of Science and Technology and discuss infrastructures, their effects, their relational and ontological character, we seek to identify entanglements of landscape and infrastructure, and their implications in the practices and ways of living of riverine Amazonian people. Elements such as gas pipelines, power transmission lines, hydroelectric plants, cargo ships, and highways emerge, affect, and are affected in these entangled landscapes in the eyes of the riverine people. They merge with other entanglements such as the rivers and creeks that perform the riverine landscape and life. Thus, they induce reflections on such relationships and the affectations permeated by fears, wishes, and (dis)trust of their operation. [ABSTRACT FROM AUTHOR]

This paper presents an innovative approach in line commutated converter-based high-voltage direct-current (LCC-HVDC) transmission line for recognizing the section of the faults. In this work, three adaptive neuro-fuzzy inference system (ANFIS) modules have been suggested to investigate the safety responsibilities in the LCC-HVDC line. The ANFIS-1 aims to ascertain the faults in both sections; ANFIS-2 is to distinguish the section of the fault; and ANFIS-3 is to recognize the characteristics of the fault. To ascertain the effectiveness of the ANFIS approach, it has been compared with the differential protection (DP), wavelet transform (WT), fuzzy and artificial neural network (ANN). Furthermore, the proposed methods have been tested by varying the fault resistance (up to 500 Ω), power angle (from 5 to 15 degrees), near and end faults, and changing the transmission line parameters (±15 %). The simulation outcomes are disclosed that the proposed ANFIS technique yields better performance than other studied methods in terms of percentage of accuracy, time of fault section recognition, and reach setting. [ABSTRACT FROM AUTHOR]

Power line maintenance and inspection are essential to avoid power supply interruptions, reducing its high social and financial impacts yearly. Automating power line visual inspections remains a relevant open problem for the industry due to the lack of public real-world datasets of power line components and their various defects to foster new research. This paper introduces InsPLAD, a Power Line Asset Inspection Dataset and Benchmark containing 10,607 high-resolution Unmanned Aerial Vehicles colour images. The dataset contains 17 unique power line assets captured from real-world operating power lines. Additionally, five of those assets present six defects: four of which are corrosion, one is a broken component, and one is a bird's nest presence. All assets were labelled according to their condition, whether normal or the defect name found on an image level. We thoroughly evaluate state-of-the-art and popular methods for three image-level computer vision tasks covered by InsPLAD: object detection, through the AP metric; defect classification, through Balanced Accuracy; and anomaly detection, through the AUROC metric. InsPLAD offers various vision challenges from uncontrolled environments, such as multi-scale objects, multi-size class instances, multiple objects per image, intra-class variation, cluttered background, distinct point-of-views, perspective distortion, occlusion, and varied lighting conditions. To the best of our knowledge, InsPLAD is the first large real-world dataset and benchmark for power line asset inspection with multiple components and defects for various computer vision tasks, with a potential impact to improve state-of-the-art methods in the field. It will be publicly available in its integrity on a repository with a thorough description. It can be found at . [ABSTRACT FROM AUTHOR]

Power Line Communication (PLC) can achieve noticeable savings in infrastructure deployment time and cost, where it uses the existing power lines for data transmission. Non-orthogonal multiple access (NOMA), is a promising technique that can accommodate multiple users via non-orthogonal resource allocation and so, it can notably improve spectral efficiency and reduce the electromagnetic compatibility of PLC networks. Data privacy is of crucial importance in PLC design due to its broadcasting nature. Therefore, this paper presents several cooperative secrecy techniques for improving physical layer security in NOMA-based PLC networks considering two different security constraints, which are signal eavesdroppers and multiple cooperative eavesdroppers. The secrecy performance is measured in terms of two performance metrics: ergodic secrecy capacity (ESC) and secrecy outage probability (SOP). Monte Carlo simulation results validate the accuracy of the analytical model and derivations. [ABSTRACT FROM AUTHOR]

Frequency scanning antennas realized by loading the radiating elements on both sides of the microstrip, asymmetrically corrugated spoof surface plasmon polariton (SSPP), and symmetrically corrugated SSPP transmission lines are discussed in this paper. Both traveling and standing wave antennas are considered and performance in terms of S-parameters, radiation pattern, scan range, and gain is reported. Additionally, the crosstalk between two transmission lines is observed in all cases. Based on the analysis, it was proved that the crosstalk was minimum in the case of symmetrically corrugated SSPP transmission lines. The proven advantages of the SSPP lines find better signal integrity, high gain, and wide-angle scan frequency scanning antennas. [ABSTRACT FROM AUTHOR]

The GTEM cell is a new version of the modified transmission line, operated at very high-frequency test equipment for EMI or EMC measurement. The equipment is designed for an electromagnetic compatibility, immunity and radiated emissions test. In this paper, GTEM is designed using ANSYS HFSS 13.0 and fabricated for 1 to 3.9 GHz frequency. This paper focuses mainly on the novel validation test for the manufactured GTEM cell characterization without using costly Vector Network Analyzer. The novel test set up comprises of GTEM cell, transmitter and the receiver is designed and tuned at 2.4 GHz. Using this set up field uniformity is checked for fabricated GTEM ranges within +/− 6dB. This makes a compact and cost-effective novel test validation set up for the designed, developed and manufactured GTEM for 1 to 3.9 GHz. [ABSTRACT FROM AUTHOR]

Generating minimum energy points (MEPs) is an optimal solution of many real-world problems, such as the selection of best locations for hospitals inside a city that reduce the overcrowding and competition and avoid the less-populated regions. The key idea is considering these locations as charged particles with the same sign (i.e., repel each other) inside a box and distribute these points by minimizing the total electric potential energy (TEPE) among them. The practice demonstrated that most of the existing techniques for generating MEPs are complex, especially for non-mathematicians. Therefore, the greedy algorithm (GreA) is the classical widely used algorithm for its simplicity even though a satisfactory result is not guaranteed. This paper gives a novel algorithm for generating MEPs from identically charged particles in 1D, 2D and 3D unit hypercubes. The results show that the new algorithm distributes the points far away from each other to reduce the TEPE of the generated MEPs more effectively than the GreA. The new algorithm is a significant improvement of the GreA to overcome its unsatisfactory results. Therefore, the new algorithm in its current form or after some improvements is highly recommended to be used instead of the GreA for many different applications. [ABSTRACT FROM AUTHOR]

—The modular multilevel converter (MMC) has proven to be the most advanced voltage source converter (VSC). For long-distance power transfer, high-voltage DC (HVDC) is the best choice. Across the globe, electric power networks are witnessing rapid growth in MMC-HVDC installation to meet the ever-growing power demand. The existing AC transmission lines can be converted to DC lines by adding converters. The MMC-based multi-pole HVDC presents an adequate solution for upgradation. However, more study is required to make it a reality. The present paper attempts to bridge this gap. The proposed study can be divided into two parts. Initially, the concept of symmetrical multi-pole MMC-HVDC is proposed, and its mathematical relations have been derived. The multi-pole has been subdivided into an even and an odd configuration. The half-bridge submodule (HBSM)-based MMC lacks DC fault handling capability. The second part of the study includes controller and fault analysis of the HBSM-based tri-pole MMC HVDC. The study shows the severity of the pole-to-pole faults, leading to a complete shutdown of the transmission line. A controller and an algorithm for the DC fault-ride-through (FRT) have been proposed. The proposed controller has digital switches to temporarily bypass the real-time measurement values with measurements taken under healthy conditions. An impact analysis of the parameters of one MMC on the equilibrium of the entire multi-pole configuration is performed. The performance of the proposed controller has been carried out on a real-time digital simulator (RTDS). The proposed controller and FRT algorithm ensure that the tri-pole HVDC maintains the power supply during all DC faults. In the worst-case scenario, the shutdown is averted with a 50% reduction in power transfer capability. The transients in active and reactive power are minimized and eliminated within a cycle. Further, using the most economical and simplest submodule ensures the configuration without any additional cost. [ABSTRACT FROM AUTHOR]

In this paper, two 50Ω terminated rat-race hybrid couplers based on uniform folded structures are proposed for equal division of power. The proposed designs are of simple in geometry and have an area of only one-fourth of the conventional coupler. The first technique is two-fold double section topology operating at 1.77 GHz designed with the conventional impedance ratio of √2 between port and transmission line which exhibits good in-band characteristics and requires a minimum track width of 0.8 mm. The second technique is stub-loaded double section topology where the novelty lies in deploying impedance matched stubs which avoids high impedance lines by maintaining an impedance ratio less than 2 between port and transmission line. In addition to good passband characteristics, it also suppresses higher harmonics up to 6.3f0 and requires a minimum track width of 0.41 mm which makes it easy for realization. The bottom line of both designs is to achieve extreme structural simplicity without using high impedance transmission lines of more than 100Ω, narrow tracks less than 0.4 mm, lumped elements, and via holes. The prototype of the proposed coupler is fabricated and the simulated results are validated using measurements. [ABSTRACT FROM AUTHOR]

In this paper, a simple coplanar waveguide fed compact electrically small antenna for dual-band operations without the use of via is presented. The resonances of the structure are obtained by spiraling one of the ground planes of an open-ended CPW transmission line with a short length center feed. The proposed antenna has a geometrical dimension of 0.079λ01× 0.079λ01 mm2 (λ01 is the free space wavelength of first resonant frequency) with a small electrical size (ka) of 0.35. The experimental studies on the fabricated prototype of the proposed antenna show a 2:1 VSWR bandwidth up to 2.53% and 4.12% for 2.3 and 5.3 GHz, respectively. The simulated antenna reflection and radiation characteristics are demonstrated with physical measurements. [ABSTRACT FROM AUTHOR]

The paper presents a robust design of Artificial Neural Network Classifier used for the classification of faults occurring on Extra High Voltage Transmission lines with multiple series compensation. The feature selection and model parameters play a vital role in providing better accuracy as well as stability of Classifier in recognition of fault patterns. The paper describes the use of Particle Swarm Optimization (PSO)-assisted training of Artificial Neural Network (ANN). The PSO is used to find the optimal number of features to attain sufficiently high accuracy along with optimal design parameters of ANN so as to reduce the computational burden. A combined use of Multiresolution Wavelet Analysis (MRA) and Statistical Features (SF) module is shown for fault pattern analysis. A Particle Swarm optimization based Neural Network with Feature Selection (PSONNFS) Algorithm developed is applied on a large database of fault patterns with a wide range of operating conditions in series compensated system. The best features found from the PSONNFS algorithm are later used to find the optimal structure of ANN. The results obtained provide an enhanced model of ANN with a high degree of accuracy with optimality in Classifier parameters. A Genetic Algorithm based Neural Network optimization with Feature Selection (GANNFS) is also developed to verify the performance of the classifier. The results of the PSONNFS algorithm are further compared with the GANNFS algorithm. The results obtained show an enhanced model of ANN using PSONNFS which has a high degree of accuracy with optimality in Classifier parameters. [ABSTRACT FROM AUTHOR]

The final position of the Norwegian–Swedish border was determined in 1751, after challenging negotiations. This paper focuses on central parts of Scandinavia and investigates the role of cartography in the border positioning process. The examination of a wide variety of historical maps before and after the border treaty provides insight into the differing opinions on the border region's shifting affiliation. Other factors that helped to shape the borderline were a turbulent political situation with shifting sovereignty over the area in question, as well as conflicts over valuable resources. The findings indicate that cartographic evidence had an important role in the position of the Norwegian–Swedish border in central Scandinavia. The paper adds to our understanding of maps as a political tool as well as of the role of resources in border processes, and provides new knowledge on how cartography influenced a national border between two countries fighting for land, resources and hegemony. [ABSTRACT FROM AUTHOR]

In the current scenario, because of government policies, environmental factors, and technological improvements, there is a rapid growth in renewable energy sector. The emphasis is to obtain better system performance by effective resource utilization and providing security and reliability. This paper discusses the design and implementation of indirect grid control of a wind power plant by controlling the parameters in both grid and rotor side converters. The proposed system consists of Doubly Excited Induction Generator (DEIG) with Wind turbine system (WTS) and Mechanical and Electrical Power Controlling Systems (MPCS-EPCS). Various transmission line faults (symmetrical and asymmetrical faults) incur power imbalances in power grid. The developed MPCS and EPCS are helpful to perform grid monitoring and controlling under different types of faulty conditions. The MPCS monitors the effective source utilization and EPCS helpful for matching the grid energy levels under normal and faulty conditions. Modification in the converter topologies to minimize the impact of adverse effects of faults on the DEIG-WTS and to improve resiliency in the power grid is also discussed. To improve the stability and enhancing resource utilization to improve the efficiency of the overall system with the enhancement of fault voltage ride-through capability in DEIG-WTS under fault conditions are also considered. The stability of the system is tested under steady-state and dynamic-state conditions by applying faulty conditions in MATLAB/Simulink environment. [ABSTRACT FROM AUTHOR]

Protection engineers and academicians are continuously working towards better relaying for modern transmission structures. This has become a requirement because transmission structure, nowadays, is being updated with new technologies, e.g. flexible AC transmission system devices. In this paper, it has been observed that the differential DC plays an important role in distinguishing the internal and external faults. A criterion is then developed based on this unique feature of the differential DC for the identification of faults in modern transmission lines. The performance of the proposed criterion has been tested with the help of simulation study carried out using EMTDC/PSCAD software for a variety of fault types with variations in fault location, fault resistance, fault inception angle, and compensation level. Furthermore, the performance of the proposed algorithm is also investigated for several rare conditions such as evolving faults, cross-country faults, noise in measurement, and measurement error. The results prove that the scheme is selective, accurate, and robust for uncompensated and series-compensated lines while it is accurate for low resistance faults in the case of a shunt-compensated line. [ABSTRACT FROM AUTHOR]

Security-Constrained Unit Commitment (SCUC) problem and subsequently employing Flexible AC Transmission Systems (FACTS) controllers including Optimal Unified Power Flow Controller (OUPFC) play a crucial role in power systems operation and control in terms of increasing the security of energy transmission networks. The principal objective of the SCUC problem is to acquire the minimum operating cost simultaneously maintaining the security of the system. In this paper, significant attention is paid particularly to simultaneously control SCUC and OUPFC, since energy loss reduction and transmission lines capacity release can be effectively achieved with incorporating SCUC and OUPFC, and subsequently setting the effective variables. In this regard, the SCUC problem with the presence of OUPFC is solved as Nonlinear Programming with Discontinuous Derivatives (DNLP) framework and the proposed algorithm is implemented on two IEEE 14-bus and IEEE 30-bus systems using General Algebraic Modeling System (GAMS) software in order to optimize the total fuel cost, power losses and cost of OUPFC installation as objective functions in the multi-objective framework. The simulation results show the capability of the proposed algorithm to simultaneously determine the optimal location of the OUPFC and its settings in the SCUC problem and to improve the controllability of the power system operation. [ABSTRACT FROM AUTHOR]

Active and reactive power tracing can play an important role in achieving a fair electricity market because system operating, usage, and service costs are appropriately apportioned. However, the presence of power flows around a closed circular trajectory causes the application of commonly used tracing algorithms to fail, leaving power tracing an open question. To overcome this drawback, a novel methodology for tracing the active and reactive power considering the existence of circulating power flows (CPFs) is presented in this paper. The strategy consists of identifying branches possibly involved in this kind of flow and merging the involved buses into a supernode allowing the tracing algorithm to perform normally. Furthermore, the approach properly classifies transmission lines according to their behavior to accurately trace the reactive power flow. The methodology is tested using two power systems presenting diverse operating scenarios. The results demonstrate that the proposed tracing methodology appropriately handles CPFs, representing an advantage over previously proposed approaches. [ABSTRACT FROM AUTHOR]

This paper proposes a new algorithm for the detection and classification of faults in transmission lines in the presence of distributed generation. The proposed algorithm uses wavelet transform-based detail and approximation coefficients of voltage and current signals over one cycle after fault inception at one end of the transmission line. The line impedance calculated from the ratio of the voltage and current approximation coefficients is fed to the fuzzy inference system to classify faults. The proposed algorithm has been tested successfully in a real-time digital simulator for nonlinear high impedance faults in the presence of wind farm, considering the effects of CT saturation. All types of faults with the variation of pre-fault loading condition, line parameters, line length and source impedance can be correctly classified using the proposed algorithm. [ABSTRACT FROM AUTHOR]

This paper presents a miniaturized Wilkinson Power Divider (WPD) with the capability of attenuating unwanted harmonics up to the 19th harmonic. In this study, a low pass filter was embedded as the quarter-wavelength transmission lines of the conventional WPD. To reduce the size of the proposed structure, the high impedance line is meandered. A simple T-shape resonator is added to suppress the high frequency. The even and odd mode analysis were reported as the analytical descriptions. The operational frequency of the presented WPD is 1.95GHz, and S21, S11, S22, and S23 in this frequency are -3.79dB, -15.56dB, -14.15dB, and -10.89dB, respectively. The overall size of implemented WPD is only 8.8 mm × 8.02 mm, and its normalized circuit size equals 0.078 × 0.071. The designed structure has been fabricated and measured on the RT-5880 substrate with a thickness of 20mil. The desired matching between the simulation results and the measurement ones has been evident. λ g λ g [ABSTRACT FROM AUTHOR]

Electric shorting induced by tall vegetation is one of the major hazards affecting power transmission lines extending through rural regions and rough terrain for tens of kilometres. This raises the need for an accurate, reliable, and cost-effective approach for continuous monitoring of canopy heights. This paper proposes and evaluates two deep convolution neural network (CNN) variants based on Seg-Net and Res-Net architectures, characterized by their small number of trainable weights (nearly 800,000) while maintaining high estimation accuracy. The proposed models utilize the freely available data from Sentinel-2, and a digital surface model to estimate forest canopy heights with high accuracy and a spatial resolution of 10 metres. Various factors affect canopy height estimation, including topography signature, dataset diversity, input layers, and model structure. The proposed models are applied separately to two powerline regions located in the northern and southern parts of Thailand. The application results show that the proposed Encoder-Decoder CNN Seg-Net model presents an average mean absolute error (MAE), root mean square error (RMSE), and coefficient of determination R 2 of 1.38 m, 1.85 m, and 0.87, respectively, and is nearly 4.8 times faster than the CNN Res-Net model in conversion. These results prove the proposed model's capability of estimating and monitoring canopy heights with high accuracy and fine spatial resolution. [ABSTRACT FROM AUTHOR]

The design, development and fabrication of compact microstrip ring-hybrid couplers are presented in the present paper. In order to obtain miniaturization, λ/4 microstrip lines in a conventional microstrip ring-hybrid are equivalently substituted with quarter-wavelength supershape transmission lines. The results show that almost 74% size reduction can be achieved as compared to a conventional ring-hybrid. For verification purpose, a sample prototype has been designed, manufactured and tested. The fabricated compact ring-hybrid coupler operates at 1.3 GHz with low amplitude and phase imbalances. The acceptable agreement between the measurement and stimulation results validates the performance of presented coupler. The proposed ring-hybrid is compact, simple, single layer, cheap and suitable for planar fabrication for utilizing in modern communication systems. [ABSTRACT FROM AUTHOR]

After restructuring of power system, independent system operator is facing a big challenge to manage operations on transmission networks due to growing renewables share and involvement of large market players in power system operation. Among all renewables, wind power has the most stochastic nature and faces penalties due to mismatch in its initial power committed and final power delivered. Also, wind power plants are generally located at remote areas and need longer transmission lines for power delivery. This leads to congestion of transmission lines and poses a threat to security and safety of power system. To manage congestion on transmission lines, this paper proposes a novel rescheduling based combined bidding approach for wind integrated hybrid (pool + bilateral) power system. Congestion management problem has been formulated as mixed integer non-linear programming problem incorporating proposed combined bidding approach with an objective to reduce total congestion management cost through rescheduling of wind and hydro units on the basis of their combined up and down generation cost bids. The hydro units that have lowest operating cost and fast turn-on time have been used in coordination with wind units to alleviate congestion cost. Secured bilateral transactions have been confirmed while implementing the combined bidding approach for congestion management. Performance of proposed strategy has been analyzed by demonstrating it on modified IEEE-24 bus RTS system. [ABSTRACT FROM AUTHOR]

The point segmentation of power lines and towers aims to use unmanned aerial vehicles (UAVs) for the inspection of power facilities, risk detection and modelling. Because of the unclear spatial relationship between the point clouds, the point segmentation of power lines and towers is challenging. In this paper, the power line and tower point datasets are constructed using Light Detection and Ranging (LiDAR) and a point segmentation method is proposed based on multiscale density features and a point-based deep learning network. First, the data are blocked and the neighbourhood is constructed. Second, the point clouds are downsampled to produce sparse point clouds. The point clouds before and after sampling are rotated, and their density is calculated. Next, a direct mapping method is selected to fuse the density information; a lightweight network is built to learn the features. Finally, the point clouds are segmented by concatenating the local features provided by PointCNN. The algorithm performs effectively on different types of power lines and towers. The mean interaction over union is 82.73%, and the overall accuracy can reach 91.76%. This approach can achieve the end-to-end integration of segmentation and provide theoretical support for the segmentation of large scenic point clouds. [ABSTRACT FROM AUTHOR]

The measurement of the line impedance in long lines is adversely affected by fault and system parameters such as, the type and location of the fault, fault resistance, short circuit MVA of the source (presence of weak source), power transfer angle etc. This paper proposes a new technique to measure the line impedance during fault condition accurately, considering wide variations in the aforementioned variables. It is based on the mathematical analysis of the sequence network diagram of a non-homogeneous 400 kV, 50 Hz double infeed line, considering a single line-to-ground fault. Instead of using voltage and current vectors for the analysis, the impedance vectors are used to calculate the new impedance seen at the time of fault. The technique is verified using MATLAB/SIMULINK software. The simulation results conclude that the new measuring technique is precise, simple to understand, and rigid to the changes in all the system and fault parameters considered in this paper. [ABSTRACT FROM AUTHOR]

The general design of N-way Bagley Power Divider (BPD) with unequal output power splitting ratio is presented through this paper for the first time. Design equations are systematically derived based on microwave engineering, transmission line, and circuit theories after considering perfect input port matching (theoretically S11 = 0). An iterative algorithm for computing the characteristic impedances of the lines between adjacent output ports and the scattering parameters (S-parameters) for N-way BPD design is developed in this article. For validation, two multi-port examples, 11-way BPD and 13-way BPD are presented to confirm the design procedure. S-parameters have been calculated theoretically and using the presented algorithm to find the value of the design impedances. After that, these values are evaluated using both ADS and HFSS. A detailed flowchart is given through this paper to implement this N-way BPD iterative algorithm for any output port number (N). A very good agreement between theoretical, simulated, and experimental results is noted. This indicates the accuracy of the presented algorithm and the derived design equations. Besides, it gives the flexibility to design BPDs with any odd number of output ports for arbitrary output power splitting ratio, which is considered as a tangible additive in BPD design. [ABSTRACT FROM AUTHOR]

This paper proposes an enhanced asymmetric dual directional silicon controlled rectifier (EADDSCR) for the applications of bidirectional electrostatic discharge (ESD) protection. The ADDSCR and EADDSCR were prepared in a 0.18 µm Bipolar CMOS DMOS (BCD) process and measured with the transmission line pulsing tester. By adding N+ injection regions in the cathode and anode, a new vertical SCR path is formed in EADDSCR, so that the failure current of EADDSCR can reach twice as much as that of ADDSCR with only a small increase in the area of EADDSCR. Moreover, the FoM of EADDSCR can be increased to more than 81.19 µA/µm. Finally, the improved device possesses a smaller on resistance and is more suitable for high-voltage circuit applications. [ABSTRACT FROM AUTHOR]

In this paper, an ultra-miniaturized triple-band antenna based on an epsilon negative transmission line (ENG-TL) approach is presented. The proposed antenna has a miniaturized electrical size of 0.247λ0×0.185λ0×0.019λ0 at 3.71 GHz which has been achieved by means of zeroth-order resonance (ZOR). This is recognized as an attractive technique to achieve compactness. It is observed from measured results that the proposed antenna is performing well over 3.63–3.81, 5.21–5.33, and 6.79–7.09 GHz. The novelty of this work lies in the fact that the peak gain has been improved by 1.73 dBi at the lowest order resonant mode. The antenna is able to exhibit measured peak gain of 1.97, 1.09, and 3.42 dBi in the broadside direction at 3.72, 5.27, and 6.92 GHz, respectively. Hence proposed antenna is suitable to work for Wi-MAX 3.5 GHz (3.4–3.8 GHz), WLAN/Wi-Fi 5.2 GHz (5.15–5.35 GHz), mobile/satellite (E-S) (6.875–7.075 GHz) applications. [ABSTRACT FROM AUTHOR]

Over the last few years, the concept of robust optimization (RO) and its application to power system problems have been at the center of much recent research due to its successful implementation in handling uncertainties. In this regard, this paper presents a new approach for hybrid stochastic/robust transmission expansion planning (TEP), considering three sources of uncertainties, including demand growth, generation capacity, and thermal capacity of transmission lines. These uncertain parameters are modeled using an ellipsoidal uncertainty set, which can capture the correlation efficiently. The TEP problem is modeled as a bilevel mathematical optimization where the lower level is replaced by its Lagrange dual optimization problem using the duality theorem (DT). One main benefit of using the dual problem is that all uncertainties will appear in the objective function and thus can be converted to convex second-order cone constraints. The entire bilevel problem is then solved using the standard column-and-constraint generation (C&CG) technique by decomposing the mathematical problem into a master and a binary variable-free subproblem. Numerical studies on two test power systems validate the effectiveness of the proposed model. The results indicate that the presented methodology is more efficient than the existing models from the computational complexity perspective. [ABSTRACT FROM AUTHOR]

Proposed in this paper is a new configuration for a quad-band antenna based on using a metamaterial-inspired defected ground structure. The presented structure is introduced as a new modified metamaterial Complementary Split Ring Resonator (CSRR) with a compact electrical size. The new modified CSRR has been employed in Composite Right/Left-Handed (CRLH) transmission line configuration for ultra-size reduction. Validation for the particle small size is introduced and the detailed analysis for the NRI characteristics has been discussed by extracting the cell constitutive parameters. Hence, a multi-band antenna is designed based on using only one cell of the proposed NRI-TL. Subsequently, a small multi-band antenna is presented for different multi-band functionalities and different radiation properties. The antenna displays quad-resonances at 1.78 GHz, with the typical omnidirectional radiation pattern, 3.28 GHz, 4 GHz, and 4.3 GHz, with the directive broadside radiation properties. The proposed antenna footprint is 10 × 10 cm2, which exhibits a size reduction of up to 80% in comparison with a rectangular patch antenna operating at the lowest frequency band. [ABSTRACT FROM AUTHOR]

Beneficial use of dredged materials (DMs) obtained using the hydraulic dredging technique is a challenge since they behave like slurry with very high-water content. This paper presents an experimental study on the impacts of initial water contents and cement content on flowability, viscosity, and strength characteristic of cement-treated DM samples at high-initial water contents. A series of flow, viscosity and unconfined compressive strength tests were conducted on cement-treated DM specimens with various initial water contents and cement contents. Tests results showed that the value of slump flow increases almost linearly with increasing initial water content. The effect of cement content on slump flow for specimens at various initial water contents follows the same decreasing trend. Fresh mixtures of cement-treated DM specimens behave like Bingham plastic. Dynamic viscosity reduces with the increase in initial water content and the decrease in cement content. Slump flow reduces with the increase in viscosity or yield stress following a power trend line. All cement-treated specimens curing for 28 days exhibit strain-softening behavior. Unconfined compressive strength reduces as the initial water content increases and cement content decreases. A quantitative equation was developed to estimate the compressive strength as a function of initial water content and cement content. [ABSTRACT FROM AUTHOR]

The line commutated converter (LCC)-high voltage direct current (HVDC) transmission lines may have various complementary protection algorithms based on derivatives of line parameters or differential line currents. The DC line fault detection based on distance relaying, traveling wave (TW), artificial neural network, fuzzy logic, and wavelet are a few of the popular schemes. However, the TW-based technique has been reported as one of the fastest techniques to detect and locate faults. The conventional TW techniques face limitations in detecting high resistance DC line faults. Therefore, this paper introduces an improved fault detection, classification, and location algorithm based on backward propagating TWs and fault classifier indices. The proposed algorithm is tested to detect, classify, and locate the faults under different system conditions such as pole-to-ground, pole-to-pole, and rectifier and inverter sides' external faults. A bipolar LCC-HVDC transmission system of 900 km length is utilized to simulate the various fault conditions. The simulation results indicate fast, accurate, and reliable detection of faults. This scheme uses only single-end data measurement. The simulation study was performed for various fault locations (0–900 km) and transition resistances (0–150 Ω). [ABSTRACT FROM AUTHOR]

The virtual power plant (VPP) is an important technology for realizing smart grids. VPPs are not limited by geographical location, which greatly aggregates the distributed energy resources. To divide a VPP across regions, we no longer limit it to power lines. This paper proposes a three-stage strategy for the classification of VPPs that includes graph model construction, communication capacity assessment and cross-regional classification. To construct the VPP graph model, complex network theory and communication matrices are used. In addition, a network representation learning and clustering algorithm is used to classify the VPP decision areas. Then, the classification results are evaluated using modularity and network communication sequence entropy to identify VPP boundaries. Finally, the validity of the method is verified by simulating the test network and the real network. [ABSTRACT FROM AUTHOR]

This paper develops an innovative model of bandpass (BP) negative group delay (NGD) inverted arm topology of parallel lines. The S-matrix model is established from impedance and admittance matrix operations of elementary transmission lines constituting the topology. Parametric analysis is performed to assess the influence of inverted arm structure sizes on the BP NGD specifications. To validate the theoretical concept, a proof of concept is designed in microstrip technology. The calculated and simulated results are in very good agreement. NGD value, center frequency and bandwidth of about −8 ns, 3.6 GHz and 4 MHz, respectively, are observed with insertion loss better than 1 dB and reflection loss better than 18 dB. The innovative NGD physical structure could be an important asset to reduce propagation delay in the upcoming telecommunications systems as the 5G system. [ABSTRACT FROM AUTHOR]

A design method of greatly widening the stopband of waveguide bandpass filter is proposed in this paper. The parasitic passband of the filter mainly comes from the high-order oscillation mode of the resonant unit. Based on the theory of capacitance loading shortening of the transmission line and the transmission characteristics of each mode in the resonant cavity, a pair of transverse one-dimensional uniform capacitive diaphragms are placed in the center of the resonant cavity to shorten the resonant cavity and suppress the high-order modes. By changing the width of the waveguide and the height of the waveguide on the distribution of out-of-band transmission poles, the out-of-band transmission poles of each resonator can be staggered, which destroys or weakens the high-order oscillation coupling transmission conditions between the resonant units of the filter and further expands the stopband width of the filter. The results show that the length of the X-band waveguide bandpass filter (center frequency 9.5 GHz, bandwidth 400 MHz) is reduced by 54%, and the 40 dB stopband rejection bandwidth is 5.7 times the cutoff frequency of the transmission waveguide, compared with the prototype half-wavelength direct-coupled filter of the conventional Chebyshev filter. [ABSTRACT FROM AUTHOR]

In this study, a mathematical model is simulated in order to collect the solar radiation; consequently, evaluate the output power generated from photovoltaic panels (PVs). The simulation is based on two models of solar panels, one with Sun-tracker and the other one is stationary to illustrate differences between the PVs output power related to either tracking the sun or with fixed installation. PVs are simulated with three types of output power, 150 KW, 300 and 600 KW. After calculating the output power for the PV panels, it is possible to find the PVs optimum placement and sizing for a 69 IEEE RTS distribution power system in order to reduce power line losses and also receiving the maximum profit by selling the generated power via PVs. Placing and sizing the PVs are limited by common power system limitation such as voltage profile as well as overcurrent violation in the distribution system. Aside from that additional limitations such as reverse power flow, power line capacity and different group of loads, such as residential, industrial and agricultural, are considered in this paper in order to make the simulation more realistic. Moreover, meteorological data is collected from metrological organization of Mashhad, Iran. Finally, after calculating the injected power using PVs the amount of reduced energy from the main feeder is calculated; and consequently, economic benefit for the customers is evaluated. Economic evaluation for this study took place in 2014 according to Iran's electricity market. [ABSTRACT FROM AUTHOR]

This paper proposes a new unbalance composite right/left handed (CRLH) transmission line that consists of a normally magnetized ferrite-loaded rectangular waveguide. The left-handed (LH) behavior of this structure is based on the negative effective permeability of the ferrite material and the negative effective permittivity of the hollow metallic waveguide at the frequencies below the cutoff. By increasing the frequency and passing through the cutoff frequency, this structure behaves as a right handed (RH) transmission line. As a main advantage of the proposed structure, the CRLH response of this transmission line can be tuned by changing the magnetic bias of the ferrite layer. This tunable CRLH transmission line can be used to design a tunable microwave filter or a tunable leaky wave antenna (LWA) with backfire-to-endfire scanning capability. Compare to previous CRLH metamaterial structures, the proposed structure has an easy design and a wide frequency range of tunability. [ABSTRACT FROM AUTHOR]

This paper reports the design and development of a planar triplexer for WLAN/WiMAX/5G Wi-Fi applications based on a composite right-/left-handed transmission line (CRLH-TL) with low passband insertion loss, high channel isolation, wide stopband and minimal fabrication complexity. Even- and odd-mode methods are used to extract resonant properties of the globe-shaped open stub loaded stepped impedance resonator (GSOSL-SIR). The transmission line model of the GSOSL-SIR is analyzed and based on that; three bandpass filters are designed at 2.4/3.5/5.5 GHz. The equivalent LC circuit model for GSOSL-SIR-based CRLH-TL is provided with all lumped parameters fully defined. Finally, Triplexer is proposed by connecting all the three bandpass filters where each channel shows measured center frequency of 2.4/3.48/5.52 GHz with 3 dB fractional bandwidth of 22.08/22.19/16.3%. The proposed triplexer achieves high channel isolation (>30 dB) and low in-band insertion losses (1.1/0.87/1.3 dB) for the three filter channels. Additionally, the triplexer has measured 20 dB rejection levels from 6.5 GHz to 14.64 GHz and 10 dB rejection levels from 6.22 GHz to 19.85 GHz. The observed concordance between measured, electromagnetic simulated and equivalent LC circuit simulated results supports the utility of the design method. [ABSTRACT FROM AUTHOR]

In this paper we propose an end-fire antenna fed by a spoof surface plasmon transmission line that can exhibit a conical directional response. The plasmonic transmission line is composed of metallic strips of periodic sawtooth grooves that taper towards the firing end of the strip. By tapering the sawtooth grooves, reflection is suppressed, and a high gain is achieved when the spoof surface plasmons radiate into free space. Simulated results indicate that our antenna can achieve high efficiency and a maximum gain of 12.4 dBi within a wide operating band from 6 to 13 GHz. The antenna proposed in this paper has a simple and compact structure with a lateral dimension of approximately 0.19 λ 0 * 0.32 λ 0 and shows great potential for use in spoof surface plasmon polariton communication systems along with integrated circuits. [ABSTRACT FROM AUTHOR]

For high phase order (HPO) transmission systems, a major hurdle to overcome is the fault analysis and protection studies needed to guarantee successful implementation. This paper presents new equations which calculate the number of fault types and significant fault types of n-phase transmission lines. In addition, this paper defines and explains symmetrically significant fault types for HPO transmission systems. Lastly, this paper figuratively shows the significant fault types and symmetrically significant fault types for multiple HPO systems, n = 3, 4, 5, 6, 9, and 12. The equations and figures presented in this paper will assist in fault analysis and protective relay designs for HPO systems. The equations presented are used to determine the number of fault types a relay will need to account for, and the figurative approach shows the faults to be studied before HPO implementation. [ABSTRACT FROM AUTHOR]

Air pollution by the fossil fuel-driven vehicles in the urban and suburban sections in the developed countries forced the adoption of electric traction in railways. Subsequently, traffic dense rail routes in many developing countries were also switched over to high voltage electric traction to reduce their dependency on petroleum products. Developing countries are the main beneficiaries of the high voltage electric railway traction system. As a result of the operational constraints evolved in maintaining partially electrified rail routes, developing countries are trending to electrify more rail routes at geographically challenged areas also. Tunnels constructed for metro railways in urban sections also raise the similar geographical challenges. Power supply interruption happened due to persisting earth fault on electric traction system even for a short duration will paralyze the rail network to a large extent. Hence precisely pin pointing the fault distance is essential to ensure the railway system reliability. Undesirable variations occurred in line parameters due to the bare conductors for the electric traction inside railway and metro train tunnels for very long stretches due to proximity of earth potential, and the subsequent nuisance crept in line fault distance locating algorithm studied through the experimentations conducted in actual working condition for re-modelling high voltage ac electric railway traction to precisely pin pointing the fault distance of it are presented in this paper. [ABSTRACT FROM AUTHOR]

This paper investigates the impact of bank competition on access to credit by informal firms in 14 Sub Saharan African countries using World Bank enterprise survey data. Access to credit is one of the main factors identified as hindering the growth of these opaque borrowers with poor financial transparency. This study uses a binary choice probit model to estimate the probability or likelihood of accessing finance conditional on the level of bank competition and other firm-level characteristics. Results show that the impact of competition measured using the recent and empirically robust Boone indicator is negative and significant in line with the market power hypothesis. These results suggest that improving the competitiveness of the banking sector by encouraging entrance of more players and curbing anti-competitive conducts should be promoted without compromising the soundness of the sector. Reducing or minimizing information asymmetry using public credit registries is good for enhancing financial access and governments should invest resources on maintaining, updating and increasing the coverage of these registries. [ABSTRACT FROM AUTHOR]

In order to run power plant operations smoothly, power plant faults need to be detected, located, and classified quickly. For this, artificial neural network approaches are considered significant tool in related application of power system. This research paper focuses on power plant faults detection and classification using intelligent approach of artificial neural network. There is frequent nature of power plant faults, in particular transmission line faults. The key intention of this research is to use ANN approach to detect and classify power plant faults, and in the end to compare their performance and accuracy. In this proposal, the three-phase current and voltage are use as input. Backpropagation (BPNN) technique is used in developing the learning algorithm for multi-layer neural network that can accurately and reliably classify faults. The multi-layer neural network such as Levenberg-Marquardt and Bayesian regularization are used for offline training of the data. Findings from this research show that both Levenberg-Marquardt and Bayesian regularization show good accuracy to detect and classify faults in transmission line. However, LM algorithm trained data much faster than BR. LM shows fastest detection of faults with overall mean square error value of 6.13785e-3 at the 91 epoch. Whereas, BR trained network at the 717 epochs with overall mse of 4.67123e-3. It is to be noted that the accuracy of trained network to classify all the fault types is found to be 81.1%, which is higher than previous studies using Backpropagation neural network technique. Training and test results show that these neural network-based methods can effectively detect and classify faults and faults types and have adequate performance. Matlab is used in this research because it has toolbox, which has effective features to train required data and achieve effective result. [ABSTRACT FROM AUTHOR]