The electrical network is the set of elements where loads are connected to the generation plants by transmission lines. They can be either overhead or underground cables. A new technology has been ...introduced to replace these transmission lines with underground cables gas insulated line “GIL”. The latest has many advantages over underground cables and overhead transmission lines, such as low transmission losses, less capacitive load, reliability, personal safety, same operation as overhead lines and negligible electrical aging. GIL can handle much more power than overhead lines due to its large conductive area. GIL is the best for high voltage. In this paper, the simulation of lightning strike effects on a 400 kV hybrid transmission line located in the Wilaya of Setif in northern Algeria is presented in the absence and presence of line arresters and GIL arresters. The results of this paper can provide a rich and valuable theoretical reference for GIL simulation modeling and evaluation of lightning strike impact on hybrid overhead – GIL lines.
Sieć elektryczna to zbiór elementów, w których obciążenia są połączone z elektrowniami za pomocą linii przesyłowych. Mogą to być linie napowietrzne lub podziemne. Nowa technologia została wprowadzona w celu zastąpienia tych linii przesyłowych podziemnymi kablami w izolacji gazowej "GIL". Najnowsza technologia ma wiele zalet w porównaniu z kablami podziemnymi i napowietrznymi liniami przesyłowymi, takich jak niskie straty przesyłowe, mniejsze obciążenie pojemnościowe, niezawodność, bezpieczeństwo obsługi, takie samo działanie jak w przypadku linii napowietrznych i znikome starzenie elektryczne. GIL może obsługiwać znacznie większą moc niż linie napowietrzne ze względu na dużą powierzchnię przewodzącą. GIL jest najlepszy dla wysokich napięć. W niniejszym artykule przedstawiono symulację skutków uderzenia pioruna w hybrydową linię przesyłową 400 kV zlokalizowaną w Wilaya, Setif w północnej Algierii w przypadku braku i obecności ograniczników liniowych i ograniczników GIL. Wyniki tego artykułu mogą stanowić bogate i cenne teoretyczne odniesienie do modelowania symulacji GIL i oceny wpływu uderzenia pioruna na hybrydowe linie napowietrzne – GIL.
•A prediction model for the conductor temperature is developed incorporating multiple temperature factors.•The dynamic response of an exemplar OTL with thermal effects is studied.•A wind-temperature ...hazard model is developed based on historical meteorological data.•The failure probabilities of the OTL under different temperatures are evaluated.
The overhead transmission line (OTL), which remains exposed to the outdoor environment for extended durations, is subjected to significant temperature fluctuations. These fluctuations can alter the structural characteristics of the OTL, thereby increasing the uncertainties associated with wind-induced responses and wind-induced failures. As a consequence, this paper introduces a probabilistic assessment methodology considering structure-ambient temperature interaction, and utilizes it to investigate the wind-induced performance of an OTL under different operator temperatures. Based on the meteorological data, a prediction model for the conductor operator temperature is developed incorporating multiple temperature factors. Nonlinear dynamic analyses are performed to numerically investigate the effect of temperature on the natural frequency and dynamic response of the OTL. Moreover, the failure probabilities of the OTL under different temperatures are evaluated combing with a Copula-based joint probability distribution of temperature and wind speed. The analytical results reveal that lower temperatures correspond to greater wind-induced response. Moreover, when considering the actual distribution of wind-temperature hazards, lower temperatures do not necessarily entail the highest wind-induced damage probability. This study provides valuable insights for evaluating the safety of OTLs under the combined influence of wind and temperature.
•Proposition of a set of open-source routines allowing to carry out the methodology as a open-source project.•Didactic presentation of a methodology to calculate buried pipeline and transmission line ...inductive and conductive influences.•Results indicate that the whole pipeline representation provides more accurate results.
Electric power systems influences on nearby structures have been widely investigated in the last decades. Generally, the practical projects contemplate simplified studies that calculate just part of the system. The literature is vague regarding whether this standard procedure may cause a difference in the calculated results. This paper investigates inductive and conductive influences along a buried pipeline from an overhead transmission line during normal load operation and fault conditions. Two situations are compared: only part of the pipeline stretch near the interfering system and its total length. A case study investigates the influences from an overhead transmission line on a buried pipeline for parallelism and crossing approaches by proposing an accessible methodology, whose results are compared with commercial programs widely used by design engineers and with good accuracy. The main focus of this work is to show that the most common practice of considering only the region where an overhead line is closest to the pipeline may lead to underestimating the induced voltage. Instead, to correctly assess pipeline-induced voltage, one may need to represent in detail the whole pipeline. High deviations indicate that a pipeline may suffer corrosion and put personal safety at risk if mitigation measures are not implemented. Computations considering the whole pipeline path are essential for structural and personal integrity. Besides, the proposed accessible methodology is useful, given alternatives to the few commercially available software.
The overhead power transmission line, as an important component of equipment for long-distance power transmission, is threatened by icing and galloping, which will lead to equipment troubles and ...cause huge economic loss. Thus, there is a great need for on-line monitoring for transmission lines. Because the photoelectric composite cable, such as optical fiber composite overhead ground wire (OPGW) is widely used, it is possible to introduce distributed optical fiber sensors (DOFS) into transmission line status monitoring. Common schemes based on DOFS usually offer low sensing density and are hard to realize global awareness, while phase sensitive optical time domain reflectometry (Φ-OTDR), as a DOFS that has the characteristic of distributed sensing, is hoping to address the limitation. In this paper, by establishing mathematical models, proposing analytical method, and building demonstration devices to analyze the dynamic strain characteristics of overhead power transmission line, an Φ-OTDR based on-line monitoring scheme of transmission line status is presented and experimentally proved for the first time. The estimation error of sag is less than 5.8% on centimeter scale, and the estimation error of ice thickness is no more than 10.84% on sub-millimeter scale, which gives an accurate description of transmission line status and provides strong support for early warning of transmission line failures.
This paper presents a framework for evaluating the wind-induced resistance of overhead transmission lines (OTLs), aiming to overcome the limitations associated with disregarding temperature effects ...and relying on a single metric for failure assessment. The proposed framework factors in temperature influence, carefully considers applied loads and structural characteristics, and accurately calculates failure probability based on a specific case study. Meteorological data is initially collected to create a probabilistic model of wind speed and temperature distribution, accounting for correlation. Components and systems are graded based on structural characteristics and damage modes. The neural network surrogate model is trained with finite element computations for load-structural response sample sets. The surrogate model, in conjunction with logistic regression, generates samples to determine fragility. Finally, the total structural failure probability and monthly failure likelihood are computed by integrating the joint probability model and fragility. Analyses highlight temperature's significant impact on conductor-ground line safety, validating the proposed framework's rationale.
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•A joint probability distribution model for wind speed and temperature based on measured data is developed.•An OTL performance classification criteria is proposed.•An RBFNN surrogate model is modeled.•Fragility and failure probability of OTL is studied in detail.
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•Non-contact measurement of the traveling wave fault location in overhead line has been proposed.•The proposed method used three TMR sensors mounted horizontally on the Overhead ...line.•The proposed method measured the traveling wave caused by the short circuit on the line.•Fault initiated time was measured by the proposed method compared to traditional one.•Accuracy of the proposed method has been investigated compared with classical methods.
Traveling wave fault location methods have gained considerable growth over the years, with the anticipation that power systems will be accurate and reliable everywhere. But the performance of classical traveling wave methods has focused only on traditional current transformer measurement in the literature till date. Therefore, in this paper, an innovative non-contact measurement of traveling wave formulation is proposed to achieve accurate fault location and time of arrival detection on a two-terminal overhead transmission line, since power cable naturally generates magnetic and electrical fields in the surrounding atmosphere. The proposed method solitary depends on the first two and successive time differences between the incident and reflective wave from the fault point of the transmission line. Thus, the proposed scheme does not depend on current transformer measurement that stimulates the accuracy and reliability of the conventional traveling wave fault location method. To ensure an accurate time of arrival waves detection, we exploit the magnetic field sensor array on each tower to measure the quality of current traveling waves generated on the transmission line and locate the transient disturbances as a result of a short circuit. By analyzing the line energization, a comprehensive fault analysis on a 500-kV line was simulated with PSCAD/MATLAB toolbox compared to the two-terminal classical method. The sensitivity analysis demonstrated that the proposed method is much accurate and reliable to be deployed and cost-effective, making it highly useful and efficient in comparison to the classical two terminals traveling wave method with an average error of 0.014%. The effectiveness of the proposed method was verified by laboratory experimental setup.
With the development of smart grid, the demand for voltage measurement along the overhead transmission lines is increasing. However, the installation of voltage transformers in the existing lines ...entails numerous difficulties. This study proposes a new non‐contact measurement method by inversely calculating the voltages on AC overhead transmission lines based on the power‐frequency electric field measurement data. To improve the calculation accuracy, the 3D model of transmission lines is built, and the relations between the 3D electric fields and voltages are presented. An improved algorithm that intermingles with the particle swarm algorithm and genetic algorithm is developed to ascertain optimal inverse solutions, meanwhile to improve the convergence speed and calculation stability. To further reduce the computational complexity, the constraint relations between the voltages and electric fields are derived, thereby the simplification from three decision variables to one is achieved. Then, some simulation cases with different measurement errors and voltage running states are conducted to show the good robustness and high accuracy of the proposed inversion method. Finally, a three‐phase experimental system is built and the actual measured data are used to inversely calculate, which verifies the practicability of the proposed non‐contact voltage measurement method.
A universal and robust wireless power transfer (WPT) system crossing insulators to feed monitoring terminals on power towers of overhead transmission lines is presented in this study. Analyses of the ...WPT system crossing high-voltage insulators string indicate that system characteristics and energy loss vary under different insulation conditions. Transfer characteristics of the WPT system with different relative positions between the coils and insulators are analysed to find an insensitive scheme. To achieve a non-interacting and relatively efficient operation under the scenarios, magnetic shielding layers are designed to further isolate the WPT system and insulators. Moreover, the resonant frequency point tracking method of this specific WPT system is studied and implemented to achieve robust transfer efficiency. Experimental results prove the feasibility, and the system displays a robust transfer performance with various high-voltage insulators. Such energy feeding system can be used in disc or composite insulation towers universally with simplified installation methods.
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