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Tytuł:
Probabilistic assessment of the short-circuit duration on the 220 kV transmission line basing on simulation analysis
Autorzy:
Frąckowiak, R.
Piechocki, P.
Powiązania:
https://bibliotekanauki.pl/articles/97379.pdf
Data publikacji:
2012
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
transmission lines
current
simulation analysis
Opis:
In the paper, the problem of defining the short circuit duration time for the short-circuit effect calculations, especially thermal and electromagnetic ones, has been discussed. In author’s opinion, the results of probabilistic research could be helpful when resolving the problem. Therefore, a tailored simulation model based on the analysis of the protections and circuit breakers operation during the transmission lines fault clearance has been developed. Due to the results of simulation study, the found values of the fault duration time could be related to the expected risk of their exceeding depending on both the protection system configuration and the type of the circuit breakers applied.
Źródło:
Computer Applications in Electrical Engineering; 2012, 10; 275-282
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of 0.2% Addition of Mg, Co and Ce on Microstructure and Mechanical Properties of 1xxx Series Aluminium Alloy Castings Designed for Overhead Transmission Lines
Autorzy:
Koprowski, Paweł
Lech-Grega, M.
Wodzinski, Łukasz
Augustyn, Bogusław
Boczkal, Sonia
Uliasz, Piotr
Ożóg, Mirosław
Powiązania:
https://bibliotekanauki.pl/articles/2048868.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
micro-additions
aluminium
hardness
microstructure
overhead transmission lines
Opis:
The effect of 0.2% addition of Mg, Co and Ce to 99.9% cast aluminium was studied by evaluation of changes in microstructure and mechanical properties. The microstructure was analyzed by scanning electron microscopy and transmission electron microscopy. The Al99.9 alloy contained only Al-Fe-Si phase particles. Similar Al-Fe-Si particles were observed in alloy with 0.2% Mg addition, because this amount of magnesium was fully dissolved in the solid solution. The addition of cobalt resulted in the formation of Al9.02Co1.51Fe0.47 phase particles assuming the shape of eutectic plates. The electron backscattered diffraction map made for the alloy with 0.2% Co addition showed numerous twin boundaries with distances between them in the range from 10 to 100 µm. The addition of cerium was located in the grain boundary area. Cerium also gave rise to the formation of two types of particles, i.e. Al4Ce and Al-Ce-Fe-Si. The Al-Ce-Fe-Si phase is a nucleation site for the Al4Ce phase, which forms eutectic plates. The results showed that the introduction of additives increases the mechanical properties of the cast materials. The 99.9% cast aluminium has a hardness of 16.9 HB. The addition of 0.2% by weight of Mg, Co, Ce increases this hardness to 21.8 HB, 22.6 HB and 19.1 HB, respectively.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 1; 303-309
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solution Methods of Overhead Transmission Line Mechanics
Autorzy:
Varga, L.
Ilenin, S.
Chladný, V.
Powiązania:
https://bibliotekanauki.pl/articles/262625.pdf
Data publikacji:
2006
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
overhead transmission lines mechanics
mechanical tension
catenaries curve
Opis:
Paper is focused to mechanics calculation of overhead transmission lines. In first part of this paper is presented mathematical model for complex solution of overhead line mechanics in a plan. Non-level overhead line can be considered. The second part of paper deals with a solution method of the mechanics of overhead line conductors in three-dimensional space in non- level span. This method enables to define three-dimensional location, vector of mechanics stress of suspended line in optional point of line under combined load caused by the ice and the wind of optional direction.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2006, 12, 1; 17-20
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods for Canceling the Power Frequency Magnetic and Electric Fields at Pre-Specified Points on the Lines’ Corridors
Autorzy:
Saied, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/262789.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
power transmission lines
magnetic field
electrostatic interference
mitigation
shielding
Opis:
Methods are presented for the cancellation of the power line’s magnetic and electric fields at pre-specified points close to the line corridor. For canceling the magnetic field, three auxiliary conductors constituting two mitigating loops are used. Their configuration should be geometrically similar to the arrangement of the 3-phase power line’s conductors, with respect to the point at which a zero magnetic field is required. A procedure is suggested for the optimal selection of the scaling factor relating the power conductors’ and the mitigating conductors’ geometrical dimensions. In a case study, the magnetic field reduction varies between 100% near the zero-field point to 35% to the right of that point, with an optimal scaling factor of 0.15. Similar procedure can be used for cance¬ling the electric field at a pre-specified point. The three auxiliary conductors should carry charges proportional to those on the active conductors, but of opposite signs. Results show that the field at the specified point will be exactly zero, instead of the original value of 2.6kV/m. The three voltages required to supply the auxiliary conductors are 76.62, 62.53 and 51.50kV, with almost equal phase angles. The fact that the potentials of the three auxiliary conductors are almost in phase suggests the possibility of using one transformer with appropriate taps to supply them.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2009, 15, 2; 13-19
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Compact Broadband Rat-Race Coupler in Multilayer Technology Designed with the Use of Artificial Right- and Left-Handed Transmission Lines
Autorzy:
Staszek, K.
Kołodziej, J.
Wilcza, K.
Gruszczyński, S.
Powiązania:
https://bibliotekanauki.pl/articles/309181.pdf
Data publikacji:
2012
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
broadband rat-race couplers
left-handed transmission lines
quasi-lumped elements
Opis:
The paper presents a compact broadband rat-race coupler for the first time designed and realized in a mul- tilayer microstrip technology. To achieve both broad operational bandwidth and a compact size the 270? transmission line of a conventional rat-race, coupler has been replaced by a -90? left-handed transmission line realized with the use of a quasi-lumped element technique. Moreover, to achieve better compactness of the resulting coupler, all 90? right-handed transmission lines have been realized with the use of the same technique. It has been also proved that simple LC approximation of a left-handed transmission line can be successfully used for the design. Moreover, it has been shown that when appropriately chosen, the multilayer dielectric structure allows for realization of structures designed with the use of this simple approximation, for both right-handed and left-handed transmission lines, without loosing too much of a performance.
Źródło:
Journal of Telecommunications and Information Technology; 2012, 2; 107-112
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A High-Accuracy of Transmission Line Faults (TLFs) Classification Based on Convolutional Neural Network
Autorzy:
Fuada, S.
Shiddieqy, H. A.
Adiono, T.
Powiązania:
https://bibliotekanauki.pl/articles/1844462.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fault detection
fault classification
transmission lines
convolutional neural network
machine learning
Opis:
To improve power system reliability, a protection mechanism is highly needed. Early detection can be used to prevent failures in the power transmission line (TL). A classification system method is widely used to protect against false detection as well as assist the decision analysis. Each TL signal has a continuous pattern in which it can be detected and classified by the conventional methods, i.e., wavelet feature extraction and artificial neural network (ANN). However, the accuracy resulting from these mentioned models is relatively low. To overcome this issue, we propose a machine learning-based on Convolutional Neural Network (CNN) for the transmission line faults (TLFs) application. CNN is more suitable for pattern recognition compared to conventional ANN and ANN with Discrete Wavelet Transform (DWT) feature extraction. In this work, we first simulate our proposed model by using Simulink® and Matlab®. This simulation generates a fault signal dataset, which is divided into 45.738 data training and 4.752 data tests. Later, we design the number of machine learning classifiers. Each model classifier is trained by exposing it to the same dataset. The CNN design, with raw input, is determined as an optimal output model from the training process with 100% accuracy.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 4; 655-664
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transitional processes at switching-off unloaded power transmission lines by modern circuit-breakers and their computer simulation
Autorzy:
Lazimov, T.
Saafan, E.
Powiązania:
https://bibliotekanauki.pl/articles/410587.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
SF6 circuit-breakers
power transmission lines
computer simulation
transitional voltages
Opis:
The article presents results of transitional processes computer simulation at switching-off unloaded power transmission line of rated voltage 220 kV by auto-compression (SF6) circuit-breakers. Transitional voltages (voltage across the line terminals and recovery voltage) at switching-off were calculated and studied in the research carried out. There was also considered dependence between transitional voltages magnitudes and power transmission lines lengths. There were studied some computational peculiarities of the problem under consideration. In particular, the numbers of pi-sections provided satisfactory adequacy of lines equivalency at computer simulation for their typical lengths were determined. There were also estimated optimum simulation parameters provided stability of transitional regime parameters.
Źródło:
Present Problems of Power System Control; 2013, 4; 67-75
2084-2201
Pojawia się w:
Present Problems of Power System Control
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurement of combined gap in whole process of transmission lines’ live working based on 3D laser point cloud
Autorzy:
Wang, Ying
Zhang, Haitao
Lv, Qiang
Gao, Qiang
Yi, Mingxing
Powiązania:
https://bibliotekanauki.pl/articles/27309938.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
3D model
combined gap
laser point cloud
live working
transmission lines
Opis:
Transmission lines’ live working is one of an effective means to ensure the reliable operation of transmission lines. In order to solve the unsafe problems existing in the implementation of traditional live working, the paper uses ground-based lidar to collect point cloud data. A tile based on the pyramid data structure is proposed to complete the storage and calling of point cloud data. The improved bidirectional filtering algorithm is used to distinguish surface features quickly and obtain a 3D model of the site. Considering the characteristics of live working, the speed of data reading and querying, the nearest point search algorithm based on octree is used to acquire a real- time calculation of the safe distance of each point in the planned path, and the safety of the operation mode is obtained by comparing with the value specified in the regulation, and assist in making decisions of the operation plan. In the paper, the simulation of the actual working condition is carried out by taking the “the electric lifting device ascending” as an example. The experimental results show that the established three-dimensional model can meet the whole process control of the operation, and has achieved practical effect.
Źródło:
Archives of Electrical Engineering; 2023, 72, 3; 737--753
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new method to reduce electromagnetic interference using signal modeling
Autorzy:
Daneshvar, Milad
Parhizgar, Nasser
Oraizi, Homayoon
Powiązania:
https://bibliotekanauki.pl/articles/949874.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
electromagnetic radiation
frequency response
interference
multi-component
signals
parameter modeling
transmission lines
Opis:
Controlling and reducing the radiation emitted by various systems helps the board designer improve systems’ performance. One proposed way to achieve these goals is to use an algorithm to control the radiation applied to systems. According to the executive structure of the algorithm and considering the nature of the existing signals in several components, the separation of the signal components is on the agenda of the algorithm. In fact, the goal is to create an intuitive view of the multi-component signals around the systems that enter the systems from different angles and have a detrimental effect on their performance. Using signal processing methods, we will be able to break down the signal into different components and simulate each component separately. To prevent high computational repetitions and increase simulation time in signal component analysis, by reducing the components, we reduce the number of mesh cells in the software and, using linear approximation, determine the exact position of the radiation signal applied to systems and thus the best linear relationship. The signal entry path is used to apply the rules required for prediction design.
Źródło:
Archives of Electrical Engineering; 2020, 69, 4; 829-840
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Obliczenia rozpływu prądów zwarciowych w przewodach odgromowych linii WN
Calculation of short-circuit currents in the overhead earth wires
Autorzy:
Klucznik, J.
Lubośny, Z.
Dobrzyński, K.
Powiązania:
https://bibliotekanauki.pl/articles/952782.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
linie elektroenergetyczne
przewody odgromowe
zwarcia doziemne
overhead transmission lines
earth wires
earth faults
Opis:
W referacie przedstawiono metodę oraz jej implementację w postaci programu komputerowego, które umożliwiają obliczenie rozpływu prądów zwarciowych w linkach odgromowych linii wysokiego napięcia. Algorytm umożliwia obliczenia dla linii dwustronne zasilanej oraz linii w układzie gwiazdowym (z odczepem). Opracowany program umożliwia weryfikację doboru przewodów odgromowych z punktu widzenia wytrzymałości zwarciowej cieplnej.
The paper presents a method and its implementation in the form of a computer program that allows calculation of the propagation of fault currents in the earth wires of a high voltage transmission lines. The proposed algorithm allows for the calculation for doubly fed transmission lines and three-terminal transmission lines. Developed program allows for verification overhead earth wires selection from the point of view of short-circuit thermal current.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2015, 42; 57-60
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculations of Short-Circuit Current Flows in Earth Wires of HV Lines
Obliczenia rozpływu prądów zwarciowych w przewodach odgromowych linii WN
Autorzy:
Klucznik, J.
Lubośny, Z.
Dobrzyński, K.
Powiązania:
https://bibliotekanauki.pl/articles/397281.pdf
Data publikacji:
2016
Wydawca:
ENERGA
Tematy:
transmission lines
earth wires
single phase short-circuit
linia elektroenergetyczna
przewody odgromowe
zwarcia doziemne
Opis:
This paper presents a method which enables calculating flows of short-circuit currents in earth wires of high voltage transmission lines, and its implementation in the form of a  computer programme. The algorithm enables performing calculations for a  double-fed line and starconnected lines (three terminal lines). The developed programme enables verifying dimensioning of earth wires in the context of their short-circuit thermal withstand value.
W artykule przedstawiono metodę oraz jej implementację w postaci programu komputerowego, które umożliwiają obliczenie rozpływu prądów zwarciowych w linkach odgromowych linii wysokiego napięcia. Algorytm umożliwia obliczenia dla linii dwustronnie zasilanej oraz linii w układzie gwiazdowym (z odczepem). Opracowany program umożliwia weryfikację doboru prze- wodów odgromowych z punktu widzenia wytrzymałości zwarciowej cieplnej.
Źródło:
Acta Energetica; 2016, 1; 45-50
2300-3022
Pojawia się w:
Acta Energetica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Corona Modeling for the Transient Analysis, Steady State and Corona Loss Performance of Transmission Lines
Autorzy:
Saied, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/262685.pdf
Data publikacji:
2013
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
corona
power transmission lines
electromagnetic modeling
computer simulation
losses
transient analysis
shunt compensation
optimization
Opis:
This paper addresses the steady state analysis and the electromagnetic transients of overhead power transmission lines exhibiting corona. After a brief survey of the currently available modeling techniques, an alternative approach to the simulation of the corona discharge is presented. It is based on adding voltage-dependent current sources at prespecified nodes within the line’s lumped, ladder-shaped, equivalent circuit including an aduqate number of sections. The characteristics of these current sources can be determined using the usually available corona power loss measurements under power frequency sinusoidal voltage conditions. The line model is used for finding its transient response using time domain techniques. Several voltage excitation waveforms and magnitudes as well as different line’s loading conditions are investigated. As a further application of the suggested approach, the minimizion of the total corona losses of a long shunt compensated line will be considered as an additional criterion in the process of identifying the appropriate rating and location of the compensating coil primarily used for improving the line’s voltage profile.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2013, 16, 2; 11-20
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nowa metoda obliczania rozpływu prądów zwarciowych w przewodach odgromowych linii wysokiego napięcia
A new method of earth wires current calculation in HV transmission lines
Autorzy:
Klucznik, J.
Powiązania:
https://bibliotekanauki.pl/articles/267645.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
linie elektroenergetyczne
przewody odgromowe
zwarcia
fault currents
earth faults
earth wires
overhead transmission lines
Opis:
Referat przedstawia nowatorską metodę obliczania wartości prądów płynących w przewodach odgromowych w czasie zwarć, pozwalającą na dobór przewodów odgromowych pod względem wytrzymałości cieplnej. Proponowana metoda charakteryzuje się większą dokładnością i większą uniwersalnością niż powszechnie stosowane metody, pozwalając tym samym na dobór przewodów odgromowych z mniejszym ryzykiem niepewności. Prezentowana metoda obliczeniowa pozwala również na ocenę ochrony przeciwporażeniowej linii, poprzez wyznaczenie wartości prądów płynących w uziomach słupów.
The paper presents a new method to compute a phase-to-earth fault current distribution in overhead transmission line. The method is based on the tableau analysis of an unbalanced, multi-wire model of a transmission line. The proposed method allows the values of the currents in earth wires to be determined for each span of the line, as well as the current and voltage for every tower of the line. The advantage of this method over others is the possibility of carrying out calculations for any system configuration, regardless of its complexity. The method can be used for analysis of any type of transmission line (single circuit, double circuit and multi-circuit lines) with any number of earth wires. The calculation results may be used for complex designs of transmission line earthing systems, earth wire thermal rating selection, and the evaluation of shock hazards.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2017, 56; 39-45
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Transient Performance of Partially-Undergrounded Overhead Lines in the Presence of Corona
Autorzy:
Saied, Mohamed M.
Powiązania:
https://bibliotekanauki.pl/articles/262791.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
distributed parameter circuits
non-uniform lines
power transmission lines
line modeling
transients
power networks
mixed
overhead-cable lines
partial undergrounding
distributions
mathematica
Opis:
The paper presents a method for investigating the electromagnetic transients of partially under-grounded high voltage overhead transmission lines in the presence of corona. It is based on a time domain model in which the corona is simulated by distributed voltage-dependent shunt current sources. The line segments and the inserted cable section are represented by a single equivalent transmission element having location-dependent circuit parameters per unit length. The numerical solution of the resulting set of differential equations yields the distributions of the voltage, the longitudinal current and the shunt corona current (per unit length) as functions of location and time. The presented two-, three-dimensional and contour plots proved to be helpful in discussing these distributions and in identifying any eventual current and/or voltage concentrations. The developed computer code in Mathematica can handle any time waveform of the source initiating the transients, any line termination as well as any lengths of the overhead line and cable section.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2019, 21, 1; 1-8
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Obliczanie prądów w przewodach odgromowych w linii napowietrzno-kablowej
Earth wires currents calculation in UGC-OHL lines
Autorzy:
Klucznik, Jacek
Dobrzyński, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/267044.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
przewody odgromowe
zwarcia
linie napowietrzne
linie kablowe
fault current distribution
earth faults
earth wires
overhead transmission lines
underground cable lines
Opis:
W referacie analizowana jest linia napowietrznokablowa 110 kV. Referat prezentuje wpływ sposobu uziemiania żył powrotnych kabla WN na wartości prądów przy zwarciach jednofazowych, ze szczególnym uwzględnieniem prądów płynących w przewodach odgromowych linii napowietrznej. Wykazano, że dobór przewodów odgromowych linii napowietrznej powinien uwzględniać nie tylko parametry odcinka linii kablowej, ale także sposób uziemienia żył powrotnych.
The high voltage overhead (OHL) and underground cable line (UGC) is analyzed in the paper. The paper presents the influence of the cable sheath earthing on the values of currents in case of earth faults, with particular focus on the currents flowing in the earth wires. It is shown that the selection of the earth wires for the overhead line should take into account not only the parameters of the cable line section, but also the method of the cable sheath earthing. The single point earthing with no earth continuity conductor (ECC) is particularly not recommended, because it leads to the earth wire currents and earth potential rise.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2019, 62; 41-44
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
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