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1
Content available Obliczanie natężenia pola elektrycznego i pola magnetycznego pod linią energetyczną z uwzględnieniem zwisu przewodów
Król K., Budnik K., Jarek P.
Poznan University of Technology Academic Journals. Electrical Engineering
|
2018
|
No. 93
265--277
PL
W artykule przedstawiono metodę obliczenia natężenia pola elektrycznego i magnetycznego z uwzględnieniem zwisów przewodów. Zwis przewodów opisano za pomocą krzywej łańcuchowej. W obliczeniach uwzględniono zmienny rozkładu ładunku wzdłuż przewodów dla natężenia pola elektrycznego, natomiast dla natężenia pola magnetycznego uwzględniono wpływ prądów indukowanych w przewodach odgromowych. Wyniki symulacji natężeń porównano z rzeczywistymi pomiarami wykonanymi dla wybranych linii elektroenergetycznych.
EN
The paper presents a calculation method of the electric and magnetic field intensity under an overhead power line, taking into account conductor sag, which is described by the catenary curve. The calculations take into account the variability of the charge distribution along the conductor and wire sag for the electric field, while the calculation of intensity of the magnetic field take into account the impact of induced currents in the ground wires. The simulation results were compared with real measurements.
2
Content available Models of traction stray currents interaction with the earth return circuits
Budnik K., Machczyński W., Szymenderski J.
Poznan University of Technology Academic Journals. Electrical Engineering
|
2018
|
No. 93
227--239
EN
The paper presents methods for analyzing the impact of stray currents generated by DC electric traction on nearby earth-return circuits (pipelines). Various simulation models were developed and compared. First the current and potential of the rail were determined using two models. A model with distributed parameters and a model with lumped parameters consisting of chain-connected two-ports of the π type, for which the potential values in the nodes and currents in the branches were determined using the node potential method. The results obtained were used to further analyze the interaction between the railway rail and the pipeline. The pipeline model is presented in the form of a chain connection of π type two-ports. To determine the impact of stray currents on the pipeline, an analysis of the electric field in its vicinity was carried out. For this purpose, two methods have been developed. First, the analysis of the distribution of the scalar potential in the ground for a rail section of finite length was performed. Second method required taking into account the mutual conductivity of the two circuits (rail and pipeline), which in connection with the knowledge of the leakage current from the rail made it possible to determine the potential of the tested pipeline (using controlled voltage sources). The paper presents the implementation of methods and a comparison of the results obtained. The usefulness and applicability of the developed models for the analysis of the impact of stray currents from DC electric traction on earth-return circuits were also assessed.
3
Content available Polarization phenomenon in underground pipeline generated by stochastic stray currents from D.C. traction
Budnik K., Machczyński W., Szymenderski J.
Poznan University of Technology Academic Journals. Electrical Engineering
|
2017
|
No. 89
111--122
EN
D.C electrified traction systems are a potential source of stray currents. The important problem, technically, is to evaluate the harmful effects (electrolytic corrosion) that an electrified railway has on nearby earth–return circuits (e.g. pipelines). This phenomenon is stochastic and may aggravate electrochemical corrosion in different places depending on the position of the vehicle, the load current, soil parameters, etc. The electric circuit approach, based on the complete field method of solution of the transmission–line problem (the earth–return circuit theory), to model stray currents interference on extended structures is presented. The electrode kinetics (polarization phenomenon) is taken into account in the model developed. Random algorithm allows to explore the phenomenon of polarization for different cases, which allows for generalization of the conclusions regarding the risk of corrosion in the studied systems.
4
Potential of the electric flow field produced in the earth by stray currents from D.C. traction of complex geometry
Budnik K., Machczyński W., Szymenderski J.
Poznan University of Technology Academic Journals. Electrical Engineering
|
2016
|
No. 85
29--40
EN
The paper presents a method of the 3D simulation of the primary scalar potential of the electric flow field produced in the earth by d.c. traction stray currents. In the method the equivalent rail is considered as an earth return circuit. The models of the equivalent rail with current energization and the concept of superposition allow one to consider more complicated d.c. railway systems using a segmental approximation of the complex railway route and taking into account a number of substations and loads at any location. It is assumed in the paper that the system considered is linear, that the earth is homogeneous medium of finite conductivity and that the effects of currents in nearby underground metal installations on the potential generated in the earth by track currents (primary earth potential) can be disregarded. An extensive parametric analysis to examine the roles of various factors, which affect the primary earth potential caused by stray currents, may be performed using simulation program developed. The technical application of the method presented, which can be useful at design stage e.g. of metal structures buried in the stray currents area, is illustrated by examples of computer simulation.
5
Content available Electrical effects of stray currents from d.c. traction of complex geometry
Budnik K., Machczyński W., Szymenderski J.
Computer Applications in Electrical Engineering
|
2016
|
Vol. 14
39--52
EN
The paper presents a method of the simulation of electrical effects of stray currents from d.c. tracrion of complex geometry. In the method the equivalent rail is considered as an earth return circuit. The models of the equivalent rail with current energization and the concept of superposition allow one to consider more complicated d.c. railway systems using a segmental approximation of the complex railway route and taking into account a number of substations and loads at any location. It is assumed in the paper that the system considered is linear, that the earth is homogeneous medium of finite conductivity and that the effects of currents in nearby underground metal installations on the potential generated in the earth by track currents (primary earth potential) can be disregarded. An extensive parametric analysis to examine the roles of various factors, which affect the primary earth potential caused by stray currents, may be performed using simulation program developed. The technical application of the method presented, which can be useful at design stage e.g. of metal structures buried in the stray currents area, is illustrated by examples of computer simulation.
6
Content available remote Calculation in 3D of magnetic fields generated by underground cable of complex geometry
Budnik K., Machczyński W.
Przegląd Elektrotechniczny
|
2015
|
R. 91, nr 7
110-114
EN
Magnetic fields generated by underground cables can be high enough that some utility customers are concerned about their health effects and electromagnetic interference. The lay-out of the underground cables is much more similar to a broken line than to straight line. In the study the magnetic flux densities above the earth surface produced by underground cables of complex geometry are estimated. It is assumed, that the currents induced in the earth can be neglected, so the magnetic field can be obtained using the Biot-Savart law. The analytical formulas for calculating the 3D magnetic field with respect to a convenient and unique reference system are derived.
PL
Praca przedstawia metodę obliczania pola magnetycznego w otoczeniu kabli podziemnych o złożonej geometrii. Trasę kabla aproksymuje się odcinkami linii łamanej, pomija się prądy indukowane w ziemi oraz wyznacza indukcję magnetyczną stosując prawo Biota-Savarta i zasadę superpozycji. Uzyskane zależności analityczne umożliwiają analizę trójwymiarowego pola magnetycznego w dowolnie przyjętym układzie odniesienia.
7
Content available Simulation of stray currents generated by DC electric traction
Budnik K., Machczyński W., Szymenderski J.
Poznan University of Technology Academic Journals. Electrical Engineering
|
2015
|
No. 82
67--76
EN
The paper presents two methods of the 3D simulation of the primary scalar potential of the electric flow field produced in the earth by d.c. traction stray currents. In the first method the equivalent rail is considered as an earth return circuit with distributed parameters, whereas in the second method the rail is treated as a circuit with lumped parameters. It is assumed in the paper that the system considered is linear, that the earth is homogeneous medium of finite conductivity and that the effects of currents in nearby underground metal installations on the potential generated in the earth by track currents (primary earth potential) can be disregarded. An extensive parametric analysis to examine the roles of various factors, which affect the primary earth potential caused by stray currents, may be performed using simulation program developed. The technical application of the method presented, which can be useful at design stage e.g. of metal structures buried in the stray currents
8
Content available Contribution to studies on calculation of D.C. stray currents
Budnik K., Machczyński W., Szymenderski J.
Computer Applications in Electrical Engineering
|
2015
|
Vol. 13
28--41
EN
The paper presents two methods of the 3D simulation of the primary scalar potential of the electric flow field produced in the earth by d.c. traction stray currents. In the first method the equivalent rail is considered as an earth return circuit with distributed parameters, whereas in the second method the rail is treated as a circuit with lumped parameters. It is assumed in the paper that the system considered is linear, that the earth is a homogeneous medium of finite conductivity and that the effects of currents in nearby underground metal installations on the potential generated in the earth by track currents (primary earth potential) can be disregarded. An extensive parametric analysis to examine the roles of various factors, which affect the primary earth potential caused by stray currents, may be performed using simulation program developed. The technical application of the method presented, which can be useful at design stage e.g. of metal structures buried in the stray currents area, is illustrated by examples of computer simulation.
9
Content available Voltage induced by currents in power-line sagged conductors in nearby circuits of arbitrary configuration
Budnik K., Machczyński W., Szymenderski J.
Archives of Electrical Engineering
|
2015
|
Vol. 64, nr 2
227--236
EN
The study presents a calculation method of the voltage induced by power-line sagged conductor in an inductively coupled overhead circuit of arbitrary configuration isolated from ground. The method bases on the solution utilizing the magnetic vector potential for modeling 3D magnetic fields produced by sagging conductors of catenary electric power lines. It is assumed that the equation of the catenary exactly describes the line sag and the influence of currents induced in the earth on the distribution of power line magnetic field is neglected. The method derived is illustrated by exemplary calculations and the results obtained are partially compared with results computed by optional approach.
10
Content available remote Electric field induced by current in overhead conductor
Budnik K., Machczyński W., Szymenderski J.
Prace Naukowe Politechniki Śląskiej. Elektryka
|
2014
|
z. 1
35--42
EN
The paper presents a theoretical study of the calculation of electric field induced in vicinity of an overhead current carrying conductor. Exact method of the determination of the induced electric field bases on the Fourier transform technique, whereas a simplified method uses the concept of complex ground return plane. As an example the induced electric field under a power line conductor is calculated.
PL
Praca dotyczy metod dokładnej oraz uproszczonej wyznaczania natężenia indukowanego pola elektrycznego wokół napowietrznego przewodu z prądem. Metoda dokładna bazuje na przekształceniu Fouriera w celu rozwiązania równania Helmholtza dla potencjału wektorowego, natomiast uproszczona opiera się na metodzie odbić zwierciadlanych od płaszczyzny umieszczonej na głębokości opisanej funkcją zespoloną. Wykazano przydatność praktyczną metody uproszczonej
11
Content available Electromotive force induced in a loop conductor under a power line conductor
Budnik K., Machczyński W.
Poznan University of Technology Academic Journals. Electrical Engineering
|
2014
|
No. 77
85--92
EN
The study presents methods of the calculation of electromotive force (emf) induced in a mitigation loop located under an overhead power line conductor. The loop can be treated as a rectangular loop (two-conductor closed mitigation loop) located near the power line horizontal to the earth surface. Exact and simplified methods of the determination of the emf are presented. The exact method bases on the earth return circuit theory, whereas the simplified method allows one to calculate the induced emf under the assumption neglecting earth currents.
12
Content available Power line induced electric field and electromotive force in a nearby overhead circuit
Budnik K., Machczyński W., Szymenderski J.
Computer Applications in Electrical Engineering
|
2014
|
Vol. 12
45--56
EN
The study presents methods of the calculation of electric field induced in vicinity of an overhead current carrying conductor. Exact method of the determination of the induced electric field bases on the Fourier transform technique, whereas a simplified method uses the concept of complex ground return plane. Exact and simplified methods of the calculation of electromotive force (emf) induced in a loop located under an overhead power line conductor are also presented. The loop is treated as a rectangular loop (two-conductor closed loop) located near the power line horizontal to the earth surface. The exact method bases on the earth return circuit theory, whereas the simplified method allows one to calculate the induced emf under the assumption neglecting earth currents. The methods presented are illustrated by exemplary calculations.
13
Content available remote Magnetic field mitigation from sagging power lines using a sagging passive loop
Budnik K., Machczyński W.
Prace Naukowe Politechniki Śląskiej. Elektryka
|
2013
|
z. 1
29--41
EN
The study presents in a tutorial manner methods of the calculation of magnetic fields in vicinity of catenary electric power lines without and with mitigation loops. A solution for modelling magnetic fields produced by sagging conductor, described by the catenary equation, is proposed. It is assumed that the equation of the catenary exactly describes the line sag and the influence of currents induced in the earth on the distribution of power line magnetic field is neglected. Moreover the mitigation effects due to the passive loop are also investigated, whereas the mitigation loop can be treated as a rectangular loop (two-conductor closed mitigation loop) horizontal located under the power line or as a closed loop with two sagging conductors.
PL
W pracy zaprezentowano metody wyznaczania pola magnetycznego pod linią elektroenergetyczną w przypadku zastosowania pasywnego ekranu – pętli utworzonej przez parę przewodów podwieszonych pod linią, z uwzględnieniem zwisu przewodów linii i pętli. Zwis przewodów opisany jest równaniem łańcuchowym. Pomija się wpływ prądów indukowanych w ziemi na rozkład pola magnetycznego. Wyprowa-dzono wzory analityczne i omówiono sposób wyznaczenia efektu ekranowania, w pierwszej kolejności dla przewodów pętli pasywnej bez uwzględnienia zwisu, a następnie z jego uwzględnieniem.
14
Content available Power line magnetic field mitigation using a passive loop conductor
Budnik K., Machczyński W.
Poznan University of Technology Academic Journals. Electrical Engineering
|
2013
|
No. 73
137--145
EN
The paper presents in a tutorial manner methods of the calculation of magnetic fields in vicinity of overhead electric power lines without and with passive mitigation loops. Exact and simplified methods of the determination of the magnetic field of a straight overhead conductor based on the Fourier transform technique are presented. The mitigation effects due to the passive loop are also investigated, whereas the mitigation loop can be treated as a rectangular loop (two-conductor closed mitigation loop) horizontal located under the power line. The decomposition of the magnetic fields in two components: magnetic field obtained in free space from the Biot-Savart law and the magnetic field produced by earth current shows that in practical cases the effects from earth currents can be neglected as compared with effects from line currents.
15
Content available Reduction of magnetic field from a power line using a passive loop conductor
Budnik K., Machczyński W.
Computer Applications in Electrical Engineering
|
2013
|
Vol. 11
46--63
EN
The study presents in a tutorial manner methods of the calculation of magnetic fields in vicinity of overhead electric power lines without and with mitigation loops. Exact and simplified methods of the determination of the magnetic field of a straight overhead conductor based on the Fourier transform technique are presented. The decomposition of the magnetic fields in two components: magnetic field obtained in free space from the Biot-Savart law and the magnetic field produced by earth current is discussed. It is shown that in practical cases the effects from earth currents can be neglected as compared with effects from line currents. Moreover the mitigation effects due to the passive loop are also investigated, whereas the mitigation loop can be treated as a rectangular loop (two-conductor closed mitigation loop) located near the power line horizontal or non-parallel to the earth surface.
16
Content available Magnetic field of complex helical conductors
Budnik K., Machczyński W.
Archives of Electrical Engineering
|
2013
|
Vol. 62, nr 4
533--540
EN
Transmission of the electric power is accompanied with generation of low –frequency electromagnetic fields. Electromagnetic compatibility studies require that the fields from sources of electric power be well known. Unfortunately, many of these sources are not defined to the desired degree of accuracy. This applies e.g. to the case of the twisted-wire pair used in telephone communication; already practiced is twisting of insulated high-voltage three phase power cables and single-phase distribution cables as well. The paper presents a theoretical study of the calculation of magnetic fields in vicinity of conductors having helical structure. For the helical conductor with finite length the method is based on the Biot-Savart law. Since the lay-out of the cables is much more similar to a broken line than to strait line, in the paper the magnetic flux densities produced by helical conductor of complex geometry are also derived. The analytical formulas for calculating the 3D magnetic field can be used by a software tool to model the magnetic fields generated by e.g. twisted wires, helical coils, etc.
17
Content available Mutual inductance of finite length twisted-wire pair
Budnik K., Machczyński W.
Poznan University of Technology Academic Journals. Electrical Engineering
|
2012
|
No. 69
143--147
EN
Twisting of a bifilar lead is commonly used in various fields of electrical instruments and measurement systems in order to reduce the electromagnetic interference (EMI). Knowledge of inductances for helical conductors is needed for fundamental electromagnetic calculations, e.g. in electromagnetic compatibility studies. In the paper, a calculation method based on the Neumann’s formula is applied for the mutual inductance calculation of a twisted-wire pair of finite length. The exemplary calculation is also presented.
PL
Skrętka jednoparowa jest zwykle wykorzystywana w różnego rodzaju urządzeniach elektrycznych i elektronicznych systemach pomiarowych w celu redukcji niekorzystnych sprzężeń elektromagnetycznych. Impedancja wzajemna skrętki jednoparowej (układu dwóch wzajemnie skręconych przewodów o kształcie helisy) jest podstawową wielkością wykorzystywaną w obliczeniach np. z zakresu kompatybilności elektromagnetycznej. W pracy do wyznaczenia impedancji wzajemnej skrętki jednoparowej o skończonej długości wykorzystano wzór Neumanna. Zaprezentowano przykład obliczeniowy.
18
Content available remote Modelowanie oddziaływań elektromagnetycznych na rurociągi podziemne z uwzględnieniem korozji przemiennoprądowej
Budnik K., Machczyński W.
Ochrona przed Korozją
|
2012
|
nr 8
332-339
PL
Na odcinkach na których następuje zbliżenie tras rurociągów podziemnych i napowietrznych linii elektroenergetycznych prądu przemiennego istnieje niebezpieczeństwo indukowania się w części stalowej rurociągu napięć przemiennych o wartościach, które mogą stanowić zagrożenie porażeniowe i korozyjne. Niebezpieczeństwo wzrasta wraz ze wzrostem wartości prądów roboczych napowietrznych linii elektroenergetycznych, stosowaniem coraz doskonalszych powłok izolacyjnych rurociągów i długości odcinków na jakich następuje zbliżenie tras obwodów ziemnopowrotnych. Istnieją programy komputerowe przeznaczone do analizy sprzężeń indukcyjnych w obwodach ziemnopowrotnych, które jednakże nie uwzględniają zjawiska korozji przemiennoprądowej w miejscu uszkodzenia powłoki izolacyjnej rurociągu. Co warte podkreślenia mechanizm korozji przemiennoprądowej, w szczególności konstrukcji stalowych umieszczonych w glebie, do chwili obecnej nie jest dobrze poznany. W artykule omówiono zagadnienie modelowania rurociągów podziemnych ze sprzężeniem indukcyjnym z uwzględnieniem korozji przemiennoprądowej części stalowej rurociągu narażonej na kontakt z elektrolitem glebowym. Przedstawiono schemat zastępczy dla korozji AC bazujący na równaniach Butlera-Volmera, podano parametry ich interpretację fizyczną i sposób wyznaczania wartości. Obliczenia wykonano w pakiecie Matlak-Simulink. W części graficznego interfejsu Simulink część liniową układu opisano przy pomocy współczynników równań stanu, korodujące ogniwo jako zjawisko nieliniowe dołączono w postaci odpowiednio zdefiniowanego sprzężenia zwrotnego. Określono wejścia układu (źródła) i wyjścia (potencjały i prądy). Na zakończenie przedstawiono uwagi końcowe i wnioski.
EN
InducedAC vo!tage is clearly identifiedas apotetttial hazard, /rom butli safety andcorrosion standpoints, for all buried pipelines coming into protimity with overhead electric transmission systems. The likełihood ofelectromagnetic interference (EMI) increases with rising operating stirrers in the overhead lines. will increasnig nalily ofthe coaling on tlie pipeline, and with the length ofa linę parallel to and ciosa lo power lines. li is possible to simulate the conditions llial are expected to ist on tliese pipelines, and calculate llie anlicipated levels of induced A C roltage as well as its intensity and density flowing into the soil through the coaling defect. Determining a pipelines response is noted easy task since it depends on three factors, nameiy the location of the structure will respect lo the magtnetic field generated by lite AC since, the magnitude of the interfering field, and the electrochemical response of the struture to the interference. Many computer programs can be used lo calculate a pipeline s AC voltage by taking into accounl the worst case under normal operatying conditions of the interfering systems. The programs however do not take into account the electrochemical phenomena on tlie pipeline surface at pipeline coating defect locations. It should be noted, that the meclianism of AC corrosion is not very well understood, particularly as ii applies to corrosion in soils. A simulation model ofa metal pipeline under indtictive influence, in which AC corrosion is taken into account has been presented in the paper. Ań electrical eqnivalent diagram is presented and lite corrosion current, the pipeline potential and the corrosion rate are calculated. The use oft he Matlab-Simulink platform for multidomain simulation and model-bused-design of dynamic systems permils the complex analysis of the interference on pipelines, whereas the electrochemical phenomena on the interjfce metal - soil arę taken into account. E MI in tlie circiiil is presented by Simulink in the form of a block diagram - a graphical representation of the process, which is composed of an input, the system, and an output. The block connected with the AC corrosion, in which the electrochemical phenomena are represented by the non-linear Butler-Yolmer equations, has been implemented in the simulation package. The system is described by stale equations, which can be solved by tools provided by Matlab.
19
Content available Inductances of coaxial helical conductors
Budnik K., Machczyński W.
Computer Applications in Electrical Engineering
|
2012
|
Vol. 10
358--371
EN
Twisting of conductors is commonly used in various fields of electrical instruments and measurement systems in order to reduce the electromagnetic interference (EMI). Knowledge of inductances for helical conductors is needed for fundamental electromagnetic calculations, e.g. in electromagnetic compatibility studies. In the paper, a calculation method based on the Neumann’s formula is applied for the inductance calculation of coaxial helical conductors of finite length. The exemplary calculations are also presented.
20
Content available Modeling magnetic field in the vicinity of single wire helix
Budnik K., Machczyński W.
Computer Applications in Electrical Engineering
|
2011
|
Vol. 9
69--77
EN
Transmission of the electric power is accompanied with generation of low - frequency electromagnetic fields. Electromagnetic compatibility studies require that the fields from sources of electric power be well known. Many of these sources are not defined to the desired degree of accuracy. This applies e.g. to the case of helical current conductors of finite length. The paper presents an analytical-numerical method of the calculation of the 3D magnetic fields in vicinity of conductors having helical structure. The method is based on the Biot-Savart law and a software tool to model the magnetic fields generated by e.g. twisted wires, helical coils, etc can use the formulas obtained.
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