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Number of results: 32
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Abstract

The paper presents an analysis of overvoltages caused by a direct lightning strike in intrusion detection system equipped with underground radiating cable sensors. Waveforms of currents and voltages in the system components are calculated using analytical formulas basing on a transmission-line model in the frequency domain. The time-domain waveforms are computed using the inverse fast Fourier transform (IFFT). Three network configurations of the intrusion detection system are analyzed.

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Authors and Affiliations

K. Aniserowicz
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Abstract

This paper presents a study on ferroresonance occurring in a high voltage 400 kV transmission grid due to energization of power transformer under no-load conditions. The system scenarios analyzed in the present paper are considered as critical for development and modernization plans as currently announced by the national grid operator in Poland. The PSCADsimulation modelwas developed and applied for several study cases of a system with double-circuit arrangement of a transmission line. It is shown that the ferroresonant oscillations can be initiated by two-phase switching operation of a line circuit breaker. The impact of the double-circuit length on the ferroresonance mode and severity is demonstrated with the use of the Poincaré map analysis and Short Time Fourier Transform. It is demon- strated that the length of the transmission line that is mutually coupled in the double-circuit arrangement has a significant impact on the ferroresonance occurrence and on its mode. As the ferroresonance can pose severe threat to the power system components due to the severe overvoltage and overcurrent oscillations, the analysis presented in this paper demonstrates the necessity of the ferroresonance analyses for any re-designed transmission system.

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Authors and Affiliations

Mateusz Polewaczyk
Sylwester Robak
Marcin Szewczyk
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Abstract

Commonly, the Park model is used to calculate transients or steady-state operations of synchronous machines. The expanded Park theory derives the Park equations from the phase-domain model of the synchronous machine by the use of transformations. Thereby, several hypothesis are made, which are under investigation in this article in respect to the main inductances of two different types of synchronous machines. It is shown, that the derivation of the Park equations from the phase-domain model does not lead to constant inductances, as it is usually assumed for these equations. Nevertheless the Park model is the most common analytic model of synchronous machines. Therefore, in the second part of this article a method using the evolution strategy is shown to obtain the parameters of the Park model.

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Authors and Affiliations

Christoph Schmuelling
Christian Kreischer
Marek Gołebiowski
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Abstract

Electric arc is a complex phenomenon occurring during the current interruption process in the power system. Therefore performing digital simulations is often necessary to analyse transient conditions in power system during switching operations. This paper deals with the electric arc modelling and its implementation in simulation software for transient analyses during switching conditions in power system. Cassie, Cassie-Mayr as well as Schwarz-Avdonin equations describing the behaviour of the electric arc during the current interruption process have been implemented in EMTP-ATP simulation software and presented in this paper. The models developed have been used for transient simulations to analyse impact of the particular model and its parameters on Transient Recovery Voltage in different switching scenarios: during shunt reactor switching-off as well as during capacitor bank current switching-off. The selected simulation cases represent typical practical scenarios for inductive and capacitive currents breaking, respectively.

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Authors and Affiliations

Piotr Oramus
Tomasz Chmielewski
Tomasz Kuczek
Wojciech Piasecki
Marcin Szewczyk
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Abstract

The authors present a numerical study of a start-up of a boiler with a thick-walled element subjected to thermomechanical loading. The significance of calculations of real heat transfer coefficients has been demonstrated. Fluid dynamics, mechanical transient thermal and static structural calculations have been conducted in both separate and coupled modes. Strain-stress analyses prove that the effect of the heat transfer coefficient changing in time and place in comparison with a constant one as recommended by standards is the key factor of fatigue calculations.

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Authors and Affiliations

Krzysztof Wacławiak
Jerzy Okrajni
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Abstract

A method for modeling of the dynamics characteristics for a 5-phase permanent magnet tubular linear motor (PMTLM) is presented. Its electromagnetic nonlinear field analysis with finite element method (FEM) has been coupled with the circuit model. The calculation model includes the equations for electrical circuits and mechanical quantities as well. They have been obtained using Lagrange's method. The calculated and measured waves of the mover position have been compared for several values of the excitation current. This comparison yields a good agreement. Presented calculation model is very useful in designing and optimization of the PMTLM and in the calculation of the parameters for the control algorithms intended for such a type of actuators.
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Authors and Affiliations

Bronisław Tomczuk
Andrzej Waindok
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Abstract

In the paper, the results of investigations on the location of generating units most affecting the angular stability of a large power system (PS) are presented. For their location, the eigenvalues of the PS model state matrix associated with electromechanical phenomena (electromechanical eigenvalues) were used. The eigenvalues were calculated on the basis of the analysis of the disturbance waveforms of instantaneous power of the generating units operating in the PS. The used method of calculating eigenvalues consists in approximation of the disturbance waveforms of generating units by the waveforms being the superposition of modal components. The parameters of these components depend on the sought eigenvalues and their participation factors. The objective function was defined as the mean square error between the approximated and approximating waveforms. To minimize it, a hybrid algorithm, being a combination of genetic and gradient algorithms, was used. In the instantaneous power waveforms of generating units most affecting the PS angular stability, the least damped or undamped modal components dominate. They are related to eigenvalues with the largest values of real parts. The impact of individual modal components on the disturbance waveforms of subsequent generating units was determined with the use of participation factors and correlation coefficients of electromechanical eigenvalues.

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Authors and Affiliations

Piotr Pruski
ORCID: ORCID
Stefan Paszek
ORCID: ORCID
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Abstract

In the paper, the application of multi-criteria optimization of the parameters of PSS3B system stabilizers to damping electromechanical swings in an extended power system (PS) is presented. The calculations of the power system stabilizer (PSS) parameters were divided into two stages. In the first stage, single-machine systems, generating unit – infinite bus, of generating units critical for the angular stability of the PS were analyzed. Time constants and preliminary values of the PSS gains were calculated. In the second stage, the main one, the main gains on which the effectiveness of operation of PSSs depends the most were calculated by multi-criteria optimization of the extended PS. The calculations were carried out in several variants: for two-dimensional objective functions and the six-dimensional objective function. In multi-criteria optimization, the solution is not one set of PSS parameters, but a set of sets of these parameters, i.e. a set of compromises that were determined for each analyzed case. Additionally, for the six-dimensional compromise set, projections of this set on the planes connected with the quantities of individual generating units and the boundary of these projections on these planes were determined. A genetic algorithm adapted to multi-criteria issues was used to minimize the multivariate objective function. Sample calculations were made for the model of the National (Polish) Power System taking into account 57 selected generating units operating in high and extra high voltage networks (220 and 400 kV). The presented calculations show that the applied multi-criteria optimization of the PSS3B stabilizer parameters allows effectively damping electromechanical swings withoutworsening the voltagewaveforms of generating units in the extended PS.
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Authors and Affiliations

Adrian Nocoń
1
ORCID: ORCID
Stefan Paszek
1
ORCID: ORCID
Piotr Pruski
1
ORCID: ORCID

  1. Faculty of Electrical Engineering, Silesian University of Technology, Akademicka 10, 44-100 Gliwice, Poland
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Abstract

The paper is devoted to the control of operability of Peltier modules based on the analysis of transient modes of their operation. Advantages of using low-power thermoelectric modules for the development of thermoelectric plants with adaptive control systems for the needs of the agricultural complex, which significantly reduce their cost characteristics, are shown. The problem of using the stationary mode of their operation, associated with the low efficiency of the modules, as well as the dynamic mode, associated with the presence of transient processes, is indicated. It is noted that overcoming this problem requires solution of the task of automation of reliability providing the well-known approaches to its solution are shown, for which the key advantages and disadvantages are given. An approach is proposed to complex control of the operability and quality of thermoelectric modules during their expluatation in three components of the physical process of thermoelectric conversion (Peltier thermoelectric effect, electrical and thermal transfer phenomena) by analyzing transients in the system based on identification algorithms. To justify it, the necessary equations and mathematical relations are given. Aprobating of the proposed approach was carried out experimentally by determining the time constants for operable and defective commercially available modules and showed its significant advantages over the standard verification procedure.
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Authors and Affiliations

Oleg Rudolfovich Kuzichkin
1
Igor Sergeevich Konstantinov
2
Gleb Sergeevich Vasilyev
1
Dmitry Igorevich Surzhik
1

  1. Belgorod State University, Pobedy 85, 308015 Belgorod, Russia
  2. Russian State Agrarian University – Moscow Timiryazev Agricultural Academy, Listvennichnaya 5, 127550 Moscow, Russia
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Abstract

The initial transient of an organ pipe is known to be of great influence to the perceived sound quality. At the same time, the unsteady process of the tone onset is essentially nonlinear and lacks exact repeatability, so the search for a robust descriptor is in place. Initial transients were recorded using an adjustable flue organ pipe. The blowing pressure and cut-up height were varied. Prony’s method was employed to analyze the results. Utilizing the Principal Component Analysis (PCA) on the standardized exponential model coefficients, it was shown that the transients are well described by just one scalar parameter. Its value is predominantly dependent on the number of important Prony’s components taking part in the transient process (i.e., the overall complexity of the transient signal). A strong correlation was found between the PCA component and the Strouhal number inverse.

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Authors and Affiliations

Viktor Hruška
Pavel Dlask
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Abstract

The purpose of this paper is to focus on the loss separation of non-grain-oriented electrical steels used for speed-variable rotating electrical machines. The impact of laser-cutting, used in prototype manufacturing and of flux density harmonics, occurring locally in the lamination, on the loss distribution is studied in detail. Iron losses occurring under operation can physically be separated in different loss components. In this paper, a frequency-based loss model with parameters identified for single-sheet tester specimens, cut in strips of different widths, is therefore used. Moreover, a time-domain approach considers loss distributions occurring from higher harmonics. Hysteresis losses having high sensitivity to cut edge effects are calculated by the well-known Jiles-Atherton model adapting the frequency-based loss parameters. The model is validated by free-curve measurements at a single-sheet tester. It has been shown that the studied elliptical hysteresis model becomes inaccurate particularly for specimens with small strip widths with similar dimensions as teeth of electrical machine laminations. The incorrect mapping of losses occurring from minor hysteresis loops due to higher harmonics is concluded. The results showconsequently that both, the impact of a cut edge effect and local distributions of flux density harmonics need to be considered in terms of accurate iron loss prediction of electrical machine design.

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Authors and Affiliations

Christoph Mülder
Silas Elfgen
Kay Hameyer
ORCID: ORCID
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Abstract

To reduce the losses of the power electronic inverter, the voltage slew rate (d u/d t) of the electric motors supplying voltage is increasing. As steep voltage slopes excite high frequencies in the megahertz range, transient phenomena in the winding of the electrical machine occur. To design the insulation system, the maximum electric potential difference between the conducting elements must be predicted. General design rules can lead to a significant overengineering of the interturn insulation, particularly when considering smaller stators with a known wire distribution. Therefore, two different winding topologies are studied comparing the voltage distribution in a round-wire winding and a winding with preformed coils.
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Authors and Affiliations

Florian Pauli
1
Niklas Driendl
1
Sebastian Mönninghoff
1
Kay Hameyer
1
ORCID: ORCID

  1. Institute of Electrical Machines (IEM), RWTH Aachen University, Germany
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Abstract

This paper proposes an electromechanical transient method to build a battery energy storage system-based virtual synchronous generator model, suitable for a large-scale grid. This model consists of virtual synchronous generator control, system limitation and the model interface. The equations of a second-order synchronous machine, the characteristics of charging/discharging power, state of charge, operating efficiency, dead band and inverter limits are also considered. By equipping the energy storage converter into an approximate synchronous voltage source with an excitation system and speed regulation system, the necessary inertia and damping characteristics are provided for the renewable energy power system with low inertia and weak damping. Based on the node current injection method by the power system analysis software package (PSASP), the control model is built to study the influence of different energy storage systems. A study on the impact of renewable energy unit fluctuation on frequency and the active power of the IEEE 4-machine 2-area system is selected for simulation verification. Through reasonable control and flexible allocation of energy storage plants, a stable and friendly frequency environment can be created for power systems with high-penetration renewable energy.
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Authors and Affiliations

Juntao Cui
1
Zhao Li
2
ORCID: ORCID
Ping He
2
ORCID: ORCID
Zhijie Gong
2
Jie Dong
2
ORCID: ORCID

  1. Lanzhou Resources and Environment Voc-Tech University, China
  2. Zhengzhou University of Light Industry, China
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Abstract

The article considers issues of ensuring sustainable agricultural production by increasing reliability of an irrigation sys-tem and water security. The article describes results of hydraulic tests performed at the water outlet with a vertical move-ment valve member. Resistance coefficients and hydrodynamic effects at the water outlet were determined experimentally. The study devel-oped a method for calculating hydromechanical transient processes in the water outlet at the stop and start of the pump. The paper substantiates the new construction of a water outlet facility with a vertical displacement of the breakdown valve. Such a design better corresponds to peculiarities of the operation of pumping stations and, if there are water pipes of considerable diameter, it has a positive effect on transition hydrodynamic processes by reducing the number of failures and downtime by up to 10%.
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Bibliography

ALTSHUL A.D., KISELEV P.G. 1975. Gidravlika i aerodinamika (Osnovy mekhaniki zhidkosti) [Hydraulics and aerodynamics (Fundamentals of fluid mechanics]. 2nd ed. revised and enlarged. Moscow. Stroiizdat pp. 327.
ANDRIIASHEV M.M. 1979. Gidravlicheskiye raschety oborudovaniya vodovodov [Hydraulic calculations of water pipelines]. Moscow. Stroiizdat pp. 104.
ARSHENEVSKII N.N., POSPELOV B.B. 1980. Perekhodnye protsessy krupnykh nasosnykh stantsii [Transition processes of large pumping stations]. B-ka gidrotekhnika i gidroenergetika. Iss. 66. Moscow. Energiya pp. 112.
BASHTA T.M., RUDNEV S.S., NEKRASOV B.B., BAYBAKOV O.V., KIRILLOVSKY YU.L. 1970. Gidravlika, gidravlicheskiye ma-shiny i gidravlicheskiye privody: Uchebnik dlya mashinostroitel’nykh vuzov [Hydraulics, hydraulic machines and hydraulic drives: Mechanical engineering college and university textbook]. Moscow. Mashinostroyeniye pp. 504.
BOGOMOLOV A.I., MIKHAILOV K.I. 1972. Gidravlik: Uchebnik dlya vuzov. [Hydraulic technician: College and university textbook]. 2nd ed. revised and enlarged]. Moscow. Stroiizdat pp. 648.
BOL’SHAKOV V.A. (ed.) 1977. Spravochnik po gidravlike [Reference book on hydraulics]. Kyiv. Vyshcha shkola pp. 320.
BRONSHTEIN I.N., SEMENDYAEV K.A. 1962. Spravochnik po matematike dlya inzhenerov i uchashchikhsiya vuzov [Reference textbook on mathematics for engineers and college or university students]. Moscow. Gosudarstvennoye izdatel'stvo fiziko-matematicheskoy literatury pp. 608.
CHEBAYEVSKIY V.F., RYCHAGOV V.V., VISHNEVSKIY K.P., TRET'YAKOV A.A. 1982. Proektirovaniye nasosnykh stantsii i ispytaniye nasosnykh ustanovok [Designing pumping stations and testing pump units]. 3rd ed. revised and enlarged. Moscow. Kolos pp. 320.
CHUGAYEV R.R. 1975. Gidravlika (Tekhnicheskaya mekhanika zhidkosti): Uchebnik dlya vuzov [Hydraulics (technical fluid mechanics): College and university textbook]. Leningrad. Energiya pp. 600.
GAVRILENKO B.A., MININ V.A., ROZHDESTVENSKII S.N. 1968. Gidravlicheskii privod [Hydraulic drive]. Moscow. Mashinostroyeniye pp. 502.
HERASYMOV H.H. 1993. Perekhidni protsesy v nasosnykh ustanovkakh z poplavkovymy vodovypuskamy [Transient processes in pumping plants with floating water outlets]. Hidromelioratyvne ta hidrotekhnichne budivnytstvo. Resp. Mizhvidomchyi n.-t. zb. No. 20 p. 57–63.
HERASYMOV H.H., BURDIUZHA P.D. 1981. Vodovypusk. A. s. No. 1086061 A SSSR, E 02 V 9/06. [Water outlet. Archived File No. 1086061 A USSR, E 02 V 9/06.] No. 3296804/29-15. Registered on February 22, 1981. Published on April, 15, 1984. Bulletin No. 141 p. 3.
IDELCHIK I.E. 1954. Gidravlicheskiye soprotivleniya (fiziko-mekhanicheskiye osnovy) [Hydraulic resistance (Physical and mathematical fundamentals)]. Moscow–Leningrad: Gosenergoizdat pp. 316.
IDELCHIK I.E. 1975. Spravochnik po gidravlicheskim soprotivleniyam [Reference book on hydraulic resistances]. 2nd ed. revised and enlarged. Moscow. Mashinostroyeniye pp. 559.
JONES G.M., SANKS R.L., TCHOBANOGLOUS G., BOSSERMAN B.E. 2008. Pumping station design. 2nd ed. Butterworth-Heine-mann. ISBN 978-1-85617-513-5 pp. 1104. DOI 10.1016/b978-1-85617-513-5.x5001-x. KARELIN V.YA., NOVODEREZHKIN R.A. 1980. Nasosnye stantsii gidrotekhnicheskikh sistem s osevymi i diagonal’nymi nasosami [Pumping stations of hydrotechnical systems with axial-flow and angular-flow pumps]. Moscow. Energiya pp. 288. KAY M. 2008. Practical hydraulics. 2nd ed. Taylor and Francis. ISBN 978-0415351157 pp. 272.
KONDRATYEV V.N., SKOSAREV E.V., CHIBISOV I.T., SHAVARIN V.N. 1976. Proektirovanie sifonnykh vodovypuskov dlya nasosnykh stantsii [Designing siphon water outlets for pumping stations]. Gidrotekhnicheskoe stroitel’stvo. No. 1 p. 54–56.
KONDRATYEVA T.F. 1976. Predokhranitel’nye klapany [Safety valves]. 2nd ed. revised and enlarged. Leningrad. Mashinostroyeniye pp. 232.
KOVALENKO P.I., TUGAI A.M. 1974. Meliorativnyye gidrotekhnicheskiye sooruzheniya [Ameliorative hydraulic facilities]. Kiev. Budivel’nik pp. 123.
KURGANOV A.M., FEDOROV N.F. 1978. Spravochnik po gidravlicheskim raschetam sistem vodosnabzheniya i kanalizatsii [Reference book on hydraulic calculations of the water supply and sewerage systems]. 2nd ed. revised and enlarged. Leningrad. Stroiizdat pp. 424.
MIKHAILOV I.E., ZOLOTUKHIN V.I. 1977. Vliianiye vysoty vodozabornykh otverstii bashennykh vodopriyemnikov na poteri napora [Influence of the height of water inlets of the tower water intakes on pressure loss]. Gidrotekhnicheskoye stroitel’stvo. No. 2 p. 27–28.
MIKHAILOV I.E., ZOLOTUKHIN V.I. 1978. Vybor form i razmerov bashennykh vodopriyemnikov [Selection of shapes and sizes of tower water intakes]. Gidrotekhnicheskoe stroitel’stvo. No. 2 p. 24–27.
NOVAK P., MOFFAT A.I.B., NALLURI C., NARAYANAN R.A.I.B. 2007. Hydraulic structures. 4th ed. Taylor and Francis. ISBN 0-203-96463-2 pp. 736.
PEPLOV E.E., KOKAYA N.V. 1956. Zatvor s vozdushnoi kameroi [Air shutter]. Gidrotekhnika i melioratsiya. No. 6 p. 37–41.
PLESEVIČIUS P.I. 1974. Vliyaniye vysoty pod"yema tareli na gidravlicheskoye soprotivleniye armatury zapornykh klapanov truboprovodov sudovykh sistem [Impact of the height of plate lifting on the hydraulic resistance of valve members of marine systems’ pipelines]. Trudy Leningradskogo korablestroitel’nogo instituta. No. 94 p. 74–84.
SHOMAYRAMOV M., NORKULOV B., RAKHMANOV J., TADJIYEVA D., SUYUNOV J. 2019. Experimental researches of hydraulic vacuum breakdown devices of siphon outlets of pumping stations. In: Construction the Formation of Living Environment. XXII International Scientific Conference (FORM-2019). Tashkent, Uzbekistan. Eds. A. Volkov, A. Pustovgar, T. Sultanov, A. Adamtsevich. E3S Web Conf. 97 05009. DOI 10.1051/e3sconf/20199705009.
SLISSKII P.M. 1974. Gidravlicheskiye raschety napornykh orositel’nykh sistem s regulirovaniyem po nizhnemu befu [Hydraulic calculations of pressure irrigation systems with downstream control]. Trudy Moskovskogo energeticheskogo instituta. No. 203 p. 134–139.
SLISSKIY S.M. 1970. Gidravlika zdanii gidroelektrostantsii [Hydraulics of hydroelectric power station premises]. Moscow. Energiya pp. 424.
STEPANOV P.M., OVCHARENKO I.KH., SKOBELTSYN YU.A. 1984. Spravochnik po gidravlike dlya melioratorov [Reference textbook on hydraulics for irrigation engineers]. Moscow. Kolos pp. 207.
SURIN A.A. 1946. Gidravlicheskii udar v truboprovodakh i bor’ba s nim [Water hammer in pipelines and combatting it]. Moscow. Transzheldorizdat pp. 372.
TSUKANOVA E.A., BARZHANSKII E.E. RAKHMANOV ZH.R. 1975. Opredeleniye koeffitsientov poter tsilindricheskikh klapanov [Determination of loss coefficients for cylindrical valves]. Mekhanika mashinostroyeniya. No. 49 p. 77–84. VALIPOUR M. 2017. Global experience on irrigation management under different scenarios. Journal of Water and Land Development. No. 32 p. 95–102. DOI 10.1515/jwld-2017-0011.
VIL'NER YA.M., KOVALEV YA.T., NEKRASOV B.B. 1976. Spravochnoye posobiye po gidravlike, gidromashinam i gidroprivodam [Reference textbook on hydraulics of hydraulic machines and hydraulic drives]. Ed. B.B. Nekrasov. Minsk. Vysheishaya shkola pp. 419
YUREV A.S. 2001. Spravochnik po raschetam gidravlicheskikh i ventiliatsionnykh sistem [Reference textbook on calculations for hydraulic and ventilation systems]. Ed. A.S. Yurev. Saint Petersburg. ANO NPO Mir i semya. ISBN 5-94365-022-9 pp. 1154
ZAKHAROV O.V., KARELIN V.YA., NOVODEREZHKIN R.A. 1976. Opyt ekspluatatsii krupnykh osevykh nasosov na magistral’nykh kanalakh [Experience of operating large axial pumps on major supply channels]. Gidrotekhnicheskoye stroitel’stvo. No. 8 p. 20–24.
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Authors and Affiliations

Ievgenii Gerasimov
1
ORCID: ORCID
Henrikh Herasymov
1
ORCID: ORCID
Oleg Pinchuk
1
ORCID: ORCID

  1. National University of Water and Environmental Engineering, 11 Soborna St., 33028 Rivne, Ukraine
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Abstract

This paper presents low-cost, configurable PCI Express (PCIe) direct memory access (DMA) interface for implementation on Intel Cyclone V FPGAs. The DMA engine was designed to support DAQ tasks including pre-triggering acquisition for transient analysis and multichannel transmission. Performance of the interface has been evaluated on Terasic OVSK board (PCIe Gen2 x4). Target configuration of this interface is based on the Avalon-MM Hard IP for Cyclone V PCIe core and Jungo WinDriver x64 for Windows. A sample speed of 1200 MB/s has been reported for DMA writes to PCIe memory.
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Bibliography

[1] PCI Express Base Specification, rev. 3.0, PCI-SIG, Nov. 2010
[2] A. Wójcik, R. Łukaszewski, R. Kowalik, W. Winiecki, “Nonintrusive Appliance Load Monitoring: An Overview, Laboratory Test Results and Research Directions”, Sensors, 2019, 19, 3621
[3] A. Wójcik, P. Bilski, R. Łukaszewski, K. Dowalla, R. Kowalik, “Identification of the State of Electrical Appliances with the Use of a Pulse Signal Generator”, Energies, 2021, 14, 673.
[4] K. N. Trung, E. Dekneuvel, B. Nicolle, O. Zammit, C. N. Van, G. Jacquemod, “Using FPGA for Real Time Power Monitoring in a NIALM System”, In Proc. 2013 IEEE International Symposium on Industrial Electronics (ISIE), 2013, pp. 1-6
[5] Intel Corporation, Modular Scatter-Gather DMA Core, In Embedded Peripherals IP User Guide v. 18.1
[6] Intel Corporation, Intel® Quartus® Prime Standard Edition User Guide v. 18.1, Platform Designer
[7] Intel Corporation, Cyclone® V Avalon® Memory Mapped (Avalon-MM) Interface for PCIe Solutions User Guide, UG-01110, 2020
[8] Intel Corporation,V-Series Avalon-MM DMA Interface for PCIe Solutions User Guide, UG-01154, 2016
[9] WinDriver, https://www.jungo.com/st/products/windriver/wd_windows/
[10] OpenVINO Stater Kit GT Edition User Manual, available on https://www.terasic.com.tw/
[11] L. Rota, M. Caselle, S. Chilingaryan, A. Kopmann, M. Weber, “A PCIe DMA Architecture for Multi-Gigabyte Per Second Data Transmission”, IEEE Transactions on Nuclear Science, vol. 62, no. 3, 2015, pp. 972 - 976
[12] A. Byszuk, J. Kołodziejski, G. Kasprowicz, K. Późniak, W. M. Zabołotny “Implementation of PCI Express bus communication for FPGA-based data acquisition systems”, In Proceedings of SPIE Vol. 8454, 2015
[13] L. Boyang, “Research and Implementation of XDMA High Speed Data Transmission IP Core Based on PCI Express and FPGA”, in 2019 IEEE 1st International Conference on Civil Aviation Safety and Information Technology (ICCASIT), Oct. 2019, pp. 408–411
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Authors and Affiliations

Krzysztof Mroczek
1

  1. Institute of Radioelectronics and Multimedia Technology, Warsaw University of Technology, Poland
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Abstract

The paper discusses the phenomena accompanying switching the sinusoidal excitation of an antenna on and off when the antenna is excited by a train of sinusoids containing several to several hundred periods. Transient phenomena are presented against the background of the resonant properties of the antenna. The processes of turning the antenna on and off take place under different conditions and therefore are different. When the antenna is switched on, the transient processes are determined by the antenna properties and the excitation properties. When the antenna is switched off, excitation is no longer present, and the properties of the antenna determine the transient process. We define a new measure of time: the effective light meter.
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Authors and Affiliations

Anna Witenberg
1

  1. Faculty of Telecommunications, Computer Science and Electrical Engineering, Bydgoszcz University of Science and Technology, Bydgoszcz, Poland
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Abstract

Turbines and generators operating in the power generation industry are a major source of electrical energy worldwide. These are critical machines and their malfunctions should be detected in advance in order to avoid catastrophic failures and unplanned shutdowns. A maintenance strategy which enables to detect malfunctions at early stages of their existence plays a crucial role in facilities using such types of machinery. The best source of data applied for assessment of the technical condition are the transient data measured during start-ups and coast-downs. Most of the proposed methods using signal decomposition are applied to small machines with a rolling element bearing in steady-state operation with a shaft considered as a rigid body. The machines examined in the authors’ research operate above their first critical rotational speed interval and thus their shafts are considered to be flexible and are equipped with a hydrodynamic sliding bearing. Such an arrangement introduces significant complexity to the analysis of the machine behavior, and consequently, analyzing such data requires a highly skilled human expert. The main novelty proposed in the paper is the decomposition of transient vibration data into components responsible for particular failure modes. The method is automated and can be used for identification of turbogenerator malfunctions. Each parameter of a particular decomposed function has its physical representation and can help the maintenance staff to operate the machine properly. The parameters can also be used by the managing personnel to plan overhauls more precisely. The method has been validated on real-life data originating from a 200 MW class turbine. The real-life field data, along with the data generated by means of the commercial software utilized in GE’s engineering department for this particular class of machines, was used as the reference data set for an unbalanced response during the transients in question.
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Authors and Affiliations

Tomasz Barszcz
1
Mateusz Zabaryłło
2

  1. AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków, Poland
  2. GE Power, ul. Stoczniowa 2, 82-300 Elblag, Poland
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Abstract

The paper has investigated the effect of wind speed on selected thermal characteristics of the contemporary ACCR line. As wind speed functions, heating curves, stationary temperature profiles, steady-state current ratings and thermal time constants, have been determined. The composite core (Al–Al2O3) and the Al–Zr alloy braid were modeled as porous solids. As a result, the physical model is composed of a solid cylinder and a hollow cylinder with different material parameters of the above-mentioned elements. The mathematical model was formulated as the boundary-initial problem of the parabolic heat equation. The problem was solved by the state-superposition of and variable-separation method. On this basis, a computer program was developed in the Mathematica 10.4 environment and the velocity characteristics sought for were plotted. The results obtained analytically were positively verified by the finite-element method in the NISA v.16 environment. The physical interpretation of the determined characteristics has been given.
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Authors and Affiliations

Marek Zaręba
1
Jerzy Gołębiowski
1

  1. Faculty of Electrical Engineering, Bialystok University of Technology, ul. Wiejska 45D, 15-351 Białystok, Poland
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Abstract

Groundings are necessary parts included in lightning and shock protection. In the case of a surge current, high current phenomena are observed inside the grounding. They are result of the electrical discharges around the electrode when the critical field is exceeded in a soil. An available mathematical model of grounding was used to conduct computer simulations and to evaluate the influence of current peak value on horizontal grounding parameters in two cases. In the first simulations, electrode placed in two different soils were considered. The second case was a test of the influence of current peak value on grounding electrodes of various lengths. Simulation results show that as soil resistivity increases in value, the surge impedance to static resistance ratio decreases. In the case of grounding electrodes lengths, it was confirmed that there is a need to use an operating parameter named effective grounding electrode length, because when it is exceeded, the characteristics of grounding is not significantly improved during conductance of lightning surges. The mathematical model used in the paper was verified in a comparison with laboratory tests conducted by K.S. Stiefanow and with mathematical model described by L. Grcev.
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Bibliography

  1.  K. Aniserowicz, “Analytical calculations of surges caused by direct lightning strike to underground intrusion detection system” Bull. Pol. Acad. Sci. Tech. Sci. 67(2), 263‒269 (2019), doi: 10.24425/bpas.2019.128118.
  2.  S. Czapp and J. Guzinski, “Electric shock hazard in circuits with variable-speed drives”, Bull. Pol. Acad. Sci. Tech. Sci. 66(3) 361‒372 (2018), doi: 10.24425/123443.
  3.  G. Parise, L. Parise, and L. Martirano, “Intrinsically safe grounding systems and global grounding systems”, IEEE Trans. Ind. Appl. 54(1), 25‒31 (2018), doi: 10.1109/TIA.2017.2743074.
  4.  R.M. Miśkiewicz, P. Anczewski, and A. J. Morandowicz, “Analysis and investigations of inductive power transfer (IPT) systems in terms of efficiency and magnetic field distribution properties”, Bull. Pol. Acad. Sci. Tech. Sci. 67(4), 789‒797 (2019), doi: 10.24425/ bpasts.2019.130188.
  5.  S. Viscaro, “The use of the impulse impedance as a concise representation of grounding electrodes in lightning protection applications”, IEEE Trans. Electromagn. Compat. 60(5), 1602‒1605 (2018), doi: 10.1109/TEMC.2017.2788565.
  6.  K.S. Stiefanow, High Voltag Technique. 1st ed., Energy, pp. 380‒403, 1967. (orig.: К.С. Стефанов, Техника высоких напряжений, 1st ed, Энергия, pp. 380‒403, 1967).
  7.  L. Grcev, B. Markovski, V. Arnautovski-Toseva, and K.E.K. Drissi, “Transient analysis of grounding system without computer” in 2012 International Conference on Lightning Protection (ICLP), 2012, doi: 10.1109/ICLP.2012.6344412.
  8.  A. Geri, “Behaviour of grounding system exited by high impulse currents: the model and its validation”, IEEE Trans. Power Delivery 14(3), 1008‒1017 (1999), doi: 10.1109/61.772347.
  9.  S. Wojtas, “Ligtning impulse efficiency of horizontal earthings”, Electrical Review, 88(10b), 332‒334 (2012), [Online]. Available: pe.org. pl/abstract_pl.php?nid=6666 [Accessed: 13. Dec. 2020].
  10.  L. Grcev, “Modelling of grounding electrodes under lightning currents”, IEEE Trans. Electromagn. Compat. 51(3), 559‒571 (2009), doi: 10.1109/TEMC.2009.2025771.
  11.  J. Trifunovic and M.B. Kostic, “An alogirthm for estimating the grounding resistance of complex grounding systems including contact resistance”, IEEE Trans. Ind. Electron. 51(6), 5167‒5174 (2015), doi: 10.1109/TIA.2015.2429644.
  12.  D. Cavka, F. Rachidi, and D. Polijak, „On the concept of grounding impedance of multipoint grounding systems”, IEEE Electromagn. Compat. Mag. 56(6), 1540‒1544 (2014), doi: 10.1109/TEMC.2014.2341043.
  13.  R. Xiong, B. Chen Gao, Y. Yi, and W. Yang, “FDTD calculation model for tranient analyses of grounding systems”, IEEE Electromagn. Compat. Mag 56(5), 1155‒1162 (2014), doi: 10.1109/TEMC.2014.2313918.
  14.  A.F. Imece et al., “Modeling guidelines for fast front transients”, IEEE Trans. Power Delivery 11(1), 493‒506 (1996), doi: 10.1109/61.484134.
  15.  CIGRE, “Guide to procedures for estimating the lightning performance of transmission lines”, CIGRE Working Group 33.01 (Lightning) of Study Committee 33 (Overvoltage’s and Insulation Coordination), 1991. [Online]. Available: books.google.pl/books/about/Guide_to_ Procedures_for_Estimating_the_L.html?id=yFzqugAACAAJ&redir_esc=y [Accessed: 13. Dec. 2020].
  16.  M. Vasiliki and E. Pyrgioti, “Simulation of transient behavior of grounding grids” in 2010 International Conference on Lightning Protection (ICLP), 2010, doi: 10.1109/ICLP.2010.7845766.
  17.  A.G. Pedrosa, M.A. Schroeder, R.S. Alipio, and S. Visacro, “Influence of frequency dependant soil electrical parameters on the grounding response to lightning” in 2010 International Conference on Lightning Protection (ICLP), 2010, doi: 10.1109/ICLP.2010.7845953.
  18.  D.S. Gazzana, A.B. Trochoni, L.C. Leborgne, A.S. Betas, D.W.P Thomas, and C. Christopoulos, „An improved soil ionization representation to numerical simulation of impulsive grounding systems”, IEEE Trans. Magn. 54(3), 7200204 (2018), doi: 10.1109/TMAG.2017.2750019.
  19.  U.C. Resende, R. Alipio, and M. L.F. Oliviera, “Proposal for inclusion of the electrode radius in grounding systems analysis using interpolating element free Galerkin method”, IEEE Trans. Magn. 54(3), 7200304 (2018), doi: 10.1109/TMAG.2017.2771394.
  20.  M. Mokhtari and G.B. Gharehpetian, “Integration of energy balance of soil ionization in CIGRE grounding resistance model”, IEEE Electromagn. Compat. Mag. 60(2), 402‒413 (2018), doi: 10.1109/TEMC.2017.2731807.
  21.  O. Kherif, S. Chiheb, M. Teguar, A. Merkhaldi, and N. Harid, “Time-domain modeling of grounding systems’ impulse response incorporating nonlinear and frequency dependant aspects”, IEEE Electromagn. Compat. Mag. 60(4), 907‒916 (2018), doi: 10.1109/TEMC.2017.2751564.
  22.  S. Yang, W. Zhou, J. Huang, and J. Yu, “Investigation on impulse characteristics of full-scale grounding grid in substitution”, IEEE Electromagn. Compat. Mag. 60(6), 1993‒2001 (2018), doi: 10.1109/TEMC.2017.2762329.
  23.  E. Clavel, J. Roudet, J.M. Guichon, Z. Gouchiche, P. Joyeux, and A. Derbey, “A nonmashing approach for modeling grounding”, IEEE Electromagn. Compat. Mag. 60(3), 795‒802 (2018), doi: 10.1109/TEMC.2017.2743227.
  24.  R. Kosztaluk, M. Loboda, and D. Mukhedkar, „Experimental study of transient ground impedances”, IEEE Trans. Power Apparatus Syst. PAS-100(11), 4653‒4660 (1981), doi: 10.1109/TPAS.1981.316807.
  25.  F. Haidler and J. Cvetic, “A class of analytical functions to study lightning effects associated with the current front”, Eur. Trans. Electr. Power 12(2), 141‒150 (2002), doi: 10.1002/etep.4450120209.
  26.  S. Vujevic and D. Lovric, “Exponential approximation of the Heidler function for the reproduction of lightning current waveshapes”, Electr. Power Syst. Res. 80(10), 1293‒1298 (2010), doi: 10.1016/j.epsr.2010.04.012.
  27.  IEC, Protection against lightning – Part 1: General principles, IEC std. IEC 62305-1:2011. [Online]. Available: www.lsp-international. com/bs-en-62305-12011-protectionagainst-lightning-part-1-general-principles [Accessed: 13. Dec. 2020].
  28.  Cademce, “PSpice User’s Guide”, [Online]. Available: resources.pcb.candence.com/i/1180526-pspice-user-guide/20? [Accessed: 13. Dec. 2020].
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Authors and Affiliations

Artur Łukaszewski
1
ORCID: ORCID
Łukasz Nogal
1
ORCID: ORCID

  1. Electrical Power Engineering Institute, Faculty of Electrical Engineering, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland
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Abstract

Full-floating ring bearings are state of the art at high speed turbomachinery shafts like in turbochargers. Their main feature is an additional ring between shaft and housing leading to two fluid films in serial arrangement. Analogously, a thrust bearing with an additional separating disk between journal collar and housing can be designed. The disk is allowed to rotate freely only driven by drag torques, while it is radially supported by a short bearing against the journal. This paper addresses this kind of thrust bearing and its implementation into a transient rotor dynamic simulation by solving the Reynolds PDE online during time integration. Special attention is given to the coupling between the different fluid films of this bearing type. Finally, the differences between a coupled and an uncoupled solution are discussed.
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Bibliography

  1. M.C. Shaw and T.J. Nussdorfer, “An analysis of the full-floating journal bearing,” NACA, Tech. Rep. RM-E7A28a, 1947.
  2. C. Kettleborough, “Frictional experiments on lightly-loaded fully floating journal bearings,” Aust. J. Appl. Sci., vol. 5, pp. 211–220, 1954.
  3. J. Dworski, “High-speed rotor suspension formed by fully floating hydrodynamic radial and thrust bearings,” J. Eng. Gas Turbines Power, vol. 86, no. 2, pp. 149–160, 1964.
  4. M. Harada and J. Tsukazaki, “The steady-state characteristics of a hydrostatic thrust bearing with a floating disk,” J. Tribol., vol. 111, no. 2, pp. 352–357, Apr 1989, doi: 10.1115/1.3261921.
  5. M. Fischer, A. Mueller, B. Rembold, and B. Ammann, “Numerical investigation of the flow in a hydrodynamic thrust bearing with floating disk,” J. Eng. Gas Turbines Power, vol. 135, 2013, doi: 10.1115/1.4007775.
  6. S. Dousti and P. Allaire, “A thermohydrodynamic approach for single-film and double-film floating disk fixed thrust bearings verified with experiment,” Tribol. Int., vol. 140, p. 105858, Dec 2019.
  7. H. Engel, “Berechung der Strömung, der Drücke und Temperaturen in Radial-Axialbund-Gleitlagern mit Hilfe eines Finite-Elemente-Programms,” Ph.D. thesis, Universität Stuttgart, 1992.
  8. T. Hagemann, H. Blumenthal, C. Kraft, and H. Schwarze, “A study on energetic and hydraulic interaction of combined journal and thrust bearings,” in Proceedings of ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, no. GT2015‒43460, 2015, pp. 1–11.
  9. G.H. Jang, S.H. Lee, and H.W. Kim, “Finite ele- ment analysis of the coupled journal and thrust bearing in a computer hard disk drive,” J. Tribol., vol. 128, pp. 335–340, 2006, doi: 10.1115/1.2162918.
  10. G. Xiang, Y. Han, R. Chen, J. Wang, X. Ni, and K. Xiao, “A hydrodynamic lubrication model and comparative analysis for coupled microgroove journal-thrust bearings lubricated with water,” Proc. Inst. Mech. Eng., Part J: J. Eng. Tribol., vol. 234, no. 11, pp. 1755–1770, Nov 2019.
  11. J.-C. Luneno, “Coupled vibrations in horizontal and vertical rotor-bearings systems,” Ph.D. thesis, Luleå University of Technology, 2010.
  12. C. Ziese, C. Daniel, E. Woschke, and H. Mostertz, “Hochlaufsimulation eines semi-floating gelagerten ATL-Rotors mit schwimmender Axiallagerscheibe,” in 14. Magdeburger Maschinen- bautage (24.–25.09.2019), Sep. 2019, pp. 105–112.
  13. H.G. Elrod, “A cavitation algorithm,” J. Tribol., vol. 103, no. 3, pp. 350–354, 1981.
  14. S. Nitzschke, E. Woschke, D. Schmicker, and J. Strackeljan, “Regularised cavitation algorithm for use in transient rotordynamic analysis,” Int. J. Mech. Sci., vol. 113, pp. 175–183, 2016.
  15. S. Nitzschke, “Instationäres Verhalten schwimmbuchsengelagerter Rotoren unter Berücksichtigung masseerhaltender Kavitation,” Ph.D. thesis, Otto-von-Guericke Universität Magdeburg, 2016.
  16. C. Daniel, “Simulation von gleit-und wälzgelagerten Systemen auf Basis eines Mehrkörpersystems für rotordynamische Anwendungen,” Ph.D. thesis, Otto-von-Guericke Universität Magdeburg, 2013.
  17. C. Ziese, E. Woschke, and S. Nitzschke, “Tragdruckund Schmierstoffverteilung von Axialgleitlagern unter Berücksichtigung von masseerhaltender Kavitation und Zentrifugalkraft,” in Magdeburger Maschinenbautage, 2017, pp. 312–323.
  18. A. Kumar and J.F. Booker, “A finite element cavitation algorithm,” J. Tribol., vol. 113, no. 2, pp. 279–284, 1991.
  19. “MAN turbochargers TCA series floating disk thrust bearing,” https://turbocharger.man-es.com/docs/default-source/ shopwaredocuments/tca-turbochargerf451d068cde04720bdc9b 8e95b7c0f8e.pdf, accessed: 2020‒10‒09.
  20. “KBB turbochargers ST27 series f loating disk thrust bearing,” https://kbb-turbo.com/turbocharger-product-series/ st27-series, accessed: 2020-10-09.
  21. C. Irmscher, S. Nitzschke, and E. Woschke, “Transient thermohydrodynamic analysis of a laval rotor supported by journal bearings with respect to calculation times,” in SIRM 2019 – 13th International Conference on Dynamics of Rotating Machines, 2019, pp. Paper–ID SIRM2019–25.
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Authors and Affiliations

Steffen Nitzschke
1
Christian Ziese
1
Elmar Woschke
1
ORCID: ORCID

  1. Institute of Mechanics, Otto-von-Guericke University, 39106 Magdeburg, Germany
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Abstract

The effect of processes of accumulating mass and enthalpy of the working medium on the dynamics of transient processes thereof is often discussed in scientific publications on the mathematical modelling of turbine engines (treated as systems that undergo control and automatic adjustment). The paper is intended to make a comparison between findings gained from simulation carried out with two alternative models of an aircraft turbine engine (of the S0-3 type). The first model takes account of the dynamics of the processes of accumulating mass and energy of the working medium within the combustion-chamber volume and that of the convergent nozzle. The second, simplified model, neglects the dynamics of the processes of accumulating mass and energy of the working medium, since it has been assumed that it is the dynamics of the kinetic-energy accumulation in the rotor mass that predominates in various representations of transient processes. To conduct simulation-based experiments, each of the alternative models of an engine was connected to a special simulation unit, which simulated operation of fuel supply and control systems. Two rounds of experiments were carried out. The first one was intended to facilitate observations of transient processes effected with quick shifting of a control lever from the idle position to that of full thrust, and back. In the second round observed were processes resulting from changes in the critical jet area. The second, alternative model was used to investigate the effect of ever-greater hypothetical volumes of the nozzle on how the transient processes proceeded. It has been found that in the case of the S0-3 engine, low nozzle capacity remains of only slight effect on how the transient processes proceed. Hence, simplified modelling methodology is fully justified.
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Authors and Affiliations

Wojciech I. Pawlak
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Abstract

A method for defects extraction for a mercury cadmium telluride (MCT) multilayer low-bandgap heterostructure is presented. The N+/T/p/T/P+/n+ epitaxial layer was deposited on a GaAs substrate by a metal-organic chemical vapour deposition (MOCVD). The absorber was optimized for a cut-off wavelength of λc = 6 μm at 230 K. Deep-level transient spectroscopy (DLTS) measurements were conducted for the isolated junctions of the N+/T/p/T/P+/n+ heterostructure. Three localised point defects were extracted within the p-type active layer. Two of them were identified as electron traps and one as a hole trap, respectively.
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Authors and Affiliations

Kinga Majkowycz
1
ORCID: ORCID
Małgorzata Kopytko
1
ORCID: ORCID
Krzysztof Murawski
1
ORCID: ORCID
Piotr Martyniuk
1
ORCID: ORCID

  1. Institute of Applied Physics, Military University of Technology, ul. gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland
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Abstract

The exponential decay of transient values in discrete-time nonlinear standard and fractional orders systems with linear positive linear part and positive feedbacks is investigated. Sufficient conditions for the exponential decay of transient values in this class of positive nonlinear systems are established. A procedure for computation of gains characterizing the class of nonlinear elements are given and illustrated on simple example.
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Authors and Affiliations

Tadeusz Kaczorek
1
ORCID: ORCID
Andrzej Ruszewski
1

  1. Bialystok University of Technology, Faculty of Electrical Engineering, Wiejska 45D,15-351 Białystok, Poland
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Abstract

As for a single line-to-ground fault in an ungrounded distribution system, the power-frequency current is too low to detect the fault. The transient current is more palpable than that at a power-frequency of 50 or 60 Hz. It is an effective method to estimate the fault using the transient fault current. To analyze and calculate the transient current of single line-to-ground faults, an equivalent circuit is proposed in this paper. This model is based on distributed parameters of power lines. And it contains positive, negative and zero sequence information. The transient equivalent circuit consists of equivalent resistance, equivalent inductance and equivalent capacitance. And the method of calculation the equivalent ele- ments is also submitted.MATLAB simulation results showthat the newtransient equivalent circuit has higher accuracy and stronger adaptability compared with the traditional one.

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Authors and Affiliations

Jun Jiang
Ling Liu
ORCID: ORCID

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