PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 14

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  traveling wave
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Design and Experiments of A New Internal Cone Type Traveling Wave Ultrasonic Motor
Chen Ye, Yang Junlin, Li Liang, Xiao Shihao
Archives of Acoustics
|
2023
|
Vol. 48, No. 3
373--380
EN
In order to simplify the motor structure, to reduce the difficulty of rotor pre-pressure application and to obtain better output performance, a new internal cone type rotating traveling wave ultrasonic motor is proposed. The parametric model of the internal cone type ultrasonic motor was established by the ANSYS finite element software. The ultrasonic motor consists of an internal cone type vibrator and a tapered rotor. The dynamic analysis of the motor vibrator is carried out, and two in-plane third-order bending modes with the same frequency and orthogonality are selected as the working modes. The other advantages of this motor are that pre-pressure can be imposed by the weight of the rotor. The prototype was trial-manufactured and experimentally tested for its vibration characteristics and output performance. When the excitation frequency is 22260.0 Hz, the pre-pressure is 0.1 N and the peak-to-peak excitation voltage is 300 V, the maximum output torque of the prototype is 1.06 N · mm, and the maximum no-load speed can reach 441.2 rpm. The optimal pre-pressure force under different loads is studied, and the influence of the pre-pressure force on the mechanical properties of the ultrasonic motor is analyzed. It is instructive in the practical application of this ultrasonic motor.
2
Nowe możliwości testowania funkcji lokalizacji miejsca zwarcia na podstawie fali wędrującej (travelling wave)
Pritchard Christopher, Lampl Heinz, Hensler Thomas
Wiadomości Elektrotechniczne
|
2020
|
R. 88, nr 12
20--26
PL
Lokalizacja miejsca zwarcia na długich liniach przesyłowych na podstawie fal wędrujących (travelling waves) okazała się dokładną i niezawodną metodą. Zarówno zintegrowane z nowoczesnymi zabezpieczeniami linii, jak i specjalistyczne lokalizatory dostarczają użytecznych informacji dla operatorów, jak i pracowników technicznych. Testowanie oraz weryfikacja poprawnego działania tych urządzeń stanowi wyzwanie oraz najczęściej nie odbywa się podczas uruchomienia. O ile rozwiązania te są akceptowalne dla lokalizatorów miejsca zwarcia, zabezpieczenia nowych generacji będą używać informacji z fal wędrujących do określenia zwarcia i właściwego wyzwalania.
EN
Fault location using traveling waves has proven to be an accurate and reliable method for precise location of faults on long transmission lines. Both integrated into modern line protection relays and within separate fault location devices they provide useful information for operators and technicians. Testing and verification of correct operation of these devices is a challenging task and mostly not done during commissioning. While maybe acceptable for pure fault locators, new protection relay generations will use traveling waves to determine fault and trip accordingly.
3
Content available Experimental study of natural gas humidity control device
Bilynsky Yosyp, Horodetska Oksana, Sirenko Svitlana, Novytskyi Dmytro
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
|
2020
|
T. 10, nr 3
86--90
EN
The means of measuring humidity based on the use of the ultrahigh frequency methodhave been recently gainingwidespread use,becauseof its simple, robust construction and high measuring accuracy. We used theadvanced waveguide ultrahigh frequency method of measuring the moisture content of natural gaswhich,in contrast to the known theuse of a traveling wave in awaveguide,is proposed. In this case, the interaction with wavesof the ultrahigh frequencyrange changes the dielectric properties of the gas, and this change is registered.On the basis of an improved ultrahigh frequencymethod of humidity measurement,a devicefornatural gashumidity control using a traveling wave in awaveguideisproposed.The investigationshave shown that a comparative channel increasedthe measurement accuracy, as a two-channel system–in contrast to a single-channel–eliminates the instability of the value of the input signal supplied to the generator.The principle of operation of a natural gashumiditycontroldevice that contains an ultrahigh frequency generator, attenuators, waveguide tees, a waveguidesectionforcomparison, temperature sensor and pressure switches for the comparative and measuring channels, a measuring cuvette, amplifier, microprocessor, and display unitis described. A mathematical model of a natural gashumiditycontrol device,which takes into account the values of the dielectric permittivity of the measuring gas and reference channels and contains correction factors for temperature, the use of which increasesthe accuracy of humidity measurement,is proposed.Thelowerand upper calibration points of thenatural gashumiditycontrol devicearedefined. The influence of correction factors for the temperatureat the measurement error of thehumidityis analyzed.
PL
Ostatnio przyrządy do pomiaru wilgotności oparte na metodzie mikrofalowej są szeroko stosowane ze względu na ich prostą, niezawodną konstrukcję i wysoką dokładność pomiaru. W pracy wykorzystano ulepszoną mikrofalową metodę falowodów mikrofalowych do pomiaru wilgotności gazu ziemnego, która, w przeciwieństwie do znanych, sugeruje zastosowanie fali podróżnej w falowodzie. Jednocześnie podczas interakcji z falami mikrofalowymi zmieniają się właściwości dielektryczne gazów, zmiana ta jest rejestrowana. W oparciu o ulepszoną mikrofalową metodę pomiaru wilgotności zaproponowano sposób pomiaru kontroli wilgotności gazu ziemnego za pomocą fali przemieszczającej się w falowodzie. Przeprowadzono badania, które wykazały, że obecność kanału porównawczego umożliwiła zwiększenie dokładności pomiaru, ponieważ system dwukanałowy,w przeciwieństwie do systemu jednokanałowego, eliminuje niestabilność wartości sygnału wejściowego dostarczanego przez generator. Opisano zasadę działania przyrządu pomiarowego do pomiaru wilgotności gazu ziemnego, który zawiera generator mikrofalowy, tłumiki, trójniki falowodu, sekcję falowodu do porównania, czujnik temperatury i ciśnienia, przełączniki kanałów porównawczych i pomiarowych, celę pomiarową, wzmacniacz, procesor, urządzenie wskaźnikowe. Zaproponowano model matematyczny środków pomiaru kontroli wilgotności gazu ziemnego, który uwzględniawartość stałej dielektrycznej gazu kanałów pomiarowych i odniesienia oraz zawiera współczynniki korekcji temperatury, których zastosowanie poprawia dokładność pomiaru wilgotności. Określane są dolne i górne punkty kalibracji zakresu pomiarowego wilgotności gazu ziemnego. Analizowany jest wpływ współczynników korekcji temperatury na błąd pomiaru wilgotności.
4
Content available Exact and approximate distributed controllability of processes described by KdV and Boussinesq equations: The Green’s function approach
Klamka Jerzy, Avetisyan Ara S., Khurshudyan Asatur Zh.
Archives of Control Sciences
|
2020
|
Vol. 30, No. 1
177--193
EN
In this paper, we study the constrained exact and approximate controllability of traveling wave solutions of Korteweg-de Vries (third order) and Boussinesq (fourth order) semi-linear equations using the Green’s function approach. Control is carried out by a moving external source. Representing the general solution of those equations in terms of the Frasca’s short time expansion, system of constraints on the distributed control is derived for both types of controllability. Due to the possibility of explicit solution provided by the heuristic method, the controllability analysis becomes straightforward. Numerical analysis confirms theoretical derivations.
5
Content available remote On the evolution of solutions of Burgers equation on the positive quarter-plane
Hanaç Esen
Demonstratio Mathematica
|
2019
|
Vol. 52, nr 1
237--248
EN
In this paper we investigate an initial-boundary value problem for the Burgers equation on the positive quarter-plane; vt + vvx - vxx = 0, x>0, t>0, v(x,0) = u+, x>0, v(0,t) = ub, t>0, where x and t represent distance and time, respectively, and u+ is an initial condition, ub is a boundary condition which are constants (u+ ≠ ub). Analytic solution of above problem is solved depending on parameters (u+ and ub) then compared with numerical solutions to show there is a good agreement with each solutions.
6
Content available remote A novel method to design an electro-kinetic platform based on complementary metal-oxide semiconductor technology using SKILL scripting of cadence
Abdelbaset Reda, Ghallab Yehya H., Ismail Yehea
Biocybernetics and Biomedical Engineering
|
2019
|
Vol. 39, no. 1
256--262
EN
The dielectrophoresis (DEP) is the motion of polarizable particles which is a result of the interaction between a non-uniform electric field and the induced dipole moment of these particles. The electro-kinetic DEP is a widely used technique for biological cells' manipulation, characterization and separation. The electro-kinetic DEP consists of three major configurations, they are; traveling wave dielectrophoresis (twDEP), electro-rotation dielectrophoresis (rotDEP), and levitation (levDEP). In this paper, a design of electrokinetic platform that includes the three electrokinetic configurations is presented and discussed. The design of the electrokinetic platform is implemented and simulated using 130 nm complementary metal-oxide-semiconductor (CMOS) technology. Also, this paper presents a developed technique to design the electrokinetic platform's electrodes. This developed technique is the usage of SKILL scripting of cadence (SSC) language. CMOS is a technology which is used to fabricate integrated circuits (IC). SKILL is a scripting language which supports the automation of a specific layout design by commands. The layout of electrokinetic DEP platform is developed using SSC. The performance of the developed electrokinetic platform using SSC versus the platforms based on the other traditional techniques is presented and evaluated using COMSOL Multiphysics®.
7
Content available Transient flow in gas networks: Traveling waves
Gugat M., Wintergerst D.
International Journal of Applied Mathematics and Computer Science
|
2018
|
Vol. 28, no. 2
341--348
EN
In the context of gas transportation, analytical solutions are helpful for the understanding of the underlying dynamics governed by a system of partial differential equations. We derive traveling wave solutions for the one-dimensional isothermal Euler equations, where an affine linear compressibility factor is used to describe the correlation between density and pressure. We show that, for this compressibility factor model, traveling wave solutions blow up in finite time. We then extend our analysis to networks under appropriate coupling conditions and derive compatibility conditions for the network nodes such that the traveling waves can travel through the nodes. Our result allows us to obtain an explicit solution for a certain optimal boundary control problem for the pipeline flow.
8
Content available remote Optimal Placement of Traveling Wave Fault Location Equipment in Power Grid Based on Characteristic Non-singular Set
Tang J., Yin X., Zhang Z., Qi X.
Przegląd Elektrotechniczny
|
2013
|
R. 89, nr 5
30-35
EN
With the widely use of traveling wave fault location equipment (TWFLE) in power grid, network-based traveling wave fault location (NBTWFL) method has been proposed. To ensure the effectiveness and economy of NBTWFL method, based on the principle of characteristic nonsingular set, an optimal placement algorithm of TWFLE is proposed in this paper. The corresponding NBTWFL method based on maximum nonsingular subset, additional installation plan of TWFLE and some other related problems are also discussed in this paper.
PL
W artykule opisano metodą wykrywania awarii w sieci elektroenergetycznej na podstawie analizy fali wędrującej. Proponowane rozwiązanie bazuje na klasycznym algorytmie wykrywania fali wędrującej, w którym zastosowano niesingularne wartości własne. Pozwoliło to na optymalizację rozmieszczenia urządzeń do wykrywania awarii.
9
Content available Influence of material used for the regenerator on the properties of a thermoacoustic heat pump
Kruk B.
Archives of Acoustics
|
2013
|
Vol. 38, No. 4
565--570
EN
Research in termoacoustics began with the observation of the heat transfer between gas and solids. Using this interaction the intense sound wave could be applied to create engines and heat pumps. The most important part of thermoacoustic devices is a regenerator, where press of conversion of sound energy into thermal or vice versa takes place. In a heat pump the acoustic wave produces the temperature difference at the two ends of the regenerator. The aim of the paper is to find the influence of the material used for the construction of a regenerator on the properties of a thermoacoustic heat pump. Modern technologies allow us to create new materials with physical properties necessary to increase the temperature gradient on the heat exchangers. The aim of this paper is to create a regenerator which strongly improves the efficiency of the heat pump.
10
Content available Exact difference schemes and schemes of higher order of approximation for convection-diffusion equation. I
Lapinska-Chrzczonowicz M., Matus P.
Annales Universitatis Mariae Curie-Skłodowska. Sectio AI, Informatica
|
2013
|
Vol. 13, no. 1
37--51
EN
The initial-boundary value problem for a convection-diffusion equation [formula] is considered. The difference scheme, approximating this problem, is constructed. It is shown that for traveling wave solutions the scheme is exact (EDS). The monotonicity of the scheme is also taken into consideration. Presented numerical experiments illustrate the theoretical results investigated in the paper.
11
Content available remote The influence of corona effect on traveling wave based transmission line protection distance to fault error calculation
Markevicius L. A., Siozinys V.
Przegląd Elektrotechniczny
|
2012
|
R. 88, nr 7b
208-210
EN
The future of smart grid protections is related to identification of fast electromagnetic transient in the electric grid. Many algorithms are developed over the world; however some physical processes are common for the overhead transmission line which makes influence to the algorithms reliability. The aim of the article is to show the corona influence on the traveling wave based line protection distance to the fault measurement error. Transmission line model with corona effect was used as the digital filter. Distance to the fault calculation errors dependence on applied voltage trigger level for different overhead line was presented. The influences of environmental conditions to the measurement error were investigated.
PL
Celem artykułu jest pokazanie wpływu zjawiska korony na błąd pomiaru na podstawie fal wędrownych odległości wystąpienia uszkodzenia linii. Przedstawiono dla różnych linii napowietrznych zależność błędów obliczeń odległości do miejsca uszkodzenia od przyjętego poziomu napięcia wyzwalającego. Badano wpływ warunków środowiskowych na błąd pomiaru.
12
Content available remote Online fractal identification of cable’s ground fault traveling wave in mine
Li W., Zhang X., Qi X., Zhang S.
Przegląd Elektrotechniczny
|
2012
|
R. 88, nr 5b
48-51
EN
In order to capture the occurrence moment of traveling wave to accurately locate the ground fault of high voltage transmission electricity cable, we analyzed the transient process of the traveling wave produced by cable ground fault, finding it is a self-similar process on specific bandwidth in a strict sense, and further proposed a fractal identification algorithm based on quadratic spline orthogonal wavelet. Experiment denotes that the occurrence moment of traveling wave can be obtained from waveform on different scales by fractal identification of test signal.
PL
Opracowano system detekcji zwarć doziemnych w kablach wysokonapięciowych stosowanych w kopalniach. System bazuje na ortogonalnych splinowych falkach i realizuje identyfikację fraktalną.
13
Content available remote Fault Location Techniques in Power System based on Traveling Wave using Wavelet Analysis and GPS Timing
Tabatabaei A., Mosavi M.R., Rahmati A.
Przegląd Elektrotechniczny
|
2012
|
R. 88, nr 6
347-350
EN
In this paper two approaches are proposed based on Discrete Wavelet Transform (DWT) and traveling wave to locate the fault of the three phase transmission line. The exact fault position is determined according to the instances in time when the fault waves arrive at each locator location and wave speed calculated on the basis of the proposed algorithms. To achieve actual data, synchronized sampling is needed which can be made possible by precise time receivers based on Global Positioning System (GPS) time reference. All the possible fault types are generated using the ATP-EMTP and results using the two methods are discussed. Extensive simulation studies indicate that the proposed approaches are reliable for rapid and correct identification of various fault cases.
PL
Przedstawiono system do badania trójfazowej lini transmisyjnej. Metoda wykorzystuje falę wędrująca i dyskretną transformatę falkową oraz system GPS. Badania wykazały przydatność systemu do lokalizacji uszkodzeń sieci.
14
Content available remote A Traveling Wave Fault Location Method for Earth Faults Based on Mode Propagation Time Delays of Multi-measuring Points
Liu Y., Sheng G., Jiang X.
Przegląd Elektrotechniczny
|
2012
|
R. 88, nr 3a
254-258
EN
A new traveling wave fault location method for earth faults is proposed based on propagation time delays between aerial mode and earth mode acquired by multi-measuring points on transmission line. Using phase-mode transformation theory and the theory of wavelet singularity detection to achieve the algorithm of propagation time difference detection. The JMarti model is used to build the system simulation model in the EMTP. The final results show that the method has high reliability and precision.
PL
Przedstawiono nową metodę wykrywania I lokalizacji błędu w linii transmisyjnej bazującą na analizie propagacji fali. Do tego celu wykorzystano transformatę falkową.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.