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Poznan University of Technology Academic Journals. Electrical Engineering
2011 No. 67-68 123-129
EN The paper presents investigation results of the effect of aluminum oxide layer located at the electrode surface on the electric strength of an insulation system with sulphur hexafluoride (SF6) subject to alternate voltage of 50 Hz frequency. The tests have been carried out under the SF6 pressure of [...]
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Poznan University of Technology Academic Journals. Electrical Engineering
2009 No 60 81-85
EN The paper presents the results of investigation of influence wavelet function parameters on chosen signal spectrum parameters. Wavelets were used in denoising AE signals connected with electrical treeing process. Analyzed spectrum parameters were: maximum, average, median and minimum amplitude. Infl[...]
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Poznan University of Technology Academic Journals. Electrical Engineering
2006 No 52 167-171
EN The paper deals with the possibilities for initiating electrical breakdown in vacuum by microparticles. Duration of the travel of charged spherical microparticles of various diameters accelerated by the electric field, and their velocities in the moment of impact against the electrode of opposite po[...]
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Zeszyty Naukowe Politechniki Poznańskiej. Elektryka
2006 Nr 50 199-208
PL W pracy przedstawiono stanowisko pomiarowe umożliwiające detekcje i rejestrację sygnałów emisji akustycznej towarzyszących destrukcji dielektryków stałych pod wpływem silnego pola elektrycznego. Zaprezentowano opracowany program komputerowy umożliwiający analizę zarejestrowanych sygnałów. Pokazano r[...]
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Poznan University of Technology Academic Journals. Electrical Engineering
2007 No 56 197-203
EN The paper presents the research of methyl polymethacrylate treeing in a strong electric field. The treeing rate and the signals of acoustic emission have been subject to the research. The counting rate of the acoustic emission, the rate of acoustic emission events, and rms signal have been used as p[...]
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Poznan University of Technology Academic Journals. Electrical Engineering
2010 No. 64 63--69
EN The paper presents analysis of voltage time patterns occurring at a low-voltage contact switch while switching off an electric circuit of induction character. In such a situation an electric discharge appears in the intercontact gap. The mechanism of generation of such a discharge is displayed and t[...]
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Poznan University of Technology Academic Journals. Electrical Engineering
2010 No. 64 71--77
EN The paper presents the result of the tests of the effects of electrode material, occurrence of dielectric coatings on the electrodes, and the pressure on the air breakdown voltage under alternative frequency of 50 Hz. Electrodes of the considered insulation systems were of plane design and made of a[...]
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Poznan University of Technology Academic Journals. Electrical Engineering
2010 No. 64 79--83
EN The paper presents a way of using the wavelet transformation for analysis of acoustic emission signals (EA) accompanying the electric treeing process in solid dielectrics. A method of noise removing from the EA signals and the use of wavelet transformation for time - frequency analysis are proposed.[...]
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Pomiary Automatyka Kontrola
2011 R. 57, nr 5 496-498
PL W pracy przedstawiono wyniki badań związanych z wykorzystaniem metody emisji akustycznej w detekcji procesu drzewienia elektrycznego dielektryków stałych. Podano opis wykorzystanego w badaniach stanowiska pomiarowego oraz opracowane i stosowane metody analizy zarejestrowanych sygnałów. Przedstawiono[...]
EN The paper presents use of the acoustic emission (AE) method in the study of electrical treeing process in solid dielectrics. The second section presents a measurement stand and the way of preparing samples for testing. The third section contains a summary description of the AE signal analysis and sa[...]
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Computer Applications in Electrical Engineering
2012 Vol. 10 118--126
EN The paper presents the studies on development of a simplified electrothermal method of measuring the soil thermal conductivity, that may be used directly in the field. A measurement system has been designed and built, that is connected to measuring sensors located in the examined soil. Two types of [...]
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Computer Applications in Electrical Engineering
2012 Vol. 10 394--401
EN The paper presents the results of the study on the effect of dielectric double layer at electrode surface on electric strength of compressed air and compressed sulphur hexafluoride. The research has been carried out at alternate voltage of 50 Hz frequency. It was found that thin insulation coating l[...]
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Poznan University of Technology Academic Journals. Electrical Engineering
2013 No. 74 181--186
The paper presents the results of the measurements of electric strength under a. c. voltage (50 Hz) of the insulation systems based on vacuum, sulfur hexafluoride and pure mineral electric insulating oil. The studied systems had electrodes with rounded-off edges of Rogowski’s profile, made of stainl[...]
PL W pracy przedstawiono wyniki pomiarów wytrzymałości elektrycznej przy napięciu przemiennym (50 Hz) układów izolacyjnych: próżniowego, z sześciofluorkiem siarki (SF6) i z olejem mineralnym. Badane układy miały elektrody płaskie wykonane ze stali nierdzewnej lub aluminium. Stwierdzono, że u[...]
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Poznan University of Technology Academic Journals. Electrical Engineering
2012 No. 72 49--56
PL W pracy przedstawiono uproszczoną metodę pomiaru wartości współczynnika przewodzenia ciepła gruntu. Zaproponowana metoda pozwala na częściowe wyeliminowanie błędów pomiarów związanych ze zmianami struktury i gęstości gruntów, które występują przy stosowaniu tradycyjnych metod. Jednocześnie pozwala z[...]
EN Results of the study on elaboration of the simple method of the measurement of the ground thermal conductivity coefficient, which may be used directly in the field, were presented in the paper. Measurement system, connected to probes-thermistor sensors, that were situated in examined ground, was des[...]
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Poznan University of Technology Academic Journals. Electrical Engineering
2014 No. 78 175--183
PL W pracy przedstawiono wyniki badań wpływu na wytrzymałość elektryczną SF6 przy napięciu stałym: rodzaju materiału elektrod, temperatury, gęstości gazu oraz odstępu elektrod. Badane układy miały obydwie elektrody płaskie bądź jedną elektrodę płaską, a drugą (katodę) w kształcie pręta o śre[...]
EN The paper presents results of the study on the effects of electrode material, temperature, gas density and electrode separation on SF6 electric strength under constant voltage. Tested systems consisted of two plane electrodes or one plane electrode and the second one (cathode) rod-shaped,[...]
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Poznan University of Technology Academic Journals. Electrical Engineering
2012 No. 70 113--119
PL W pracy przedstawiono wyniki badań wpływu podwójnej warstwy dielektrycznej na powierzchniach elektrod na wytrzymałość elektryczną sprężonego powietrza i sprężonego sześciofluorku siarki. Badania prowadzono przy napięciu przemiennym o częstotliwości 50 Hz. Stwierdzono, że cienka powłoka izolacyjna na[...]
EN The paper presents results of an investigation of the impact of dielectric double layer located at the electrode surface on the electric strength of an insulation system provided with compressed air and compressed sulphur hexafluoride (SF6) subject to alternate voltage of 50 Hz frequency.[...]
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Poznan University of Technology Academic Journals. Electrical Engineering
2009 No 60 97-102
EN The paper presents a computer program allowing for determining a time pattern of the current flowing through a vacuum or gas high-voltage insulation system, in result of the motion of a microparticle (being a small charged metallic particle) occurring in the inter-electrode gap. Moreover, the progra[...]
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Poznan University of Technology Academic Journals. Electrical Engineering
2006 No 52 201-210
EN The paper presents the results of frequency and time-frequency analyses of the acoustic emission signals arising during degradation of methyl polymetacrylate in a strong electric field. The frequency analysis was carried out with the use of Fourier Fast Transform method (FFT), while the time-freque[...]
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Poznan University of Technology Academic Journals. Electrical Engineering
2007 No 56 165-170
EN The paper presents a computer program aiding analysis of properties of vacuum insulation systems. The program enables determining the following relationships: range of the bombarding electron beam beyond the metallic surface of the anode and the heating time-constant of the anode area bombarded with[...]
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Przegląd Elektrotechniczny
PL W artykule przedstawiono wyniki badań zjawisk występujących przy wyłączaniu nieobciążonych linii kablowych SN łącznikiem próżniowym. Badania przeprowadzono na rzeczywistej linii kablowej oraz na jej modelu fizycznym. Stwierdzono występowanie wczesnych i późnych powtórnych zapłonów łuku, znacznych pr[...]
EN Results of investigations of the effects occuring while switching off unloaded medium cable lines by means of a vacuum circuit-breaker. The investigations were carried out on a real cable line and on its physical model. There were ascertained the occurence of early and late arc reignitions, consider[...]
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Computer Applications in Electrical Engineering
2015 Vol. 13 143--152
EN The paper presents results of the study on electrochemical potentials of metallic dental materials. Seven alloys, amalgam and chromium-nickel steel were examined as well as the effect of the solution conductivity ranging from 12.5 μS/cm to 2.01 mS/cm and solution pH within the range of 5.5 to 11.2 o[...]
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