Osmokrović, Predrag, 1949- Lončar, Boris, 1968- Vujisić, Miloš Stanković, Koviljka http://creativecommons.org/licenses/by/2.0/at/legalcode info:eu-repo/semantics/bachelorThesis 2013 OSNO - Opšta sistematizacija naučnih oblasti, Elektrotehnički i elektronski materijali OSNO - Opšta sistematizacija naučnih oblasti, Elektrotehnički i elektronski materijali Gasna smeša SF6/N2, sinergistički efekat, moderacija spectra slobodnih elektrona, impulsni napon SF6/N2 gas mixture, synergetic effect, moderation of free electron spectrum,impulse voltage srp https://phaidrabg.bg.ac.rs/o:10115 cobiss:45423119 thesis:2260 PDF/A ( 112 listova) 2541790 bytes U disertaciji "Statička i dinamička sinergija izolacionih osobina gasne smeše SF6/N2" razmatrana je efikasnost moderacionog efekta (efekta usporavanja slobodnih elektrona neelastičnim sudarima sa molekulima N2 gasa koji povećava verovatnoću, tj. efikasni presek, za formiranje negativnog SF6 jona) u smeši gasova SF6/N2 u slučaju primene impulsnih napona različite brzine porasta impulsa sa promenjivim vremenom porasta. Procentualni sastav smeše, pritisak, međuelektrodno rastojanje, oblik električnog polja i način obrade površina elektroda su bili promenjivi parametri. Statističkom analizom eksperimentalno dobijene slučajne promenjive impulsnih probojnih napona i njihovim prikazivanjem preko impulsnih karakteristika je ustanovljeno da se pri manjim brzinama impulsa javlja pozitivan sinergistički efekat dodavanja N2 gasa u smešu, koji se gubi pri većim brzinama impulsa. Dobijeni rezultati su objašnjeni odnosom vremenske konstante moderacionog procesa spektra (statistička raspodela po energiji) slobodnih elektrona u gasu sa karakterisičnim vremenom elementarnih procesa električnog pražnjenja u gasovima. Naučna oblast: . Uža naučna oblast: Elektrotehnički materijali. UDK broj: Dissertation "Static and Dynamic Synergy of Insulating Properties of Gas Mixture SF6/N2" investigates the efficiency of a moderation effect (effect of slowing down free electrons by inelastic collisions with molecules of N2 gas, which increases the probability, cross section for formation of SF6 negative ions) in a mixture of SF6 and N2 gases, in case of the application of impulse voltages with varying rise times. The moderation in question pertains to the slowing down of free electrons through nonelastic collisions with molecules of N2 gas, which increases the probability, i.e. the effective cross-section, for the formation of negative ions of SF6. Variable parameters included relative mixture composition, pressure, inter-electrode gap, shape of the electric field, and the manner of electrode surface processing. By applying statistical analysis to experimentally obtained values of the impulse breakdown voltage random variable, and presenting the results as impulse characteristics, it was established that a positive synergetic effect of adding N2 gas into the mixture was achieved at smaller impulse speeds. This effect was lost at greater impulse speeds. The obtained results were explained by examining the relative ratio of the time constant characterizing the process of moderating the spectrum (statistical distribution of energy) of free electrons, to the characteristic time of elementary electric discharge processes in gases. Keywords: . Scientific field:. Special topic: Elektrotehnika / Electrical Engineering Elektrotehnički materijali / Materials in Electrical Engineering Datum odbrane: 27.9.2013. Statička i dinamička sinergija izolacionih osobina gasne smeše SF6/N2 : doktorska disertacija Stojkanović, Mirko, 1980-