| En/De/Fr/It- (first 9 out of 1819 sentences)
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| n1 | ELECTROSTATIC PRECIPITATOR HIGH-FREQUENCY AR70/1000 SUPPLY SYSTEM OPERATIONAL TESTING RESULTS | n1 | REZULTATI – EKSPLOATACIONIH ISPITIVANJA VISOKOFREKVENTNOG SISTEMA AR70/1000 ZA NAPAJANJE ELEKTROFILTARA |
| n2 | Increase of electricity generated from fossil fuels over the past few decades raised the awareness about the harmful effects caused by fine dust particles emission created by coal and other fossil fuels combustion. Thermal power plants emit substantial fly ash and ultra fine particles amounts into the atmosphere. Maximum permitted dust value is 50 mg/m3 requiring ESP efficiency ratio higher than 99 %, which calls for an increase of active electrode surface, the filter volume and the filter steel weight. In the previous decades, electrostatic precipitators in thermal power plants were fed by thyristor controlled, single-phase fed devices having a high degree of reliability, but with a relatively low handling efficiency, requiring large effective collection plate surface and a large steel structures weight to achieve the prescribed emission limits. Electrostatic precipitator collection efficiency and energy efficiency can be increased by applying high frequency high voltage power supply (HF HV). The Faculty of Electrical Engineering (ETF) of the University of Belgrade developed an ESP power supply technology together with the HF HV equipment. This solution was extensively investigated at the Morava TPP between 2008 and 2010. High frequency power supply is proven to reduce emission two times under the controlled conditions while increasing the precipitator energy efficiency compared to the conventional thyristor controlled 50 Hz supply. Two high frequency high voltage AR70/1 000 units, 70 kV and 1 000 mA, were installed at the Morava TPP and comprehensively tested. It was discovered that the Morava TPP ESP HF HV power supply increases collection efficiency whereby fine particles and fly ash emission is cut in half to only 50 % of the emissions obtained with the conventional 50 Hz thyristor driven power supplies. Based on the above it was concluded that HF HV supplied equipment is the best solution for the new ESP installations, as well as for the reconstructed ones. The paper describes the HF HV power supply topology, power control, together with the most important implementation details. The proposed HF HV solution achieves several significant improvements over the conventional thyristor system. With the Morava TPP HF HV, fine dust particles emission was cut in half compared to the emission with T/R 50 Hz sets. This paper also describes the results and measurements obtained during extensive experimental investigations involving the comparison of the 50 Hz based thyristor unit with T/R sets and the HF HV power supply. | n2 | Dimni gasovi koji izlaze iz kotlova termoelektrana i toplana sadrže pored gasovitih zagađujućih materija i značajne količine praškastih materija (letećeg pepela). Tipične vrednosti emisije čvrstih čestica na izlazu kotlova na većini termoblokova u Elektroprivredi Srbije kreću se u opsegu 20–60 g/m3, dok su granične vrednosti emisije za praškaste materije do 50 mg/Nm3. Najefikasnije sredstvo za otprašivanje dimnog gasa pre uvođenja u dimnjak i ispuštanja u atmosferu su elektrostatički izdvajači, koji se najčešće nazivaju i elektrostatički filtri ili skraćeno elektrofiltri. Napajanje elektrostatičkih filtra u termoelektrani konvencionalno se ostvaruje monofaznim 50 Hz tiristorski regulisanim, visokonaponskim ispravljačima, koji su poka-zali visok stepen pouzdanosti u radu, ali daju relativno malu efikasnost izdvajanja. Da bi se dostigao propisani limit granične vrednosti emisije, neophodno je rekonstruisati ova postrojenja, što se postiže uvećanjem površine elektroda, odnosno količine utrošenog čelika. Efikasnost izdvajanja, kao i energetska efika-snost elektrostatičkih filtara mogu se značajno uvećati primenom visokofrekventnog visokonaponskog na-pajanja. Pored ovoga, visokofrekventno napajanje obezbeđuje značajno smanjenje veličine i težine komponenata postrojenja, a najveći uticaj smanjenja gabarita odnosi se na elektrodni sistem, koji je i najskuplji deo postrojenja. Razvojnoistraživački tim Elektrotehničkog fakulteta u Beogradu razvio je tehnologiju i vi-sokofrekventno visokonaponsko napajanje elektrofiltara pod komercijalnim nazivom AR70/1 000, koje ostvaruje izlazni napon 70 kV i izlaznu struju 1 000 mA. Ovo rešenje je podvrgnuto eksploatacionim ispitivanjima na elektrofiltar postrojenju u termoelektrani "Morava“ u toku 12 meseci. Utvrđeno je da se viso-kofrekventnim visokonaponskim napajanjem, u kontrolisanim uslovima, ostvaruje udvostručavanje efika-snosti izdvajanja. Na osnovu obavljenih ispitivanja zaključeno je da je visokofrekventno napajanje najbolje rešenje za gradnju novih ili remont postojećih postrojenja. U radu su prikazani topologija i način upravljanja i dat detaljan opis implementacije. Predloženim visokofrekventnim visokonaponskim napajanjem postig-nuto je nekoliko ključnih poboljšanja u odnosu na konvencionalni tiristorski sistem. Pored konkretne realizacije visokofrekventnog napajanja postrojenja u termoelektrani "Morava“, u radu su predstavljeni i eks-perimentalni rezultati dobijeni tokom eksploatacionih ispitivanja i poređenja s primenjivanim 50 Hz siste-mom napajanja. |
| n3 | Key words: Electrostatic precipitator, HVHF transformer, power converter, IGBT, high frequency power supply, maximum particulate emission level | n3 | Ključne reči: elektrostatički filtar, VNVF transformator, energetski pretvarač, IGBT, visokofrekventno napajanje, granične vrednosti emisije (GVE) |
| n4 | SOME TEHNICAL SOLUTIONS FOR BRUSHLESS SYNCHRONOUS GENERATORS EXITATION IN SMALL HYDROPOWER PLANTS | n4 | NEKA TEHNIČKA REŠENJA POBUDE SINHRONIH GENERATORA BEZ ČETKICA U MALIM HIDROELEKTRANAMA |
| n5 | This paper shows the structure and some technical solutions for brushless synchronous generator excitation used in small hydropower plants. | n5 | U ovom radu su prikazane strukture i neka tehnička rešenja pobude sinhronih generatora bez četkica koja se koriste u malim hidroelektranama. |
| n6 | Small hydropower plants with brushless synchronous generators have been classified together with the block diagrams of the automatic voltage regulation excitation used by the brushless synchronous generator with a synchronous exciter and the brushless synchronous generator with an asynchronous exciter. | n6 | Izvršena je i klasifikacija malih hidroelektrana sa sinhronim generatorima bez četkica i opisane su blok-šeme automatske regulacije pobude za sinhroni generator bez četkica sa sinhronom budilicom i sinhroni generator bez četkica sa asinhronom budilicom. |
| n7 | Key words: synchronous generator, voltage regulator, exciter | n7 | Ključne reči: sinhroni generator, regulator napona, budilica |
| n8 | INTERNATIONAL STANDARDS FOR ENERGY EFFICIENT MOTORS AND ENERGY SAVING | n8 | INTERNACIONALNI STANDARDI ZA ENERGETSKI EFIKASNE MOTORE I UŠTEDA ENERGIJE |
| n9 | Electric motors with improved efficiency can save about 5?6% of the consumed energy. | n9 | Korišćenjem elektromotora sa povećanim vrednostima stepena iskorišćenja mogu se postići uštede od 2 % (za motore ≥110 kW) do 10 % (za motore oko 1 kW i ispod toga). |