Title Nadomjesni modeli energetskih transformatora
Title (english) Electrical models of power transformers
Author Tin Brubnjak
Mentor Rene Prenc (mentor)
Committee member Viktor Sučić (predsjednik povjerenstva)
Committee member Rene Prenc (član povjerenstva)
Granter University of Rijeka Faculty of Engineering Rijeka
Defense date and country 2022-09-20, Croatia
Scientific / art field, discipline and subdiscipline TECHNICAL SCIENCES Electrical Engineering Power Engineering
Abstract Energetski transformator ključni je element u funkcioniranju bilo koje električne mreže, te neizostavan dio prijenosa električne energije. Energetski transformator sastoji se od jezgre, na koju se motaju prvo niskonaponski, a zatim visokonaponski namoti transformatora. Kako bi sustav ostao u radnoj temperaturi zadužen je kotao u kojemu se najčešće nalazi posebno ulje koje hladi elemente transformatora. Da na priključcima ne dođe do kratkog spoja zaduženi su provodni izolatori. Energetski transformator radi na principu elektromagnetske indukcije te izmjeničnu struju primara prenosi na sekundar. Struja i napon primara i sekundara ovisni su o omjeru broja zavoja njihovih namota. Prijenos energije kod autotransformatora je sasvim drugačiji, naime on prenosi energiju direktnim putem, a omjer ulaznog i izlaznog napona je omjer zajedničkog i cjelokupnog namota.
Nadomjesni modeli transformatora omogućuju nam da prije no što se transformator uključi u mrežu naprave određeni matematički proračuni sigurnosti. Na taj način poznato je što se očekuje u normalnom pogonskom stanju, kao i pri pojavi kratkog spoja. Pošto u praksi kod tronamotnog transformatora jedna priključnica se ne koristi, te se autotransformator može svesti na dvonamotni, za proračune se koriste nadomjesni modeli dvonamotnog transformatora. Od nadomjesnih modela dvonamotnog transformatora najtočniji je T model jer prikazuje impedancije transformatora tamo gdje jesu i u stvarnosti. Π i Γ nadomjesni modeli manje su točni od T modela, ali se zato Γ model više koristi zbog njegove jednostavnosti. Kada nije potrebna posebna točnost koristi se i samo uzdužna grana impedancije transformatora, odnosno tzv. I nadomjesni model.
Abstract (english) The energy transformer is a key element in any electrical network, and is an indispensable part of electricity transmission. The energy transformer consists of his core, on which the low-voltage and the high-voltage windings of the are wound. A boiler, which usually contains special oil that cools the transformer elements, is in charge of keeping the system at working temperature. Conductive isolators or bushings are responsible for preventing a short circuit at the transformer connections. The energy transformer works on the principle of electromagnetic induction and transmits alternating current from the primary to the secondary coil. The current and voltage of the primary and secondary winding depend on the ratio of the number of turns of their windings. The energy transfer in an autotransformer is completely different, namely it transfers energy directly, and the ratio of input and output voltage is the ratio of the common and the whole winding.
Electrical transformer models allow us to make certain mathematical safety calculations before the transformer is connected to the network. In this way, it is known what is expected in normal operating conditions, as well as in the event of a short circuit. Since in practice one socket is not used for a three-winding transformer, and the autotransformer can be reduced to a two-winding one, electrical models of a two-winding transformer are used for all calculations. Out of the electrical models of the two-winding transformer, the T model is the most accurate because it shows the impedances of the transformer where they are in reality. The Π and Γ electrical models are less accurate than the T model, but the Γ model is therefore used more because of its simplicity. When special accuracy is not required, only the longitudinal branch of the transformer is used, i.e. the so-called I electrical model.
Keywords
Energetski transformator
dvonamotni energetski transformator
tronamotni energetski transformator
transformator u štednom spoju (autotransformator)
Nadomjesni model
gubici.
Keywords (english)
Power transformer
Two-winding power transformer
Tree-winding power transformer
autotransformer
Electrical model
electrical losses
Language croatian
URN:NBN urn:nbn:hr:190:854378
Study programme Title: Undergraduate University Study of Electrical Engineering Study programme type: university Study level: undergraduate Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka elektrotehnike (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka elektrotehnike)
Type of resource Text
File origin Born digital
Access conditions Open access
Terms of use
Created on 2022-09-20 11:32:32