20.500.12556/RUL-167724 Analiza nesimetrične obremenitve transformatorja z uporabo metode končnih elementov in zunanjega vezja Analysis of Asymmetrical Transformer Loading Using the Finite Element Method and an External Circuit V diplomskem delu ugotavljam, ali je sklopljena analiza 3D modela transformatorja z zunanjim vezjem primerna za obravnavo nesimetričnih obremenitev trifaznega transformatorja. V nalogi prikažem primerjave rezultatov preizkusov, opravljenih na dejanskem transformatorju, in tistih, pridobljenih z analizo 3D modela transformatorja v programu Ansys Maxwell 3D. Analize so v programu opravljene s sklopljeno izmenično analizo metode končnih elementov in zunanjega električnega vezja. Diplomsko delo pričnem z izdelavo 3D modela, in sicer 3- in 5-stebrnega transformatorja za primerjavo rezultatov že izdelanih dejanskih transformatorjev. Pri modeliranju je bil cilj univerzalnost modela, saj želimo, da je model uporaben za različne dimenzije transformatorjev in za različne obremenitve. V nadaljevanju najprej opravim meritve in analize 3-stebrnega transformatorja, kjer se posvetim karakteristikama prostega teka in kratkega stika ter meritvi ničnih impedanc. Za bolj popolno primerjavo z meritvijo in analizo določim še elemente nadomestnega vezja transformatorja. V 5. poglavju analiziram še nesimetrične obremenitve 5-stebrnega transformatorja pri različnih vezavah navitij in preverim, kako pri tej izvedbi transformatorja različne vezave vplivajo na vrednosti ničnih impedanc. Pri primerjavi ugotovim, da na ujemanje rezultatov analize z meritvami vpliva predvsem izbrana magnetilna krivulja, v primerih, kjer pa se večina sofaznega magnetnega polja kompenzira in je nična reaktanca majhna, pa tudi upornost samih navitij. In my thesis, I examine whether a coupled analysis of a 3D transformer model with an external circuit is suitable for addressing unbalanced loads in a three-phase transformer. The work presents comparisons between test results conducted on an actual transformer and those obtained through the analysis of a 3D transformer model using Ansys Maxwell 3D software. The analyses are carried out in the software using a coupled AC finite element method (FEM) analysis and an external electrical circuit. The thesis begins with the creation of 3D models, specifically for 3- and 5-legged transformers, to compare results with existing real transformer data. The goal during modelling was to achieve a universal model that can be adapted to various transformer dimensions and load conditions. Subsequently, I perform measurements and analyses on the three-legged transformer, focusing on its no-load and short-circuit characteristics as well as measurements of zero-sequence impedances. For a more comprehensive comparison, I also determine the elements of the transformer's equivalent circuit using both measurements and analysis. In Chapter 5, I extend the study to unbalanced loads on a five-legged transformer with different winding connections. I analyse how various winding configurations affect the values of zero-sequence impedances in this transformer design. Through the comparisons, I find that the accuracy of the analysis results in relation to measurements depends primarily on the selected magnetization curve. Additionally, in cases where most of the in-phase magnetic field is compensated and the zero-sequence reactance is small, the resistance of the windings themselves plays a significant role. trifazni transformator sklopljena analiza nesimetrična obremenitev nična impedanca three-phase transformer coupled analysis unbalanced load zero sequence impedance true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2025-03-10 08:15:02 2025-03-10 08:15:09 2025-03-24 14:27:17 0000-00-00 00:00:00 2025 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 62744 230050307 Novak_Dominik_-_Analiza_nesimetricne_obremenitve_transformatorja_z_uporabo_metode_koncnih_elemen.pdf Novak_Dominik_-_Analiza_nesimetricne_obremenitve_transformatorja_z_uporabo_metode_koncnih_elemen.pdf 1 A060141FA2525D84820CBD16897358A3 f8d72bf4017d8f5d24543121a4d69cd9bfa58bb1c84530d7110a5c2ef28c3700 70937794-fd7e-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=200445 Fakulteta za elektrotehniko 0 0 0