Power transformers modelling for short-circuit calculation in software package PSS/E

U ovom radu obrađena je tema modeliranja različitih energetskih transformatora za proračun kratkog spoja. Kroz rad obavljene su detaljne analize čitavog elektroenergetskog sustava s posebnim naglaskom na transformatore, tokovi snage te kratki spojevi. Kod dvonamotnih i tronamotnih transformatori obrađeni su modeli u direktnom i nultom sustavu. Izvedbe transformatora se razlikuju ovisno o njihovoj namjeni, snazi, naponskim razinama i uzemljenju zvjezdišta. Nadalje u radu su provedeni proračuni struja kratkog spoja na modificiranoj IEEE 14 bus mreži. U nju su uključeni autotransformator, distribucijski transformator i nekoliko blok transformatora grupe spoja YNd5. Na ovoj test mreži provedeni su proračuni tropolnog i jednopolnog kratkog spoja u programskom paketu PPS-E prema međunarodnoj normi IEC 60909 te analizirani dobiveni rezultati.This paper deals with the theme of modeling various energy transformers for short-circuit calculation. Throughout the work, detailed analyzes of the entire power system were performed with special emphasis on transformers, power currents and short circuits. Two winding and three winding transformers are modeled in direct and zero systems. Transformer configurations are different depending on their purpose, power, voltage levels, and starvation grounding. In addition, the short-circuit current calculations on the modified IEEE 14 bus network were performed. It includes an autotransformer, a distribution transformer, and several block transformers of the YNd5 group. On this test network, calculations of three phase and single phase short circuits in the PPS-E program package were carried out in accordance with the international standard IEC 60909 and then analyzed the obtained results