Interaction between Transformers and the Power System

Rad sadrži teoretski uvod u problem oscilatornih prenapona u mreži, koji za posljedicu imaju pojavu unutrašnjih rezonantnih prenapona na transformatoru. Opisano je modeliranje transformatora i ostalih elemenata elektroenergetske mreže prilikom prijelaznih pojava. Razmatrane su interakcije transformatora s ostalim elementima elektroenergetskog sustava prilikom prijelaznih pojava, proučavana je izolacija transformatora, njena svojstva i utjecaj starenja na parametre izolacije, prikazani primjeri različitih kvarova transformatora iz prakse, napravljen model ovisnosti impedancije transformatora o frekvenciji u ATP-u, te su na kraju date preporuke za zaštitu transformatora od unutrašnjih rezonantnih prenapona nastalih zbog različitih prijelaznih pojava u mreži.The thesis contains a theoretical introduction to the problem of oscillatory overvoltages in the network, that result in emergence of internal resonant overvoltages in the transformer. The modeling of transformers and other elements of the power network during transient phenomena was described. The interactions of the transformer with other elements of the power network, the insulation of the transformer, its properties and the effect of aging on the parameters of insulation were studied, examples of various failures of transformers from practice shown, a model of dependency of the impedance of the transformer on frequency in the ATP made, and in the end, recommendations for transformer protection against internal resonant overvoltages caused by various transient phenomena on the network were given