OVERVIEW OF TRANSFORMER'S FREQUENCY RESPONSE ANALYSIS METHOD AND FIRST EXPERIENCES

SAŽETAK Transformatori predstavljaju važan dio opreme u energetskom sustavu, te o njihovoj ispravnosti u visokoj mjeri ovisi i pouzdanost sustava, kvaliteta elektricne energije, te ekonomski troskovi odnosno cijena elektricne energije koju placa krajnji korisnik. Metodu analize frekvencijskog odziva (ili skraceno FRA) koristi danas veliki broj elektro kompanija i proizvođaca i ubraja se u napredne dijagnosticke metode. Posebno je pogodna za otkrivanje pomaka namota u radijalnom ili aksijalnom smjeru i deformacije namota. Glavni problem predstavlja ocjena rezultata i promjena (pomaka) na FRA karakteristikama, kako bi se detektirali vec nastali ili potencijalni kvarovi. SUMMARY Transformers represent important part of equipment in the utility grids and on their proper functioning depend in a high degree reliability of the system, power quality, economic costs and the price of the electrical energy that pays the customer. Frequency Response Analysis method (or abbreviation FRA) are nowadays widely used by the electric companies and producers and it represents an advanced diagnostic methods. It is especially useful for detection of the winding movements in the radial or axial direction or winding deformations. The main problem represents interpretation of the results and alternations (shifts) in the FRA characteristics, in order to detect already present failures or failure tendencies.