Mathematical model and equivalent circuit for cost-benefit analysis of using alternative materials in power transformer manufacturing

U ovom radu je izveden matematički model energetskog transformatora te pripadne nadomjesne sheme. Matematički model i nadomjesne sheme zatim su primijenjene za analizu specifičnih pogonskih stanja (prazni hod, nazivno opterećenje, uključenje transformatora na mrežu, kratki spoj, pad napona). Uz parametre nadomjesne sheme napravljena je analiza gubitaka u namotima i jezgri. Izveden je matematički model ovisnosti gubitaka namota i gubitaka u jezgri o karakteristikama korištenih materijala i faktoru opterećenja energetskog transformatora. Napravljena je analiza isplativosti korištenja alternativnih materijala (bakar, aluminij, srebro, razne legure za namote; razne vrste željeznih limova za jezgru) ovisno o cijeni materijala u odnosu na cijenu izgubljene energije u namotima i jezgri u obliku topline u energetskom transformatoru kroz njegov radni vijek.In this work, power transformer mathematical model and the corresponding equivalent circuit are explained. Mathematical model and equivalent circuit are then used for analysis of specific operating conditions (no load, rated load, inrush current, short circuit, voltage drop). Furthermore, an analysis of winding and core losses using the parameters of the equivalent circuit are made. In addition, mathematical model for winding and core losses depending on used materials and load factor of the power transformer is made. Cost-benefit analysis of using alternative materials is then made (copper, aluminum, silver, various alloys for windings; various iron laminated materials for core) taking into account the prices of the materials compared to the energy losses (heat) in power transformer during its life expectancy