Iron loss optimisation of a distribution transformer

In the paper an approach to loss reduction for a distribution transformer is presented. The particular emphasis is put on optimisation of no-load loss, i.e. iron loss. The object of investigation is an oil immersed three-phase transformer 50 kVA, 20/0.4 kV, Y_Zn5, from the production program of the factory ´Rade Koncar´ in Skopje. First, the new prototype transformer with increased efficiency and reduced mass has been designed and built; computed results are validated and proved through measurements. After, an investigative study on further reduction of the transformer iron loss is presented.