An optimization technique for transformer magnetic and thermal design

This paper faces with the design of oil filled distribution transformers by a feasible and simple optimization procedure. The original aspect of the proposed methodology rests on the ability in properly integrating both electromagnetic and thermal aspects at the aim of deriving the principal specifications of the transformer. The generality of the procedure allows designers to examine every type of transformer, even if the present paper focuses on the three phase design of wound core transformers type, equipped with winding regulator. The finite element analysis is also employed for verifying the goodness of the results obtained from the proposed technique by properly taking into account the non uniform distribution of ampere-turns due to tap changing. Some useful considerations are made for demonstrating the incidence of the thermal constraints on the transformer geometrical parameters. A numerical application is presented with respect to 630 kVA transformer having losses parameters aligned with the new European standards.