Influence of harmonics on traction transformers losses

This paper presents the influence of harmonics on the windings' resistances, corresponding to the losses of a traction transformer. Concentric and pancake windings transformers have been analyzed. Various simulations with the 2D finite elements program "Flux2D" have been performed and compared to measurements done on real transformers. A simple law is proposed, it allows determining the variation of the resistance with the frequency for each transformer type.