Winding temperature prediction in split-winding traction transformer

Abstract

Incombustible features of resin make multiwinding dry-type transformers suitable for use in traction systems. Nevertheless, due to resin's heat transfer property and the special structure of traction transformers, temperature distribution in traction transformers is undesirable and it is essential to study its thermal behavior. In this research paper, the thermal behavior of traction transformers is modeled using the finite difference approach. After validating the model results (using the experimental results), the temperature distribution in a cast-resin traction transformer with split windings is calculated. The thermal behavior of the split-winding traction transformer is compared to the normal two-winding cast-resin transformer. A traction transformer usually feeds electronic converters; the converter system as a nonlinear load causes harmonics to appear in the winding currents. Thus, the thermal behavior of a traction transformer has been modeled in the presence of harmonic currents and their effects on temperature distribution have been discussed.