Accurate modeling of core-type distribution transformers for electromagnetic transient studies

This paper proposes a model of core-type distribution transformers for electromagnetic (EM) transient studies. The model accurately reproduces not only the impedance characteristics seen from each terminal of a core-type distribution transformer but also the surge-transfer characteristics between the primary and secondary sides in a wide range of frequencies. Due to the above capability, the proposed model enables the accurate evaluation of overvoltages on distribution lines including consumer-side overvoltages. In this paper, a 10-kVA transformer is modeled, and transient-simulation results agree well with laboratory-test ones.