Behavior of three-phase transformers supplying non linear loads using time domain representation and finite element analysis

This paper aims to present and discuss the magnetic and electrical results derived from three-phase power transformers modeling under nonlinear load conditions. The approach uses time-domain techniques and the finite element method. The transformer internal electromagnetic equations and the external equivalent circuit are simultaneously solved through a well-established computational package. The nonlinear load is a 6-pulse rectifier supplied by a nonlinear modeled power transformer. The waveform for different currents and voltages, as well as the flux line distribution are given and fully described. The results obtained from the simulation are compared to experimental tests.