Equivalent circuits of transformers with distorted and asymmetrical currents and supply voltages and with regard to magnetizing current

The aim of the paper was to work out the generalized equivalent circuits of three-phase power converter transformers of average and greater power, with 3and 5-column cores and with connection diagrams Yy _o, Dy_o, Yz_o, Dz_o, Yy and Dy, supplying basic commutation units connected in star and bridge configurations. These equivalent circuits should refer to a steady state and take into account: transformer magnetizing current; asymmetry of distorted supply voltages; and asymmetry of transformer distorted currents. In comparison with the linear equivalent circuits in use, the generalized linear equivalent systems worked out have an extended area of use through taking into account magnetizing current and distorted asymmetrical supply voltages. The study also justifies the permissibility of investigation of operating conditions with asymmetry of transformer secondary and primary currents in the equivalent circuits proposed