Analysis of parallel operation of converters with interphase transformer

Abstract

The parallel operation of two three-pulse controlled converters with interphase transformer (IPT) is modeled and analyzed. An IPT absorbs voltage difference between DC voltages of the two converters at any instant and ensures independent operation without any circulating current. It also results in six-pulse output voltage resulting in less harmonic distortions. The complete circuit is solved by using modified nodal analysis (MNA) and magnetic nonlinearity in the IPT core is taken into account by dynamic inductance model. Power electronic switches are modeled as small and large resistances during ON and OFF states. A code has been written to model and simulate the circuit under balanced and short circuit conditions.