Transformerless DC/DC converter based on the autotransformer concept for the interconnection of HVDC grids

Abstract

DC/DC autotransformers present several advantages compared to Front-to-Front (F2F) topologies. This work presents the Transformerless (TL) DC/DC autotransformer topology, which consists on the substitution of the AC transformer in the DC/DC autotransformer for an AC filter, with the objective of reducing its cost. The TL topology is modelled, its control presented and its operation validated by means of simulations. Also, the losses of the converter are estimated for partial and full load.