Abstract

Hybrid transformers are an attractive solution for improving power quality problems in distribution grids, due to the capability of power converters to provide precise current and voltage regulation. A hybrid transformer using a low-frequency transformer, which processes the biggest amount of power, and two converters connected in series and shunt, with an additional cascaded H-bridge converter connected in parallel, is presented. The use of a series converter on the primary side and a shunt converter on the secondary side allows to provide voltage regulation and load current compensation, respectively. Both converters improve the transformer power quality, extending its lifetime. Meanwhile, the cascaded H-bridge converter establishes a common DC-Link to support both converters operation. In this work, the model, control, and simulation results of the proposed configuration are presented, showing the improvement on the distribution transformer.