An Application of Interleaved Zeta-Buck-Boost Combination Converter in Distributed Generation

Low-voltage bipolar-type DC microgrid is an emerging alternative for electric systems with high penetration of distributed generation (DG). The DG sources usually generate energy in DC form. This type of generation needs an interface to adapt the level of voltage from the source to the network. These interfaces usually consist of DC-DC converters. In this work, a new DC-DC converter is proposed for this application. This topology allows obtaining a DC bipolar output from a single DC input. The new converter consists of combining two basic converters, Zeta and Buck-Boost single inductor converter sharing the switch. It is possible because both converters have the same instantaneous duty cycle. For high power, various combined converters connected in parallel and operating in interleaved mode is proposed. This configuration gives high power with low ripple at the output and input currents. An analysis of the proposed configuration for different performance modes and load conditions is carried out. Simulation results show as this interleaved converter topology with appropriated modulation schemes is adequate to use in bipolar DC microgrid (MG).