A Buck-Boost topology based hybrid converter for standalone nanogrid applications

This paper proposes a novel hybrid converter derived from a conventional Buck Boost DC-DC Converter. The principle of Augmented Sinusoidal Pulse Width Modulation (ASPWM) is used to derive the hybrid topology. It provides both AC and DC voltages using a single DC source as input. As a result of ASPWM switching, the voltage across the Buck-Boost stage inductor will contain a line frequency component, which can be extracted by a frequency selective network. The DC voltage gain for buck-boost converter with ASPWM has been derived and it is shown that buck-boost converter acts as a boost converter for all ranges of DC offset under ASPWM switching. The circuit has been extensively simulated in MATLAB/Simulink for various load conditions. The proposed circuit will have applications in standalone nanogrids where the loads will essentially be AC as well as DC.