A Novel Integrated DC/AC Converter With High Voltage Gain Capability for Distributed Energy Resource Systems

In this paper, a novel high voltage gain single-stage dc/ac converter is proposed for distributed energy resources. A flyback-type auxiliary circuit is integrated with an isolated Ćuk-derived voltage source inverter to achieve a much higher voltage gain. It is seen that through this integration, the capacitors of the flyback and the Ćuk circuits are paralleled for charging and in series for discharging automatically. Due to the capacitive voltage dividing, the dc-side switch voltage stress can be reduced and the losses can be reduced as well. Besides, the low influence of coupling coefficient of flyback-type auxiliary circuit on the inverter characteristic renders the proposed inverter design rather flexible and easy. Steady-state characteristics, performance analysis, simulation and experimental results are given to show the merits of the proposed integrated inverter. Finally, based on the same integration concept, a family of different topologies is also presented for reference.