A central capacitor partial power processing DC/DC converter

This paper proposes a novel central capacitor partial power processing (CCPPP) DC/DC converter, which can be used to boost dual input sources to a desired output voltage with reduced semiconductor voltage stress and current stress. Compared to the traditional DC/DC boost converter, the proposed circuit reduces both voltage and current stresses for switches and diodes but could maintain the same operation function as boost converter without adding extra devices. The proposed circuit is suitable for string PV inverter, where the traditional first-stage boost converters can be replaced by the proposed circuit to increase efficiency. This paper analyzed the operational principle of CCPPP converter and also developed the control method of a grid-tied PV inverter using CCPPP DC/DC converter in front. Besides, the key issues regarding voltage and current stress analysis, efficiency comparison are discussed in this paper either. Finally, the proposed converter is verified through MATLAB simulation and a laboratory prototype.