An integrated multifunction DC/DC converter for PV generation systems

Due to the stochastic characteristic of photovoltaic (PV) generation, energy storage devices are indispensable to smooth the power flow and provide the electric energy with high quality. In this paper, an integrated DC/DC converter is proposed to realize high performance interfaces for PV array, battery and load. This converter consists of a boost converter for the PV array and a buck/boost converter for the battery, which can realize multifunction including power generation, charge and discharge. The grid-connected and stand-alone operation modes of this converter are analyzed. From this analysis, the control strategies are developed for both modes. A coordination scheme is proposed for the power balance at the stand-alone mode. Simulation and experiments verify the practical feasibility and effectiveness of this multi-function converter.