Differential Power Processing Converter with an Integrated Transformer and Secondary Switch for Power Generation Optimization of Multiple Photovoltaic Submodules

In recent years, to increase the fuel efficiency of environment-friendly vehicles, a large volume of research is ongoing regarding applying photovoltaic (PV) systems. However, in PV systems, a power imbalance between submodules is common due to shading or pollution, and this degrades the power generation efficiency of the system. To solve this problem, various differential power processing (DPP) converters have been developed. In order to adopt the DPP converter to environment-friendly vehicles, the DPP converter must have a small volume, high efficiency, and high price competitiveness. In this regard, we propose a DPP converter with a single multi-winding transformer by integrating multiple transformers and secondary sides of the conventional flyback DPP converter. Since the proposed DPP converter can be applied to battery balancing circuits as well as photovoltaic systems, the proposed circuit is a valuable converter. In the PV system, the maximum output power of each submodule is 60 W, and the total PV system is 240 W by connecting four submodules in series. To verify the validity of the proposed DPP converter, a prototype with 8 V input and 60 W/30 V output specification was built and tested, and the effectiveness of the proposed converter is supported by the experimental results.