Comparison of Bidirectional Flyback and Split-Inductor Boost Converter Topologies for Photovoltaic Differential Power Processing Systems

Series-connected photovoltaic (PV) systems are widely used for their clean energy production, but they are susceptible to power reduction when PV cell characteristics become mismatched. PV-to-bus differential power processing (DPP) converter systems are one solution to solve these mismatch problems with low power loss in the converter system. Bidirectional flyback converters are commonly used in PV-to-bus DPP systems because their isolation allows for a series-input and parallel-output configuration. However, the coupled inductor of a flyback converter topology usually causes high power loss due to its high leakage inductance. To further improve converter efficiency in PV-to-bus DPP systems, we propose using a bidirectional split-inductor boost converter. In this work, we compare its power loss and efficiency to that of an equivalent flyback converter through simulation and hardware experimentation. Experimental results show that the measured peak efficiency of the split-inductor boost converter is 89.2%, which is 14.7% higher than that of the flyback converter (74.5%).