Design of a Multi-Mode Input-Parallel-Output-Series Power Optimizer for Wide-Voltage Range Photovoltaic Applications

This paper presents a new hybrid multi-mode Input-Parallel-Output-Series converter to be employed as a Parallel Power Optimizer (PPO) for photovoltaic (PV) applications. The converter combines the high efficiency conversion of an LLC processing the largest fraction of the input power with the possibility to provide a fine gain modulation thanks to a synchronous boost working in the Boundary Conduction Mode. The achievable input voltage range is further extended by a topology-morphing rectifier in the LLC. The proposed optimizer is designed based on the specifications of a target bifacial PV module and preliminary simulation results show that the converter achieves a high efficiency above 94.5% over the wide 15V-45V input voltage range, exhibiting a California Energy Commission (CEC) efficiency of 97.0% at the rated 36.5V voltage.