Switched-Capacitor-Based Hybrid Resonant Bidirectional Buck-Boost Converter for Improving Energy Harvesting in Photovoltaic Systems

Photovoltaic (PV) modules are often connected in series to achieve the desired voltage level in practical applications. A common issue with this setup is module mismatch, which can be either permanent or temporary and is caused by various factors. The differential power processing (DPP) concept has emerged as a prominent solution to address this problem. However, a significant drawback of current DPP topologies is their reduced performance under certain conditions, particularly in cases of permanent mismatch. As a result, applications involving the DPP concept for permanent mismatches remain underexplored. In this context, the goal of this work is to develop and implement a novel DPP topology capable of increasing energy harvesting in PV systems under permanent mismatch. The proposed hybrid architecture combines features from both bidirectional buck-boost (BBB) and resonant switched capacitor (ReSC) converters. The ReSC converter operates under soft-switching conditions, minimizing undesirable losses. Key advantages of the proposed converter include fewer switches, lower voltage stress, and soft-switching operation, making it suitable for PV systems with mismatched modules. Experimental tests showed an energy harvesting improvement under the assessed conditions.