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.