Architecture for Parallel PV Strings using the Switched-Capacitor-Based Differential Power Processing Techniqu

Abstract

Mismatch effects are common in photovoltaic (PV) systems, which affect the overall system performance and the PV module life. A mismatch causes an imbalance in the PV module voltages, and therefore, it is not recommended to connect PV modules in parallel due to increased power losses and stresses. To mitigate the effect of mismatch, module-level power electronics converters are considered as an effective solution. Accordingly, this paper introduces a differential power processing (DPP) converter based on switched-capacitors (SCs) for parallel-connected PV strings. The proposed DPP converters are connected across each PV module, which equalizes the PV module voltages. The technique can help to generate more output power regardless of mismatch between PV modules and make the parallelization of PV strings possible. The proposed architecture is analyzed through simulations and compared with parallel-connected PV strings using Schottky diodes.