Series Balancing Capacitor (SBC) based DMPPT Scheme for string of PV Modules operating under non-uniform operating conditions

In a Photovoltaic (PV) system, modules are connected in series and parallel combinations to achieve desired voltage and current ratings. However, a string of PV modules can have a vastly reduced energy output during non-uniform operating conditions. This paper introduces a new Distributed MPPT (DMPPT) architecture using a Balancing Capacitor connected in series with a string of PV modules, having MPP and non-MPP functionality (where the system will output a desired amount of power). Each PV module in this scheme has a partial power processing (PPP) DC-DC converter connected across them to allow them to operate at a desired voltage depending on the system requirements. In comparison to other DMPPT schemes, this architecture can easily be integrated with a DC grid without the need of additional power electronic stages, at the same time allowing the PV modules to operate at their maximum power points (MPPs) if the system demands it. This scheme has been validated using detailed simulations and results are presented to verify the proposed architecture.