Steady-state analysis of photovoltaic full power processing architecture with constant power region operation

Full power processing (FPP) and differential power processing (DPP) are two fundamental power-flow concepts used in photovoltaic (PV) power conversion. This work focuses on FPP implemented at the module level as one realization of distributed maximum power point tracking (DMPPT) architectures. In the considered FPP architecture, each PV module is interfaced by a dedicated direct current power optimizer (DCPO), and the DCPO outputs are interconnected in series or parallel to meet the DC-link or grid requirements. The performance of the entire system, including the constant power region (CPR) at the string level, can be influenced by the steady-state characteristic curve of the FPP at the string level. This study employs a quantitative approach to investigate the characteristic curve of the output terminals of the DCPO in the FPP structure, specifically while utilizing boost converters and buck converters in series and parallel connections. Meanwhile, the physical constraints, including the maximum permissible output voltage/current and duty cycle limitations, are considered in this work to get more realistic results.