Hierarchical PV to PV series differential power processing for photovoltaic applications: Power flow and converter rating analysis

Abstract

The energy yield of Photovoltaic (PV) systems is significantly reduced by mismatch among PV (sub)modules. To counter this, a solution known as PV-to-PV (PV2PV) Series Differential Power Processing (SDPP) has been thoroughly explored in literature. However, conventional PV2PV SDPP architectures can lead to the so-called "accumulation effect", which significantly increases the total power processed by the converters forming the architecture as well as their component ratings. This paper focuses on a hierarchical PV2PV SDPP architecture as an alternative to mitigate this issue. The equations describing the operation of the hierarchical PV2PV SDPP architecture are derived and its performance analyzed. A comparison between conventional and hierarchical PV2PV SDPP architectures is conducted, and simulations in MATLAB/Simulink environment validate the hierarchical architecture's ability to reduce the accumulation effect, enhancing PV system energy yield.