Power Controller Design for Photovoltaic Generation System under Partially Shaded Insolation Conditions

Partially shaded photovoltaic (PV) modules typically exhibit additional difficulties in tracking maximum power point (MPP), since their power-voltage (P-V) characteristics are complex and may have multiple local maxima. For this reason, conventional techniques fail to track MPP effectively, if the PV array is partially shaded. This paper presents a novel power compensation and control system for PV arrays under complicated non-uniform insolation conditions. The proposed system is based on forward biasing bypass diode of shaded modules by monitoring dynamic resistance and voltage of PV modules. For this purpose, the proposed system is used DC/DC converter equipped with each PV string in PV array. The proposed system can identify which modules are shaded. The effectiveness of the proposed system is investigated and confirmed for complicated partially shaded PV array.