A Fast GMPPT Algorithm for PV Array under Non-uniform Shading Conditions

Abstract

The major challenge in operating the PV arrays with maximum efficiency is non-uniform irradiation over it. These conditions lead to multiple peaks in the P-V curve. This paper proposes a new global maximum power point tracking (GMPPT) algorithm which tracks the global peak irrespective of shading conditions. It takes voltage as a reference and starts tracking for the global peak. It first finds the minimum voltage below which absence of the global peak is ensured. Then the local peaks present in the P-V curve are estimated by calculating the knee points. The algorithm uses a maximum power triangle concept and a skipping scheme to speedup the tracking process. The region where the global peak is present is estimated and P&O is used to track the exact global peak. The proposed algorithm is simulated in MATLAB Simulink and results are verified experimentally. Delta SM100AR75 PV simulator is used as a PV source connected to a boost converter. TMS320F28335 digital signal processor is used to implement the proposed algorithm. The results show that using the proposed algorithm tracking time is low.