Maximum power point tracking of multiple photovoltaic arrays

This paper introduces a novel maximum power point tracking (MPPT) technique for multiple photovoltaic (PV) arrays operating under different environmental and load conditions. Variations in these conditions will cause multiple local maximum power points (MPPs) on the P-V and I-V curves of the PV modules. In these conditions it is difficult to find the global MPP using conventional MPPT techniques. To overcome this difficulty in this paper an extended perturb and observe (P&O) MPPT technique has been implemented. The proposed technique requires only one pair of sensors to find global MPP of multiple PV arrays, thereby resulting in lower cost, higher overall efficiency, and simplicity. This paper also discusses about comparative analysis of extended P&O algorithm and conventional P&O algorithm. In addition to this the proposed technique has been verified by comparing with theoretical analysis under different environmental and load conditions. The validity of the proposed algorithm is verified by simulation studies. Algorithm robustness was verified under several partial shading conditions and for different loads. All the simulation study has been performed in PSCAD/EMTDC 4.2 version simulation software.