MPPT techniques for photovoltaic system under uniform insolation and partial shading conditions

The photovoltaic energy is one of the renewable energies that has attracted the attention of researchers in the recent decades. The photovoltaic generators exhibit nonlinear I-V and P-V characteristics. The maximum power produced varies with solar insolation and temperature. It requires maximum power point tracking (MPPT) control techniques to extract the maximum available power from PV arrays. Due to partial shading condition, the characteristics of a PV system considerably change and often exhibit several local maxima with one global maxima. Conventional Maximum Power Point Tracking techniques can easily be trapped at local maxima under partial shading. This significantly reduced the energy yield of the PV systems. In this paper, various MPPT algorithms for uniform insolation and partial shading conditions are reviewed with their merits and demerits. Also, some new algorithms are proposed which are shown to be more efficient than the existing ones.