Modelling of fuzzy logic controller for variable-step MPPT in photovoltaic system

The output power of photovoltaic electrical systems is highly dynamic and non-linear in nature. In order to extract maximum power from such systems, maximum power point tracking (MPPT) technique is required. MPPT techniques with variable step-size of perturbation track the maximum power point (MPP) with more efficiency. In this paper, a model of a fuzzy logic controller (FLC) for determining the step-size of perturbation in duty-cycle of a photovoltaic electrical system to track MPP is presented and its result is compared with a classical method of exponential approximation in MATLAB/Simulinke.