Adaptive fuzzy logic controller as MPPT optimization technique applied to grid-connected PV systems

Abstract

This chapter presents a complete design of maximum power point tracking control scheme applied to single-phase single-stage and two-stage grid-connected PV systems based on an adaptive fuzzy controller (AFLC). This technique is proposed to enhance the efficiency of a photovoltaic (PV) array and diminish the output power oscillations. The adaptive nature of the proposed controller provides online tuning of fuzzy rules parameters to deal with varying sun radiation and ambient temperature. Ranges of input variables of fuzzy system are defined using genetic algorithm. The adaptive MPPT controller is compared with existing setups, namely the “incremental conductance” (IC) technique and fuzzy logic controller (FLC). The inverter controller is designed in the synchronous frame so that a simplified controller such as PI-controller is implemented. Simulation and experimental results demonstrate the supremacy of the adaptive technique in terms of the speed of tracking and oscillations reduction around the maximum point of power–voltage (P–V) curve.