Fuzzy controller based maximum power point tracking technique of standalone photovoltaic module for lead-acid battery charging

摘要

This paper provides the design and simulation of photovoltaic module based charger for lead-acid battery. To maximize energy storage, the battery is charged through the integrating fuzzy logic controller (FLC) based on maximum power point tracking (MPPT) and the constant current-voltage charging (CCCV) method. The FLC is designed to directly take the voltage and current from the PV pannel to compute the derivative of power with respect to voltage and its difference as the inputs to produce the duty cycle for achieving the MPP in the constant current step. The continued constant voltage completes the battery charging until the battery current decreases to nearly zero. To optimize the FLC, a Multi-Objective Hierarchical GA (MOHGA) is used to extract the significant fuzzy rules and simultaneously fine-tune the shape of membership functions and the system parameters. The charge control simulation has shown that FLC performs the power utilization about 95.0% and achieves the voltage control accuracy by 99.8%.