Maximum power point tracking using a GA optimized fuzzy logic controller and its FPGA implementation

Maximum power point tracking (MPPT) must usually be integrated with photovoltaic (PV) power systems so that the photovoltaic arrays are able to deliver the maximum power available. In this paper details of the work, carried out to optimize and implement a fuzzy logic controller (FLC) used as a maximum-power-point tracker for a stand-alone PV system, are presented. The near optimum design for membership functions and control rules were found simultaneously by genetic algorithms (GAs) which are search algorithms based on the mechanism of natural selection and genetics. These are easy to implement and efficient for multivariable optimization problems such as in fuzzy controller design. The FLC thus designed, as well as the components of the PV control unit, were implemented efficiently on a Xilinx reconfigurable field-programmable gate array (FPGA) chip using VHDL Hardware Description Language. The obtained simulation results confirm the good tracking efficiency and rapid response to changes in environmental parameters.