Intelligent PID-Fuzzy logic control for three-phase grid-connected photovoltaic inverter

The aims of this works are to present an intelligent control based in fuzzy logic and PID controller for the maximum power point tracking (MPPT) of a photovoltaic system under variable temperature and irradiance conditions, to improve the dynamic response, the efficiency and the stability of single stage three-phase photovoltaic grid-connected inverter. The combination of the flexible and intelligent fuzzy logic with the classical PID controller makes the control of nonlinear characteristic of photovoltaic array more feasible. The proposed intelligent PID-Fuzzy logic controller automatically varies the coefficients K_p, K_i and K_d under variable temperature and irradiation. Finally the comparison of results, obtained separately from PID controller and proposed intelligent controller of PID-Fuzzy logic show the advantages of the proposed intelligent algorithm in terms of correctness and the feasibility, overshooting and stability and maintains its response better than the PID controller in many aspects.