A self-tuning fuzzy PI controller for PV-Wind-Diesel-Battery hybrid energy systems

Generation of electricity for urban regions usually depends on the national electricity grid. But, the generation of the electricity in remote and rural areas which, are far from the national grid is diffuclt and very expensive. Therefore, PV-Wind-Diesel-Battery hybrid energy systems represent an attractive alternative solution. But, these systems are usually non linear in nature and have unpredicatable parameters variations with time. This paper presents a robust self-tuning PI-type fuzzy logic controller (STFPIC). Depending on the process trend, the output scaling factor (SF) of the controller is modified on-line by an updating factor (r). The value of r is determined from a rule-base defined based on error (E) and change of error (DeltaE) of the controller variable. The proposed self-tuning controller is designed using a very simple control rule-base and the most natural membership functions (MF). The proposed scheme is tested for a different numbers of membership functions with using Matlab-Simulink. Also, the comparative between FLC and the self-tuning fuzzy PI controller is cleared. The results show that our proposed scheme gives a more robust performance the normal fuzzy logic controller (FLC).