Frequency control of fully-renewable interconnected microgrid using fuzzy cascade controller with demand response program considering

The main purpose of this paper is to design a good fuzzy cascade controller for interconnected microgrids (μGs) with supporting a frequency perturbation-based demand response program. A fuzzy PD-(1+I) controller is optimally designed to perform the load frequency task in a fully-renewable interconnected μGs. In the proposed control strategy, exact adjusting of controller parameters and membership functions has a key role to achieve the robust performance. Thus, the fuzzy PD-(1+I) controller is automatically designed and updated using a nature-inspired mayfly optimization algorithm for finding a better controller and reducing system control cost. It combines the fuzzy theory and cascade control advantages to enhance load disturbance rejection effort in each μG and dump frequency fluctuations considering system parametric uncertainties and renewable energy sources (RESs) generation changes. The studied two-area islanded μG system by applying a fuzzy PD-(1+I) controller has been investigated in six different situations in comparison with the fuzzy PID and PD-(1+I) cascade controllers to demonstrate capability of load disturbance rejection, RESs generation changes and system parameters variation. The results in all cases show the decisive superiority of the fuzzy PD-(1+I) controller and its high adaptability than the other controllers.