Microgrid Decentralized Frequency Control Performance Improvement: An Optimal Fuzzy-LQR Design Approach

This study addresses an optimal decentralized controller optimized using fuzzy logic, to improve frequency performance and meliorate active power sharing in a microgrid. The proposed controller can achieve frequency regulation and active power allocation without a communication network for information exchange. The design of this controller is based on a linear-quadratic cost function, for which an optimal solution has been provided using the LQR method. The weighing matrices Q and R in the proposed LQR controller are determined based on fuzzy logic, which results in the selection of the best weighing matrices and, as a result, better performance of the controller. In the design of this controller, only the dynamics of the low-pass filter in the droop control loop have been used. The proposed controller can be used in both online and offline operation modes. The simulation results have shown desirable frequency alignment and active power sharing in the presence of various disturbances.