Combined Voltage and Frequency Regulation for Isolated Microgrid via Flow Direction Algorithm

Frequency and voltage regulations are the most significant aspects of power system reliability, especially with the lack of overall inertia, such as in isolated microgrids (IMGs). This paper proposes a combined load frequency control (LFC) and automatic voltage regulation (AVR) to stabilize frequency and voltage simultaneously in an IMG. The IMG's sources are diesel engine generators, battery energy storage devices, fuel cells, and renewable energy resources (RES) like photovoltaic and wind turbines. A PID controller is deployed in the combined model to control diverse sources of the IMG. Flow direction algorithm (FDA), a recent optimization algorithm, optimizes the controllers' parameters simultaneously. To demonstrate the efficacy of the FDA-based combined model, MATLAB/SIMULINK simulates the system under load deviation and the stochastic nature of RES. The results show that the FDA-based combined model outperforms three optimization techniques concerning minimum error criteria, overshoot/undershoot/settling time, frequency, and voltage deviations in different load and RES scenarios.