Frequency control of Autonomous Hybrid Multi-Microgrid System

Load frequency control (LFC) of the multi-microgrid system has been addressed in this paper. The multi-microgrid system consists of RES (solar power and wind power), diesel engine generator (DEG) and battery energy storage system (BESS). Large frequency fluctuations are experienced by the microgrids and interconnecting lines due to the intermittent nature of RES in addition to low inertia of microgrids. Secondary frequency controller has been considered in this paper as the primary frequency controller fails to bring back the frequency to the nominal value. TLBO algorithm, which is free from algorithm-specific parameters has been considered for tuning the gains of the PID controller. The robustness of TLBO-PID controller has been verified with different scenarios and the transient response characteristics obtained using various controllers proves the supremacy of the proposed controller.