Adaptive Fuzzy Droop Control for Optimized Power Sharing in an Islanded Microgrid

With the serious environment pollution and power crisis, the increasing of renewable energy resource (RES) becomes a new tendency. However, the high proportion of RES may affect the stability of the system when using the conventional droop control with a fixed droop coefficient. In order to prevent the power overloading/curtailment, this paper proposes an adaptive fuzzy droop control (AFDC) scheme with a P-f droop coefficient adjustment to achieve an optimized power sharing. The droop coefficient is adjusted considering the power fluctuation of RES units and the relationship of power generation and demand, which can realize the stability requirements and economic power sharing for the islanded microgrid. What is more, a secondary control is considered to restore the frequency/voltage drop resulting from the droop control. The proposed strategy improves the stability and economics of microgrid with a droop-based renewable energy source, which is verified in MATLAB/Simulink with three simulations which are variations in load, in generation and in load and generation simultaneously. The simulation results show the effectiveness of the proposed control strategy for stable and economic operation for the microgrid.