Fuzzy Logic-Based Adaptive Droop Control Designed with Feasible Range of Droop Coefficients for Enhanced Power Delivery in Microgrids

Power electronic converter-based microgrids generally suffer from poor power delivery/handling capability during sudden load changes, especially during islanded operations. This is due to a lack of transient energy support to compensate for sudden load changes. The literature has suggested the use of adaptive droop control to provide compensation during transient conditions, thereby improving their power delivery capability. In this context, fuzzy logic-based adaptive droop control is a state-of-the-art technique that was developed based on empirical knowledge of the system. However, this way of selecting the droop coefficient values without considering mathematical knowledge about the system leads to instability during transient conditions. This problem is further worsened when dominant inductive load changes occur in the system. To address this limitation, this paper proposes an improved fuzzy logic-based adaptive droop control method. In the proposed methodology, the values of droop coefficients that are assigned for different membership functions are selected based on a stability analysis of the microgrid. In this analysis, the feasible range of active power–frequency droop values that could avoid instability during large inductive load changes is identified. Accordingly, infeasible values are avoided in the design of the fuzzy controller. The performances of the proposed andconventional fuzzy logic methods are verified through simulations in MATLAB/Simulink. From the results, it is identified that the proposed method improved the power delivery capability of the microgrid by 14% compared to the conventional method.