Optimal allocation of distributed power in adaptive droop controlled isolated DC microgrid under renewable energy intermittency and uncertainty using fuzzy logic controllers

Abstract

This study presents an innovative adaptive droop control framework based on Interval Type-2 Fuzzy Logic Control (IT2FLC) for co-ordinated control and DC link stability of multiple Renewable Energy Systems (RES) during heavy transient in varying operating conditions in DC Microgrid (DC MG). The proposed method integrates voltage and current loop in primary layer into one unit based on adaptive droop characteristics, reducing controller complexity and tuning requirements. Voltage and current error are simultaneously used to restore DC link voltage and correct current sharing errors. Additionally, uncertainties in system parameters are incorporated as uncertainty in the degree of membership of FLC. The system integrates different RES namely, Photo-Voltaic (PV) array, Wind Turbine (WT), and Energy Storage System (ESS), and carries out comparative study against traditional PI through multiple case studies. Simulation results demonstrate superior performance of the proposed IT2FLC, achieving up to 14.5% improvement in power regulation under environmental variations and 15.5% better resilience to communication errors compared to PI control. Further testing on an OPAL-RT real-time simulator confirms that the controller maintains robust power delivery across varying operational scenarios, consistently outperforming conventional controllers in stability and precision.