An auto-tuned droop coefficient-based controller for microgrid system to enhance grid resilience during blackouts

This paper presents a reliable auto-tuned droop coefficient-based controller (ATDC) for a microgrid (MG) system for enhancing grid resilience during blackouts. Existing power system networks experience blackouts due to inevitable failures such as overloading on lines, failure of a protection system, and imbalance in the power lines. The consequences of blackouts can be resolved by adapting to the concept of resilient MGs with high dynamic stability for power restoration. However, impedance parameters of power lines will change during blackouts, this eventually affects system's performance. Therefore, synchronization of MG sources to the utility grid and providing power supply to the critical loads during power system blackouts are the key factors to be resolved by maintaining system within permissible limits. The proposed ATDC-based controller adapts to changes in system parameters and auto-tunes the droop coefficients to provide proper control coordination between the each of distributed generator (DG) in MG. The proposed ATDC-based controller is designed in silico, and its effectiveness is tested under various conditions of MG operations. Results are compared with conventional and improved droop controller strategies. The test results demonstrate that the proposed controller maintains grid supply frequency within IEEE-1547 standards while ensuring appropriate power-sharing between load and MG sources.