Droop Control Based Virtual Inertia Emulation for Stability Enhancement of a Microgrid System

Due to the decreased total system inertia, the large-scale integration of inverter-based RE sources in a microgrid system raises stability concerns. By imitating virtual inertia, battery energy storage systems (BESS) can significantly improve the system inertia of a microgrid system, especially in islanded mode. The designing of inverter controller to keep the system stable is a challenge for a microgrid system under abnormal grid situations. Droop control technique is widely used for controlling the active and reactive power flow of an inverter for microgrid application. The inverter controller demonstrated in this research uses the droop control technique and is equipped with a synchronization unit that can emulate virtual inertia and give the microgrid system enough inertial support in islanded mode of operation and dynamic grid scenarios. The presented controller has been designed and validated using MATLAB/SIMULINK software to demonstrate its efficacy for improving stability of a PV-BESS integrated microgrid system.