Enhanced Grid Stability Using Virtual Inertia Control Strategy for DC Microgrids

This study demonstrates the use of virtual inertia and its effects on DC microgrid (DCMG) operating under grid-connected mode. The DCMG is comprised of an inertia-less solar photovoltaic system, and a battery energy storage system (BESS) with a bidirectional DC-DC converter (BDDC). The system has AC and constant power loads. The DCMG fails to participate in inertia support due to associated poor inertia and power electronics interface. As per the present grid code, the DCMG in grid-connected mode should participate in inertia support. Therefore, the emulation of virtual inertia utilizing the control loop of BDDC in DCMG is addressed and simulated in this work. Consequently, the battery's life cycle will be enhanced by avoiding high peaks of the BESS caused by low inertia. The simulation result demonstrates that using the proposed virtual inertia concept on BDDC would increase the inertia of DCMG and prolong the lifespan of the battery bank while maintaining the stability of the DC bus voltage. In order to assess the effectiveness of the suggested control strategy, a simulation-based experiment is implemented within the MATLAB/Simulink environment.