Enhancement of Stability Region by Virtual Inertia and Damping Control for Micro-Grids with Communication Time Delay

This paper investigates the impact of virtual inertia and damping (VID) control on stability regions defined in the gain space of the proportional integral (PI) controller for a micro-grid (MG) with communication time delays. In a MG-centralized controller equipped with communication links, controller performance and the system frequency are adversely affected by time delays in communication channel. For improving the stability of the time-delayed MG, this study considers the VID control which is integrated to reduce the adverse effects of high penetration of renewable energy sources and to emulate the required inertia response and damping into MG having low inertia. Therefore, this paper aims to determine all stabilizing PI controller gains, defining a region in PI controller parameters space of the time-delayed MG system with VID control. The qualitative impact of VID control parameters on the stability regions and MG frequency responses is thoroughly analyzed. Results clearly demonstrate that the inclusion of the VID control loop considerably increases the stability regions and improves the frequency dynamic behavior. Finally, the accuracy of stability region boundaries is verified by quasi-polynomial mapping-based root finder algorithm and time-domain simulations.