Adaptive Virtual Inertia and Damping for Frequency Stability Enhancement using A Seamless Compensator

The inverter-based distributed generator (IBDG) does not inherently provide inertia and damping capability since the inverter is a static part. Lack of system inertia and damping properties leads to frequency instability issues. To overcome these issues, virtual inertia and damping are control concepts that effectively improve system inertia and damping by manipulating the active power of the controlled IBDG to ensure frequency stability in low-inertia systems. This paper aims to enhance the performance of virtual inertia and virtual damping emulation by adding a compensator to the virtual inertia and damping-based battery energy storage (BESS) control loops. The compensator speeds up the transient response, reduces the settling time and rise time, and, as a result, improves frequency regulation in terms of frequency nadir, overshoot, and oscillation. Moreover, the proposed compensator helps reduce the BESS-mandated size, thus lowering the initial cost. The particle swarm optimization technique is used to obtain the optimal parameters that minimize the frequency deviation and BESS size. A frequency dynamic control model with the proposed compensator is presented, considering a wide range of system operations. To assess the dynamic stability of the new proposed compensator, eigenvalues analysis, and time-domain simulation are given.