  An increasing penetration of renewable generation has led to reduced levels
of rotational inertia and damping in the system. The consequences are higher
vulnerability to disturbances and deterioration of the dynamic response of the
system. To overcome these challenges, novel converter control schemes that
provide virtual inertia and damping have been introduced, which raises the
question of optimal distribution of such devices throughout the network. This
paper presents a framework for performance-based allocation of virtual inertia
and damping to the converter-interfaced generators in a low-inertia system.
This is achieved through an iterative, eigensensitivity-based optimization
algorithm that determines the optimal controller gains. Two conceptually
different problem formulations are presented and validated on a 3-area, 12-bus
test system.
