  Rotational inertia is stabilizing the frequency of electric power systems
against small and large disturbances, but it is also the cause for oscillations
between generators. As more and more conventional generators are replaced by
renewable generation with little or no inertia, the dynamics of power systems
will change. It has been proposed to add synthetic inertia to the power system
to counteract these changes. This paper presents an algorithm to compute the
optimal placement of synthetic inertia and damping in the system with respect
to explicit time-domain constraints on the rate of change of frequency, the
frequency overshoot after a step disturbance, and actuation input. A case study
hints that the approach delivers reliable results, and it is scalable and
applicable to realistic power system models.
