  To ensure adequate and economic reserve for primary frequency response in the
current and future power system, this paper proposes real-time frequency
response reserve (FRR) requirement based on system inertia. This minimum FRR
will help power system operators adjust the current frequency response
requirement and accommodate more renewable generations while achieving a saving
of both energy and facility costs. Most importantly, the ability to adaptively
vary the FRR will provide the additional agility, resiliency, and reliability
to the grid.
