Abstract:
The modern power system is witnessing an unprecedented increase in the
penetration of renewable variable generation (VG) sources. Increased uptake
of converter interfaced VG like solar PV and wind power while replacing
conventional synchronous generators (SGs) introduces new challenges to
grid operators in terms of dynamically handling frequency stability and
regulation. Reducing the number of SGs while increasing non-synchronous,
inertia-less converter interfaced VG reduces grid natural inertia, which is
critical for maintaining frequency stability. To cure inertia deficiency,
researchers, broadly, have proposed implementing supplemental control
strategies to VG sources or energy storage systems to emulate natural inertia
(virtual inertia (VI)). Alternatively, VG sources can be operated below their
maximum power point (deloaded mode), making available a reserve margin
which can rapidly be deployed in case of a contingency with the help of
power electronic devices, to provide fast frequency response. This paper
reviews recent solutions proposed in literature to address the low inertia
problem to improve frequency stability. Additionally, it highlights the
formulation of an optimization problem for VI sizing and placement as well
as techniques applied in solving the optimization problem. Finally, gaps in
literature that require further research were identified.
This is an open access article under the CC BY-SA license.
