  This paper studied the solar PV frequency control in the U.S. Eastern
Interconnection (EI) and Texas Interconnection (ERCOT) systems. The studied
frequency control approaches include droop frequency control, inertia control,
and droop-inertia-combined frequency control. The control effects of different
frequency controls of PV in the EI and ERCOT are studied using actual high PV
penetration interconnection grid models to provide suggestions to the future
revision of future PV frequency control standards.
