Generator Inertia Constant

Units:	s
Mode:	Input Only
Multi-band:	False
Default Value:	0
Validation Rule:	≥0
Key Property:	No
Description:	Stored energy per unit of capacity
Detail:

Generator Inertia Constant represents how much stored energy the generator has per unit of capacity. This means the inertia constant represents how long the generator could generate at its rated power using only its stored rotational kinetic energy, so the inertia constant is measured in units of seconds. A 1-GW generator with an inertia constant of 4 seconds could deliver 1 GW of power for 4 seconds (or has 4 GW⋅s of stored energy). Typical power plants have inertia constants in the range of 2 to 7 seconds, with hydro plants having the lowest inertia, and gas plants having the highest inertia per unit of capacity.

The Inertia Constant must be defined for a generator to provide inertia to a Reserve of Type = "Inertia". The generator provides inertia whenever it is operating, which includes generating, pumping (for pumped storage) or when operating as a synchronous condenser (see Sync Cond Units). The total amount of inertia available is thus equal to:

Inertia (MW⋅s) = Inertia Constant (s) × Max Capacity (MW) × ( Units Generating + Units Pumping + Units Sync Cond )