Robust Distributed Model Predictive Load Frequency Control of Interconnected Power System

Table 1

Variables and parameters used in thermal and hydro power plant.

Parameter/variable	Description	Unit
Δ𝑓(𝑡)	Frequency deviation	Hz
Δ𝑃𝑔(𝑡)	Generator output power deviation	p.u.MW
Δ𝑋𝑔(𝑡)	Governor valve position deviation	p.u.
Δ𝑃𝑟(𝑡)	Reheater output deviation	p.u.
Δ𝑋𝑔ℎ(𝑡)	Governor valve servomotor position deviation	p.u.
Δ𝑃tie(𝑡)	Tie-line active power deviation	p.u.MW
Δ𝑃𝑑(𝑡)	Load disturbance	p.u.MW
Δ𝛿(𝑡)	Rotor angle deviation	rad
𝐾𝑃	Power system gain	Hz/p.u.MW
𝐾𝑟	Reheater gain	p.u.
𝑇𝑃	Power system time constant	s
𝑇𝑊	Water starting time	s
𝑇1,𝑇2,𝑇𝑅	Hydrogovernor time constants	s
𝑇𝐺	Thermal governor time constant	s
𝑇𝑇	Turbine time constant	s
𝑇𝑟	Reheater time constant	s
𝑇𝑠	Interconnection gain between CAs	p.u.MW
𝐵	Frequency bias factor	p.u.MW/Hz
𝑅	Speed droop due to governor action	Hz/p.u.MW
ACE	Area control error	p.u.MW