Use of the Flexibility Characteristics of Hydroelectric Power Plants and Pumped-Storage Power Plants in a Power System with Renewable Energy Sources

Consideration is given to the possibilities of using the flexibility characteristics of hydroelectric power plants (HPP) and pumped-storage power plants (PSPP) and their reservoirs for the storage and distribution of energy and the improvement of the operational reliability of the electric power system (EPS). This is especially important nowadays, when the share of wind (WPP) and solar (SPP) power plants is increasing. The curves of equipment parameters, flow and wind conditions, and reservoir storages are analyzed using the HPP-WPP and PSPP-WPP power-generating complexes as examples. The mechanism of water flow redistribution by regulating the power output of HPP and PSPP so that the reservoir is an energy accumulator is shown.