Determination of the optimal PID control law for RPM of hydroelectric power plant units

This article examines the solutions and the typical mistakes in solving the problem that became evident during the blackout of the Georgia’s power system on July 27, 2014. One of the problems turned out to be the inability of hydroelectric power plants (HPP) connected to the grid to operate autonomously and ensure energy consumption for their own needs and for priority consumers. The main problem was that, in order to restore the disconnected part of the power system from a zero state, these HPPs did not have at least one unit capable of quickly starting up after receiving the corresponding instruction from the dispatching licensee. This unit was needed to connect to the grid and provide the reference frequency and voltage for synchronizing the units of the stopped HPPs, all in the absence of voltage in the grid. Undoubtedly, the fulfillment of all these requirements depends on the control systems of the units, in particular, on the quality of the control of the RPM of the units.