A system for dispatching and controlling generation in an electric power system consisting of a plurality of power units comprises a computer with dispatching optimization module connected by communications means to the power units. According to the invention, in the electric power system consisting of a plurality of subsystems each comprising a plurality of power plants provided with power units, said computer is a higher-layer computer and the specified load dispatching optimization module is designed to determine parameters for an optimal interchange of power and energy between subsystems. The inventive controlling system further comprises a plurality of computers according to a number of subsystems, said computers being lower-layer computers each comprising a specified subsystem dispatching optimization module designed to determine parameters for an optimal allocation of generation between power plants within a subsystem, and a unit for computation of functional characteristics for each subsystem, wherein each lower-layer computer is connected by lower-layer communications means to respective power plants of respective subsystems. The inventive controlling system also comprises higher-layer communications means, wherein the lower-layer computers are connected to a higher-layer computer via the higher-layer communications means.