POWER-GENERATION SCHEDULING FOR MULTIAREA HYDROTHERMAL SYSTEMS WITH TIE LINE CONSTRAINTS, CASCADED RESERVOIRS AND UNCERTAIN DATA

This paper proposes a new approach to solve the short-term generation scheduling of large-scale hydro-thermal power systems(GSHT). The objec tive of GSHT is to minimize the total operation cost of thermal units over the scheduling time horizon. In order to solve the problem within a reasonable time, the problem is decomposed into thermal and hydro s ubproblems. The coordinator between these subproblems is the system La grange multiplier. For the thermal subproblem, in a multi-area power p ool, it is necessary to coordinate the area generations for reducing t he operation cost without violating tie limits. A probabilistic method is employed in considering load forecasting errors and forced outages of generating units to satisfy system reliability requirements. For t he hydro subsystem, network flow concepts axe adopted to coordinate wa ter usage over the entire study time span and the reduced gradient met hod is used to overcome the linear characteristic of the network flow method in order to obtain the optimal solution. Three case studies for the proposed method axe presented.