A robust unit commitment and optimal dispatch for hydro-thermal plants

A Genetic Algorithm is applied to the problem of unit commitment and determining the optimal hourly schedule of power generation in a hydro-thermal power system. A multi reservoir cascaded hydro-electric system with a non-linear relationship between water discharge rate, net head and power generation is considered. The water transport delay between connected reservoirs is also taken into account. In order to deal effectively with the constraints of the problem and prune the search space of the GA in advance, the difficult minimum up/down time constraints of thermal generation units are embedded in the binary strings that are coded to represent the ON/OFF status of the generating units. The refined genetic algorithm is used to solve the economic dispatch problem. The proposed approach is applied to a sample system consisting of four hydro units and five thermal units. The simulation results reveal that the features of easy implementation, convergence within an acceptable execution time and optimal solution in solving the hydro-thermal scheduling problem can be achieved.