Branch-and-bound scheduling for thermal generating units

A branch-and-bound method for scheduling thermal generating units is presented. The decision variables are the start and stop times and the generation levels of the units. A simple rule is defined to compute the lower bound of each candidate schedule for interim computation usage, and the branching process takes place on the subschedule with the lowest lower bound. The heap data storage structure and space saving encoded data representations for partially fulfilled unit commitment schedules are utilized to facilitate the branch-and-bound procedure. By successive branching and bounding, the unit commitment schedule with the minimum cost can be obtained. Two examples, a 10 unit, 24 h and a 20 unit, 36 h case, are shown to illustrate the effectiveness of the proposed algorithm