A DYNAMIC PROGRAMMING APPROACH FOR DETERMINING THE OPTIMAL DISPATCHING SEQUENCE FOR A COMBINED HYDRO—THERMAL—PUMPED-STORAGE UTILITY SYSTEM

摘要

The optimal dispatching of the various types of gener¬ating units in order to minimize the weekly system operating cost is an important utility planning problem. A simplified problem, which considers the use of five coal-fired fossil plants, three gas turbine peaking units, a pumped-storage hydroelectric unit, and a conventional hydroelectric unit has been formulated. Several constraints specifying the spinning-reserve requirements for the system, minimum shutdown time for coal-fired units, and reservoir limits and operating efficiencies of the hydroelectric units were included to reflect actual utility operation. A deterministic weekly load forecast was used. The effects of interchange with neighboring systems and transmission losses were not considered.nThe optimal operating sequence for the various gener¬ating sources was determined by using a dynamic programming algorithm that employs a successive approximations technique and treats all types of units in a consistent manner. Two sample problems were run. In the first problem, the pumped-storage unit was limited to peak shaving duty;in the second problem, this restriction was relaxed.