An economic scheduling of generation utilizing the concept of economic decommitment

A method is presented for determining a generating schedule appropriate for use in long-range power system planning applications. The execution of loadflow studies involving a proposed future power system requires the determination of a generation schedule which models the manner in which the system will actually be operated. The proposed technique employs the concept of an equivalent generator to represent the fuel cost characteristics of the system by means of a second order polynomial equation. This solution approach is modified by the incorporation of a new economic decommitment theory which determines the proper combination of generating units to be scheduled. The proposed scheduling technique was programmed for use on an IBM 370 model 158 computer, and was applied to a sample power system. The sample study required approximately 60 kilobytes of computer storage and 1.21 seconds of central processor time. The resulting schedule for the sample system was compared to a schedule which was obtained using more conventional scheduling techniques. The comparison shows that the incorporation of the new economic decommitment concept with an equivalent generator scheduling approach results in a generating unit schedule representing a reasonable balance between the degree of accuracy obtained and the cost of computation.