Demand Control of Two-Position Process Ensembles of Finite Magnitude

The control by computer of the electrical demand due to two-position process ensembles of finite magnitude is discussed. The purpose of the computer control is, first, to minimize the total kW demand upon the generating equipment and, second, to maximize the generating plant utilization, as defined by the load factor (average load/maximum load). Where these two requirements conflict, the former is to take precedence. A mathematical analysis is given for a computer strategy where the incidence of the individual loads is symmetrically staggered to minimize the maximum demand. The number of processes to be controlled is in the range of 2¿10, where the incidence of individual loads may be precisely defined, thus eliminating statistical considerations. In order to keep the analysis perfectly general, certain constraints have to be applied which in many cases are justifiable and realistic, although some plants have special requirements dictated by the process which require individual treatment. The constraints imposed are detailed within the text.