الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
. Nature of Unit Comnlitmenffroblem The variation of the load demand durirg a time period of a day or several Jays is a major problem in the operation of thepowersystem.Thenonstorablenature .of electrical energy calls forpermanentadjustment of production to consumption,sinceconsumptionvariesconstantlythroughaday. Any utility shouldforecast thesevariations and each day draw up a schedule for its production facilities for the next day. Theideatocommitenough units to, cover the maximum system load and leave them on line is one of the economics. This is because to commit a unit is to bring the unit up to speed, synchronize it to the system anconnect it so that it can deliver power to the network and hence, it is quiteexpensive to run too many generating writswhenthey are not needed’. A great deal ofmoney can be saved by turning some of the units off (decommitingthem)whentheyarenotneeded.So,theobjective of unit commitment is toeconomicallyscheduleavailablegenerating units on an hourly basis over a study periodofuptoseveraldays.Costscomefromstarting up, shutting down generatingunits and from dispatching them. Thetotalcost over the study period is tobeminimized. 1.2 ConstraintsinUnitCOInmitmen.tlllffi From previoussection one can conclude that the problemcanbesuccessfullysolved by the commitment of the most economic generating units with (i.e combination of some of generating units withminimum cost) to meet the load demand. Although this is the prime goal to beachievedbut unfortunately, other