SENSITIVITY OF THE RESERVE CAPACITY FOR FORCED OUTAGES

The determination of the power needed to be installed within an electric power system can be done by a proper estimation of the reserve capacity for forced outages optimum level by means of probabilistic statistical methods. This level depends mainly on the following parameters : the forced outage rates (FOR) of the generating units, the capital costs of the new plants, the fuel prices and the unserved energy cost. Considering the evolution of these parameters in time, the paper determines the maximum probability interval into which the optimum reserve capacity for forced outages and implicitly the related system reliability level will be placed when the above parameters are varying.within foreseenable inter vals for the period under study. It has been found that the optimum levels of the reserve capacity for forced outages and of the reliability are greatly influenced by the forced outage rates of the generating units.But, if the rest of parameters are varying within a sufficiently large range the optimum values of the percentual reserve capacity for forced outages and of the system reliability remain within a restricted interval of maximum probability.While , within this interval the electric power system development and operation costs are the minimum ones, the overexpansion and especially the underexpansion of the electric power system would be harmful for the national economy.