AbstractIn power systems economic generation scheduling using a network loss model, it is important to evaluate the loss model coefficients with a high degree of accuracy. The size of the network model depends on the number of generation buses in the network. The loss coefficients are usually evaluated by the method of least squares from a set of load flow results of the system. Two problems are encountered in the evaluation of a large network loss model. The first is that a large number of load flow results will have to be available, a costly proposition. The second is the problem of ill-conditioning.In this paper, these two problems are addressed and remedied. A new method to evaluate the economic dispatch schedules of large power networks is presented. The proposed method uses diakoptical techniques in the evaluation of the network loss model coefficients. A practical power system is used to illustrate the method described in this paper.