Power systems economic dispatch by a rearranged active-reactive power loss model

In this paper, the economic dispatch conditions of a power system are evaluated using a rearranged active-reactive power loss model. The active-reactive power loss model is divided into two separate submodels. In this formulation, the network total active and reactive power losses are expressed in terms of the active and reactive powers of the generation buses. The network purely reactive sources are modeled in terms of the total reactive load demand. The advantages gained by this separation are discussed in this paper. The parameters of the network submodels are estimated by least squares with a high degree of accuracy from a set of load flow results. Based on the above submodels, the constrained fuel cost function is then minimized to obtain the economic dispatch solutions of the power system under consideration. Results are presented for a standard IEEE test system for a wide range of system load levels. The results obtained by the proposed method are also compared to the economic dispatch solutions based on the active power loss model.