Theoretical study of the convergence of the fast decoupled load flow

A theoretical study of Stott´s fast decoupled load flow (DLF) is presented. Convergence conditions for the DLF are obtained. The conditions can be checked by using the data of the network parameters and the calculation from the first iteration. The dependence of the conditions on the line R/X ratio, scheduled power injections, etc. is explained. At each iteration an error estimate of the computed value to the true solution is given. The convergence conditions also guarantee the existence and the uniqueness of load flow solution in a specified region of interest.