Power flow solution in asymmetrical multiconductor systems

The power flow solution of a three-phase network can be more easily computed if the power system is assumed as having a symmetrical structure with balanced loads. In this way, only the single-phase positive sequence circuit can be considered since it is wholly representative of the balanced operation of the electrical system. However, technical literature has investigated general methods to compute power flow solution in asymmetrical/unbalanced situations, since these situations may occur in real networks, especially in the distribution ones. Thus, in this paper the authors provide an iterative algorithm (easily implementable into common PCs) for the study of asymmetrical-structure networks and with unbalanced load scenarios. This calculation approach is different from the classical numerical ones (e.g. Newton-Raphson and derived) and it is characterized by a high solution accuracy and low CPU time, even in ill-conditioned cases. Eventually, real case studies showing the existence of negative, zero sequence currents, and voltages in balanced-load and asymmetrical networks are presented.