The optimization in the operation of distribution electric systems has become an acute problem. In order to evaluate some essential criteria (e.g., active power losses) the computation of power flow is absolutely necessary. Taking into account the real operating conditions (unbalance, harmonics) it is of great interest for accurate steady state estimation. The existent solutions proposed in literature are complex and it is difficult to implement them in unbalanced and harmonic polluted systems. By the original adaptation of the backward/forward sweep algorithm, the authors propose a novel paradigm to analyze the propagation of asymmetries and harmonic distortions through radial electric networks.