JEE_V3_N2_RP4 Ganesh Vulasala Sivanagaraju Sirigiri Journal on Electrical Engineering 2230 – 7176 3 2 26 39 Distribution Systems, Unbalanced Three-phase Load Flow, Distributed Load Models, Transformers, Voltage Regulator This paper presents a simple method of three phase power flow algorithm for application to unbalanced radial distribution systems (URDS) with inclusion of voltage regulators and transformer modeling. Distribution systems are usually unbalanced due to unbalanced loading at the different phases. In this paper forward - backward propagation algorithm is used to calculate branch currents and node voltages at each node. The proposed method has been tested to analyze several distribution networks. The application of this method is also extended to find optimum location for reactive power compensation and network reconfiguration for planning and day-to-day operation of distribution networks. The proposed method exactly finds out the critical lines as that of the conventional method. The effectiveness of the proposed method was successfully applied to 19 bus and 25 bus unbalanced radial test systems. October - December 2009 Copyright © 2009 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=1046