This paper presents a simple three phase power flow method for solution of three-phase unbalanced radial distribution system (RDN) with voltage dependent loads. It solves a simple algebraic recursive expression of voltage magnitude, and all the data are stored in vector form. The algorithm uses basic principles of circuit theory and can be easily understood. Mutual coupling between the phases has been included in the mathematical model. The proposed algorithm has been tested with several unbalanced radial distribution networks and the results are presented in the article. 8- bus and IEEE 13 bus unbalanced radial distribution system results are in agreements with the literature and show that the proposed model is valid and reliable., {"references":["D. Das, D. P. Kothari, and A. Kalam, 1995. Simple and efficient\nmethod for load flow solution of radial distribution networks,\nElectrical Power and Energy Systems, 17(5):335-346.","S. Ghosh, D. Das, 1999. Method for load flow solution of radial\ndistribution networks, IEE Proc. Generation, Transmission and\nDistribution, 146(6):641-648.","P. Aravindhababu, 2003. A new fast decoupled power flow method\nfor distribution systems, Electric Power Components and Systems,\n31(9):869-878.","R. D. Zimmerman and H. D. Chiang, 1995. Fast decoupled power\nflow for unbalanced radial distribution systems, IEEE-PES Winter\nMeeting, paper no. 95, New York.","S. K. Goswami and S. K. Basu, 1991. Direct solution of distribution\nsystems, IEE Proc. C, 188(1):78-88.","D. Thukaram, H. M. Wijekoon Banda, and J. Jerome, 1999. A Robust\nthree phase power flow algorithm for radial distribution systems,\nElectric Power System Research, 50(3):227-236.","W. M. Lin, Y. S. Su, H. C. Chin, and J. H. Teng, 1999. Three-Phase\nunbalanced distribution power flow solutions with minimum data\npreparation, IEEE Trans. on Power Systems, 14(3):1178-1183.","P. A. N. Garcia, J. L. R. Pereira, S. Carnerio, V. M. da Costa, and N.\nMartins, 2000. Three-Phase power flow calculations using the current\ninjection method, IEEE Trans. on Power Systems , 15( 2):508-514.","P. A. N. Garcia, J. L. R. Pereira, and S. Carneiro, Jr., 2001. Voltage\ncontrol devices models for distribution power flow analysis, IEEE\nTrans. Power Syst., 16(4):586-594.\n[10] P. A. N. Garcia, J. L. R. Pereira, and S. Carneiro, Jr., 2004.\nImprovements in the representation of PV buses on three-phase\ndistribution power flow, IEEE Trans. Power Del., 19(2):894-896.\n[11] K. N. Mui and H. D. Chiang, 2000. Existence, uniqueness and\nmonotonic properties of the feasible power flow solution for radial\nthree phase distribution networks, IEEE Trans. Circuit and Syst.,\n47(10):1502-1514.\n[12] W. M. Lin and J. H. Teng, 2000. Three-Phase distribution networks\nfast decoupled power flow solutions, Electric Power and Energy\nSystems, 22(5):375-380.\n[13] T. H. Chen, M. S. Chen, K. J. Hwang, P. Kotas, and E. A. Chebli,\n1991. Distribution system power flow analysis-a rigid approach,\nIEEE Trans. on Power Delivery, 6(3):1146-1153.\n[14] J. H. Teng, 2002. A Modified gauss-seidel algorithm of three-phase\npower flow analysis in distribution network, Electrical Power and\nEnergy Systems, 24(2):97-102.\n[15] J. H. Teng, 2000. A Network-Topology-based Three-Phase Load\nPower Flow for Distribution Systems, Proceedings of National\nScience Council ROC (A), 24(4):259-264.\n[16] L. L. Grgsby: Editor-in-Chief, The Electric Power Engineering\nHandbook, CRC Press 1999, pages 6-53 to 6-62.\n[17] W. H. Kersting, Distribution System Modeling and Analysis, CRC\nPress 2002, chapter 9.\n[18] J. Nagarath and D. P. Kothari, Power system Engineering, New\nDelhi: Tata McGraw Hill Publications, 2nd edition, 1998.\n[19] D. Shirmohammadi and Carol S. Cheng, 1995. A Three phase power\nflow method for real time distribution system analysis, IEEE Trans.\non Power System, 10(2):671-679.\n[20] IEEE Distribution System Analysis Subcommittee, 1991. Radial\ndistribution test feeders, IEEE Trans. on Power Systems, 6(3):975-\n985.\n[21] Radial Distribution test feeders -\nweb:http://www.ewh.ieee.org/soc/pes/dsacom/testfeeders.html."]}