A Direct Method Based on Incidence Matrix for Unbalanced Three-phase Distributed Network

Different from the transmission network with transposition, a distribution system usually can not be considered as a balanced network, let alone the given branch may be single or two-phase rather than three phases. This paper presents a direct power flow method for unbalanced three-phase distribution systems. A set of index matrices for multi-phase is introduced to indicate each bus and branch, simplifying the initialization of the unbalanced network treatment. Also, no extra modification is needed for meshed and radial networks. Results of tests and comparisons with 13-bus meshed and radial systems illustrate the performance of the proposed method.