Distributed power flow calculation for whole networks including transmission and distribution

Traditionally, transmission and distribution power flows are studied separately. But lots of large cities have their hybrid transmission and distribution networks. In order to achieve a global unified power flow solution, transmission and distribution networks are studied as a whole in this paper. Global power flow (GPF) equation is built as a mathematical model for the global power system. Based upon the master-slave-typed feature of the global power system, a master-slave-splitting (MSS) iterative method is developed for balancing the boundary mismatch between the transmission and distribution networks. In this method, the GPF problem of large scale is split into a transmission power flow and lots of distribution power flow sub- problems, which supports on-line geographically distributed computation. In order to fit the different features between transmission and distribution networks, each sub-problem can be solved with different algorithms. Several case studies are carried out, and accuracy, efficiency and reliability of the proposed method are verified.