Linear Load Flow Formulation for Unbalanced Distribution Systems

In this work, a linear model is presented to determine voltages at the nodes and currents in branches of unbalanced distribution networks. An approximate solution for the load flow is obtained from the solution of a system of linear equations, without the need to apply an iterative process as is done in the conventional nonlinear load flow. Numerical studies are carried out using a modified version of the IEEE 34 node test feeder. For the sake of validation, results obtained with the linear model are compared to the results obtained with a conventional nonlinear load flow using the OpenDSS software. Operational indexes are obtained to compare differences regarding power losses and voltages.