Modeling issues on load flow calculation for meshed distribution systems

Load flow solution is required for determining a steady-state condition of electric power systems for various load demands. This motivated the development of several methods for load flow calculation in transmission and distribution systems. However, there are some scenarios of meshed operation in distribution systems that pose additional challenges for the direct application of load flow calculation methods. This paper reports a detailed study of these scenarios, some without a detailed analysis in the literature, highlighting the modeling issues of each one to perform a load flow calculation in meshed distribution systems. The paper also proposes some alternatives to overcome these modeling issues, which are related to the substation model and the reference bus of the network. To illustrate the main theoretical conclusions, computational simulations based on real distribution feeders from a Brazilian utility are presented and analyzed.