Sparse and numerically stable implementation of a distribution system state estimation based on Multifrontal QR factorization

Abstract Enhancing situational awareness of distribution networks is a requirement of Smart Grids. In order to fulfill this requirement, specialized algorithms have been developed to perform Distribution System State Estimation (DSSE). Due to the particularities of such networks, those algorithms often rely on simplifications and approximations of the measurement model which make difficult to generalize their results. This paper presents a sparse and numerically stable implementation of an algorithm for DSSE, which does not require any additional assumption from the traditional state estimation formulation. The numerical stability is guaranteed by using Multifrontal QR factorization and an optimal ordering technique is evaluated to reduce fill-in. Simulation results are carried out with IEEE three-phase unbalanced test feeders to evaluate the algorithm.