"Fault analysis in electric networks having a plurality of multi-phase buses"

Fault analysis for an electric network having a plurality of multi-phase buses is performed by computing equivalent circuits for the multi-phase buses of interest. Each equivalent circuit includes an NxN impedance matrix, N corresponding to the number of phases of the multi-phase bus for which that equivalent circuit is computed. Elements of the impedance matrices are determined based on voltages resulting from a plurality of experimental current injection vectors and a factorized pre-fault admittance matrix. The pre-fault admittance matrix represents nodal admittance of the multi-phase buses without faults. A fault current injection vector for each multi-phase bus and fault type of interest is determined based on the equivalent circuit determined for that multi-phase bus. A fault voltage vector for each multi-phase bus and fault type of interest is determined based on the factorized pre-fault admittance matrix and the fault current injection vector determined for that multi-phase bus and fault type.