Sparse Computation of Power System Fault Impedance Matrices

This paper presents a contribution that enhances the efficiency of sparsity techniques for solving some problems in large-scale power systems. Alterations are introduced on storage schemes and node ordering to lead to a reduction of the computation time and space memory. The fast sparse vector approach (FSV) is presented and implemented in a short circuit program to compute fault currents and fault bus voltages. It is based on a formulation that computes only the required column of the Z impedance matrix (or some elements of the column) for any particular type of fault. The tests carried out on several power systems ranging from the IEEE 30 bus to a 1084 bus test system show that the proposed approach gives an important reduction of computation time.