Impedance-based methods for detection of voltage sag sources

Abstract

The research reflects impedance-based methods for detection of voltage sag sources, whereas measured voltages and currents are treated as average functions, and also as instantaneous values. Evaluation of the discussed methods has been performed by applying extensive numerical simulations and field testing. The obtained results show that all methods are very effective in the cases of symmetrical voltage sags. When instantaneous values are applied the best effectiveness is obtained also for asymmetrical voltage sags.