PHASE SELECTION BASED ON SUPERIMPOSED COMPONENTS

A method is described for faulted phase selection for non-unit-distanc e protection using the superimposed voltages and currents initiated by faults. Even though superimposed voltages and currents are comprised of many incident and reflected waves it is shown for the first time th at the criteria used for phase selection remain valid throughout the f ault period. The proposed method is hence very powerful. To demonstrat e the potential of the scheme, its response to a number of fault condi tions is presented.