The Egyptian Electricity Authority strategy for distance relay setting: problems and solutions

This paper presents a study of the problems associated with improper zone s ettings of a distance relay. These problems include the difficulties of adj usting the setting when a short line follows a long line or visa versa, It deals also with setting problems like high fault impedance, in-feed current and load encroachment. A proposed setting algorithm suitable for digital r elays is presented. It helps in improving the dependence and the selectivit y of distance relays. (C) 2000 Elsevier Science S.A. All rights reserved.