First-zone performance assessment of a symmetrical component based improved fault impedance estimation method

Abstract

This paper describes the first-zone performance assessment of a symmetrical component based fault impedance estimation method that has previously been proposed by the authors. The performance equation of the proposed method is briefly reviewed and various performance assessment techniques are also discussed. The Alternative Transient Program, which is available on personal computers, was used in these performance assessment studies. This Program was used to model a power system and to simulate many fault conditions on a selected transmission line. Fault data thus obtained were used in calculating the fault impedance using the proposed method. Fault impedance estimates were inserted in R-X plane characteristics to determine the suitability of the proposed method for first-zone digital protection. The results of these performance assessment studies are presented and discussed in the paper. © 1993.