Performance comparison of symmetrical component based fault impedance estimation methods for digital distance relay applications

This paper reviews performance equations of two fault impedance estimation methods that are based on the symmetrical component theory. A comparative study to evaluate computational aspects of these two methods was performed. Findings of this study are reported in this paper. Assessment of various performance assessment methods is also discussed in the paper and the chosen method is used for performance comparison of the symmetrical component based fault impedance estimation methods. Relaying application for digital distance protection is proposed that uses a method described in the paper. Some results of these studies are also reported in the paper.