Comparative Experiences with Static and Numerical Protections in Extra High Voltage Lines

This work illustrates the results obtained of a comparative statistic appeared from year 2002 to 2005 with respect to the reliability, selectivity and the operation time parameters between distance static protection relay type LZ96 and the numerical protection relay type REL 316*4 installed in the lines terminals of CVG EDELCA 765 kV transmission system. The characteristics previously evaluated altogether are known as equipment performance. The investigation determined that the distance function of REL 316*4 numerical protection relay has displayed a similar performance respect to the LZ96 static distance protection in the evaluated period, considering it satisfactory. This information improves our expertise and provides a valuable data base to us for future evaluations related to replacements, acquisitions and in general to the decision making referring for future protections systems