PERFORMANCE OF HIGH-SPEED DISTANCE RELAYS WITH PARTICULAR REFERENCE TO TRAVELING-WAVE EFFECTS

Traveling waves on env transmission lines often cause considerable distortion of relaying measurands. Modern methods of digital simulation are used to examine the performance of crosspolarized mho relays under more realistic conditions than have been possible in the past, using conventional conjunctive test methods. It is shown that traveling-wave effects can cause a significant delay in the fault-detection process and that, in this respect, the bandwidth of the voltage transformers is an important influencing factor. The block-average comparator arrangement is examined. It is shown that a recently developed processing technique can provide faster fault-clearance times when coupled with a small degree of overreach. The performance of the block-average comparator mho relay in a long-line application is considered.