On-site experience of an adaptive autoreclose relay for HV overhead lines

In power sysem protection autoreclose schemes, the ability to adapt the dead time allows the mean time to reclosure to be reduced whilst allowing a greater number of successful reclosures. In this respect, adaptive single pole autoreclose (ADSPAR) offers many advantages such as increased rate of successful reclosure, improved stability and a reduction in system and equipment shock for a permanent fault. This paper describes how the ADSPAR technique exhibits clear benefits over conventional SPAR only techniques. The possibility of adapting SPAR introduces a range of new possibilities. It is useful to redefine the ideal response to transmission line faults and thus examine the priorities of electric utilities. Comparisons are made with conventional single shot schemes; however the advantages of inclusion of ADSPAR into a two- or multi-shot scheme is clear.