Impact of optical current transformer on protection scheme of hybrid transmission line

Continuity of power transmission is important to ensure the reliability electricity supply. As most system faults are temporary, auto reclose (AR) scheme has been used extensively minimise outage duration, prevent widespread outages, thus increase stability. Meanwhile, hybrid line (HTL) combining overhead (OHL) and high voltage cable introduced provide an inexpensive solution for urban grid. Protecting HTL with a conventional protection would forbid operation AR due difficulty whether fault occurred on OHL or section. Therefore, circulating current (CCP) in section location block scheme. The technology optical transformer (OCT) as one non-conventional instrument transformers (NCIT) emerged drawbacks (CCT). Consequently, this paper investigated impact using OCT over CCT CCP HTL. result shows that could be much longer sections its can multiple