<> "The repository administrator has not yet configured an RDF license."^^ . <> . . . "Under-reach correction in twin circuits without residual current input from the parallel line"^^ . "Mutual coupling poses difficult problems witnessed during single phase to earth fault, in transmission line protection. In parallel lines on the same right of way, mutually coupled zero-sequence circuits cause error in the apparent impedance seen by the relay. This causes the distance relay at one end of the faulty line to over-reach while the one at the other end to under-reach. Incorrect sensing of the ground fault due to zero-sequence voltage inversion caused by mutually coupled zero-sequence network may lead to false trip of the neighbouring healthy line. The paper develops characteristic expressions for effective sequence impedances of twin circuit lines and presents a non-iterative microprocessor based algorithm for fault distance and under-reach estimation in real time, for under-reach correction in basic distance relaying scheme. The residual current measurement from the parallel circuit is not required for this purpose. © 2008 IEEE."^^ . "2008" . . "23" . "3" . . "IEEE Transactions on Power Delivery"^^ . . . "08858977" . . . . . . . . . . "R.N."^^ . "Mukerjee"^^ . "R.N. Mukerjee"^^ . . "M.F.B."^^ . "Abdullah"^^ . "M.F.B. Abdullah"^^ . . . . . "HTML Summary of #461 \n\nUnder-reach correction in twin circuits without residual current input from the parallel line\n\n" . "text/html" . .