Impact of designed line parameters on Distance protection - Investigation on a 110 kV Double Circuit Transmission Line Fault

Measuring the impedances in overhead lines and cables is absolutely essential for ensuring selectivity and accurate fault location by means of distance relays. This paper investigates a double-circuit line fault with nonselective tripping caused by the parameterization of the relay based on inaccurate/lack of knowledge of the line impedances. Analysis of the fault is based on the measured line impedances and the simulation/system-based testing using RelaySimTest. An appropriate procedure was adopted and documented to measure the line impedances of double circuit lines in a minimally invasive manner.