Adaptive Distance Protection Scheme for High Resistance Phase to Phase Faults on Double-Circuit Transmission Line

In the context of smart grid, is desired a safe and correct functionality of the relay protection, by rapid fault isolation and ensure continuous supply of electricity to consumers. Implementing smarter protection as adaptive protection is one way of tackling some of the performance issues. The variable nature of the fault resistance in certain situations influence the distance protection, even if the distance protection, through polygon feature, allows sufficient arc reserve. To ensure proper functionality of the distance protection of double circuit lines, in the case of two phase faults with high resistance fault, the paper proposes an impedance correction algorithm, in order to compensate the influence of the reactance effect. Considering the measured currents and voltages from the local distance protection, the deviation vector is calculated and used for changing the position of the fault impedance in the R-X plane. As a result, the fast tripping command is initiated for faults with high resistance in the zone 1 or blocked for faults in the zone 2.