A novel distance protection scheme using single-ended transient voltage based on generalized S transform

Concerning the distance protection steady-state over-reach or under-reach caused by the transition resistance, a novel distance protection scheme based on transient information is proposed. First, multiple fault features are extracted using the Generalized Stockwell Transform (GST), and a criterion for identifying low-resistance and high-resistance ground faults is constructed. Then, a GST coefficient matrix is established for the single-ended transient voltage of the line, the attenuation coefficient and delay coefficient are derived by the least-squares method and the beat phenomenon, and the transition resistance is calculated. On this basis, adjust the operation boundary in the +R axis direction of the operation zone according to the transition resistance value. Finally, test results on real-time digital simulation system (RTDS) demonstrate that the protection scheme operates reliably in different fault cases and is highly immune to fault resistance. Compared with the traditional distance protection scheme, this scheme performs better when the transition resistance is large.