Cross Country Fault Detection Algorithm for Transmission Line Protection

This paper designed a method using Stockwell transform (ST), Wigner distribution function (WDF) and alienation coefficient to detect the cross country faults incident on single circuit power transmission line (PTL). Currents are processed using ST and cross country Stockwell fault index (CSFI) is computed. These current signals are processed to compute cross country Wigner fault index (CWFI). Alienation coefficient is used to process current signals for computing cross country alienation fault index (CAFI). SFI, CWFI and CAFI are multiplied with a cross country weight factor (CWF) to compute cross country hybrid fault index (CHFI). This is established that proposed method effectively detects the different types of cross country faults incident on PTL. Proposed CHFI is effective to detect cross country faults with variations in the fault incidence angle and fault impedance. Performance of designed method is better relative to the artificial neural network (ANN) based technique for detection of cross country faults.