Fault Diagnosis Scheme for Cross-Country Faults in Dual-Circuit Line With Emphasis on High-Impedance Fault Syndrome

Abstract

In a power system network, transmission lines are exposed to atypical fault scenarios. The transmission line is the longest component in a power system and sometimes it passes through forest areas where the occurrence of cross-country faults (CCFs) associated with high-impedance fault (HIF) syndrome is more due to thunderstorms, cyclones, and poor vegetation management/tree trimming. Detection and classification of CCFs which are associated with HIF syndrome is the most challenging task. In this article, maximal overlap discrete wavelet packet transform (MODWPT) has been employed to extract the characteristics of the signals during CCF with HIF syndrome which are more complex and aperiodic/asymmetric/nonlinear. Thereafter, maximum change in wavelet packet energy of MODWPT coefficients of currents/voltages have been deliberated as unique features to design proposed fault diagnosis scheme for a dual-circuit transmission line. The efficacy of the proposed scheme has been investigated on the Chhattisgarh State Power Transmission Network. The proposed scheme is appraised with exclusive case studies such as switching of capacitor bank, switching of reactor string, switching of load/feeder, effect of power swing, nonlinear loads, lightly loading conditions, and measurement noise. The proposed scheme has been also validated on standard IEEE 13 bus distribution system with nonlinear loads to confirm its adaptability.