Protection challenges are common issues in low-voltage direct current systems

particularly in scenarios involving high-impedance faults and arc faults. These faults may escalate into flashovers

accompanied by current distortion

thereby causing severe damage to equipment. To address these issues

this paper proposes a backup protection scheme based on the discrete wavelet transform to reliably detect and classify such faults in distribution lines. Distinguishing fault conditions from resistive load is challenging due to their similar current magnitudes

the proposed method introduces a technique for square pulse injection into the power lines. This active approach effectively differentiates these cases

thereby preventing erroneous tripping. The proposed standalone approach can be easily integrated into existing intelligent electronic devices to enhance conventional current-based protection methods. The algorithm generates binary signals representing the magnitude of current waveform distortion at both positive and negative poles. By analyzing these signals through decoders

the system state is accurately identified

triggering protective actions as necessary. This ensures robust protection and continuous power delivery despite challenging fault conditions.