Directional protection scheme using impedance approach for transmission lines

Area of Science:

• Electrical Engineering
• Power Systems Protection

Background:

• Accurate fault direction identification is critical for transmission line protective schemes.
• Existing methods face challenges with high resistance, noise, and system variations.

Purpose of the Study:

• To develop and validate a new directional protection technique for transmission lines.
• To assess the proposed scheme's performance under diverse fault scenarios.

Main Methods:

• Utilizing instantaneous positive sequence voltage and current components.
• Calculating the impedance matrix (Z matrix) for fault direction determination.
• Employing ATP-EMTP software for simulation and verification.

Main Results:

• The proposed positive impedance approach successfully determines fault direction.
• The scheme demonstrates robustness against high fault resistance, far-end faults, and cross-country faults.
• Performance remains reliable despite power flow changes, single pole tripping, CT saturation, and noise.

Conclusions:

• The presented directional protection technique is feasible and accurate.
• The method offers a reliable solution for transmission line protection, outperforming existing schemes in various challenging conditions.