Current differential relay characteristic for bipolar HVDC transmission line fault detection. Issue 23 (21st October 2020)

• Record Type: Journal Article
• Authors: Saber, Ahmed; Zeineldin, Hatem; El‐Fouly, Tarek; Al‐Durra, Ahmed
• Is Part Of: IET generation, transmission & distribution. Volume 14:Issue 23(2020)
• Page Start: 5505
• Page End: 5513
• Publication Date: 2020-10-21
• Subjects: fault diagnosis -- power transformer protection -- wavelet transforms -- power transmission lines -- relay protection -- HVDC power transmission -- fault location -- power transmission faults -- power transmission protection; bipolar HVDC system -- internal faults -- external faults -- current differential relay characteristic -- different fault resistances up to 1000 Ω -- different fault locations -- internal HVDC line faults -- protection scheme -- bipolar HVDC transmission lines fault detection -- bipolar HVDC transmission line fault detection -- high voltage direct current -- timely manner both internal -- conventional differential protection characteristic -- nuisance fault detection -- sampling currents -- current signals -- current differential scheme; Electric power production -- Periodicals; Electric power transmission -- Periodicals; Electric power distribution -- Periodicals; 621.3105
• DOI: 10.1049/iet-gtd.2020.0556
• Languages: English
• ISSNs: 1751-8687

Abstract

Abstract : This study proposes a new differential relay characteristic to detect internal faults on bipolar HVDC (high voltage direct current) transmission lines and discriminate accurately and in a timely manner both internal and external faults. In comparison with the conventional differential protection characteristic, the proposed relay characteristic avoids the need for an intentional time delay typically required to avoid nuisance fault detection. The sampling currents of the positive and negative poles are obtained from both line ends, and the noise is eliminated from the current signals using a stationary wavelet transform. Initially, a startup unit is utilised to activate the proposed protection scheme. The proposed current differential scheme adopts a biasing technique, which is based on the inherent transient behaviour of the bipolar HVDC system during both external and internal faults. The HVDC transmission line is implemented on the PSCAD/EMTDC platform utilising the frequency‐dependent phase model, and it is tested considering numerous internal and external faults. Finally, the proposed current differential relay characteristic is tested considering different fault resistances up to 1000 Ω as well as different fault locations, including internal HVDC line faults and external faults at both rectifier and inverter sides. The obtained results confirm the robustness of the proposed protection scheme for bipolar HVDC transmission lines fault detection.