Open AccessCurrent differential relay characteristic for bipolar HVDC transmission line fault detection
Author(s) -
Saber Ahmed,
Zeineldin Hatem,
ElFouly Tarek,
AlDurra Ahmed
Publication year - 2020
Publication title -
iet generation, transmission and distribution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 110
eISSN - 1751-8695
pISSN - 1751-8687
DOI - 10.1049/iet-gtd.2020.0556
Subject(s) - relay , transmission line , fault (geology) , protective relay , electric power transmission , control theory (sociology) , transient (computer programming) , inverter , high voltage direct current , fault detection and isolation , engineering , electronic engineering , computer science , voltage , direct current , electrical engineering , physics , power (physics) , control (management) , quantum mechanics , artificial intelligence , seismology , geology , actuator , operating system
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.