Adaptability of phase selectors based on phase-to-phase superimposed currents when confronting cross-voltage faults in mixed-voltage quadruple-circuit line system

• Published in: IET generation, transmission & distribution transmission & distribution, 2018-07, Vol.12 (13), p.3242-3247
• Main Authors: Zheng, Tao, Zhang, Jiaqin, Wu, Qiong
• Format: Article
• Language: English
• Subjects: confronting cross‐voltage faults; cross‐voltage short‐circuit calculation; fault model; mixed‐voltage quadruple‐circuit line system; mixed‐voltage quadruple‐circuit transmission lines; multicircuit faults; phase selector adaptability; phase‐to‐phase superimposed currents; poles and towers; power transmission faults; power transmission lines; PSCAD; PTPSC; Research Article; single transmission line; tower; voltage level systems
• ISSN: 1751-8687; 1751-8695; 1751-8695
• DOI: 10.1049/iet-gtd.2017.1956

For the mixed-voltage quadruple-circuit transmission lines on the same tower, its special construction form makes the cross-voltage faults, i.e. multi-circuit faults that occur between different voltage level systems, easy to occur. Although the phase selector based on phase-to-phase superimposed currents (PTPSC) shows excellent performance in the single transmission line, it cannot guarantee to identify faulted phases when confronting cross-voltage faults. In this study, the adaptability of phase selectors based on PTPSC is analysed and a new method of phase selection is put forward. First, the PTPSC measured by the relay can be obtained on the basis of cross-voltage short-circuit calculation. Then, the influencing factors and possible selection results are comprehensively analysed, and the corresponding measure has been proposed. Finally, a fault model of mixed-voltage quadruple-circuit transmission lines is constructed in PSCAD and simulation results agree well with the theoretical analysis, verifying the validity of this method.