Research Of Extinguishing Secondary Arc Current Method In UHV Parallel Lines

Ultra-High-Voltage(UHV) double-circuit parallel lines could use the neutral reactor of single line compensating model, the neutral reactor of double lines compensating model and High-Speed-Grounding-Switch (HSGS) to extinguish secondary arc of single-phase to ground and cross-country transient faults. In this paper, the effect of these three methods of decreasing secondary arc current and recovery voltage has been analyzed. By formula and EMTDC simulation, correspondingly, the optimal compensating schemes, and a particular analysis of HSGS are provided. Adding a resistance in the neutral of the shunt reactors is useful for decreasing maximum peak of recovery voltage and rate of rise of recovery voltage of single-phase to ground and cross-country transient faults. The neutral reactor of double lines compensating model in the maintenance state could be optimized by three methods, which could be used to keep separated of the two circuits and extinguish the secondary arc effectively. The characteristics of secondary arc current and recovery voltage when HSGS is used are analyzed, in which, the single end closed and other key influence factors are also analyzed. In this paper, the line length, loading, transposition degree, secondary arc resistance, and other factors which influence these three methods are also discussed.