Faulty line selection for single-phase ground short circuits
in non-direct earth neutral systems based on fourier algorithm

HUANG Qi-xin, YANG Zheng-li, LU Zhu-wei

                                          (Mechanical and Electrical Engineering School, Sanjiang University, Nanjing 210012, China)

Abstract: Aiming at the shortages of maximizing D(I sin ψ) which required an intermediate referenced sine signal decreasing the algorithm’s reliability and its computation process became more complicated, Fourier algorithm based-on maximizing D(I sin ψ) principle was proposed in this paper, which was applied to neutral non-direct earth neutral systems as an example for analysis. This algorithm improved the reliability of problem solving and extremely simplifies the computation complexity of the original algorithm by avoiding computing phase angle between voltage and current. Based on the neutral non-grounded system as an example for analysis, it is effective in single-phase earth fault transient process in arc suppression coil grounded system. The simulation was conducted by ATP-EMTP in 10 kV neutral non-grounded system to choose the fault line when it was on lines and buses. The results prove that the algorithm is faster and more reliable to the faulty line selection.
Key words: non-direct earth neutral systems; single-phase ground short circuits; Fourier algorithm; faulty line selection