Research on Improvement Measure of Fast Fault Point Transfer Technology

Abstract

Abstract The fast fault point transfer technology has been widely used in China. Aimed at the single-phase arc-grounding fault in the neutral point non-effective grounding system, the principle is to suppress arc re-burning by grounding the faulty phase bus directly to limit the voltage of fault phase. However, the on-site operation found that the technology could not guarantee the arc on the fault point extinguished reliably. The effects of arc characteristics, bus grounding time, impedance of lines, load current and transition resistance on arc extinguishing are analysed in depth. Among these factors, the grounding time is the only controllable factor. The improvement measure of grounding the faulty phase bus at the zero point of the arc current is proposed, and the hardware and software flow are designed. The proposed method was simulated and analysed by ATP software. The simulation results verified the reliability and accuracy of the proposed method.