Analysis of the arc high impedance grounding faults voltage characteristics in non-effective grounding feeders

The difficulty of single-phase arc high impedance grounding fault detection in neutral ineffectively grounded system lies in how to realize sensitive start. The current detection methods use the zero sequence voltage amplitude limit as the starting criterion, but the setting of the limit value directly affects the sensitivity and reliability of detection, it is often difficult to take into account both in practical operation. Aiming at this problem, based on the field wave recording data, this paper analyzes the transient voltage characteristics in the event of the single-phase arc high impedance grounding fault by means of numerical statistics, Fourier transform and graph comparison from the time domain and frequency domain. Meanwhile, the transient model of arc high impedance grounding fault is established, which verifies the validity of the transient voltage characteristics features extracted. It lays a foundation for the subsequent development of sensitive start criterion of faulty line selection device when single-phase arc high impedance grounding fault occurs. © 2019, Power System Protection and Control Press. All right reserved.