A Fault line identification method of resonance grounded system based on active disturbance technique

In resonance grounded system, arc suppression coil compensates capacitive fault current to improve power supply reliability. The approach of fault line identification based on active injection signal has not been widely used. A fault line identification method of resonance grounded system is proposed, which can produce signals on the primary side of the system. In this paper, a line identification signal is obtained in the damping resistance of the pre-regulating arc suppression coil for a short time, which can accurately obtain zero sequence frequency response of each feeder, when occurring the single-phase grounding faults. Fault line selection criteria are established based on the difference of frequency response characteristics of zero sequence frequency between fault and health feeders. Theoretical derivation, simulation analysis show that the scheme can select fault feeders quickly and accurately.