Fault property identification before reclosing can overcome the secondary impact problems caused by the reclosing of the three-phase automatic reclosing in the traditional distribution network when the permanent fault occurs. Some scholars have proposed the use of split-phase switches to identify fault property
but there are problems such as low sensitivity of fault property identification or influence of neutral point grounding mode. Based on the split-phase switch
this paper further proposes permanent fault identification method for grounding faults and phase-to-phase faults
and gives the sequential reclosing scheme. Firstly
the analysis model of sequential reclosing is established
and it is verified that the fault current impact of reclosing one phase is much smaller than reclosing three-phase. Secondly
for the grounding faults
the zero-sequence impedance expressions for different fault types are derived
the difference of zero-sequence impedance angle characteristics between transient fault and permanent fault is analyzed
and the identification criterion of permanent grounding faults is constructed. For phase-to-phase fault
the difference of line voltage characteristics between transient fault and permanent fault is analyzed. The fault property identification criterion based on average Hausdorff distance algorithm is proposed. Finally
the influences of load capacity
transition resistance and system capacitance current change on the proposed method are analyzed
and the sequential reclosing scheme is given by combining the algorithms. The closed-loop test experiment based on RTDS shows that the proposed permanent fault identification scheme can reliably identify the fault property
has the advantages of robust tolerance to transition resistance
and is not affected by the neutral point grounding mode.