The invention relates to the technical field of power
system fault detection, in particular to a factory power
distribution system fault interval section determining method and
system and terminal device.The factory power
distribution system fault interval section determining method comprises the steps that when a power failure fault of a power
distribution system is monitored,
voltage and current data within a preset duration before the fault is obtained; comparing the phase
current amplitude with a rated
current threshold value, judging that the phase
current amplitude is an external fault if the phase
current amplitude does not exceed the limit, calculating a zero-sequence current if the phase current amplitude exceeds the limit, and comparing the zero-sequence current with a zero-sequence threshold value to distinguish a ground fault or an inter-phase fault; adaptively calling a
phase difference analysis process according to an identification result, calculating a
phase difference between a zero-sequence current and a zero-sequence
voltage during a grounding fault, calculating a
phase difference between a fault phase
voltage and a fault phase current during an inter-phase fault, and judging whether a fault interval is internal or external according to a phase difference interval; and a structured message is automatically generated by integrating fault types, interval judgment and triggering criterion paths, so that quick and accurate fault positioning and handling are realized.