The invention provides a single-phase grounding protection method which is used for judging and isolating a single-phase grounding fault of a small-current grounding
system. The single-phase grounding protection method comprises the following steps of: 102, synchronously acquiring the
power frequency voltage of a
bus of the small-current grounding
system and current traveling
waves of all outgoing lines corresponding to the
bus in real time; 104, when the small-current grounding
system is disturbed, determining a disturbance outgoing line according to the current traveling
waves of all the outgoing lines; 106, determining whether the small-current grounding system has the single-phase grounding fault according to the
power frequency voltage; and 108, determining that the disturbance outgoing line is a faulted outgoing line if the small-current grounding system has the single-phase grounding fault, sending a
tripping instruction and insolating the faulted outgoing line. Correspondingly, the invention also provides a single-phase grounding
protection system. By the single-phase grounding protection method and the single-phase grounding
protection system, a requirement for judging the single-phase grounding fault of the small-current grounding system and a requirement for quick, reliable, sensitive and
selective isolation can be met.