The invention relates to the technical field of residual current protection, in particular to a power distribution network residual current protection method and
system based on a distributed photovoltaic power supply, and the method comprises the following steps: obtaining a zero-sequence current waveform in a disturbance period, recognizing an abrupt change node, analyzing the fluctuation
rhythm and trend, and constructing a response structure; the method comprises the following steps: extracting a sequence relationship between abrupt change nodes and fluctuation rhythms, constructing a response fragment set
with trend consistency and
rhythm coherence, screening response fragments capable of triggering protection, adjusting a starting point and a sequence, completing action triggering
rhythm merging, and generating a residual current protection strategy, in the method, through sequence
relationship extraction between the abrupt change nodes and the fluctuation rhythms, constructing a response fragment set
with trend consistency and rhythm coherence, and combining a change cooperation relationship between sections; key paragraphs capable of triggering protection are screened out, the triggering sequence and the starting point position are adjusted according to trend continuity, the starting
time sequence matching degree is improved, behavior stability is judged through trend coherence, rhythmic merging of response structures is achieved, action strategies with
directivity and continuity are output, and the precise control capacity of protection response under variable disturbance is enhanced.