Anti-harmonic interference frequency measurement method and device applied to intelligent circuit breaker

The invention relates to the technical field of low-voltage power distribution detection. The embodiment of the invention provides an anti-harmonic interference frequency measurement method and device applied to an intelligent circuit breaker. The anti-harmonic interference frequency measurement method applied to the intelligent circuit breaker comprises the steps of obtaining a rectangular wave signal corresponding to a to-be-measured signal, and obtaining a duration sequence according to a time sequence and duration of a level in the rectangular wave signal; searching the duration time sequence by adopting a reverse order mode, and respectively taking the previous two low levels greater than a preset duration as a first feature point and a second feature point; accumulating the value of the duration from the second feature point to the first feature point in the duration sequence, and taking the accumulated value as the period of the signal to be detected; and obtaining the frequency of the to-be-measured s