The invention discloses a
partial discharge signal extraction method and device for a
transformer active protection device, and the method comprises the steps: collecting a partial
electric signal of a
transformer, and marking a preliminary suspicious moment if the partial
electric signal is greater than an
electric signal threshold value; reading back local electric signals at a plurality of sampling moments before the preliminary suspicious moment, acquiring local electric signals at a plurality of sampling moments after the preliminary suspicious moment, and performing
Fourier transform on the local electric signals one by one to obtain
frequency spectrum signals; selecting
signal amplitudes of characteristic frequency points in the
frequency spectrum signal, and comparing the signal amplitudes with an amplitude threshold one by one; and if a plurality of signal amplitudes are simultaneously greater than the amplitude threshold, marking the preliminary suspicious moment as a height suspicious moment, and reporting the height suspicious moment to the
active protection device. By adopting the technical scheme, the requirements on the
operand and the storage capacity are effectively reduced, and the real-time operation on the
transformer can be realized.