METHOD FOR DETECTING A DC MAGNETIC BIAS IN TRANSFORMER

The present invention relates to a method for detecting DC magnetic bias in a transformer, comprising the following steps: a signal acquisition step (S52), a signal processing step (S54) and a determination step (S56). The signal acquisition step consists of acquiring a vibration signal of an oil tank of the transformer. The signal processing step comprises: forming a time domain waveform of the vibration signal (S542); subjecting the time domain waveform to frequency domain decomposition, to convert the time domain waveform into a frequency domain waveform (S544); calculating an amplitude of each odd number frequency and an amplitude of each even number frequency of the frequency domain waveform (S546). The determination step is as follows: if the amplitude of an odd number frequency is greater than half of the amplitude of an even number frequency, then there is DC magnetic bias in the transformer.