Research on the winding and iron core operation state of transformer based on the vibration acoustic fingerprint

Extensive studies show that the winding and iron core is the component of power transformer which is most prone to failure. The vibration detection of transformer is an effective method to evaluate the operation state and diagnose the condition of the winding and iron core. In this paper, the vibration system is applied to detection the signal of tow 220kV transformers. The spectrum distribution of the transformer vibration signal is analyzed by means of the wavelet transform, through which the vibration acoustic fingerprint and two typical characteristic parameters, i.e., the energy ratio of odd and even harmonics, and the waveform distortion ratio, are extracted respectively. The analysis results show there is a certain degree of deformation in the winding of the 1# transformer. It is discovered that the equivalent capacitance of the low voltage C phase winding of the 1# transformer is increased by 7% by off-line test. It further confirms the conclusion of the vibration detection and indicates the validity and practicability of the transformer vibration acoustic fingerprint and the two typical characteristic parameters.