The study on vibration characteristic of power transformer in short circuit by transfer function

The vibration of power transformer is closely related to the mechanical condition of transformer and current when the external short circuit occurs. In this paper, the vibration sensors based on piezoelectric effect are attached to the oil tank of transformer to acquire the vibration signals in short circuit condition, and then the transfer function is applied to study the relationship between the vibration and short- circuit current under multiple short circuit shocks. Compared with traditional frequency domain or time- frequency domain analysis, this method can normalize the vibration in different short circuit condition and clearly illustrate the relationship between vibration and current. The conclusion shows that this method is feasible to evaluate the mechanical condition of transformer by using the correlation analysis of amplitude- frequency characteristic of transfer function in different short circuit condition.