To monitor the operating conditions of power transformers in real-time and predict the loosening faults of the transformers, the finite element simulation software is used to model the transformer, to simulate the vibration of the transformer core under different compressive stresses during its operation, and to analyze the vibration signal in this paper. Firstly, the transformer is modeled, and the electromagnetic field distribution of the transformer is solved through field-circuit coupling. Then, the force condition and vibration displacement distribution of the transformer are solved through the coupling of the electromagnetic field and structural force field. Finally, the simulation results of normal and fault conditions are compared, and the vibration characteristics of fault conditions are obtained. The experimental results show that the high order harmonic components in the vibration acceleration spectrogram increase significantly when the transformer core has a loosening fault, among which the 600Hz harmonic component increases the most.
 

Transformer; Multi-field coupling; Vibration; Core loosening; Fault diagnosis .