Research on the Mechanical Characteristics and Deformation of Windings and Spacers of Power Transformer Under Short‐ Circuit Condition

ABSTRACT To address the limitations of traditional models in representing spacer mechanics during winding vibration, the Mooney‐Rivlin model is employed for experimental curve fitting. This approach enables the extraction of higher‐precision material parameters, thereby leading to more accurate predictions in winding vibration analysis. Firstly, taking a 110 kV transformer as the research prototype, the distribution of leakage field and winding electromagnetic force in transformer short circuit condition is calculated based on field‐circuit coupling method, and the accuracy of finite element model is verified by transformer magnetic leakage experiment. Secondly, the nonlinear mechanical characteristics of the radial spacers are obtained by compression test. Finally, the axial vibration response of the winding is calculated based on the coupling field of electromagnetic and structure. The results indicate that the axial electromagnetic force exhibits a symmetrical distribution about the mid‐height of the winding, with the maximum electromagnetic force occurring at the winding ends. The maximum vibration displacement of winding disks occurs at the 1/5 and 4/5 axial height positions, In the time domain, the vibration of the middle disk lags behind the change of the electromagnetic force, and the extreme value of the vibration of 1/5 disk appears at 30 ms. In the frequency domain, from the end of the winding to the middle of the winding, the vibration of the disk appears 70 and 140 Hz, and the natural vibration characteristics of the winding have more and more influence on the vibration response of the winding. With the decrease of preload, winding vibration intensifies and winding axial stability decreases.