Experimental dataset on the compressive mechanical properties of high-density pressboard used in power transformers spacers

Oria, C.; Carrascal, I.; Ferreño, Diego; Méndez, Cristina; Fernández, Alfredo Ortiz

doi:10.1016/j.dib.2023.109471

Cited by 1 publication

(1 citation statement)

References 7 publications

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“…Reference [18] investigated the impact of cushion blocks on the axial winding strength and of bracing ribs on the radial winding strength, with specific consideration of factors such as the number and width of cushion blocks. References [19,20] indicated that, over the transformer's lifespan, cushion blocks were immersed in dielectric fluid and exposed to high temperatures, thermal aging, and chemical reactions, resulting in the degradation of their dielectric and mechanical properties and weakening the transformer short-circuit resistance. In references [21,22], a two-dimensional simulation was established and the leakage flux and stress distribution of high-and low-voltage winding were analyzed; short-circuit tests were carried out and it was pointed out that the electromagnetic force generated by the fault current might lead to instability in and the collapse of the winding.…”

Section: Introductionmentioning

confidence: 99%

Research on the Influence of Compression and Offset of Cushion Blocks on the Axial Strength of Transformers

Sun,

Gao,

et al. 2023

Applied Sciences

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The instability of the winding-cushion structure is one of the primary causes of transformer failures. Insulation cushion compression and offset are the predominant forms leading to structural instability. Therefore, this paper, using the SFSZ7-31500/110 transformer as an example, first derives the theoretical formula for mechanical stress calculation. It clarifies the key influencing parameters of the winding-cushion block structure on the axial bending stress of the winding. Subsequently, an electromagnetic force finite element calculation model is established to obtain the axial force distribution in the winding and the distribution of unbalanced displacement during short-circuit processes. Based on the force and offset distribution, a specific cushion block compression and offset test platform is constructed. By setting different cushion block variables, the effects of cushion block unbalanced height and cushion block offset on the winding’s bending elastic modulus are determined. Finally, a simulation model for stress calculation of the winding-cushion block structure is established, revealing the influence pattern of cushion block compression and offset instability on the axial strength of the winding. The results of this study indicate that the greater the uneven cushion block height, the lower the axial strength of the winding. Under the same cushion block offset angle, winding structures with non-uniform cushion block offsets exhibit the worst axial stability. When the offset angles are 30°, 45°, and 60°, the maximum axial bending stress of the winding increases by 1.73%, 3.46%, and 7.82%, respectively. Increasing the offset angle exacerbates the decrease in the axial strength of the winding up to a certain extent. The findings in this study have significant implications for enhancing a transformer’s short-circuit resistance.

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