Dynamic Response of Power Transformer Tanks

Coutinho, Cristiano P.; Novais, C.; Tavares, S.M.O.; Pinto, Marta; Vieira, Antônio Wilson; Linhares, Cassiano; Mendes, Hélder; Lopes, R.

doi:10.1109/epim.2018.8756359

Cited by 3 publications

(4 citation statements)

References 5 publications

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“…None of the research conducted to date where transformer tank FEM simulations were used did not consider welded joint modeling problems in the context of modal, harmonic vibration, or acoustic analysis. That includes the research where stiffeners are considered [2,3,7] and even those where tanks without stiffeners, as is the case in this research, are taken into account [4,6,9,10]. The most important contribution and novelty that this work provides is that it considers and, in detail, analyzes the problem of welded joint modeling and proposes a developed methodology and solution for the given problem.…”

Section: Discussionmentioning

confidence: 99%

“…In FEM analysis, challenges include adequate welded joint modeling, contact definition, mesh size, etc. Compared to previous research that considered transformer tank modeling [2][3][4]6,7,9,10], this study fills the gap in a welded joint modeling methodology for FEM models of the transformer tanks. As the tank is an emitter of the sound coming from the active part, adequate tank modeling in FEM is a crucial step in the accurate numerical calculation of radiated noise.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, the FEM modal analysis can be used to compare the resonances of the different tank design solutions [7]. A similar approach can also be applied to various machines, such as turbine rotors [8].…”

Section: Introductionmentioning

confidence: 99%

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Comparison of Empty and Oil-Filled Transformer Tank Mode Shapes Using Experimental and FEM Modal Analysis

Petrović,

Dobrić,

Gotić

et al. 2024

Energies

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In this paper, the mode shapes of an empty and oil-filled transformer experimental model tank are obtained using 3D finite element method (FEM) modal analysis. For verification of the FEM analysis results, experimental modal analysis (EMA) is carried out in both cases using appropriate impact hammers and accelerometers. Simulated and measured results are visualized and compared for mode shapes in a frequency range of interest for both empty and oil-filled tanks. In order to avoid overly stiff FEM models of transformer tanks, the welded joint modeling technique is presented and analyzed in detail. For an oil-filled tank, the most accurate results are calculated in the model where the welded joint is modeled as half the tank wall’s thickness. In that case, the mean absolute error for the given ten-mode shapes is 1.7 Hz. Also, mesh sensitivity analysis is performed. It is concluded that a 10 mm maximum element size is an optimal solid (3D) mesh. However, shell mesh can be used to reduce computing requirements.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Comparison of Empty and Oil-Filled Transformer Tank Mode Shapes Using Experimental and FEM Modal Analysis

Petrović,

Dobrić,

Gotić

et al. 2024

Energies

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“…According to several studies [3][4][5], core noise is the dominant source of noise for transformers whose rating is below 150 MVA. Since transformers rated power is usually lower near consumption, the mitigation of core noise has been the focus of many studies during the past years [6].…”

Section: Introductionmentioning

confidence: 99%

Magnetostriction Assessment with Strain Gauges and Fiber Bragg Gratings

Linhares¹,

Santo²,

Teixeira³

et al. 2020

EAI Endorsed Transactions on Energy Web

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Power transformers have an imperative role in the future developments of the electrical grids. Treated as crucial assets for transportation and distribution of electrical energy, transformers are currently being studied regarding to the integration of technologies aiming to diagnose problems and monitoring data of electrical power grid. Furthermore, environmental noise pollution has gained importance, especially in active units of the power grid, located near consumers, such as transformers. Transformers noise can be classified according to its source: core, windings and cooling. This study addresses an experimental characterization of one of the main causes of transformers core noise-magnetostriction of electrical steel. An evaluation of magnetostriction properties of electrical steel, including resistive strain gauges and Fiber Bragg Gratings (FBGs) measurements with an Epstein frame, are presented and discussed. The magnetic flux density influence on hysteretic strain behavior of magnetostriction was evaluated, as well as the effect of a clamping load on core joints. Nowadays, optical interrogators for Bragg gratings have a high acquisition frequencies and wavelength sensitivity when compared to former optical interrogation systems, allowing to evaluate physical phenomena without electromagnetic interference and with equivalent resolution of conventional strain gauges.

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