Faults Diagnosis of Power Transformer Winding by Means of Finite Element Method and Frequency Response Analysis

In this paper the influence of core parameters in Frequency Response Analysis is analyzed through the equivalent circuit impedance matrix of the transformer winding; the parameters of the circuit have been computed using the Finite Element Method. In order to appreciate the behavior of the iron core in comparison to the air core, the frequency dependence of resonances is calculated to show how the air core only influences the results at low frequencies. The core is modeled using a complex permeability, and the parameters of conductivity and permeability are varied to show their influence in the resonances, which turned out to be negligible. In order to explain this behavior, the eigenvalues of the inverse impedance matrix are calculated showing that they are similar for different values of conductivity and permeability. Finally, the magnetic flux inside and outside the core and its influence in the frequency response is studied.<br style="font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" />

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Frequency Response Analysis by Finite Element Method in Relaxor Single-Crystal Plates with Giantk31

Japanese Journal of Applied Physics ◽

10.1143/jjap.46.7058 ◽

2007 ◽

Vol 46 (10B) ◽

pp. 7058-7062 ◽

Cited By ~ 2

Author(s):

Rakuko Kato ◽

Toshio Ogawa

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Single Crystal ◽

Frequency Response ◽

Response Analysis ◽

Frequency Response Analysis ◽

Element Method

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Frequency response analysis of cylindrical shells conveying fluid using finite element method

Journal of Mechanical Science and Technology ◽

10.1007/bf02916184 ◽

2005 ◽

Vol 19 (2) ◽

pp. 625-633 ◽

Cited By ~ 7

Author(s):

Young-Soo Seo ◽

Weui-Bong Jeong ◽

Wan-Suk Yoo ◽

Ho-Kyeong Jeong

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Frequency Response ◽

Cylindrical Shells ◽

Response Analysis ◽

Frequency Response Analysis ◽

Conveying Fluid ◽

Element Method

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A Coupled Smoothed Finite Element-Boundary Element Method for Structural-Acoustic Analysis of Shell

Archives of Acoustics ◽

10.1515/aoa-2017-0006 ◽

2017 ◽

Vol 42 (1) ◽

pp. 49-59 ◽

Cited By ~ 2

Author(s):

Wanyi Tian ◽

Lingyun Yao ◽

Li Li

Keyword(s):

Finite Element ◽

Boundary Element Method ◽

Frequency Response ◽

Boundary Element ◽

Acoustic Analysis ◽

Response Analysis ◽

Frequency Response Analysis ◽

Acoustic Problem ◽

Element Boundary ◽

Element Method

Abstract Nowadays, the finite element method (FEM) - boundary element method (BEM) is used to predict the performance of structural-acoustic problem, i.e. the frequency response analysis, modal analysis. The accuracy of conventional FEM/BEM for structural-acoustic problems strongly depends on the size of the mesh, element quality, etc. As element size gets greater and distortion gets severer, the deviation of high frequency problem is also clear. In order to improve the accuracy of structural-acoustic problem, a smoothed finite-element/boundary-element coupling procedure (SFEM/BEM) is extended to analyze the structural-acoustic problem consisting of a shell structure interacting with the cavity in this paper, in which the SFEM and boundary element method (BEM) models are used to simulate the structure and the fluid, respectively. The governing equations of the structural-acoustic problems are established by coupling the SFEM for the structure and the BEM for the fluid. The solutions of SFEM are often found to be much more accurate than those of the FEM model. Based on its attractive features, it was decided in the present work to extend SFEM further for use in structural-acoustic analysis by coupling it with BEM, the present SFEM/BEM is implemented to predict the vehicle structure-acoustic frequency response analysis, and two numerical experiments results show that the present method can provide more accurate results compared with the standard FEM/BEM using the same mesh. It indicates that the present SFEM/BEM can be widely applied to solving many engineering noise, vibration and harshness (NVH) problems with more accurate solutions.

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