The main objective of this paper is to assist in the investigation of electromagnetic forces, structural deformation, stresses, and Safety factor when energizing unloaded transformers. The methodology is based on modeling of a single-phase 50 MVA transformer subjected to inrush currents through finite element method (FEM). In this perspective, the conditions of inrush currents are used to estimate the magnetic field density dispersion in the transformer and to find the values of forces in axial and radial directions. These components are distributed along the energized windings for observing the loads in high-voltage windings. Thus, this article will contributes with the investigations of a structural Analysis on transformers when subjected to inrush current.
FitzgeraldA.E., KingsleyC. and UmansS.D., MáuinasElétricas, EditoraArtmed, Nova York, (2006).
2.
FaizJ., EbrahimiB.M. and ElhaijaW.A., Computation of static and dynamic axial and radial forces on power transformer windings due to inrush and short circuit currents, IEEE Jordan Conference on Applied Electrical Engineering and Computing Technologies (AEECT) (2011), 8.
3.
FonsecaW.S., LopesA.C. and NunesM.V., Modelagem de esforços eletromecânicos de transformador de núcleo amorfo através do método de elementos finitos, Anais do T&D Transmition and Distribuition IEEE Latino América, S. Paulo, Brasil, (2010), 6.
4.
AzevedoA.C., Estresse eletromecânico em transformadores causados por curtos-circuitos passantes e correntes de energização, Tese (Doutorado) - Universidade Federal de Uberlândia, Uberlândia, Brasil, (2007), 111p.
5.
AhnH., LeeJ., KimJ.K., OhY., JungS. and HahnS.C., Finite-element analysis of short-circuit electromagnetic force in power transformer, IEEE Transactions on Industry Applications47(3) (May/Jun 2011), 1267-1272.
6.
AhnH., OhY., KimJ.K., SongJ.S. and HahnS.C., Experimental verification and finite element analysis of short-circuit electromagnetic force for dry-type transformer, IEEE Transactions on Magnetics, Fevereiro 28(2) (2012), 819-822.
7.
DhayalanR., KumarA., RaoB.P.C. and JayakumarT., A hybrid finite element model for spiral coil electromagnetic acoustic transducer (EMAT), International Journal of Applied Electromagnetics and Mechanics (May 2014).
8.
RatnajeevanS., HooleH., KarthikV.U., SivasuthanS., RahunanthanA., ThyagarajanR.S. and JayakumarP., Finite elements, design optimization, and nondestructive evaluation: A review in magnetics, and future directions in GPU-based, element-by-element coupled optimization and NDE, International Journal of Applied Electromagnetics and Mechanics (Apr 2014).
9.
BakshiA. and KulkarniS.V., Analysis of buckling strength of inner windings in transformers under radial short-circuit forces, IEEE Transactions on Power Delivery29(1) (Feb 2014), 241-245.
10.
BakshiA. and KulkarniS.V., Coupled electromagnetic-structural analysis of the spiraling phenomenon in a helical winding of a power transformer, IEEE Transactions on Power Delivery29(1) (Feb 2014), 235-240.
11.
ZhangmH., YangB., XuW., WangS., WangG., HuangfuY. and ZhangJ., Dynamic deformation analysis of power transformer windings in short-circuit fault by FEM, IEEE Transactions on Applied Superconductivity24(3) (Jun 2014).
12.
AmoiralisI.E., TsiliA.M. and KladasG.A., Transforms design and optimization: A literature survey, IEEE Transactions on Power Delivery24(4) (Oct 2009).
13.
GuimarãesR., DelaibaA.C., SaraivaE., RosentinoA.J.P. and de OliveiraJ.C., Electromechanical stress in transformers caused by inrush and short circuit currents, Journal of the Brazilian Society of Mechanical Sciences an Engineering37(1) (Jan 2015), 243-253.
14.
KulkarniS.V. and KhapardeS.A., Transformer engineering: Design and practice, Marcel Dekker, Inc, New York, 2004.
15.
PeterG.P., Calculations for short circuit withstand capability of a distribution transformer, Int J Adv Technol2(1) (2011), 142-150.
16.
ErtlM. and VossS., The role of load harmonics in audible noise of electrical transformers, Journal of Sound and Vibration333(8) (Apr 2014), 2253-2270.
17.
BastosJ.P.A., Eletromagnetismo and Cálculo de Campos, Florianópolis: Editora da UFSC, 3 ed, 1996, 452.
18.
SchulzC.A., RogerD., DuchesneS. and VincentJ.N., Experimental characterization of interlamination shorts in transformer cores, IEEE Trans Magn46(2) (Feb 2010), 614-617.
19.
HibbelerR.C., Resistência dos Materiais, 5° ed., Editora Livros Técnicos and Científicos, 2006.
20.
NajdenskoskiK. and ManovD., Electromagnetic forces calculation on power transformer windings under short circuits, The International Journal Computation Mathematics in Electrical and Electronics Engineering17(1/2/3) (May/Jun 1998), 374-377.
21.
BrunkeJ.H. and FrohlichK.J., Elimination of transformer inrush currents by controlled switching - Part I: Theoretical considerations, IEEE Transactions on Power Delivery16(2) (Apr 2001), 276-280.
22.
SteurerM. and FrohlichK., The impact of inrush currents on the mechanical stress of high voltage power transformer coils, IEEE Transactions on Power Delivery17(1) (Jan 2002), 155-160.
23.
AddlyA.A., Computation of inrush current forces on transformer windings, IEEE Transactions on Magnetics37(4) (Jul 2001), 2855-2857.
