INFLUÊNCIA DAS TENSÕES COMPRESSIVAS NAS PROPRIEDADES MAGNÉTICAS DOS AÇOS ELÉTRICOS DE GRÃO ORIENTADOS
COMPRESSIVE STRESS INFLUENCE ON MAGNETIC PROPERTIES OF GRAIN ORIENTED ELECTRICAL STEEL
Mateus Botani de Souza Dias, Ramon Valls Martin, Luiz Alberto Franco, Fernando José Gomes Landgraf
Resumo
Transformadores de potência são equipamentos fundamentais para reduzir as perdas nas etapas de transmissão e distribuição da energia elétrica. Durante a montagem do mesmo, tensões compressivas são geradas no núcleo magnético em decorrência da montagem, da não uniformidade da magnetização e das tensões térmicas, diminuindo a eficiência dos transformadores. O presente trabalho tem por finalidade apresentar a influência das tensões de compressão nos ciclos histeréticos, nas perdas magnéticas de potência (P) e na magnetostricção pico-a-pico (λp-p) dos aços elétricos com grãos orientados (GO). A aplicação de 10 MPa introduziu uma anisotropia externa ao material, diminuindo a permeabilidade magnética. Consequentemente, o campo remanente e o campo coercivo variaram -56% e +52%, aumentando as P em 24%. Além disso, a λp-p aumentou 86%. Em suma, a aplicação de tensões compressivas é deletéria para as propriedades magnéticas dos aços elétricos, diminuindo a eficiência e aumentando o ruído gerado pelos transformadores.
Palavras-chave
Abstract
Power transformers are fundamental devices to reduce power loss at electrical energy transmission and distribution steps. During the transformer assembly, compressive stresses are applied at magnetic cores due the assembly, the non-uniform magnetization and thermal stresses, reducing the transformer performance. The present work shows the compressive stress influence at the hysteretic loops, power losses and peak-to-peak magnetostriction of the grain oriented electrical steel. The apply of 10 MPa introduced an extrinsic anisotropy in the material, reducing the magnetic permeability. Consequently, the remanence and the coercive field changed -56% e +52%, increasing the power loss at 24%. Moreover, the peak-to-peak magnetostriction increases 86%. In sum, the compressive stress application is deleterious to magnetic properties of grain oriented electrical steel, reducing the performance and increasing the noise produced by power transformers.
Keywords
Referências
1 Cullity BD, Graham CD. Introduction to magnetic materials. Piscataway: IEEE Press Editorial Board; 2009.
2 Alcântara FLD, Cunha MAD. Estudo da recristalização secundária do aço silício de grão orientado. Tecnologia em Metalurgia e Materiais. 2006;2:32-36.
3 Weiser B, Pfutzner H, Anger J. Relevance of magnetostriction and forces for the generation of audible noise of transformer cores. IEEE Transactions on Magnetics. 2000;36(5):3759-3777.
4 Moses AJ, Anderson PI, Phophongviwat T, Tabrizi S. Contribution of magnetostriction to transformer noise. In: Proceedings of the Universities Power Engineering Conference; 2010 31 Aug-3 Sep; Cardiff, Walles. Cardif: IEEE; 2010.
5 Shilyashki G, Pfutzner H, Hamberger P, Aigner M, Kenov A, Matkovic I. Spatial distributions of magnetostriction, displacements and noise generation of model transformer cores. International Journal of Mechanical Sciences. 2016;118:188-194.
6 Medeiros LB. Ruído: efeitos extra-auditivos no corpo humano. [monografia]. Porto Alegre: Centro de Especialização em Fonoaudiologia Clínica; 1999.
7 Weiser B, Hasenzagl A, Booth T, Pfutzner H. Mechanisms of noise generation of model transformer cores. Journal of Magnetism and Magnetic Materials. 1996;160:207-209.
8 Arai S, Mizokami M, Yabumoto M. Magnetostriction of grain oriented Si-Fe and its domain model. Przeglad Elektrotechniczny. 2011;87(9B):20-23.
9 Yamamoto T, Nozawa T. Effects of tensile stress on total loss of single crystals of 3 percent silicon-iron. Journal of Applied Physics. 1970;41(7):2981.
10 Swift WM, Wolfe GF. Influence of compressive stress on magnetic-properties of a (110) 001 single-crystal of 3 percent Si-Fe. IEEE Transactions on Magnetics. 1976;12(3):244-248.
11 Perevertov O, Schafer R. Magnetic properties and magnetic domain structure of grain-oriented Fe-3%Si steel under compression. Materials Research Express. 2016;3(9):12.
12 Dias MBS, Bormio-Nunes C, Pacheco CJ, Machado VO, Hubert O. Magnetomechanical behavior of a directly solidified Fe-Al-B alloy. Smart Materials and Structures. 2015;24:105004.
13 Wun-Fogle M, Restorff JB, Clark AE, Dreyer E, Summers E. Stress annealing of Fe-Ga transduction alloys for operation under tension and compression. Journal of Applied Physics. 2005; 97(10):10M301.
14 Bormio-Nunes C, Cardoso FM. Assessment of Fe-Ga-B alloy magnetomechanical behavior. Journal of Materials Research. 2018;33(15):2207-2213.
15 Bormio-Nunes C, Dias MBD. Piezomagnetic performance of Stress-Annealed FeAlB Alloys. IEEE Transactions on Magnetics. 2017;53(11):4.
16 Anderson PI, Moses AJ, Stanbury HJ. Assessment of the stress sensitivity of magnetostriction in grain-oriented silicon steel. IEEE Transactions on Magnetics. 2007;43(8):3467-3476.
17 Schmid E, Boas W. Plasticity of crystals. London: F. A. Hughes & CO. Limited; 1950.
18 Anderson P. Measurement of the stress sensitivity of magnetostriction in electrical steels under distorted waveform conditions. Journal of Magnetism and Magnetic Materials. 2008;320(20):E583-E588.
Facebook
Google+
Twitter
LinkedIn
Mendeley
StumbleUpon
CiteULike
Reddit
Email