# Macro element method for modeling eddy currents in the multi-conductor windings of electrical machines

 dc.contributor Aalto-yliopisto fi dc.contributor Aalto University en dc.contributor.author Szücs, Áron dc.date.accessioned 2012-02-13T12:29:19Z dc.date.available 2012-02-13T12:29:19Z dc.date.issued 2001-11-09 dc.identifier.isbn 951-22-5691-6 dc.identifier.issn 0001-6845 dc.identifier.uri https://aaltodoc.aalto.fi/handle/123456789/2358 dc.description.abstract The computation of the magnetic field in electromagnetic devices - especially rotating electrical machines - usually excludes the effect of eddy currents in the multi-conductor windings. Eddy-current losses are frequently calculated from a magnetic field solution in which the effect of eddy currents is not considered. The aim of this research has been the development of efficient methods to consider the effect of eddy currents in multi-conductor windings accurately within electromagnetic field computation. There are methods, which take the effect of eddy currents on the magnetic field into account in multi-conductor windings but all those approaches have serious drawbacks. Analytical formulations lead to very complicated models while numerical analysis leads to enormously large problem size for many conductors or in small penetration depth cases. The thesis suggests a novel combination of the elimination of inner nodes method with the conventional finite element technique. Based on the magnetic linearity of the winding regions the creation of numerical macro elements is suggested. The Gauss elimination of the nodes inside the finite element model of the multi conductor winding resulted in significantly decreased problem size and in accelerated solution of the system of equations in the nonlinear iteration process. The new macro element method, has been developed by the creation of constant macro elements for the duration of the whole time-stepping analysis. The macro element method has been verified with test computations and it is found to be faster in nonlinear problems and it requires significantly less memory than the traditional approach. The advantages and limitations of the method are presented in this thesis. en dc.format.extent 88, [38] dc.format.mimetype application/pdf dc.language.iso en en dc.publisher Helsinki University of Technology en dc.publisher Teknillinen korkeakoulu fi dc.relation.ispartofseries Acta polytechnica Scandinavica. El, Electrical engineering series en dc.relation.ispartofseries 106 en dc.relation.haspart Szücs, Á., Arkkio, A., Palko, S., Saitz, J. and Yatchev, I. 1996. Study of electrical machines, using a new interactive finite element preprocessor. Proceedings of PEMC'96, Budapest, Hungary, 2-4 September 1996, Vol. 2, pp. 273-277. dc.relation.haspart Áron Szücs, Antero Arkkio, 1999. Consideration of Eddy Currents in Multi-Conductor Windings Using the Finite Element Method and the Elimination of Inner Nodes, IEEE Transactions on Magnetics, Volume 35, Number 3, Part I of two parts, May 1999. dc.relation.haspart Áron Szücs, Antero Arkkio, 1998. Newton Raphson Iteration Using the Finite Element Method and the Elimination of Inner Nodes for the Consideration of Eddy-Currents in Multi-Conductor Windings at IEEE CEFC'98 The Eighth Biennial IEEE Conference on Electromagnetic Field Computation, Tucson, Arizona, USA, June 1-3, 1998. dc.relation.haspart Áron Szücs, 2000. Macro Elements In the Finite Element Analysis of Multi-Conductor Eddy-Current Problems, IEEE Transactions on Magnetics, Volume 36, Number 4, July 2000. dc.relation.haspart Áron Szücs, 2000. Advanced Utilization of Macro Elements that Replace the Multi-Conductor Windings in the Finite Element Analysis of Rotating Electrical Machines, Laboratory Report, No. 66, 12 p, 2001, Helsinki University of Technology, Laboratory of Electromechanics. dc.relation.haspart Áron Szücs, Antero Arkkio, Tapani Jokinen, 2000. Modeling of Eddy Currents in the Stator Winding of Asynchronous Machines Using Macro Elements at ICEM 2000 Proceedings of the International Conference on Electrical Machines, Helsinki, Finland, August 28-30, 2000. dc.subject.other Electrical engineering en dc.title Macro element method for modeling eddy currents in the multi-conductor windings of electrical machines en dc.type G5 Artikkeliväitöskirja fi dc.description.version reviewed en dc.contributor.department Department of Electrical and Communications Engineering en dc.contributor.department Sähkö- ja tietoliikennetekniikan osasto fi dc.subject.keyword eddy currents en dc.subject.keyword finite element methods en dc.subject.keyword machine windings en dc.subject.keyword macro elements en dc.subject.keyword skin effect en dc.identifier.urn urn:nbn:fi:tkk-003037 dc.type.dcmitype text en dc.type.ontasot Väitöskirja (artikkeli) fi dc.type.ontasot Doctoral dissertation (article-based) en dc.contributor.lab Laboratory of Electromechanics en dc.contributor.lab Sähkömekaniikan laboratorio fi
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