1D and 2D Magnetization in Electrical Steels under ...

1 1D and 2D Magnetization in Electrical Steels under Uniaxial StressViatcheslav PermiakovPromotoren: prof. dr. ir. J. Melkebeek, prof. dr. ir. L. Dupr Proefschrift ingediend tot het behalen van de graad van Doctor in de Toegepaste WetenschappenVakgroep Elektrische Energie, Systemen en AutomatiseringVoorzitter: prof. dr. ir. J. MelkebeekFaculteit IngenieurswetenschappenAcademiejaar 2004 - 2005 ISBN 90-8578-022-5 NUR 961, 967 Wettelijk depot: D/2005 1 Acknowledgement The author kindly thanks the two promoters, Prof. Jan Melkebeek and Prof.

2 Luc Dupr , for a chance to obtain an internationally recognized degree from Ghent University, Belgium, and for a great help with improving my English writing skills when preparing the thesis. The author would like to thank the following people for their contribution to the current research and many discussions we had: Jehudi Maes, engineer at PICANOL BELGIUM Dimitre Makaveev, engineer at BOMBARDIER BELGIUM Marc De Wulf, researcher at OCAS, ARCELOR GROUP Josef Ghijselen, engineer at INVERTO BELGIUM Jan Declercq, head R&D at PAUWELS INTERNATIONAL Tony Moses, head of Wolfson Center, Cardiff, UK Fausto Fiorillo, research director at IEN, Torino, ITALY Martin J.

3 Sablik, senior researcher in San Antonio, TX, USA Johannes Sievert, senior researcher at PTB, GERMANY Philip Beckley, senior researcher at European Steels , UK Special thanks to a former colleague from Urals Technical University, Alexander Pulnikov, for his contribution to this study. Voor de administratieve taken kon ik steeds terecht bij Ingrid Dubois. Bij technische problemen stonden Christian Vervust en Fernand De Boever steeds paraat. This work was financially supported by the STWW-project IWT 980357, the Interuniversity Attraction Poles project IAP-P5/34, the GOA-project 99-200/4, the FWO-project The author would like to thank the project partners, participating in the above mentioned R&D projects.

4 The work is devoted to my parents, as it is them who gave me the birth and the education for life. Спасибо моим родителям за то, что дали мне возможность получить лучшее образование и путевку в жизнь. 2 Summary Summary The aim of this study is to expand the knowledge about electromagnetic behaviour of non- oriented and grain - oriented Electrical Steels , used in all parts of Great Chain of Energy Transformation. This study deals with the effects of uniaxial stress on magnetic properties of Electrical Steels . The work consists of two major parts.

5 The first part defines the framework of the present study. The second part starts from a 1D study, followed by a more complex 2D Magnetization in Electrical Steels . Chapter 1 is an introduction, positioning the subject of this study. A better understanding of various production procedures leads to a more accurate prediction of energy losses and the "building factor". Chapter 2 deals with the analysis of the working conditions, affecting the behaviour of Electrical steel in actual machines. A detailed study is performed for 2D magnetic conditions in induction machines, from theoretical and experimental point of view.

6 The iron energy losses depend on magnetic flux patterns as well as on mechanical stresses. Chapter 3 presents the art of magnetic measurements, followed by the choice of the magnetic measurement technique employed in the present study. The advanced magnetomechanical setup created in EELAB allows to control and maintain sinusoidal induction and to carry out an unique range of 2D magnetic measurements under 1D stress. Evidently, the extensive know-how in magnetic measurements created by the team of EELAB, where the author had the chance to reside for five years, has contributed to this doctoral research.

7 Chapter 4 is an investigation of the simplest 1D case of uniaxial Magnetization at uniaxial stress. A physically sound explanation is presented for the stress effects. The loss separation is applied for a statistical characterization of Electrical Steels under magnetomechanical conditions. Although some effects of stresses are known in literature, a few new aspects are presented. Chapter 5 deals with the complex 2D magnetic measurements under uniaxial compression and tension. This chapter of the study includes both alternating Magnetization and rotational Magnetization .

8 Chapter 6 concludes this study with the recommendations on how the energy loss in various Electrical Steels can behave under stress, as well as what other subjects are related to the present study. The author hopes that the work has extended the know-how of EELAB as well as has consolidated the position of EELAB worldwide. Contents 3 CONTENTS Acknowledgement 1 Summary 2 Contents 3 List of Symbols 7 1. INTRODUCTION. Energy transformation. Energy losses and magnetism. The history of magnetism. Magnetic materials and domain theory.

9 Application of magnetic materials in energy transformation. Electrical Steels . Lamination. Resistivity and various alloys. grain size and orientation of grains. Production of Electrical Steels . Stress effects in Electrical Steels . Production stress in Electrical Steels . The effect of punching. The effect of core building. Engineering choice of Electrical Steels . 9 9 10 11 15 18 20 21 21 22 24 25 26 26 28 29 2. WORKING CONDITIONS OF Electrical Steels . Standard characteristics of Electrical steel . Target research of working conditions in Electrical Steels . Target research in grain - oriented Steels . Target research in non- oriented Steels .

10 2D magnetic working conditions in induction machines. 2D mechanical working conditions in induction machines. Conclusions. 31 32 36 36 39 40 51 56 4 Contents 3. MAGNETIC MEASUREMENTS under STRESS. Standard magnetic measurements in Electrical Steels . Epstein frame. Single sheet tester. DC magnetic measurements of iron and steel . Magnetic measurement techniques used in standard methods. State of the art in 2D magnetic measurements. 2D single sheet testers. Shift to a horizontal rotational single sheet tester.