Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 173 Electric Power Generation and Storage Using a High Voltage Approach BJÖRN BOLUND ACTA UNIVERSITATIS UPSALIENSIS ISSN 1651-6214 UPPSALA ISBN 91-554-6552-8 2006 urn:nbn:se:uu:diva-6833 ! "##$ %& ' ( ( ( ) * + , ) - -) "##$) , + . / 0 1 2 ) 2 ) 3%) ! ) ) 4/-5 ! 6''76$''"68) ( + ) 5 + ( ( ( ( ) * ( + ( ( ) + ( + 9 : ) * ( + ( (( ( + + ) / ( ) 2 (+ ( 9 ) 4 + ( ( + ) + . . 0 1 + ( + !" # $ # % &'(# # $)*&+,+ # ; -< - "##$ 4//5 $' 6$" 7 4/-5 ! 6''76$''"68 & &&& 6$8%% = &>> )?)> @ A & &&& 6$8%%B List of Publications Most of the content in this dissertation is based on the work described in the following journals and conference reports. Capital letters refer to appendices in this report. A. U. Lundin, B. Bolund, M. Leijon, ‘Energy Flow in Synchronous Generators; a Poynting Vector Analysis from Field Simulations’, submitted to IEEE Transac- tions on Magnetics B. B. Bolund, M. Leijon, U. Lundin ‘Poynting Theory for Cable Wound Genera- tors’ submitted to IEEE Transactions on Dielectrics and Electrical Insulation C. M. Leijon, B. Bolund, U. Lundin, ‘High Voltage Generators; Ideas Behind them and Operation Data’, Invited and refereed conference paper to International Conference on Conditioning Monitoring and Diagnostics, Korea in April 2006 D. B. Bolund and M. Leijon, ‘Rotor Configuration Impact on Generator Ventila- tion Needs’ Reviewed and presented at IEEE-PES conference, New York 10-13 October 2004 E. B. Bolund, K. Thorburn, E. Sjöstedt, M. Eriksson, E. Segergren and M. Leijon, ‘Upgrading Generators with new Tools and High Voltage Technology’ Interna- tional Journal on Hydropower and Dams, vol. 11, issue 3, May 2004, pp 104-8 F. E. Segergren, B. Bolund, H. Bernhoff, M. Leijon, ‘Rotor Concept Comparison for Underwater Power Generation’, Proceedings from MAREC 2002 Two Day International Marine Renewable Energy Conference. Newcastle, UK, Septem- ber 2002 G. B. F. Bolund, M. Berglund, H. Bernhoff, ‘Dielectric Study of Water/methanol Mixtures for use in Pulsed-Power Water Capacitors’, Journal of Applied Phys- ics, v 93, n 5, 1 March 2003, p 2895-9 H. B. Bolund, H. Bernhoff and M. Leijon, ‘Flywheel Energy and Power Storage Systems’, Renewable and Sustainable Energy Reviews, Available online March 2005 I. M. Leijon, H. Bernhoff, B. Bolund, ‘System for Storage of Power’ International Patent WO 2004/045884 A1, May 3, 2004 J. B. Bolund, E. Segergren, A. Solum, R. Perers, L.Lundström, A. Lindblom, K. Thorburn, M. Eriksson, K. Nilsson, I. Ivanova, O. Danielsson, S. Eriksson, H. Bengtsson, E. Sjöstedt, J. Isberg, J. Sundberg, H. Bernhoff, K-E Karlsson, A. Wolfbrandt, O. Ågren and M. Leijon, ‘Rotating and Linear Synchronous Gen- erators for Renewable Electric Energy Conversion - an Update of the Ongoing Research Projects at Uppsala University’, Proceedings from NORPIE 2004 con- ference 14-16 June 2004, Tronheim, Norway Contents Preface ............................................................................................................9 Acknowledgements.......................................................................................11 1. Introduction and Aim of the Thesis ..........................................................13 2. Theory.......................................................................................................16 2.1 Mathematical model of the generator.................................................16 2.2 Losses in a generator ..........................................................................19 2.3 FEM- Background..............................................................................21 2.4 Method for time stepping ...................................................................22 2.5 Power flow and Poynting’s theorem ..................................................23 3. Power Generation......................................................................................28 3.1 CHP ....................................................................................................28 3.1.1 CHP background.........................................................................28 3.1.2 CHP in Sweden and the plant in Eskilstuna ...............................29 3.1.3 Tests performed in Eskilstuna ....................................................31 3.2 The turbogenerator .............................................................................36 3.2.1 Cooling .......................................................................................36 3.3 Hydropower........................................................................................37 3.3.1 History ........................................................................................37 3.3.2 Hydropower generators ..............................................................38 3.3.3 Upgrading hydropower in Sweden .............................................39 4. Power Flow in Generators ........................................................................41 4.1 Aim with simulating power flow in generators..................................41 4.2 How were the simulations done .........................................................42 4.3 What does the power flow look like...................................................46 5. Energy and Power Storage........................................................................51 5.1 Flywheel basics ..................................................................................51 5.1.1 Flywheel energy storage.............................................................51 5.1.2 High voltage................................................................................52 5.1.3 Build-up and limitations .............................................................52 5.1.4 Magnetic bearings.......................................................................55 5.2 Flywheel technical considerations......................................................56 5.2.1 Permanent magnets and steel......................................................56 5.2.2 Motor/generator ..........................................................................56 5.2.3 Power electronics........................................................................59 5.2.4 Magnetic flux..............................................................................60 5.2.5 Work done to date.......................................................................60 5.2.6 Losses .........................................................................................63 5.2.7 External gyroscopic aspects........................................................64 5.3 Water capacitors.................................................................................64 5.3.1 High power Pulses ......................................................................64 5.3.2 Water capacitor...........................................................................65 5.3.3 Water/methanol...........................................................................67 6. Summary of Papers...................................................................................70 Paper A: Poynting vector analysis of synchronous generators using field simulations ...............................................................................................70 Paper B: Poynting theorem for cable wound generators..........................70 Paper C: High voltage generators; ideas behind them and operation data ..................................................................................................................71 Paper D: Rotor configuration impact on generator ventilation needs ......71 Paper E: Upgrading generators with new tools and high voltage technology ................................................................................................72 Paper F: Rotor concept comparison for underwater power generation....72 Paper G: Dielectric study of Water/methanol mixtures for use in pulsed power water capacitors.............................................................................72 Paper H: Flywheel energy and power storage systems ............................73 Patent I: System for storage of power ......................................................73 Paper J: Rotating and linear synchronous generators for renewable electric energy conversion - an update of the ongoing research projects at Uppsala University...................................................................................74 7. Summary of Results and Discussion.........................................................75 Generators ................................................................................................75 Generation of electricity...........................................................................78 Energy Storage .........................................................................................79 8. Conclusions...............................................................................................81 9. Future Work..............................................................................................82 10. Svensk Sammanfattning..........................................................................83