Electrodynamic magnetic suspension-models, scaling laws, and experimental results

A simple experiment illustrating the principles of electrodynamic magnetic suspension is described and test results are given. A disk-shaped coil made of insulated copper magnet wire and energized with 60 Hz AC line voltage is levitated in a stable equilibrium position above a wide aluminum plate. The mechanisms generating levitation force are identified by the use of Maxwell's equations. A lumped-parameter inductance model is used to model magnetic energy storage. By using energy methods, the current necessary to achieve coil lift-off and levitation is estimated, with good results. A stability analysis is done which shows that the levitation is stable, but underdamped. Thermal models are also developed for determining temperature rise in the coil. The magnetic scaling law is developed which shows that larger magnetic structures are more efficient in energy conversion than small ones.

[1]  M. T. Thompson.  Inductance Calculation Techniques---Part II : Approximations and Handbook Methods , 1991 .

[2]  P. Geary.  Magnetic and electric suspensions : a survey of their design, construction, and use , 1964 .

[3]  S. L. Wipf,et al.  Magnetic Suspension and Guidance for High Speed Rockets by Superconducting Magnets , 1969 .

[4]  R. D. Thornton,et al.  Flux-canceling electrodynamic maglev suspension. II. Test results and scaling laws , 1999 .

[5]  H. A. Wheeler.  Simple Inductance Formulas for Radio Coils , 1928, Proceedings of the Institute of Radio Engineers.

[6]  William Gerard Hurley,et al.  Electromagnetic design of a magnetic suspension system , 1997 .

[7]  Marc T. Thompson.  High temperature superconducting magnetic suspension for Maglev , 1997 .

[8]  W. G. Hurley,et al.  Calculation of self and mutual impedances in planar magnetic structures , 1995 .

[9]  R. D. Thornton,et al.  Flux-canceling electrodynamic maglev suspension: Part I. Test fixture design and modeling , 1999 .

[10]  Frederick Warren Grover,et al.  Inductance Calculations: Working Formulas and Tables , 1981 .

[11]  Hermann A. Haus,et al.  Electromagnetic Fields And Energy , 1989 .

[12]  G. C.,et al.  Electricity and Magnetism , 1888, Nature.

[13]  Robert W. Erickson,et al.  Fundamentals of Power Electronics , 2001 .

[14]  R. M. Desmond,et al.  Engineering heat transfer , 1977 .

[15]  H. D. Wiederick,et al.  Magnetic braking: Simple theory and experiment , 1987 .

[16]  M. T. Thompson.  Modeling of HTSC-Based Iron Core Flux-Canceling Electrodynamic Suspension for Maglev , 1998 .

[17]  S. Earnshaw.  On the Nature of the Molecular Forces , 1842 .

[18]  Marc T. Thompson.  Inductance Calculation Techniques --- Part I: Classical Methods , 2001 .

[19]  R. D. Thornton,et al.  Magneplane: guided electromagnetic flight , 1972 .

[20]  J. Geary,et al.  Cryogenic wafer prober for Josephson devices , 1983 .

[21]  M. Adler.  A field-theoretical approach to magnetic induction heating of thin circular plates , 1974 .