Analysis and Restraining of Eddy Current Damping Effects in Rotary Voice Coil Actuators

2017 ◽  
Vol 32 (1) ◽  
pp. 309-317 ◽  
Author(s):  
Yiqian Li ◽  
Yong Li ◽  
Liuyang Ren ◽  
Zhe Lin ◽  
Qian Wang ◽  
...  
Keyword(s):  
Eddy Current ◽  
Eddy Current Damping ◽  
Damping Effects

Modeling Eddy-Current Damping Force in Magnetic Levitation Systems With Conductors

2017 ◽  
Author(s):  
Mohammad Khodabakhsh ◽  
Mehran Ebrahimian ◽  
Bogdan Epureanu
Keyword(s):  
Permanent Magnet ◽  
Eddy Current ◽  
Eddy Currents ◽  
Magnetic Levitation ◽  
Analytical Models ◽  
Damping Force ◽  
Element Analysis ◽  
Wide Range ◽  
Eddy Current Damping ◽  
Damping Effects

An analytical method is used to develop a model to calculate steady-state eddy-current damping effects in two configurations of magnetic levitation (maglev) systems. The eddy-current based force (eddy-current force) is used for high precision positioning of a levitated permanent magnet in maglev systems. In these systems, the motion of the levitated permanent magnet and changes of the coil’s currents, generate eddy current in the conductors. The proposed analytical model is used to calculate both effects. A conductive cylindrical shell around the levitated object is implemented as a new technique to generate eddy currents in maglev systems. The model is also employed to obtain eddy-current damping effects in a system with a conductive plate beneath the levitated object. The analytical models match results from high fidelity finite element analysis (FEA) with acceptable accuracy in a wide range of operations. Advantages of the two configurations are discussed.

Modeling of a New Active Eddy Current Vibration Control System

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Henry A. Sodano ◽  
Daniel J. Inman
Keyword(s):  
Magnetic Field ◽  
Vibration Control ◽  
Electric Fields ◽  
Eddy Current ◽  
Eddy Currents ◽  
Vibration Suppression ◽  
Frequency Doubling ◽  
Damping Force ◽  
Theoretical Derivation ◽  
Eddy Current Damping

There exist many methods of adding damping to a vibrating structure; however, eddy current damping is one of few that can function without ever coming into contact with that structure. This magnetic damping scheme functions due to the eddy currents that are generated in a conductive material when it is subjected to a time changing magnetic field. Due to the circulation of these currents, a magnetic field is generated, which interacts with the applied field resulting in a force. In this manuscript, an active damper will be theoretically developed that functions by dynamically modifying the current flowing through a coil, thus generating a time-varying magnetic field. By actively controlling the strength of the field around the conductor, the induced eddy currents and the resulting damping force can be controlled. This actuation method is easy to apply and allows significant magnitudes of forces to be applied without ever coming into contact with the structure. Therefore, vibration control can be applied without inducing mass loading or added stiffness, which are downfalls of other methods. This manuscript will provide a theoretical derivation of the equations defining the electric fields generated and the dynamic forces induced in the structure. This derivation will show that when eddy currents are generated due to a variation in the strength of the magnetic source, the resulting force occurs at twice the frequency of the applied current. This frequency doubling effect will be experimentally verified. Furthermore, a feedback controller will be designed to account for the frequency doubling effect and a simulation performed to show that significant vibration suppression can be achieved with this technique.

Magnetic Moments and Eddy Current Damping in Spherical Superconductors

1949 ◽  
Vol 76 (4) ◽  
pp. 580-581 ◽  
Author(s):  
J. J. Fritz ◽  
O. D. Gonzales ◽  
H. L. Johnston
Keyword(s):  
Eddy Current ◽  
Magnetic Moments ◽  
Eddy Current Damping

Effects of eddy-current damping on satellite attitude stability.

AIAA Journal ◽  
1966 ◽  
Vol 4 (6) ◽  
pp. 1123-1125 ◽  
Author(s):  
PETER W. LIKINS ◽  
RICHARD L. COLUMBUS
Keyword(s):  
Eddy Current ◽  
Attitude Stability ◽  
Satellite Attitude ◽  
Eddy Current Damping
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