| Autor(en): |
Wolfgang Amrhein, Siegfried Silber, Michael Huber, Martin Reisinger, Peter Jenckel und Christian Redeman |
| Journal: |
The 10th of International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, Honolulu, Hawaii |
| Jahr: |
2004 |
| Monat: |
März |
| Zusammenfassung: |
The extraordinary wide variety of application fields as well as high technical and commercial demands combined with large scale manufacture lead to an enormous diversity of design variations with electromagnetic small and micro drives. This process is accelerated by further developments in signal and power electronics technologies as well as by the progresses of technical materials. Beside technical standard features as for example the range of speed, the torque constancy, the robustness or the lifetime demands on low energy consumption, high power densities and motor dynamics become more and more significant. There is an efficient way to improve the performance of electromagnetic converters in view of energy consumption, power density and motor dynamics by the use of high energy permanent magnets. Conventional permanent magnet circuit design configurations as the construction of brushless DC-motors are based on the interaction between the permanent magnetic field and the specific current density of the armature. There is no significance being attached to the armature field in this case. In ideal circumstances the armature field should be as small as possible to avoid the torsion of the excitation flux vector, demagnetization problems and saturation effects in the ferromagnetic iron. A different kind of force or torque generation is based on the principle of Maxwell forces acting between ferromagnetic parts. A typical example is given by switched reluctance motors using wide ferromagnetic teeth and slots in the stator as well as in the rotor. In this case the quadratic function between the tangential air gap forces respectively the torque and the armature mmf has an detrimental effect on the motor utilization at low power range. |
