Title :
Eddy Current Loss Minimization in Conducting Sleeves of High Speed Machine Rotors by Optimal Axial Segmentation and Copper Cladding
Author :
Shah, Manoj R. ; EL-Refaie, Ayman M.
Author_Institution :
GE Global Res. Center, Niskayuna
Abstract :
When a non-magnetic, high-strength metallic retaining sleeve offers advantages over a non-metallic (e.g. carbon fiber) one, it is possible to consider the application of a high conductivity shield "coating" on this sleeve to reduce the surface eddy current losses due to non-synchronous fields. One can start by using a Maxwell\´s equations based analytical model to "screen" for the optimal shield thickness and then employs a "2.5D" FE method that accounts for periodic fields and finite rotor length including axial segmentation and/or copper cladding. These are quantified to help design a low loss rotor sleeve for a high speed SPM machine with fractional-slot concentrated armature winding. With this type of windings the sleeve losses can be significant due to its rich asynchronous harmonic armature reaction mmf content.
Keywords :
Maxwell equations; claddings; copper; eddy current losses; finite element analysis; machine theory; machine windings; permanent magnet machines; rotors; synchronous machines; 2.5D FE method; Cu; Maxwell´s equations; SPM machine; asynchronous harmonic armature reaction; conducting sleeves; copper cladding; eddy current loss minimization; fractional-slot concentrated armature winding; high-speed machine rotors; low-loss rotor sleeve design; nonmagnetic high-strength metallic sleeve; nonsynchronous fields; optimal axial segmentation; Analytical models; Coatings; Conductivity; Copper; Eddy currents; Machine windings; Maxwell equations; Permanent magnets; Process design; Scanning probe microscopy;
Conference_Titel :
Industry Applications Conference, 2007. 42nd IAS Annual Meeting. Conference Record of the 2007 IEEE
Conference_Location :
New Orleans, LA
Print_ISBN :
978-1-4244-1259-4
Electronic_ISBN :
0197-2618
DOI :
10.1109/07IAS.2007.88
