Factors affecting errors due to 2-D approximate analysis of 3-D magnetic fields with eddy currents [rotating machines]

The effects of the leakage flux, eddy current path, and end coil of electric machines on the flux and eddy current density analyzed by the 2-D approximation are investigated systematically by making a comparison with 3-D analysis. It is shown that, when the gap length is relatively large, the difference between the fluxes calculated by 2-D and 3-D analyses is pronounced due to the leakage flux. The flux in the pole obtained by 3-D analysis is larger than that obtained by 2-D analysis under constant current excitation, and the flux obtained by 3-D analysis is less than that obtained by 2-D analysis under constant voltage excitation. When the eddy current flows in the thin core, a larger error occurs in the 2-D analysis, because there is a great difference in eddy current paths between 2-D and 3-D models

Digital Object Identifier: 10.1109/20.278794
Published with permission from the copyright holder. This is the institute's copy, as published in Magnetics, IEEE Transactions on, Nov 1991, Vol. 27, Issue 6, Pages 5223-5225.
Publisher URL:http://dx.doi.org/10.1109/20.278794
Copyright © 1991 IEEE. All rights reserved.