In large permanent magnet motors, the permanent magnet in the motor is segmented into parts in order to reduce the eddy current loss. It is reported that the insulation between NdFeB sintered magnets is possible only by contacting the segmented permanent magnets without the insulation. But the mechanism for such a phenomenon has not been clear yet. In this paper, the effect of force on the apparent contact resistance between permanent magnets is examined. The idea of contact resistance coefficient is also discussed. It is shown that the eddy current loss of segmented sintered NdFeB magnets is almost the same as the loss of the case when an insulating material is inserted between magnets.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering