Losses in the axial‐flux permanent‐magnet machine housing

Abstract

Purpose

The purpose of this paper is the investigation of eddy currents induced in the axial‐flux permanent‐magnet machine housing by the leakage flux and the introduction of permanent magnets in the steady‐state AC finite‐element analysis and coupling their effects with the transient thermal analysis.

Design/methodology/approach

The proposed approach is based on the finite‐element method as well as on using the basic analytical equations. The approach was first applied in the magneto transient analyses. Because of the different physical transient‐time constants, the steady‐state AC analysis coupled with transient thermal should be used.

Findings

The permanent magnets in the steady‐state AC analysis coupled with the transient thermal analysis can be simulated by coils with an imposed current of a frequency depending on the number of pole pairs and rotation speed. Using any of the electrically conductive materials for the axial‐flux inner slotless stator permanent‐magnet machine housing should be avoided.

Originality/value

The leakage flux induced by permanent magnets and spreading into the axial‐flux permanent‐machine housing is first defined by using the magneto‐transient finite‐element analysis and further used in the steady‐state AC analysis coupled with the transient thermal analyses, all in 3D. Based on the results of these analyses, the temperature distribution in entire machine is calculated and compared with the measurement results.

Citation

Šrekl, M., Bratina, B., Zagirnyak, M., Benedičič, B. and Miljavec, D. (2013), "Losses in the axial‐flux permanent‐magnet machine housing", COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Vol. 32 No. 4, pp. 1366-1382. https://doi.org/10.1108/03321641311317176