Augmented Temperature Degrading Effect of Rare Earth Magnets Arranged in Segmented Halbach Arrays

If rare earth magnets are arranged in a Halbach array, flux concentration occurs at one side of the array. This principle can be utilized in electric machines to augment the air-gap flux density or even to omit flux carrying iron parts. Highly utilized electric machines are operated at elevated temperatures requiring an appropriate selection of the material. However, the uncommon magnet orientation required in a Halbach array entails an augmented temperature degrading effect in the magnets. The effect is studied in three test cases with linear arrangements of Halbach arrays by means of 2-D and 3-D Finite Element Analysis and is validated through measurements.