Stator iron loss of tubular permanent magnet machines

Whilst methods of determining the iron loss in rotating permanent magnet machines have been investigated extensively, the study of iron loss in linear machines is relatively poorly documented. This paper describes a simple analytical method to predict flux density waveforms in discrete regions of the laminated stator of a tubular permanent magnet machine, and employs an established iron loss model to determine the iron loss components, on both no-load and on-load. Analytical predictions are compared with the iron loss deduced from finite element analyses for two tubular permanent magnet machine designs, and it is shown that if a machine has a relatively high electrical loading, the on-load iron loss can be significantly higher than the no-load value.