Prediction and Measurement of Iron Loss in a Short-Stroke, Single-Phase, Tubular Permanent Magnet Machine

This paper describes analytical prediction and measurement techniques for quantifying iron loss in a short-stroke, single-phase, tubular permanent-magnet machine which is developed for direct-drive linear compressors in domestic refrigeration applications. The technique is based on the analytically derived magnetic field distributions in three discrete regions of the stator core and a well established iron loss model, and is validated by finite element analysis. An iron loss measurement technique is developed in which the moving magnet armature is supported by flexural springs that eliminate frictional loss and facilitate resonant operation during measurement. A good agreement between the prediction and measurement is observed.