Alternating-Current Energy Losses in Iron Laminations at Magnetic Saturation

Abstract

A LIMIT to the power output of most rotating electrical machines is set by magnetic saturation in the teeth of the punchings employed. Designers of these machines have, however, never had data available on the specific iron losses of the materials they use for alternating flux densities higher than about 75 per cent of the saturation value. The usual methods of measurement, applied to specimens of the material, fail completely at higher flux densities than this because the power factor becomes very-small and the magnetizing current very high. The former introduces difficulties when wattmeters are used, and the latter when thermal methods are contemplated. We have successfully used the following method.