Measurement of loss in stator cores built with silicon-iron laminations cut at various angles to the rolling direction

Three model cores of the stator of a large turbogenerator were built with grain-oriented silicon-iron laminations, with rolling directions tangential and perpendicular to the circumference of the stator and also non-oriented silicon-iron laminations. Three more models were built with combinations of two of these three types of material. The total iron loss in each of them was measured and the results have been compared with one another. It has been found that the cores built with combinations of different types of material had lower losses than those built with one type of material, especially at 1.4 T. The effect of two different types of lapping arrangement on the total iron losses was also considered.