Effect of clamping stress on power loss in POWERCORE strip and Si-Fe transformer cores

A three-limb, three-phase transformer core having a power rating of 14 kVA was assembled from a 101-mm-wide and 0.14-mm-thick amorphous POWERCORE strip using butt and lap T and corner joints. The effect of stresses due to clamping and bending of the laminations on the losses and magnetizing power of this core was investigated. It was found that the stresses were far more harmful in the core assembled from amorphous material than in a similar core assembled from high-permeability grain-oriented 3% silicon iron.<
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