Control of local flux distortion in single phase cores by corner joints with non-constant overlap length

Abstract

The possibility of controlling the local flux distortion in single phase cores was tested by model core experiments. The method used was based on an overlap zone which increased in width towards the inner edge of the core. It was found that the local flux distortion in the limbs was affected by introduction of such joints. However, an overall reduction of the distortion level was not obtained, nor was it possible to improve the building factor in this way. The investigation also showed that the level of flux distortion in the limbs is not mainly determined by the overlap length. This is in conflict with the hypothesis that differences in magnetic path lengths in transformer cores could be compensated for by means of the overlap length. Some of the results obtained are difficult to interpret. This indicates that complex mechanisms are involved in the generation of harmonics in the local flux, and should stimulate further work.