Effect of stack of transformer core lamination on losses and flux distribution in 3-phase distribution transformers 1000kVa

Abstract

This paper describes the results of an investigation on the effect of different amount of layers per stack of core lamination in the three of 3-phase distribution transformers 1000kVA. The investigation involves the variation of power loss, building factor, total harmonic distortion of flux and flux leakages. The power loss and flux distribution have been measured using no load test in three types of model of setting of core built from the same size and type of M5 (CRGO) laminations. The power loss of the transformer core assembled with 1 layer per stack of lamination is 6.58% better than the power loss of the transformer core assembled with 2 layers per stack of lamination and is also 8.31% better than the power loss of the transformer core assembled with 3 layers per stack of lamination, at 1.5T, 50 Hz. The flux leakage at the corner joint in the core assembled with 1 layer per stack of lamination is the lowest among the three of the transformer cores, over the whole flux density range. Total harmonic distortion flux is the largest in the transformer core with 3 layers per stack of lamination and the smallest in the transformer core with 2 layers per stack of lamination. Using 1 layer per stack of lamination in transformer core is more efficient than using the other two the three lamination of the transformer core.