Effect of Flexibility of Axial Supporting Spacers on the Buckling Strength of Transformer Inner Winding

The transformer inner winding conductors may fail due to buckling when an enormous compressive electromagnetic force is applied on them under the short-circuit situation. In literature, the analytical expression for the critical forced buckling stress of the transformer winding is given in which the winding section, between the three adjacent axial supporting spacers, has been modeled as a circular arch. In the model, the axial spacers are considered as a rigid body, but they may have some flexibility. In this paper, an investigation has been done, through case studies, to analyze the influence of the flexibility of the spacers on the critical stress of the inner winding.