Effects of Axial Sticks and Proof Stress of Conductor Material on the Buckling Strength of Transformer Inner Winding

The inner winding of transformers may get buckled under the short-circuit condition. To avoid the buckling of the inner winding, the critical stress at which buckling occurs should be more than the applied stress during a short-circuit event. The important parameters on which the critical buckling stress depends are the inner winding radial dimension, number and dimension of strands, distance between the two adjacent axial sticks, dimension of the axial sticks, proof stress of the conductor material, etc. In literature, for the given geometrical details of the inner winding, the variation of critical stress with the number of axial sticks and the value of proof stress of the conductor material are not reported. In this letter, the effects of varying the number of axial sticks and the proof stress of the conductor material on the value of critical stress of the inner winding have been investigated.