Oil-immersed transformer low-voltage winding structure adopting transposed conductors

Abstract

The invention relates to the technical field of a transformer, and particularly relates to an oil-immersed transformer low-voltage winding structure adopting transposed conductors. The oil-immersed transformer low-voltage winding structure comprises an insulting cylinder; three layers of transposed conductors are wound on the periphery of the insulating cylinder turn by turn and layer by layer, and respectively are an inner layer transposed conductor, a middle layer transposed conductor and an outer layer transposed conductor; interlayer oil passages are formed between three layers of transposed conductors; an interlayer oil passage is also formed between the inner layer transposed conductor and the outer wall of the insulating cylinder; the interlayer oil passages are axially distributed along the insulating cylinder; and end rings are mounted at both ends of each layer of transposed conductor. The oil-immersed transformer low-voltage winding structure disclosed by the invention has the advantages that eddy current loss and circulation current loss in the conductors are greatly reduced; material cost is reduced; heat dissipation efficiency is high; mechanical intensity is high; a winding process is simple; and the like.

Description

technical field [0001] The invention belongs to the technical field of transformers, in particular to an oil-immersed transformer low-voltage winding structure using transposed wires. Background technique [0002] For a long time, the low-voltage windings of 110kV oil-immersed power transformers have been wound with ordinary wires, that is, paper-wrapped flat copper wires. For example, the low-voltage winding phase current of SZ11-50000 / 110 oil-immersed power transformer reaches 1587A, and the cross-sectional area of ​​the wire through which the current passes is very large. In order to meet the above requirements, the number of parallel wires needs to reach 28. The low-voltage winding is wound with single-helical, ordinary wires, and three group transpositions are used for winding. If the parallel wires are not completely transposed, the eddy current loss of the wires in the longitudinal and transverse leakage magnetic field is large, and the unbalanced current circulation...

AI Technical Summary

Problems solved by technology

If the parallel wires are not completely transposed, the eddy current loss of the wires in the longitudinal and transverse leakage magnetic field is large, and the unbalanced current circulation loss between the wires caused by multiple wires in different leakage magnetic field positions is very large, which can sometimes account for low voltage. 10% to 20% of the winding load loss; in addition, the structure of this single helical winding is more complicated, and the winding process is more difficult

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