Concentric vs Disc (Layer) Transformer Windings?

Published 27 Aug 2026Updated 27 Aug 20266 min readIntermediateDesign
Quick answer — A concentric (layer) winding has the turns wound axially along the core in stacked layers; a disc winding has the turns wound as a series of horizontal discs (or coils) connected in series. Concentric windings are simple and robust for smaller units and give high impulse strength; disc windings are common for larger HV units where the axial current distribution and impulse response must be controlled.
Contents
What is the difference between concentric and disc windings?

Concentric / layer winding

The winding is wound as continuous layers along the core. It is mechanically simple, forgiving, and often used for LV windings and moderately sized HV windings, with good impulse strength when correctly designed.

Disc winding

The winding is a series of disc-shaped coils stacked axially. It allows a controlled radial distribution of inter-turn voltage and is well-suited to large HV and very high-voltage units, though it needs careful clamping against axial forces.

Choosing

The choice depends on the voltage rating, impulse requirement, short-circuit duty and the design philosophy; both are proven, and the manufacturer optimises for the specific transformer.

References & standards

Related

Book seriesAcademy

Related manufacturers

Prolec GE (GE Vernova) · Prolec GE Waukesha · Hitachi Energy USA · Siemens Energy · Eaton · Virginia Transformer Corp

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Technical content is prepared from engineering references, standards frameworks, manufacturer documentation and industry sources. Contractual or compliance decisions should refer to current official standards. TransformerPath Technical Editorial.
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