Distribution transformer cores · manufactured in Shanghai, shipped worldwide
3D Wound Core
Distribution transformer cores
3D Wound Transformer Core
Three-phase three-limb wound core with a fully symmetrical, joint-free magnetic path — the mainstream way to cut loss and noise in distribution transformers.
Symmetrical magnetic path, balanced three-phase current
Vacuum annealing relieves stress and lowers loss further
A 3D wound core is wound as one continuous triangular prism, so each limb carries exactly the same magnetic circuit and there is no butt joint anywhere in the path. The result is a transformer that runs measurably quieter and cooler: no-load loss typically falls 10–20% below an equivalent stacked core, and the three-phase no-load current stays balanced.
ZWILLIS winds these cores under constant tension and then vacuum-anneals them to remove winding stress, which keeps the loss stable over the transformer's whole service life. For the same kVA rating the 3D core also gives a shorter, more compact tank — useful wherever the transformer must fit a compact substation or a pad-mounted enclosure. Standard range covers 30 to 2,500 kVA in 10, 20 and 35 kV classes.