S11–S22 Three-Dimensional Wound-Core Oil-Immersed Transformer

Product overview

The core is wound continuously from high-grade grain-oriented silicon steel strip, so the magnetic circuit has no joints and no air gaps; the rolling direction of the strip follows the flux path, which reduces reluctance and eddy-current loss. The three limbs form an equilateral triangle, so all three phases have an equally short magnetic path and the circuit is fully balanced and symmetrical. Nested cutting of the strip achieves zero-waste use of raw material. Built from proven electrical materials, the design delivers lower operating noise, a more compact body and better short-circuit withstand.

Structure and operating principle

• Triangular magnetic circuit: the core is assembled from three identical frames in a three-dimensional equilateral triangle, so the three phases have equal path lengths and low reluctance.
• Continuous winding process: silicon steel or amorphous alloy strip is wound continuously with no joints, no air gaps and no high-reluctance zones; the coils are wound directly on the limbs for a solid, compact body.
• Electromagnetic induction: the primary coil creates an alternating field and the secondary coil develops the induced voltage; the fully sealed tank keeps air and moisture out.

Product characteristics

• Energy efficiency: no-load loss is 25–35% lower than a comparable stacked-core unit and no-load current up to 92% lower, a significant saving over the service life.
• Very low noise: a continuous gap-free magnetic circuit removes the vibration caused by magnetostriction and by core joints.
• Short-circuit and overload strength: circular coils and a triangular frame are loaded evenly, while the central duct through the body gives fast heat dissipation and a low temperature rise.