S20 New Energy-Saving Three-Dimensional Rolled Core Oil-Immersed Transformer

　　The S11-type three-dimensional rolled-core distribution transformer has a capacity range of 30 to 2500 kVA. The core adopts a three-phase, three-column structure with an internally and externally wound frame. It features a high degree of mechanization and a large stacking factor. The high- and low-voltage windings are continuously wound on the core columns, ensuring excellent concentricity and tight winding.

　　The S11 series distribution transformers with wound-iron-core construction feature low losses, and their load losses are comparable to those of the new S11 stacked-iron-core distribution transformers. Compared to GB/T6415-2008, their no-load losses have been reduced by an average of 50%. These transformers require less primary material and are lighter in weight. They exhibit a small no-load current, and the magnetic flux aligns completely along the crystal lattice direction of the cold-rolled silicon steel sheets. The noise level is low, dropping by approximately 3–5 dB compared to the standard values specified in JB/T10088-2004. They possess strong short-circuit withstand capability and high reliability. The clamping components primarily serve to tighten the windings, while the iron yoke insulation is integrated with trapezoidal spacers, ensuring uniform pressure distribution throughout the transformer core.

　　Core: Made of 30Q120 cold-rolled silicon steel sheets. The core features a three-phase column with an inner and outer frame winding structure; the core columns have a multi-stage stepped cylindrical cross-section. After winding, the core is vacuum-annealed and shaped. Tensioning bolts on the upper and lower clamping plates secure the core body. The surface of the core is coated with epoxy resin to ensure it remains deformation-free and rust-free.

　　Windings and Core Assembly: The low-voltage winding is a four-layer (or two-layer) cylindrical structure consisting of 1 to 6 conductors twisted together, using paper-insulated flat copper wire. The high-voltage winding is a multi-layer cylindrical design with excellent impulse distribution, employing high-strength polyacetal-coated round copper wire. The coils are wound directly onto a rotating form composed of a gear disc and a soft paper tube, which is clamped onto the core column. The iron yoke insulation is integrated with trapezoidal spacers, ensuring uniform pressure distribution throughout the core assembly. A novel suspension plate positioning structure is adopted, providing both longitudinal and lateral positioning to guarantee the stable and non-displaced installation of the core assembly.

　　Fuel tank: Primarily a corrugated fuel tank. It can also be designed as a rectangular plate-type radiator fuel tank.

　　 Product features: (Compared to conventional stacked-core transformers)

　　 Low loss

　　Due to its features—such as seamless construction with low magnetic reluctance, magnetic flux paths in the corners aligned with the magnetization direction of the silicon steel sheets, tight winding resulting in a high filling factor, and lightweight core—the three-dimensional wound-core oil-immersed transformer exhibits significantly improved performance compared to conventional laminated-core oil-immersed transformers. Specifically, its no-load loss (Po) can be reduced by 18% to 28%, and its no-load current (Io) can drop by 50% to 60%. This results in remarkable energy savings and enhanced operational economy.

　　 Low noise

　　The noise level of a three-dimensional core oil-immersed transformer is 5 to 10 decibels lower than that of a laminated-core oil-immersed transformer, making it an exceptionally quiet product.

　　 High mechanical strength

　　Solid-core transformers all feature circular core cross-sections, which offer superior short-circuit resistance compared to elongated-oval cross-sections. Moreover, the spacer blocks provide high coverage and excellent clamping performance, significantly enhancing the product’s short-circuit resistance.

　　 Technical Parameters of S11 Three-Dimensional Wound Core Oil-Immersed Transformer