A Precision Revolution in Transformer Core Manufacturing: Shuhong Machinery's Equipment Technology Practice

From material cutting to winding, from slitting to annealing, how does specialized equipment for 3D triangular wound cores define new standards in power equipment manufacturing?

I.Transformer Energy Efficiency Upgrades: Equipment First

The global power equipment market is undergoing a profound transformation. Upgrades to the European power grid, expansion of Southeast Asian distribution networks, and a surge in demand for renewable energy grid connection are all driving continuous improvements in transformer energy efficiency standards. The S13 energy efficiency rating has become the new benchmark for distribution transformers, the application range of amorphous alloy materials is expanding, and the 3D triangular wound core structure is moving from the laboratory to large-scale production.

Behind these changes lies a fundamental leap in transformer equipment technology capabilities. Every key indicator of a transformer—no-load loss, load loss, noise level, and overload capacity—is directly constrained by the precision of core manufacturing and coil winding processes. Achieving this precision relies on the non-destructive processing capabilities of core shearing equipment, the precise tension control of automatic winding machines, and the thermal repair capabilities of vacuum annealing furnaces for magnetic domain structures.

Wuxi Shuhong Machinery Technology Co., Ltd.'s production base in Hai'an, Nantong, responds daily to the same question: how to make the magnetic circuit of transformer cores closer to the ideal state of theoretical design. The answer is written in every piece of equipment leaving the factory—from CNC slitting lines for silicon steel sheets to automatic winding machines for three-dimensional cores, from foil winding machines to vacuum annealing furnaces, the manufacturing precision of power equipment is being redefined.

II.Winding: A Technological Leap from Planar to Three-Dimensional

Traditional laminated cores have an inherent defect: discontinuous magnetic circuits. Distortions in magnetic flux density at the joints lead to increased no-load current, increased noise, and increased losses. The emergence of three-dimensional core winding solves this problem, but it places higher demands on winding equipment.

Shuhong's SHJR-1200 automatic core winding machine is specifically designed for closed-type core winding and is also suitable for winding planar single-phase, planar three-phase, and three-dimensional triangular cores. It has a maximum core outer diameter of 300mm, a steplessly adjustable winding speed of 0-60r/min, and a total installed power of 7.5KW. The equipment employs servo drive, PLC control, and a touchscreen interface, featuring automatic reset, automatic stop, processing parameter setting, and real-time display functions.

For three-dimensional triangular wound cores, winding precision directly determines the magnetic circuit symmetry. After combining three identical single-frame cores, the three-phase magnetic circuit lengths are completely equal, the magnetic flux distribution is uniform, there are no obvious interlayer zones, and no distortion of magnetic flux density at the joints. This is the technical basis for the 25-35% reduction in no-load loss of three-dimensional transformers compared to national standards.

III.Winding: Precision Control with Multi-Material Compatibility

After the core is completed, the next crucial process is coil winding. The transformer windings must withstand the thermal stress of long-term operation and the electrodynamic forces during short circuits; the winding quality directly affects the transformer's lifespan.

Shuhong's SHRX-2 three-dimensional wound core winding machine is suitable for transformer capacities ranging from 30-630KVA. It adopts a horizontal winding method, with the drive gear speed infinitely adjustable from 0-300r/min. The internal positioning method ensures smooth operation, low noise, and high reliability. The equipment employs a PLC control system, a touchscreen interface, encoder counting, and features automatic stop and power-off memory functions. The internal top-mounted core clamping device reduces clamping time, making it convenient and efficient.

A more complex type is the three-dimensional triangular foil winding machine, which simultaneously processes four materials: enameled wire, flat wire, paper-insulated wire, and foil strip, and must quickly switch between winding and foil winding modes. This machine supports winding requirements for φ0.3-4mm enameled wire, 4×10mm flat wire/paper-insulated wire, and 100-400mm foil strip, and is specifically designed for round coils.

IV.Foil Winding: Automatic Welding and Tension Control

Foil coils are widely used in distribution transformers and reactors. Unlike round wire winding, foil winding requires simultaneous processing of foil strip, interlayer insulation, and end insulation, demanding a higher level of equipment integration.

Shuhong's SH series foil winding machines cover a foil strip width range from 600mm to 1400mm. Taking the SH-1100 as an example, the coil outer diameter is 200-1000mm, the foil width is 200-1100mm, the winding speed is 0-20r/min, and the maximum foil tension is 10000N. The equipment adopts an active tension-applying technology using a motor, applying constant tension during winding, stopping, and unwinding, avoiding uneven coil tightness caused by loss of tension during winding.

For transformer manufacturing equipment, the technical challenge of foil winding machines lies in the coordinated control of multiple systems. The timing of each step—unwinding, feeding, correction, welding, and rewinding—affects the final coil quality. Shuhong's equipment uses PLC and touchscreen control, resulting in fewer potential failure points, no frictional noise, reliable operation, and high production efficiency.

 V. Slitting and Cross-cutting: Precision Control of Silicon Steel Sheet Processing

The slitting of silicon steel sheets is a front-end process in transformer core manufacturing. Slitting accuracy directly affects material utilization and the quality of core stacking.

Shuhong's SH-1000 CNC slitting line for silicon steel sheets is suitable for silicon steel materials with a thickness of 0.20-0.5mm. The coil width is 1000mm, the coil weight is 5 tons, and the shearing speed is adjustable in three levels: 0-60m/min, 0-90m/min, and 0-150m/min. The shearing width error is ±0.1mm, the shearing burr is ≤0.02mm, and it can shear up to 10 strips, with a strip edge straightness ≤0.2mm/m.

For cross-cutting, the SH-600 CNC cross-cutting line for silicon steel sheets has a shearing width of 60-640mm, a shearing length of 400-3500mm, a shearing thickness of 0.20-0.35mm, a shearing length accuracy of ±0.1mm, a shearing angle accuracy of ±0.025°, and a maximum feeding speed of 250m/min. The equipment adopts an imported controller and an AC servo control system, capable of automatic cross-cutting with one to seven levels of stepping, suitable for the production of ferrosilicon chips of different widths.

VI.Conclusion: Precision Equals Performance

From raw material preparation to winding, from winding to annealing, from the oil tank to assembly, every step in transformer manufacturing accumulates or diminishes the final equipment performance. Shuhong Machinery's technological path is clear and consistent: using equipment precision to support transformer energy efficiency.

In the global power equipment market in 2026, the focus of competition has shifted from price to performance. Equipment capable of producing S13 efficiency transformers, processing amorphous alloy materials, and achieving large-scale three-dimensional core manufacturing is becoming the mainstream choice in the market. And the starting point for all of this is the tension stability of every automatic coil winding machine, the sharpness of every slitting shear, and the temperature uniformity of every annealing furnace.

On the production line of Wuxi Shuhong Machinery Technology Co., Ltd., these details are being repeatedly verified and continuously optimized.