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The Era of 3D Winded Cores: A Technological Leap in Transformer Manufacturing Equipment
2026-03-06
From Silicon Steel Sheet Slitting to Automated Winding: How Wuxi Shuhong Machinery Defines a New Height in Precision Manufacturing of Power Equipment
I.Transformer Industry Transformation: Equipment First
The global power system is undergoing a profound transformation. The integration of renewable energy into the grid, grid expansion and upgrades, and industrial energy-saving renovations are driving sustained growth in transformer market demand. More importantly, market demands for transformer energy efficiency are undergoing a qualitative change—the S13 energy efficiency rating has become the entry threshold for distribution transformers, the application ratio of amorphous alloy materials continues to increase, and the 3D triangular wound core structure has moved from a technological concept to large-scale production.
The core driving force of this transformation comes from the technological advancements in transformer equipment. 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 automated 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 technical challenge: how to make the magnetic circuit of a transformer core infinitely close 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 core winding, from foil winding machines to vacuum annealing furnaces, the manufacturing precision of power equipment is being redefined.
II.Winding: A Leap from Planar Lamination to Three-Dimensional Magnetic Circuits
The core technology of transformer winding machines lies in tension control. This equipment is equipped with both manual and automatic voltage adjustment devices. During the continuous winding of hundreds of meters of silicon steel strip, tension fluctuations are strictly controlled within ±3%. Excessive tension causes plastic deformation of the silicon steel sheets, reducing magnetic permeability; insufficient tension results in loose core winding, also creating air gaps and affecting magnetic circuit closure.
For three-dimensional triangular core windings, winding precision directly determines the symmetry of the magnetic circuit. After combining three identical single-frame iron cores, the three-phase magnetic circuit lengths are completely equal, the magnetic flux distribution is uniform, there are no obvious interlayer regions, 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, and it is also the fundamental reason why global transformer manufacturers are shifting towards three-dimensional wound iron core technology.
III. Winding: A Precision Manufacturing Platform Compatible with Multiple Materials
The three-dimensional triangular foil winding machine presents an even greater technical challenge. It needs to simultaneously process four materials: enameled wire, flat wire, paper-insulated wire, and foil strip, and must quickly switch between winding and foil winding modes. This equipment supports the winding requirements of φ0.3-4mm enameled wire, 4×10mm flat wire/paper-insulated wire, and 100-400mm foil strip, specifically matched to the geometric characteristics of circular coils.
When switching from winding to foil winding, the foil strip and layer insulation device shift 600mm to the right, cleverly avoiding the winding area; when switching back to winding, the foil winding device automatically resets. This mechanical design reduces single-changeover time from 45 minutes with traditional equipment to 8 minutes. The encoder counting accuracy reaches 0.1 revolutions, and it features forward/reverse segmentation, parameter setting, and power-off memory functions.
For instrument transformer equipment manufacturers, this multi-material compatibility means a significant increase in production line flexibility. A single machine can cover the entire range from fine wire winding for current transformers to foil coil winding for voltage transformers, increasing equipment utilization by nearly 40%. Technological advancements in coil winding equipment are changing the traditional manufacturing landscape where multiple specialized machines were required for instrument transformer production.
IV. Large-Scale Winding: Load-Bearing Capacity and Stability of Vertical Structures
Shuhong's LRJ series vertical winding machines cover a coil bearing capacity range from 2 tons to 40 tons. Taking the LRJ-20T-3000 as an example, the maximum coil bearing capacity is 20 tons, the maximum rotation diameter is 3000mm, the coil speed is infinitely adjustable, and the maximum torque is 21000 N·m. The equipment adopts a telescopic platform with photoelectric protection, an anti-reverse design, and pneumatic clamping for multi-wire systems.
The core advantage of vertical winding machines lies in their stability under heavy loads. Even with a 20-ton bearing capacity, the machine maintains stepless speed regulation of 0-10 rpm and rapid braking, and features a counting system with power-off memory. The lifting mechanism employs a synchronous design with a lifting height of 3000mm, and an automatic lubrication system with a low-oil alarm prevents bearing damage due to lubrication interruptions, ensuring long-term reliable operation.
V.Foil Winding: Automatic Welding and Tension Control
Shuhong's SH series foil winding machines cover foil widths 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 uses an active tension-applying technology powered by a motor, applying constant tension during winding, stopping, and unwinding, completely avoiding uneven coil tightness caused by loss of tension during winding.
The web-correction system employs photoelectric analog sensors, operating without contact with the foil edge, ensuring precise web correction regardless of foil thickness, with a correction accuracy of ±0.5mm. The winding reducer utilizes a worm gear reducer, maintaining spindle self-locking regardless of power supply, ensuring safety. The end insulation device allows for synchronous unwinding, coordinating with foil 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, web correction, welding, and winding—affects the final coil quality. Shuhong's equipment utilizes PLC and touchscreen control, minimizing potential failure points, eliminating frictional noise, ensuring reliable operation, and achieving high production efficiency.
VI. Slitting and Cross-cutting: The Precision System of Silicon Steel Sheet Processing
The slitting of silicon steel sheets is the initial process in transformer core manufacturing and the source of precision in the entire manufacturing process. Slitting accuracy directly affects material utilization and core stacking quality, thus impacting the final transformer performance.
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.
Conclusion: Precision Defines Performance, Equipment Determines the Future
From raw material preparation to winding, from coil winding to annealing, from oil tank to assembly, every step in transformer manufacturing accumulates or diminishes the final equipment performance. Shuhong Machinery's technological path is clear and unwavering: using equipment precision to support transformer energy efficiency, and using manufacturing certainty to address market uncertainty.
In the global power equipment market in 2026, the focus of competition has shifted from price to performance, and from single equipment to system solutions. Equipment capable of producing S13 efficiency transformers, handling 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 technical details are being repeatedly verified and continuously optimized.