Step-Lap Cutting Technology of TSTY Silicon Steel Transformer Core

Step-Lap Cutting Technology of TSTY Silicon Steel Transformer Core

1. Introduction

The core is the core magnetic component that determines the energy efficiency, noise and service life of power transformers. Traditional butt or single-layer overlapping silicon steel joints will form concentrated air gaps in the magnetic circuit, resulting in high core loss, large magnetizing current and obvious operating noise. TSTY Electric adopts advanced 45° miter seven-stage step-lap cutting & stacking technology for all 10kV–220kV oil-immersed & dry-type transformer cores. Combined with high-grade CRGO cold rolled grain-oriented silicon steel, this process greatly optimizes the magnetic flux path, and makes our transformers more energy-saving and stable for power grid projects in Global Markets.

2. What Is Step-Lap Cutting Technology?

Step-lap cutting means cutting silicon steel sheets at a 45° miter angle, and stacking 5–7 laminations as one staggered step unit. Each layer’s joint position is offset like a staircase, dispersing the air gap that originally concentrated at a single corner.

Core Production Flow at TSTY

1. Raw material inspection: Baosteel and Wuhan Iron and Steel silicon steel sheets incoming magnetic performance test

2. CNC longitudinal slitting & precision transverse step-lap shearing

3. Deburring control (burr ≤0.03mm) to avoid inter-sheet short circuit

4. Automatic staggered step stacking with positioning holes

5. Stress relief annealing to eliminate machining stress

6. Tight clamping & overall performance inspection before delivery

3. Core Advantages of TSTY Step-Lap Core

• Lower No-Load Core Loss Compared with conventional two-step lap cores, total core loss reduces by 2%–6%, exciting power drops 31%–37%. It effectively cuts long-term power consumption for grid operation, perfectly matching energy-saving standards of GOST and IEC.
• Low Operating Noise Staggered step joints average magnetic stress at corners, weaken magnetostriction vibration, noise level decreases by 5%–8%, suitable for urban substations and residential nearby power projects.
• Uniform Magnetic Flux Distribution 45° miter cut aligns flux parallel to silicon steel grain orientation, eliminates local high flux density hot spots, improves transformer overload resistance.
• Higher Mechanical Stability Staggered overlapping structure enhances overall rigidity, anti-vibration during long-distance land transportation to Central Asia, no loose lamination risk.
• Full Customization for OEM/ODM TSTY supports step-lap core customization for 10kV, 35kV, 110kV, 220kV transformers, independent core supply available for local electrical manufacturers.

4. Application Scenarios of TSTY Step-Lap Cores

• 110kV / 220kV high voltage main power transformers for national grid renovation
• Prefabricated box substations for solar & wind new energy projects
• Dry type distribution transformers for industrial parks, mining factories
• OEM separate silicon steel core export to electrical traders

5. Conclusion

Step-lap cutting stacking is the core competitive craft of TSTY transformer production. Strict full-process precision control from silicon steel cutting to core inspection ensures every transformer core reaches ultra-low loss standards. If you need customized transformer cores or complete power transformers compliant with local Central Asian power standards, send your technical parameters to our team for free technical solution and quotation.