35kV S11 & SZ11 Power Transformer – Low Loss Medium Voltage Substation Transformer

The 35kV S11 and SZ11 series power transformers are designed and manufactured in accordance with IEC 60076 international standards. These medium-voltage transformers are widely used in substations, industrial power systems, and renewable energy applications. The transformers support manual, electric, or automatic voltage adjustment through on-load tap changers, ensuring stable output voltage under varying load conditions. For capacities of 16000kVA and above, a bell-type tank design is adopted to enhance mechanical strength and improve structural reliability, making this product a next-generation energy-efficient solution with excellent operational economic benefits.

Energy Saving and Low Loss Performance

The transformer features optimized magnetic circuit design that significantly reduces energy consumption. The no-load loss is approximately 25% lower than the requirements specified in GB/T6451-2008, helping users reduce operating costs while improving overall system efficiency.

High-Quality Core Construction

The transformer core is manufactured using high-quality cold-rolled grain-oriented silicon steel sheets. Advanced precision cutting technology ensures burr size below 0.02mm. Fully oblique step-lap joints without punching or overlapping reduce magnetic resistance and improve performance. Double-H adhesive bonding integrates the core columns and yokes into a compact structure, effectively reducing no-load current, losses, and operational noise.

Reliable Winding Structure

The windings are made of high-purity oxygen-free copper to reduce copper loss and improve conductivity. Rounded coil pads and support bars create a uniform electric field and enhance insulation reliability. Reinforced internal supports improve mechanical strength and prevent deformation. For transformers rated 16000kVA and above, integrated support plates and pressure plates ensure consistent axial height and significantly improve short-circuit withstand capability.

Robust Mechanical Structure

Plate clamps and side beams form a strong frame structure. The transformer body and tank are fixed in six directions, allowing the transformer to withstand transportation impacts without displacement. When transportation impact values remain within specified limits, the transformer can be directly commissioned on-site without core lifting inspection, reducing installation workload and commissioning time.

Corrugated Tank with Enhanced Cooling

The tank wall is formed from a single steel plate folded into a corrugated structure. This design reduces welding points, increases mechanical strength, expands heat dissipation area, and improves cooling performance. The corrugated structure also minimizes sound wave reflection, effectively reducing operating noise while maintaining an aesthetically simple appearance.

Advanced Oil Conservator and Protection Design

A capsule-type oil conservator slows transformer oil aging and improves insulation reliability. Pointer-type oil level indicators prevent false readings and ensure accurate monitoring. Gas relays equipped with gas collection devices simplify maintenance and enhance operational safety.

Enhanced Sealing and Surface Treatment

The sealing structure undergoes strict quality control to prevent oil leakage. Steel materials are carefully inspected to eliminate rust, scratches, or deformation. Tank sealing surfaces are specially processed, and the entire tank is painted after burr and slag removal to improve coating adhesion and corrosion resistance.

Normal Operating Conditions

The transformer is designed for ambient temperatures up to +40℃. The average temperature of the hottest month is +30℃ and the annual average temperature is +20℃. The minimum ambient temperature is -25℃. Installation altitude should not exceed 1000 meters above sea level. The installation environment should be free from significant pollution, and the transformer is suitable for outdoor installation.

Voltage Regulation Design

The non-excitation or on-load voltage regulating design ensures stable voltage output and flexible operation in different grid conditions. This makes the transformer suitable for utility substations, industrial plants, and renewable energy grid connections.