35kV Dry-Type Transformer Solution for Mongolian Power Project

Dingxin Electric supplied a 35kV SC(B) Series dry-type transformer solution for a power distribution project in Mongolia. The customer needed to step down the local 35kV grid voltage to a usable distribution voltage while ensuring reliable operation under Mongolia’s demanding environmental conditions.

The selected transformer complies with the requirements of IEC 60076-11 and IEEE C57.12.01 and is suitable for industrial facilities, commercial buildings, substations, renewable-energy projects, and other locations requiring safe and dependable power distribution.

Customer Challenges

The customer’s main concerns included:

• Reliable operation in Mongolia’s cold and highly variable climate
• Low energy losses during long-term continuous operation
• Reduced noise near occupied or sensitive areas
• Strong resistance to lightning impulses and switching overvoltages
• Sufficient overload capacity during periods of peak demand
• Improved fire safety compared with oil-immersed transformers
• Simple maintenance and dependable local power distribution

Voltage fluctuations and transient overvoltages in the power network also placed additional demands on the transformer’s insulation performance.

Dingxin Electric Solution

After reviewing the customer’s power capacity, incoming voltage, output voltage, installation environment, and expected load profile, Dingxin Electric proposed a customized 35kV SC(B) Series non-excitation voltage-regulating dry-type transformer.

Optimized Low-Loss Magnetic Core

The transformer core uses high-quality silicon steel sheets. By optimizing the core structure and reducing the operating magnetic flux density, Dingxin Electric minimized core losses and magnetostriction.

This design helps the customer reduce:

• No-load energy consumption
• Transformer operating noise
• Long-term electricity costs
• Mechanical vibration during operation

Enhanced High-Voltage Coil Design

The high-voltage winding structure was optimized to improve the distribution of voltage and capacitance between winding layers. This provides greater resistance to atmospheric overvoltage and switching overvoltage.

The improved electric-field distribution also reduces local electrical stress and helps prevent partial discharge, supporting a longer and more reliable service life.

Temperature Monitoring and Forced-Air Cooling

A temperature-control system and forced-air cooling device can be integrated into the transformer. When the winding temperature or load reaches the preset threshold, the cooling fans start automatically.

This arrangement provides:

• Real-time temperature monitoring
• Automatic fan control
• Overtemperature alarm and protection
• Improved short-term overload capability
• Safer operation during peak-load periods

Dry-Type Safety and Easier Maintenance

Because the transformer does not use insulating oil, it eliminates the risk of oil leakage and significantly reduces fire and environmental hazards. It is particularly suitable for indoor substations, industrial plants, commercial facilities, and other locations with strict safety requirements.

The dry-type design also reduces routine maintenance work and helps lower the customer’s overall operating costs.

Typical Project Configuration

Project Results

The Dingxin Electric solution helped the customer establish a safer and more efficient power distribution system. The transformer delivered stable voltage conversion while addressing the customer’s concerns regarding low-temperature operation, energy losses, noise, insulation reliability, and peak-load capacity.

The customer benefited from:

• Stable and dependable 35kV voltage conversion
• Lower operating losses and lifecycle costs
• Reduced transformer noise
• Improved resistance to impulse and switching overvoltages
• Enhanced overload capability with automatic cooling
• Lower fire and environmental risks
• Easier inspection and maintenance

Conclusion

The Mongolian project demonstrates Dingxin Electric’s ability to provide customized dry-type transformer solutions for demanding power environments. With its low-loss core, optimized high-voltage windings, reliable insulation system, and intelligent temperature-control options, the Dingxin Electric 35kV SC(B) Series dry-type transformer provides customers with a safe, efficient, and durable power-distribution solution.

Dingxin Electric — Reliable Power Solutions Engineered for Demanding Environments.