Power Supply Solution for a 6,300 kVA - 35 kV Overseas Camp Project in Mongolia: A Full-Lifecycle Scheme Featuring Low-Loss and Highly Cost-Effective Oil-Immersed Distribution Transformers

Writer： Hengfeng you electric Time：2026-06-30 views：times

I. Project Overview and Technical Specifications of SFZ11-6300 kVA - 35 kV/0.4 kV Power Transformers for the Mongolia Camp Project

This tailored solution is engineered and rolled out by Qingdao Hengfengyou Electric Co., Ltd. (Hengfengyou Electric). For an overseas field camp power supply infrastructure project in Mongolia, the company has successfully delivered 5 units of high-performance oil-immersed distribution transformers. This project falls under procurement for overseas camp power supply facilities in electrical engineering. Its core purpose is to provide long-term, stable, and highly reliable power support for the overseas camp engineering project under Mongolia's extreme cold and severe sandstorm environments.

• Commercial Inquiry & Global Technical Support Email: hfy@hengfengyou.com

• Product Information: SFZ11-6300 kVA - 35 kV/0.4 kV Power Transformer (Extracted from translated documents)

II. Technical Specifications and Standards for SFZ11-6300 kVA - 35 kV/0.4 kV Power Transformers

1. Applicable Standards

The power transformers shall strictly comply with the requirements of the following international, regional, and specialized standards:

2. General Requirements

• Operating Environment and Conditions:

  • Installation Site: Compliant with the U1 condition under the ГОСТ 15150-69 standard, Category II environmental type (Industrial Environment).

  • Altitude: Suitable for continuous operation at altitudes exceeding 1,500 meters above sea level.

  • Ambient Temperature Range: -45°C to +40°C.

  • Relative Humidity: Shall not exceed 80% when the ambient temperature is at 25°C.

• Product Qualification Documents: The product shall be delivered with manufacturer qualification certificates, certificates of conformity alignment with international standards, operation and maintenance manuals, engineering drawings, product catalogs, and all inspection/test reports prescribed by the manufacturer's internal quality control standards.

• Production and Warranty: All units must be manufactured in 2026 or later. The manufacturer shall provide a warranty period of no less than 5 years, and the designed service life shall be no less than 30 years.

3. Structure and Performance Parameters

• （1） Core Structural Requirements

  1. Equipped with an anti-resonance structure and an oil-insulated, forced-cooling tap-changer.

  2. The transformer oil shall be Polychlorinated Biphenyls (PCB) free, verified and certified by strict testing.

  3. The core steel plates shall utilize low-loss CRGO (Cold-Rolled Grain-Oriented) silicon steel.

  4. The main oil tank height exceeds 3 meters, designed for track/rail installation.

  5. Technical Requirements for Cooling Fans:

     • Airflow Rate: 6,000 - 9,000 $m^3/h$

     • Motor Power: 1.0 kW - 2.2 kW

     • Frequency: 50 Hz

     • Operating Temperature Range: -45°C to +40°C

     • Ingress Protection Rating: IP65 (Waterproof, dustproof, and protection against foreign objects)

     • Phase / Voltage: 3-Phase / 380 V

     • Rotational Speed: 960 - 1,450 rpm

• （2） Key Performance Parameters of SFZ11-6300 kVA - 35 kV/0.4 kV Transformer

• （3） Specialized Performance Requirements for SFZ11-6300 kVA - 35 kV/0.4 kV Transformer

  1. On-Load Tap-Changer (OLTC / РПН):

     • Regulation Range: ±5 × 1.5%

     • Tap Positions: 11 positions (Supplied by Huaming)

     • Mechanism Type: Dual-driven mechanism featuring both motorized operation and manual control.

     • Mechanical Endurance / Switching Cycles: Not less than 300,000 operations.

  2. HV Winding Configuration: Integrated with current transformers (CTs) with an accuracy class of not lower than 10P.

  3. Short-Circuit Withstand Capability Duration: Maximum 3 seconds.

  4. Cooling Method: ONAF (Oil Natural Air Forced / 油浸自冷 + 强制风冷).

4. Inspection and Testing Items for SFZ11-6300 kVA - 35 kV/0.4 kV Transformer

The certified inspection and test reports for the following items must be fully completed and provided upon delivery:

1. Dielectric withstand test (Voltage withstand test)

2. Mechanical strength test of the transformer tank/body

3. Tightness/leakage test of the transformer tank/body (Sealing test)

4. Insulation dielectric strength test

5. Short-circuit withstand capability test (Short-circuit strength test)

6. Acoustic sound level measurement (Acoustic test)

7. Transformer insulating oil analysis and testing

8. Mechanical strength test of operational and moving parts

9.  Measurement of winding vector group, verification of no-load loss and load loss.

III. Why Choose Hengfengyou Electric's Distribution Transformer Solutions?

In the power equipment procurement markets of Mongolia and Central Asia, Chinese enterprises and overseas general contractors (EPCs) often face the dual challenge of "tight budgets" and "harsh operating conditions." Hengfengyou Electric's distribution transformer solution, custom-tailored for this camp project, strikes a flawless balance between ultimate cost-effectiveness and military-grade stability. Its core competitive edges are reflected in the following four innovative dimensions:

1. Commitment to "100% Genuine All-Copper": Obliterating the "Temperature Rise and Capacity Fraud" Pitfall of Low-Price Competitors

Overseas field camps typically host high-power domestic appliances, heavy construction machinery, and pumping stations, resulting in an exceptionally high 24-hour electricity load. A large number of low-priced competing products or small-workshop devices on the market resort to malicious tactics such as "copper-clad aluminum" or "reduced wire gauge" to fit low price points. This causes the transformer's temperature rise to severely exceed limits during actual operation, reducing its actual carrying capacity to only 70%–80% of its rated capacity. Continuous operation under such conditions easily triggers overheating trips or catastrophic burnouts.

Hengfengyou Electric guarantees 100% pure electrolytic copper windings. Electrolytic copper features low electrical resistivity and high mechanical strength. Combined with our scientifically engineered internal oil duct design, it ensures the equipment runs continuously and safely under 100% rated load. The transformer's temperature rise is strictly controlled within national and international standard limits, fundamentally eliminating the safety risks of camp shutdowns caused by transformer failures.

2. "1-Day Ultra-Fast Production Scheduling" Agile Supply Chain: Setting a New Efficiency Record for Overseas Deliveries

Field camp construction is a time-critical engineering undertaking, where transformers serve as the critical bottleneck for "temporary substation power." A single day's delay means a delay for the entire site timeline. For distribution transformers of such conventional capacities, Hengfengyou Electric activates its modernized "agile digital workshop." Within 24 hours of contract signing and parameter confirmation, conventional capacity scheduling is completed and rapid production begins, harnessing the absolute speed of "Made in China" to ensure early energization for the camp.

3. Specialized "Anti-Cold and Sand-Proof" Engineering Tailored for the Mongolian Climate

Mongolia features a typical continental climate with long winters, where extreme temperatures can plummet below -45°C, accompanied by violent sandstorms in field regions. For this project, Hengfengyou Electric utilized a fully sealed corrugated oil tank structure, completely isolating the insulating oil from ambient air, which effectively blocks external moisture and sand dust ingress. Concurrently, top-tier special transformer oil with a low pour point was formulated, ensuring the equipment's dielectric strength and fluid heat dissipation performance remain uncompromised in extreme cold, achieving field maintenance-free operation across the full lifecycle.

IV. Cross-Border Logistics, Export-Standard Packaging, and On-Site Delivery

1. Export-Grade Reinforced Packaging (Anti-Vibration and Moisture-Proof)

Given that cross-border land transport (highway-railway intermodal logistics) to Mongolia involves complex road conditions and long-distance jolts, Hengfengyou Electric’s logistics department implemented the highest level of protection:

• Transformer Body Anchorage: The transformer tank base is tightly locked and bolted to heavy-duty steel skids to prevent any slippage or shifting during long-distance transit.

• Fully Enclosed Wooden Crating: Upgraded with high-strength, fumigation-free wooden cases dedicated for export protection.

• Moisture-Proof Sealing: Industrial-grade, high-capacity desiccants are hung inside the enclosure, and the entire unit is completely wrapped and vacuum-sealed with heavy-gauge stretch film to shield it from rain, snow, humidity, and sand erosion during cross-border transit.

2. Flawless Delivery Outcomes

The equipment smoothly cleared customs at the border ports and arrived at the Mongolian camp project site precisely on schedule. Under the guidance of our on-site technical personnel, following commissioning preparation, oil static degassing, and the Site Acceptance Test (SAT), two transformers successfully achieved seamless, one-time energization.

Since commissioning, the equipment has operated with exceptional stability (with overall noise levels strictly below 60 dB). All instrument parameters and oil temperature rise indicators reside well within optimum ranges. The 100% full-capacity load assurance provides an unshakeable power backbone for the camp's domestic lighting and engineering machinery operations, winning high acclaim from both the Mongolian owners and the Chinese engineering contractors.

V. Solution Summary

The flawless wrap-up of the SFZ11-6300 kVA - 35 kV/0.4 kV distribution transformer project for the Mongolian field camp once again highlights Hengfengyou Electric’s core competencies in "highly cost-effective customization, ultra-fast supply chain fulfillment, and extreme environment adaptation." We deeply understand the pain points of overseas EPC turnkey projects. We do not just supply premium hardware that can be "put to work immediately upon arrival and delivers reliability once powered up"—we provide a comprehensive, one-stop turnkey export solution encompassing transparent pricing, 1-day rapid production scheduling, full export-standard packaging, and full-lifecycle warranty support.

Backed by more than 30 years of deep technical expertise, Hengfengyou Electric has successfully exported its products to over 50 countries and regions worldwide. Whether your project is located on African plateaus, in Middle Eastern deserts, or in the frigid zones of Central Asia, we can customize the optimal power transmission and distribution equipment for you in strict accordance with local grid certification standards (IEC, GB, IEEE, etc.).