Project Background

A refinery located in a coastal area with an altitude of less than 1000 meters faces complex environmental conditions, including high temperatures, high humidity, and high salt corrosion. To ensure the stable operation of its power system, the refinery decided to upgrade its power distribution system by procuring oil-immersed distribution transformers designed for tropical conditions.

Environmental Challenges

• Temperature Range: Minimum 15.1°C, maximum 37.4°C, average 26.6°C.
• Humidity Range: Minimum 80% (at 15.1°C), maximum 100% (at 37.4°C), average 97% (at 26.6°C).
• Corrosiveness: Salt-laden air with corrosive properties.
• Tropicalization Requirement: Equipment must withstand high-temperature and high-humidity environments.

Equipment Requirements

• Enclosure Protection Level: Rotating motors and electrical equipment must have a minimum IP55 rating. Equipment in areas with combustible dust must have a minimum IP65 rating.
• Indoor Electrical Requirements:
• Wet/Damp Locations: Rotating motors and electrical equipment must have a minimum IP42 rating.
• Dry Locations: Rotating motors and electrical equipment must have a minimum IP41 rating.

Product Solution

Based on the refinery’s requirements, we provided the following oil-immersed distribution transformer solutions:

1. 35kV 10.5kV 25000kVA Oil-Immersed Distribution Transformer

• Quantity: 4 units
• Rated Capacity: 25000 kVA
• Input Voltage: 35kV
• Output Voltage: 10.5kV
• Cooling Method: ONAN/ONAF
• Winding Material: 100% Copper
• Vector Group: Dyn11/Yyn0/Yd11/YNd11
• Enclosure Protection Level: IP55

2. 2000kVA ~ 3150kVA Distribution Transformers

• Quantity: 12 units
• Rated Capacity: 2000kVA ~ 3150kVA
• Enclosure Protection Level: IP55

3. Transformers Below 250kVA

• Quantity: 10 units
• Rated Capacity: Below 250kVA
• Enclosure Protection Level: IP55

4. 250kVA ~ 500kVA Distribution Transformers

• Quantity: 4 units
• Rated Capacity: 250kVA ~ 500kVA
• Enclosure Protection Level: IP55

Project Implementation

1. Equipment Selection: Oil-immersed distribution transformers compliant with IEC, ANSI, and IEEE standards were selected based on the refinery’s environmental conditions and power requirements.
2. Tropicalization: All transformers were tropicalized to withstand high-temperature and high-humidity environments.
3. Installation and Commissioning: The transformers were installed in the refinery’s substation buildings, ensuring operation within the specified temperature and humidity ranges.
4. Protection Measures: Equipment in high-humidity and corrosive areas was reinforced with higher enclosure protection levels to ensure long-term stability.

Project Outcomes

• Improved Stability: The new power distribution system operates stably in high-temperature and high-humidity conditions without failures.
• Enhanced Safety: High protection-level enclosures effectively prevent salt mist and dust corrosion, improving equipment safety.
• Energy Efficiency Optimization: Efficient cooling methods and high-quality materials reduce energy consumption and improve efficiency.

Through this project, the refinery’s power distribution system has been comprehensively upgraded, ensuring stable and safe power supply and providing strong support for the refinery’s continuous production.