Oil Transformer

Oil-immersed transformers are a type of electrical transformer that relies on oil as both a cooling medium and an insulator. These transformers are widely used in power distribution systems to convert high voltages to lower voltages for residential, commercial, and industrial use. Here's an overview of oil-immersed transformers, their types, features, and applications:

Types of Oil-Immersed Transformers

1. Single-phase Transformers: These use one pair of windings and are suitable for lower-load situations, such as rural areas.

2. Three-phase Transformers: Comprised of three pairs of windings, these are used in higher-load areas and can supply three circuits with energy.

3. Power Transformers: Designed to handle much higher loads, stepping voltages up or down and transmitting current from one place to another.

4. Distribution Transformers: Transmit lower voltages from the electrical grid to homes and businesses; they are smaller than power transformers.

5. Pole-mounted Transformers: Connected directly to electrical poles.

6. Pad-mounted Transformers: Mounted to a concrete pad on the ground.

Features of Oil-Immersed Transformers

1. Cooling and Insulation: The windings and core are submerged in transformer oil, which acts as a cooling agent and an insulator. Convection moves the oil through the windings and core, preventing overheating.

2. Cost-Effectiveness: Oil-immersed transformers are often more affordable than dry-type transformers with the same capacity.

3. High Voltage Capacity: While dry-type transformers operate below 35 kV, oil-immersed transformers have no such limitations, making them more versatile.

4. Environmental Friendliness: They are easier to recycle than dry-type transformers and are smaller, which is beneficial for outdoor environments in case of oil spill or accidents.

5. Reliability and Stability: These transformers use reliable insulation materials and structural designs, offering excellent resistance to short circuits and voltage surges.

6. Efficient Winding Design: Low-voltage windings use cylindrical copper foil structures for even current distribution, while high-voltage windings use multi-layer cylindrical designs for balanced ampere-turns, improving efficiency and short-circuit resistance.

7. Mechanical Structure: Core and windings are securely fastened, ensuring integrity during transport and operation under harsh conditions.

8. Drying and Oil Filtration: Coils and cores undergo vacuum drying to eliminate moisture, and transformer oil is vacuum-filtered, enhancing insulation performance.

9. Tank Design: Corrugated tanks accommodate oil expansion and contraction due to temperature changes, reducing transformer height and isolating oil from external air, preventing oxidation and moisture intrusion.

Applications of Oil-Immersed Transformers

Oil-immersed transformers are used in various power distribution systems, including:

• Electric Power Systems: For converting voltage levels in generation, transmission, and distribution networks.
• Industrial and Commercial Facilities: Providing power to industries and commercial buildings where high reliability and efficiency are required.
• Outdoor Installations: Suitable for outdoor environments due to their robust design and ability to handle bad conditions.

In summary, oil-immersed transformers are a critical component in the electrical power infrastructure, known for their efficiency, reliability, and adaptability to various power distribution needs.