What is an Oil-Immersed Transformer?

An oil-immersed transformer is a power transformer that uses insulating oil for cooling and insulation. It is widely used in high-voltage power networks, as well as in industrial and commercial settings.
Structure and Function

The main components of an oil-immersed transformer are the core and the windings. The core is made of thin steel sheets to reduce energy loss, while the windings, usually made of copper or aluminum, carry electrical power. Both the core and windings are submerged in oil, which makes up the oil-immersed transformer.

The oil used in these transformers can be either mineral oil or ester oils (natural or synthetic).

1.Mineral Oil: This is used in most standard transformers but poses fire risks and can cause environmental pollution.
2.Ester Oils (natural or synthetic): These are used in transformers that need to meet higher environmental standards, such as those in wind farms or solar power plants.

Functions of the Oil

1.Cooling: The oil absorbs heat from the core and windings, then releases the heat through radiators or cooling fans. This prevents the transformer from overheating.
2.Insulation: The oil also enhances insulation, helping to prevent electric shocks and electrical failures.

Types and Advantages
Oil-immersed transformers come in two main types: single-phase and three-phase.

Single-phase transformers are typically used for homes and small businesses.
Three-phase transformers are more suited for factories and large power networks because they handle larger loads more efficiently.

Compared to dry-type transformers, oil-immersed transformers have clear advantages:

1.Higher efficiency: Oil has better cooling properties, allowing the transformer to run efficiently under heavy loads, reducing energy loss.
2.Better insulation: Oil provides superior insulation compared to air, reducing the risk of electrical failure.
3.Lower long-term cost: Although oil-immersed transformers require regular maintenance, they have a long lifespan, making them more cost-effective over time.
4.High adaptability: These transformers perform well outdoors and in harsh environments, showing strong adaptability.

Maintenance and Safety

Regular maintenance is crucial for oil-immersed transformers. The oil quality must be checked regularly to ensure its insulation properties remain intact. Since the oil is flammable, any leaks or damage can pose a fire risk.
A Buchholz relay can be used to monitor the buildup of gases inside the transformer. If a fault is detected, the system automatically shuts down, preventing accidents.

Market Trends

As wind and solar energy continue to grow, the demand for efficient power systems has driven the market growth for oil-immersed transformers.

The global market for oil-immersed power transformers is expected to grow from $13.2 billion in 2023 to $22.9 billion by 2032, with a compound annual growth rate of 6.2%.

In emerging markets, grid infrastructure upgrades and the shift toward sustainable energy are driving this growth.
North America and the Asia-Pacific region are key markets, with North America's market projected to exceed $3.2 billion by 2032, benefiting from accelerated grid upgrades and the integration of renewable energy sources.

Leading companies such as ABB, Siemens, and Schneider Electric are driving technological innovation, focusing on improving efficiency and using more environmentally friendly insulating oils.

Conclusion
Oil-immersed transformers are essential to modern power systems, offering high efficiency, strong insulation, and the ability to perform well in various environments. While maintenance and safety challenges exist, new oil technologies and better safety equipment are improving performance. As electricity demand grows and renewable energy becomes more common, the market for these transformers will continue to expand and evolve.