Why Do Distribution Transformers Prefer Mineral Oil?

With the deepening of environmental protection and sustainable development concepts, power grid equipment is also facing a “green” upgrade. Some people question whether traditional mineral oil transformers are outdated? The answer may surprise you. Despite the continuous emergence of new insulating liquids, mineral oil still demonstrates strong vitality with its comprehensive advantages, especially in terms of technological maturity and full life cycle assessment.

Oil immersed transformer

2.1 Environmental attributes: Misunderstood sustainability

When it comes to mineral oil, people often associate it with ‘not environmentally friendly’. But in fact, modern mineral oil transformers have their unique advantages in environmental protection.

2.1.1 New understanding of biodegradability

In fact, mineral oil that has been deeply refined already has a certain degree of biodegradability. Although its speed is not as fast as natural esters (vegetable oils), it is far superior to silicone oil. More importantly, the database of its environmental impact is the most complete.

2.1.2 Mature Recycling and Regeneration Cycle

Mineral oil has a globally mature recycling and regeneration system. Waste oil can be collected, refined, and reused after restoring its performance. This circular economy model greatly reduces resource consumption and waste generation, meeting the core requirements of sustainable development.

2.2 Safety Performance: Excellent Fire Protection

Safety is the first principle of electrical equipment. How does mineral oil perform in terms of safety?

2.2.1 Ignition point and fire resistance

Mineral oil typically has a flash point above 140 ° C and is classified as a K-grade liquid. This means that it is very safe during normal operation. Even if a leak occurs, its combustibility is far lower than people’s imagination. For outdoor distribution transformers, the risks are completely controllable.

2.2.2 Safety comparison with other liquids

Compared to flammable silicone oil and expensive natural esters with high ignition points, mineral oil achieves the best balance between cost and safety, meeting the safety standards of the vast majority of power distribution scenarios.

2.3 Technological Maturity: Unparalleled Reliability Record

The power system is most averse to uncertainty. Mineral oil has a widely used history of over a hundred years.

2.3.1 Massive operational data support

There are millions of mineral oil transformers in operation worldwide, accumulating an incredibly large database of operations, faults, and maintenance. This enables operations personnel to accurately predict its lifespan and develop scientific maintenance strategies. This experience cannot be surpassed by any new liquid in the short term.

2.3.2 Compatibility and Convenience

The entire industry chain, from transformer manufacturing, installation to operation and maintenance, is built around mineral oil. There are standardized processes and easily accessible spare parts for replacing oil products and handling faults. This convenience greatly reduces the operational costs throughout the entire lifecycle.

superior cooling, insulation, and diagnostic capabilities

2.4 Future Outlook: Evolution and Coexistence of Mineral Oil

In the face of the future, mineral oil is not static, it is also evolving and complementing new types of liquids.

2.4.1 Continuous optimization of performance

Refining technology continues to advance, producing mineral oil with higher purity, better oxidation stability, and continuously improving performance.

2.4.2 Market complementarity with new liquids

In special places such as indoor or underground spaces with extremely high fire prevention requirements, natural esters and other liquids have more advantages. However, for a large number of outdoor power distribution networks, mineral oil will still be the mainstream choice in the next few decades due to its excellent comprehensive cost-effectiveness. Their relationship is complementary, not substitutive.

Mineral oil transformers are not outdated. On the contrary, it continues to play an indispensable key role in the process of building a green and sustainable power grid, with its time tested excellent reliability, mature and perfect circular economy system, and perfect balance between cost and performance. Choosing mineral oil is a carefully considered, economical, and reliable technical decision.

Luoyang Datang Energy Technology Co., Ltd. is a high-tech enterprise integrating R&D, manufacturing and supply of power equipment such as transformers, new energy components, distribution cabinets and inverters. With technological innovation as the core, we focus on creating high-reliability and high-performance power solutions to serve global customers. With a strict quality control system and international standard certification, we continue to output excellent products and enable customers to build safe and stable power systems.