Why Oil-Immersed Transformers Are More Durable | Heat Dissipation & Insulation Benefits
Time：2025-05-10 Auther：ZTelec-www.ztelectransformer.com
Oil-immersed transformers play a vital role in modern power systems by converting voltage and transmitting energy efficiently. Known for their long-term stability, these transformers are commonly used in power stations, industrial plants, and residential communities. Their durability stems from an advanced heat dissipation design and the exceptional properties of insulating oil.
Efficient Heat Dissipation System
During transformer operation, heat is generated by winding resistance and core hysteresis. Without effective dissipation, internal temperatures rise, accelerating insulation aging and risking performance degradation, local overheating, or even fires. Heat management is crucial for transformer safety and lifespan.
Oil-immersed transformers utilize insulating oil to transfer and dissipate heat. As the transformer heats up, the insulating oil warms, becomes less dense, and rises, while cooler oil descends to create natural convection. This continuous cycle carries heat to the outer casing, where it disperses into the air through radiators. Large transformers enhance this process with oil pumps and fans that boost oil circulation and air flow, maximizing heat dissipation under high load conditions.
Compared to dry-type transformers, which depend solely on air convection, oil-immersed transformers perform better. Air has low thermal conductivity, making dry-type transformers prone to overheating during heavy loads, which accelerates insulation wear. In contrast, oil-immersed transformers ensure stable cooling and reliable operation even in demanding environments, thanks to superior thermal conductivity and circulating insulating oil.
Advantages of Insulating Oil
Insulating oil not only dissipates heat but also provides robust electrical insulation. It fills the spaces between windings and between windings and the core, isolating live parts to prevent current leakage and short circuits. Its ability to penetrate microscopic gaps eliminates hidden insulation risks.
Additionally, insulating oil offers fast arc extinguishing capabilities. When an arc forms due to abnormal switching, sudden load changes, or faults, the extreme heat can damage internal components. The insulating oil decomposes into gas upon contact with the arc, cooling it rapidly and suppressing its spread. For example, in the event of an internal short circuit, the gases from the oil form bubbles that quickly extinguish the arc, safeguarding critical parts like the windings.
Furthermore, insulating oil slows down insulation aging. Factors such as high temperatures, oxygen, and moisture accelerate the degradation of insulating materials. Insulating oil creates a barrier against oxygen and moisture, reducing oxidation and humidity exposure. When antioxidants are added, the oil further inhibits oxidation, prolonging the lifespan of insulation materials and maintaining transformer stability over time.
Structural Design and Material Quality
The durability of oil-immersed transformers is also enhanced by precise engineering and superior materials. The outer casing is constructed from high-strength steel plates, offering excellent sealing and mechanical strength to block moisture and dust. High-quality materials are used for the core to minimize losses, and windings are crafted from pure conductive materials that undergo specialized treatment to ensure both conductivity and mechanical integrity.
From heat dissipation and insulation to robust construction and premium materials, oil-immersed transformers integrate a suite of technologies that ensure long-term reliability. Their proven performance continues to support stable power supply across diverse applications worldwide.
