What is the main purpose of oil in a transformer?Why is oil added in transformers?

2025,07,07

In the power system, oil-immersed transformers (also known as oil transformers) are vital equipment and are widely used in power transmission and distribution networks.

As its core component, transformer oil (insulating oil) plays multiple key roles. So, what is the main role of oil in transformers? Why do transformers need oil?

The following will give you a detailed answer and introduce Hubei Jutai's professional solutions in the field of Power Transformers.

The main role of transformer oil

Transformer oil is not just a simple cooling medium. It has the following key functions in the operation of oil-immersed transformers:

1. Insulation

The high-voltage coil and the iron core inside the transformer need extremely high insulation performance to prevent short circuit or arc discharge. Transformer oil has excellent dielectric strength and can effectively isolate live parts to ensure safe and stable operation of the equipment.

2. Cooling and heat dissipation

The transformer will generate a lot of heat during operation. If the heat cannot be dissipated in time, it will cause the equipment to overheat or even damage. Transformer oil has good thermal conductivity and can absorb heat and dissipate heat to the external environment through the oil circulation system (natural convection or forced circulation), keeping the transformer working at a suitable temperature.

3. Arc extinguishing effect

In an Oil-immersed Transformer, when partial discharge or short circuit occurs inside, transformer oil can quickly suppress the generation and spread of arcs to prevent equipment failure due to arc burning.

4. Protect the iron core and windings

Transformer oil can effectively isolate oxygen and moisture, prevent the iron core and windings from oxidation and moisture, thereby extending the service life of the equipment. In addition, high-quality transformer oil can also slow down the corrosion of internal metal parts and keep the transformer running efficiently for a long time.

5. Detect the transformer status

By regularly testing the transformer oil (such as testing the acid value, moisture content, gas composition, etc.), the operating status of the transformer can be judged, potential faults (such as local overheating, insulation aging, etc.) can be discovered in time, and corresponding maintenance measures can be taken.

Why transformers need oiling

Since transformer oil plays such an important role, oil-immersed transformers must maintain proper oil level and oil quality. Here are the specific reasons:

1. Ensure insulation and cooling performance

If the transformer oil is insufficient or deteriorated, its insulation and cooling capacity will be greatly reduced, causing equipment overheating, insulation breakdown, and even serious accidents.

2. Prevent internal oxidation and moisture

Transformer oil can isolate air and moisture, prevent internal metal parts from oxidizing or insulation materials from getting wet. If the oil level is too low, air and moisture may enter the transformer and accelerate equipment aging.

3. Maintain arc extinguishing ability

In the case of sudden load changes or short circuits, sufficient transformer oil can quickly suppress arcs and protect equipment from damage.

4. Extend transformer life

High-quality transformer oil can effectively reduce internal pollution and corrosion, making power transformers run more stably and have a longer service life.

Summary

Transformer oil plays multiple roles in Oil Transformer, including insulation, cooling, arc extinguishing and protection, and is the key to ensuring safe and stable operation of equipment. Regularly checking the oil level and oil quality, and choosing high-quality transformer oil can effectively extend the life of the equipment and reduce the risk of failure.

If you are looking for high-performance and high-reliability oil transformers, Hubei Jutai will be your ideal partner! We are committed to providing customers with excellent power equipment and technical support to help the global power system operate efficiently.

Author:

Mr. jiawenhan

E-mail:

JT13797437282@gmail.com

Phone/WhatsApp:

+86 13797437282