The harm and treatment of water in transformer insulating oil

In the power system, the transformer is the core energy conversion and transmission equipment. The safety and stability of its operation are directly related to the reliable power supply of the entire power grid. The transformer insulating oil, as the key medium for internal insulation and cooling, is directly related to the service life and performance. 

Among them, water and sludge in the insulating oil are two potential threats that cannot be ignored. They will not only reduce the insulation strength of the oil and accelerate the aging of the equipment, but also may cause serious faults such as partial discharge and short circuit. Therefore, the moisture treatment of transformer insulating oil is particularly important.

Hazards of moisture in transformer insulating oil

The moisture in the insulating oil mainly comes from the residue during the manufacturing and installation of the equipment, as well as the external intrusion during operation. These moistures exist in the oil in dissolved, free, or emulsified states, and their impact on the transformer is mainly reflected in the following aspects:

1. Reduced insulation performance: 

Water will significantly reduce the breakdown voltage of the insulating oil, increase the probability of discharge in the oil gap, and affect the insulation safety of the transformer.

2. Accelerated aging: 

The interaction between water and acidic substances and oxygen in the oil will accelerate the aging process of the insulating material and shorten the service life of the equipment.

3. Cause failure: 

Under high electric field strength, moisture may cause partial discharge, or even insulation breakdown, resulting in equipment damage or shutdown.

Treatment methods for moisture in transformer insulating oil

1. Vacuum degassing: 

Using a vacuum pump to extract gas and moisture from insulating oil is one of the most commonly used dehydration methods. By heating the oil to a certain temperature, the evaporation rate of water is increased, and it is quickly discharged under vacuum.

2. Adsorbent dehydration: 

Add high-efficiency adsorbents such as silica gel and molecular sieves to the insulating oil. These materials can selectively adsorb moisture in the oil to achieve the purpose of dehydration. The adsorbent needs to be replaced or regenerated regularly after use.

3. Online monitoring and automatic processing system:

 Some modern substations have adopted online monitoring technology to monitor the moisture content in insulating oil in real time, and start the dehydration device through the automatic control system to achieve unmanned intelligent management.

Comprehensive management and maintenance strategy

To ensure the long-term stable operation of transformer insulating oil, in addition to taking the above-mentioned targeted treatment measures, it is also necessary to strengthen comprehensive management and maintenance work:

1. Regular testing and analysis: 

Regularly sample and test the insulating oil, analyze its physical and chemical properties, electrical properties, moisture content and other indicators, and promptly discover and solve problems.

2. Optimize the operating environment: 

Keep the transformer room dry and well ventilated to reduce the impact of the external environment on the insulating oil. At the same time, pay attention to controlling the oil temperature to avoid excessive oil temperature, which can cause accelerated deterioration of the oil quality.

3. Strengthen equipment inspection:

 Regularly inspect the transformer to check whether the oil level, oil temperature, oil color, etc., are normal, and promptly discover and deal with oil leakage, oil seepage and other problems.

4. Develop an emergency plan: 

Develop a detailed emergency plan for possible faults, including fault handling procedures, spare parts preparation, personnel division of labor, etc., to ensure rapid response and effective disposal when a fault occurs.

In short, the moisture treatment of transformer insulating oil is an important part of ensuring the safe operation of the transformer. Through scientific and effective treatment methods and strict management and maintenance measures, the impact of oil deterioration on transformer performance can be significantly reduced, the service life of equipment can be extended, and the reliability and stability of power supply to the power grid can be improved.