dry transformer svel

Many novice engineers and even experienced specialists often perceivedry transformerlike 'just a transformer without oil'. However, in practice this is a much more complex and responsible system that requires special attention to detail. I often see situations where, during the design or operation of such transformers, important points are missed, leading to premature failure. This article is an attempt to share the experience gained over the years of working with such equipment, dispel some myths and draw attention to critical aspects.

Review: Not just 'dry' - a complete solution

Dry transformer- this is not just a design in which the windings are cooled by air. This is a complex electrical installation, including a cooling system, protection against overloads and short circuits, as well as a condition monitoring system. Wrong choice of parameters, especially the cooling system, can lead to serious consequences.

The need to take into account local climatic conditions and the operating features of the facility is often overlooked. For example, installation in a hostile or humid environment will require additional protection measures and possibly a different type of cooling system. Ultimately, successful workdry transformerdepends on an integrated approach to design, installation and operation.

Technological features and advantages

The advantage of a dry transformer, of course, is the absence of oil, which eliminates the risk of fire and environmental pollution. This is especially important in premises where increased fire safety is required, for example, in hospitals, schools, office buildings. In addition,dry transformereasier to install, as it does not require special containers for oil and a system for its removal. However, this comes at the cost of a more complex cooling system and, as a result, higher cost.

There are different types of cooling: natural ventilation, forced ventilation (using fans) and air cooling using heat exchangers. The choice of a specific type depends on the power of the transformer, the permissible ambient temperature and reliability requirements. A very important factor is monitoring the temperature of the windings - it must remain within acceptable values, otherwise the service life of the transformer will be significantly reduced.

Cooling systems: from ventilation to heat exchangers

In practice, the most common option is forced ventilation using electric motors that rotate fans. But even in this case, it is important to correctly select the power of the fans and their location to ensure effective heat removal. A situation often occurs when the fans are not powerful enough and the temperature of the windings rises, which leads to a decrease in voltage and overheating. Regularly checking fan functionality is a critical maintenance item.

Larger transformers use air heat exchangers. This is a more efficient, but also more expensive cooling option. The heat exchanger is blown by fans, which remove heat from the windings to the environment. It is important to monitor the condition of the heat exchanger - it must be clean and free of dust to ensure maximum efficiency.

Protection and control: ensuring reliability

The importance of a protection and condition monitoring system cannot be underestimateddry transformer. Modern transformers are equipped with various sensors for temperature, voltage, current, as well as relays for protection against overloads, short circuits and other emergency situations. It is important not only to have these sensors, but also to correctly configure the protection relay parameters.

I have personally encountered situations where protection relays were set too sensitively, which led to false alarms and equipment downtime. Another common problem is the lack of an automatic protection reset system. This means that once the relay has tripped, the transformer must be manually reset, which can be labor-intensive and time-consuming. Automatic reloading systems are more common in modern transformers.

Real example: From mistakes to solutions

Recently we were modernizing the power supply of a large industrial enterprise. There was an old man standing theredry transformer, which often failed due to overheating. Upon initial inspection, it turned out that the cooling system was designed for a less intense load than was actually installed. The fans were not powerful enough, and dust and dirt clogged the heat exchanger.

We replaced the fans with more powerful ones, cleaned the heat exchanger and adjusted the protection relay. After modernization, the reliability of the transformer has increased significantly, and the number of emergency situations has decreased several times. This case showed us how important it is to correctly assess the existing load and select a cooling system of the appropriate capacity. Optimizing existing equipment is often a more cost-effective solution than replacing it with new equipment.

Problems encountered during operation

One of the most common problems is the formation of condensation inside the transformer. This may occur due to high humidity in the room or due to leaks in the housing. Condensation can lead to corrosion of the windings and deterioration of their electrical performance.

To prevent the formation of condensation, it is recommended to use special air dryers and regularly check the condition of the housing seals. In addition, it is necessary to monitor the cleanliness of the room and avoid getting moisture on the transformer. Often the problem is solved by installing a ventilation system that provides constant air exchange.

Defects and ways to eliminate them

In addition to overheating, problems with winding insulation are common. Insulation can deteriorate due to aging, overheating or mechanical damage. Detection of insulation damage requires a special examination using a megohmmeter. If damage is found, the insulation must be restored or replaced.

Another common defect is damage to contacts and connections. They can occur due to vibration, overload or corrosion. To eliminate damage, it is necessary to thoroughly clean the contacts and connections and, if necessary, replace damaged elements. It is important to use high-quality materials and follow installation technology.

Conclusion: Prevention is the key to longevity

Dry transformer- This is reliable and durable equipment, but only with proper operation and regular maintenance. It is necessary to take into account all factors affecting its operation and promptly eliminate problems that arise. Remember that prevention is always cheaper than repair.

Wenzhou Qiaonasen Electrical Equipment Co.,Ltd

https://www.qnasen.ru/

Specializing in solutions for high and low voltage transmission and distribution and electrical control systems in the power equipment industry.