Dry transformers

Dry transformers are air-cooled transformers. Unlike their oil-cooled counterparts (https://uea.com.ua/product/tmg-oil-transformers, https://uea.com.ua/product/transformers-tm-zigzag, https://uea.com.ua/product/transformers-tmg-630-1600-three-winding) there is no liquid dielectric between the housing and the windings. Due to their special design, these transformers are used in various applications and are considered to be safer.

Field of application

Manufacturers of dry-type transformers claim that they are the future of dry-type transformers. They are in great demand and are used

• in chemical plants;
• in the oil and gas, power industry;
• in steel mills;
• in extractive industries.

Dry-type transformers also have a specific purpose. They are used in the transport industry – on ships and in railway traction substations. These high-voltage units are also used in the wind power industry. Wind power plants can be found in different climatic conditions, so the power transformer type is designed according to the regulations of the country in which it is installed. In addition, environmental, safety and efficiency requirements are taken into account.

Operating principle

Dry-type transformers are made according to their principle of operation. The essence of the operation is to apply voltage to the primary winding of the dry-type transformer, after which the electric current flows. This results in an electromagnetic flux, which induces an electromotive force in the secondary winding. There are three types of winding – cast coil, open coil and monolithic coil. Cast coils and monolithic windings have a lower heat dissipation efficiency, which is why they use conductors with a larger cross-section.

Advantages

Dry transformers are significantly superior to oil transformers (single-phase or three-phase type) in terms of technical characteristics. Their main advantages include:

High degree of environmental friendliness and safety (in emergency situations).
Easy maintenance (no need to monitor the chemical composition of transformer oil, flash point).
Simple design (no need to monitor the tightness of the enclosure).
Low weight (due to the absence of liquid dielectric).
Maintenance

The manufacturer indicates in the technical specifications the information about the main requirements which must be observed during the use of dry-type cast resin transformers. During operation, they must be inspected for soiling and, if so, cleaned every six months. During maintenance it is also recommended to check the moisture level on the winding, the temperature monitoring device, the functionality of the temperature sensors and the correct operation of thermal protections. Switching off the transformer according to safety regulations is a prerequisite before carrying out inspection work.

With routine technical diagnostics, faults can be detected and repaired in good time to ensure proper operation of the transformer.