Tìm hiểu về máy biến áp khô – Ưu và nhược điểm

Introduction to dry transformers

What is a dry-type transformer?
A dry-type transformer is a type of transformer that changes the voltage of the current, has a monolithic structure, and is naturally cooled by air.

The working principle of a dry-type transformer is based on the phenomenon of electromagnetic induction to convert an alternating current system at one voltage to another.

Learn about dry transformers – Advantages and disadvantages

Common types of dry transformers
Dry transformers have a magnetic circuit structure and windings that are not immersed in insulating liquid. Currently, there are 4 most popular types of dry transformers:

1. Cast Coil resin transformer (CRT): The transformer coil is covered with Epoxy resin and vacuumed.
2. The structure of the machine meets the requirements for use in high humidity environments.
3. Vacuum pressure impregnation transformer (VPI): The coil is tied in a vacuum protection box and uses polyester resin as the coil insulation material.
4. Vacuum Pressure Encapsulated (VPE) transformer: High-end dry transformer with the coil placed in a vacuum box and using VPE silicon as the coil insulation material.
5. Open transformer: Dry transformer is produced by heating the coil and dipping it in varnish at high temperature.

Top dry transformer brands on the market

– Dry transformer group from foreign brands: Schneider dry transformer, ABB dry transformer, KP dry transformer, THIBIDI dry transformer in cooperation with General Electric Company (GE) of the US.

– Dry transformer group from Vietnamese brand: Thu Duc Electromechanical Joint Stock Company – is currently the pioneer in investing in dry transformer production lines with the capacity to meet 3,000 machines/year.

With the advantage of production capacity, the dry transformer product line has TSKT in accordance with current electricity standards, while also meeting the progress earlier, having more competitive prices and better after-sales service

Comparison of dry and oil transformers

1.Distinguish between dry and oil transformers.

The biggest difference between dry-type transformers and oil-based transformers is the cooling method:

• Oil-based transformers are cooled by mineral oil (insulating oil).
• Dry-type transformers are naturally cooled by air.

2. Compare prices of dry and oil transformers

Investment cost is the leading factor in deciding whether to choose a dry-type transformer or an oil-based transformer for a project. In fact, the manufacturing cost of a dry-type transformer is often higher than that of an oil-based transformer. However, in terms of maintenance costs, a dry-type transformer is more economical because there is no need to monitor oil levels, change oil, or deal with oil leaks.

3. Comparison table of dry transformers and oil transformers

Advantages of dry transformers

Dry transformers were born to limit many of the existing disadvantages of oil transformers. In particular, the higher allowable temperature of dry transformers provides the ability to prevent fire and explosion, improving safety for people and equipment during operation.

• High safety: Fireproof dry transformers meet the requirements for use in key projects that require fire safety.
• High mechanical and electrical durability: The design of the Epoxy resin-cast coil in a vacuum environment can withstand short circuit forces and abnormal vibrations.
• Perfect capacity: The 3-phase dry-cast transformer line has good overload resistance, high efficiency and limited noise during operation.
• More convenient: Dry-type transformers have many advantages in transportation, simple installation, and occupy less space.
• Environmental protection: Dry-type transformers do not generate exhaust gas or waste oil, minimize the risk of fire and explosion and are more environmentally friendly.
• Good price dry transformers: In addition to investing in improving product quality, there is also a competitive price policy, bringing more cost-saving transformer products to customers.