What are the types of power transformer?

power transformers are electrical devices that transfer power from one circuit to another without changing the frequency. They are used in various applications, such as power generation, transmission, distribution, and industrial processes. power transformers can have different sizes, ratings, and configurations depending on their functions and specifications. In this article, we will explore the uses, working principles, and types of supply transformers.

• What are the uses of power transformer?

• How does a power transformer work?

• What are the types of power transformer?

What are the uses of power transformer?

1. Generator step-up transformers (GSU): These transformers increase the voltage from the generator level to the transmission level (high voltage). They are usually located near the power plants and operate at full load for long periods. They have high efficiency and reliability.

2. Grid access transformers: These transformers connect different transmission networks with different voltage levels. They enable the exchange of active and reactive power between the networks. They have to withstand electrical stress from fault currents and transients.

3. Unit auxiliary transformers (UAT): These transformers provide the auxiliary power supply for an entire power plant. They lower the voltage from the generator level to the plant level (low voltage). They are mostly equipped with off-circuit tap changers to adjust the output voltage.

4. Plant-feeding transformers: These transformers supply power to industrial plants and facilities. They can have various ratings and voltages depending on the load requirements. They can also have special features such as cooling systems, on-load tap changers, or bushings.

5. Distribution transformers: These transformers reduce the voltage from the transmission or sub-transmission level to the distribution level (medium or low voltage). They are located near the end-users and serve residential, commercial, or industrial loads. They can be pole-mounted, pad-mounted, or underground.

How does a power transformer work?

A power transformer works based on the principle of electromagnetic induction. It consists of two or more windings that are wound around a magnetic core. When an alternating current (AC) flows through one winding (the primary), it creates a magnetic flux in the core. This flux induces an electromotive force (EMF) in the other winding (the secondary). The EMF is proportional to the number of turns and the rate of change of flux in each winding. The ratio of the primary and secondary voltages is equal to the ratio of their turns.

What are the types of power transformer?

1. Large power transformer: This type has a rating of 100 MVA or more and a voltage of 230 kV or more. It is used for high-power transmission applications.

2. Medium power transformer: This type has a rating of 10 to 100 MVA and a voltage of 69 to 230 kV. It is used for sub-transmission or distribution applications.

3. Small power transformer: This type has a rating of less than 10 MVA and a voltage of less than 69 kV. It is used for industrial or commercial applications.

4. Dry-type transformer: This type has a core and windings that are enclosed in a metal or resin case. The air provides insulation and cooling for the transformer. It is safer and more environmentally friendly than oil-immersed transformers.

power transformers are essential components in power systems that transfer power from one circuit to another without changing the frequency. They have various uses, working principles, and types depending on their functions and specifications.