Power Transformers

The Power transformer is a one kind of transformer, that is used to transfer electrical energy in any part of the electrical or electronic circuit between the generator and the distribution primary circuits. These transformers are used in distribution systems to interface step up and step down voltages. The common type of power transformer is liquid immersed and the life span of these transformers is around 30 years. Power transformers can be classified into three types based on the ranges. They are small power transformers, medium power transformers and large power transformers.

• The range of small power transformers can be from 500-7500kVA
• The range of medium power transformers can be from -100MVA
• The range of large power transformers can be from 100MVA & beyond

Specification

Power transformers can be designed as either a single phase or a three phase configuration. There are numerous important specifications to identify when searching for power transformers. The specifications of power transformer include a maximum power rating, maximum secondary current rating, maximum voltage rating and o/p type. Power transformer specifications mainly include

• Phase is 3Ø
• Frequency if 60Hz,50Hz
• Primary Voltage is 22.9 kV
• Secondary Voltage is 6.6/3.3 kV
• Tap Voltage 23.9-R22.9-21.9-20.9-19.9kV
• Vector Dd0, Dyn11, etc.

Application

Power transformers can alter from one voltage to another at high power levels. These transformers are used in various electronic circuits and also available in various types and applications.

The applications of the power transformer include the transmission and distribution of electrical power These transformers are widely used by power plants, industrial plants and traditional electric utility companies.
Power transformers are used in the high voltage transmission network to step up and step down the voltage. These transformers are generally used for the purpose of transmission of heavy loads.
These transformers are big in size compared with distribution transformers, that are used in producing station and transmission substation. Power transformers are used in the transmission n/w. So they do not connect directly connect to the consumers. So load fluctuations of transformer are less.
These transformers are used as a step up devices for transmission, so that the I2r loss can be reduced to a specified power flow.
Power transformers are mainly designed to use the core part for maximum and will function very much near to the knee point of the B-H curve. This takes down the mass of the core extremely. Naturally, power transformers have the corresponding copper losses and iron losses at higher load.