Power Transformer Specifications and Its Applications

A transformer is an electrical device which is used to transfer power from one circuit to another through electromagnetic induction.The power transfer is accompanied without frequency change. In an electronic system, the term power transformer is used to provide a number of AC supplies of several voltages and appropriate values of current from the public electricity supply. And also used to denote to transformers with a 500KVA rating or greater.

Power Transformer
Power Transformer

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.

Power Transformers
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

The average life of a transformer is around 30 years

These transformers transform the voltage. It holds a low voltage, high current circuit at one side of the transformer and on the other side of the transformer it holds high voltage low current circuit. Power transformer depends on the principle of Faradays induction. They describe the power system into zones where every gear connected to the system is sized per the ratings set by the power transformer.

Power Transformer Design

The skeleton of the power transformer is designed with metal which is laminated by sheets. It is fixed into either a core type or shell type. The skeletons of the transformer are wound and connected using conductors to make three 1-phase or one 3-phase transformer. Three 1-phase transformer requires each bank isolated from the additional and thus offer continuity of service when one bank flops. A single 3-phase transformer, whether the shell or core type, will not function even with one bank out of service. The 3-phase transformer is inexpensive to make and it has a smaller footprint, and functions comparatively with higher efficiency.

Power Transformer Design
Power Transformer Design

The skeleton of the transformer is absorbed in a fire retardant protecting oil inside a tank. The conservatory on top of the oil tank lets for the increasing oil to fall into it. The charger of the load taps to the side of the tank changes the no of turns on the high voltage-low current winding for superior voltage regulation. The bushings of the tank permit for conductors to carefully enter and exit the tank without stimulating the outer shell. The power transformer can be worked beyond its small rating as long as it stays within the 65ºC rise of the temperature. To allow the above nominal operation, transformers are built-in with fans that cools the core of the transformer to a point below the indicated temperature.


Power Transformer Specifications

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.
Power Transformer Specifications
Power Transformer Specifications

Power Transformer Applications

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.

Thus, this is all about power transformer construction, power transformer specifications and applications. We hope that you have got a better understanding of this concept. Furthermore, any queries regarding this concept or power transformer circuit diagram, please give your feedback by commenting in the comment section below.

Photo Credits:

  • Power Transformer Design peguru

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