Power and Distribution Transformer Difference, Applications, Use
In this article, we will discuss the Power Transformer and Distribution Transformer difference, their use, and applications. Actually, all transformers work in the same principle means electromagnetic induction but according to their use, applications, construction, and connections, there are different types of transformers available.
Power transformers and distribution transformers are also types of transformers according to their use and function. So let's go to know about the distribution transformer and Power Transformer.
What is a Power Transformer?
In simple words, the transformer with a large capacity used to power up a whole electrical transmission system is called a Power Transformer.
A power transformer is nothing but a normal transformer with a very high power transfer capacity and some special design. The main function of a power transformer is to transfer high power by stepping down or stepping up the voltage level.
Remember that, power transformers are designed to work at full efficiency with a 100 percent load. Power transformers are available from 200 MVA up to several MVA. They are also designed to operate with an exactly balanced load in each phase. Power transformer voltage ratings are 400KV, 200KV, 110KV, 66KV, 33KV
As the power transformer is designed for a very high capacity, so it's one side carrying a very high current and low voltage and another side carrying a very high voltage and low current.
Why we need Power transformers?
We know that the system through which electricity comes into our home is divided into three major parts-
1. Electrical Power Generation
2. Electrical Power Transmission
3. Electrical Power Distribution
We know that for electrical power transmission purposes, we use very high voltage to reduce copper loss, but in power generation plants electrical power is generated at low voltage(mostly 11KV). So to transmit the electrical power at high voltage we need to step up the generation voltage. So the power transformer is used in the generation plant to step up the voltage.
Again after transmitting the electrical power, we cannot distribute that power at very high voltage to the consumer. So the power transformer is used in transmission substations to step down the voltage.
Read Also: [Explained] Transformer Size VS Frequency
How Power Transformer is used?
In an electrical power generation plant, a step-up power transformer is used. Here the primary winding of the transformer is star-connected and the secondary winding of the transformer is delta-connected. The star connection is used on the primary side because its neutral is to be connected to the neutral of the alternator. But on the secondary side delta connection is used because for transmission purposes neutral wire is not required.
In transmission substations or power receiving stations, step-down power transformers are used. Power transformers are intended to work with continuous power supply and low load fluctuations. Power transformer mainly works with voltage step-up and step-down purpose so it is embedded with a very high insulation level.
Applications of Power Transformer
1. The main application of a power transformer is to power up the electrical transmission system.
2. In electrical power generating stations, power transformers are used to step up the generation voltage to transmit the power at high voltage.
3. In electrical power transmission substations or receiving stations, power transformers are used to step down the high transmission voltage for further distribution with consumers at low voltage.
What is a Distribution Transformer?
The transformer used for electrical power distribution at low voltage is called a distribution transformer. The distribution transformer is directly connected to the consumer loads and it is designed to withstand high load fluctuations. The distribution transformer is mainly a step-down transformer with delta-star configurations. The distribution transformer has one primary winding and one or more secondary windings with a tap-changing system.
Distribution transformer voltage ratings are 11KV, 6.6 KV, 3.3 KV, 440V, 230V, and its power rating is less than 200 MVA. Distribution transformer carrying high voltage, low current on its primary side, and low voltage high current on the secondary side. The distribution transformer is smaller in size than the power transformer and has a low insulation level.
The distribution transformer is not put in the full-load operation, it is designed in such a way that it works at maximum efficiency at 75% of full load. As the load fluctuation is more so copper loss also more occur. As the copper loss and iron loss are time-dependent, so all all-day efficiency technique is used to calculate the efficiency of the distribution transformer.
Why we need a Distribution Transformer?
Although the power transformer helps to transmit electrical power over a long distance, it can not be used for power distribution purposes because it is designed for high voltage, low fluctuation, constant current flow, and continuous power supply. So the distribution transformer is specially designed for electrical power distribution to different consumers with high load fluctuations.
The distribution transformer is smaller in size, with no complicated circuit, and protection system, so it is easy to do maintenance by disconnecting a few consumers only.
How Distribution Transformer is used?
In a substation power transformer is used to step down the transmission voltage and then it is supplied to the distribution transformer. Distribution transformers are mostly installed near to the consumer, not in a substation. The distribution transformer is mostly installed on the electrical pole near the consumer. Distribution transformer delta-star connected, so consumer loads are connected in such a way that loads are equally distributed in each phase of the transformer.
For the single-phase requirement, the consumer load is connected with any phase and the neutral. For the three-phase requirement, the consumer load is connected with each phase of the transformer.
Applications of Distribution Transformer
1. The main application of the distribution transformer is to distribute the electrical power to different consumers.
2. A distribution transformer is used to distribute both single-phase and three-phase power at low voltage.
3. A distribution transformer is used to distribute electrical power to both industrial and domestic consumers.
Difference between Power Transformer and Distribution Transformer
Here are the main differences between distribution transformer and power transformer are given below,
| Power Transformer | Distribution Transformer |
| The main function is to help transmit electrical power at high voltage | The main function is to distribute electrical power at low voltage |
| Step Up and Step Down are both type available | It is a Step Down Transformer |
| Voltage ratings are 400KV, 200KV, 110KV, 66KV, 33KV | Voltage ratings are 11KV, 6.6 KV, 3.3 KV, 440V, 230V |
| Power rating more than 200 MVA | Power rating less than 200 MVA |
| Designed for maximum efficiency at 100% load | Designed for maximum efficiency at 75% load |
| It is designed to withstand very low load fluctuations | It is designed to withstand high load fluctuations |
| Used in Power generation plant, receiving end substations | Used for power distribution and installed near to the consumer |
| It is manly star-delta connected | It is mainly delta-star connected |
| It is independent of time | It is time-dependent |
Download Image
Power and Distribution Transformer Difference, Applications, Use
Reviewed by Author
on
November 06, 2020
Rating:
Reviewed by Author
on
November 06, 2020
Rating: