Transformer is a machine that helps in transforming the power from one circuit to another without any frequency change. This post will discuss what is Transformer, How it works, it’s parts, various types with brief introduction, applications, advantages and disadvantages.
What is Transformer
It is an electrical equipment that works on the Induction principle. It is basically used in electricity supply to transmit electrical energy from one voltage level to another.
Fig. 1 – Introduction to Transformer
They are dated back to the 1880’s. Post discovery of Induction propertie, the evolution of the Transformer took place making it more efficient and smaller in size. In 1830, Otto Blathy, Miksa Deri, Karoly Zipernowsky of the Austro-Hungarian Empire were the first gentlemen who designed the Transformers. They experimented and used it commercially.
Main Parts of Transformer
It consists of three main parts. They are:
- Primary Winding
- Secondary Winding
It creates path for Magnetic Flux.
It receives input from AC source.
It receives energy from the primary winding and conveys it to the load.
Fig. 2 – Main Parts of Transformer
How does Transformer Work
To understand how it works, let us consider single-phase Transformers as shown in the Fig. 3 below. One or more electrical conductors of insulated copper or aluminium are wound around the vertical section of the magnetic core called ‘limbs’. When Voltage V1 is applied to the Primary Winding, an AC voltage V2 occurs in the Secondary Winding by Mutual Induction.
The electrical conductors in the Core are magnetically coupled and Energy is transmitted through this Electrical/ Magnetic coupling. The ratio between the number of turns of the coils is equal to voltages at ‘0’ load. The number of turns of the Primary Winding is termed as N1 and similarly the number of turns of the Secondary Winding is referred to as N2.
Thus, Transformer Equation is:
Fig. 3 – (a) Schematic diagram of Single Phase Transformer (b) Circuit Diagram of Single Phase Transformer
Types of Transformers
Depending on the purpose and the objective of the Transformers, there can be various types of them as mentioned below:
- Step Up and Step Down Transformers
- Three Phase and Single Phase Transformers
- Power, Distribution and Instrument Transformers
- Two Winding and Auto Winding Transformers
- Outdoor & Indoor Transformer
- Oil Cooled & Dry Type Transformers
- Core Type, Shell Type and Berry Type Transformer
Step Up and Step Down Transformer
These kinds of Transformers usually help during the voltage fluctuations. They stabilize the power supply and distribute them normally.
Fig. 4 – Step Up & Step down Transformers
Three Phase and Single Phase Transformer
The Three Phase power system is used due to its cost effectiveness than the Single Phase Transformers. However, looking at the size and the ease for transportation, the Single Phase Transformers are suitable. They are further divided into:
- Core Type
- Shell Type
In this type, both the Winding (Primary and Secondary) are placed on the side limbs and has two magnetic circuits.
Fig. 5 – Single Phase and Three Phase Transformer
Power, Distribution and Instrument Transformer
Power Transformers are meant for stabilizing the power voltage fluctuations. This is used during the high power load duration.
Distribution Transformers are meant for the commercial or the residential purpose. This has a good efficiency level with 50% full load capacity and can operate for 24 hours with good voltage regulation.
Instrument Transformers includes Current Transformers and Potential Transformers, which are used to reduce the voltage. They provide electrical isolation between high voltage power circuit and measuring instruments.
Fig. 6 – Distribution Transformers
Two Winding and Auto Winding Transformer
These are the Transformers used depending on the ration of the voltage. Two winding transformers are utilized with the ratio is greater than 2 while the later is used at the time of voltage ratio being less than 2.
Fig. 7 – Winding Transformer
Outdoor & Indoor Transformers
As the name suggests, the Outdoor Transformers are installed for outdoor equipment. The Indoor Transformers are usually for office or residential purposes.
Fig. 8 – (a) Outdoor Transformers (b) Indoor Transformers
Oil-Cooled & Dry-Type Transformers
The difference between both the Transformers is the cooling system. While the Oil-Cooled requires oil and the Dry-Type Transformer uses air as the cooling medium.
Fig. 9 – Dry-Type and Oil-Cooled Transformers
Applications of Transformers
Some of the applications are listed below:
- Due to the feature of equal transmission and distribution of electrical power, the Transformers are used in power plants, industrial plants and the traditional electric utility companies.
- They are used for the purpose of controlling heavy power supply.
- They are used as step up/down devices in power transmission.
Advantages of Transformers
The advantages are mentioned below:
- Its foremost advantage is controlling and stabilizing the voltage transmission.
- It does not require any starting time.
- It is highly efficient with less capital investment and low maintenance.
- They provide isolation to the ground.
- There are no moving parts in Transformers.
Disadvantages of Transformer
There are some drawbacks in the performance of Transformers. Some of them are mentioned below.
- Due to its material in the making of the iron core, there is wastage in the current flow.
- It gives out lot of heat which requires cooling. This creates a break in the flow of the current.