Contents
·
What
is an electrical transformer?
·
Construction
of a Transformer
·
Working
Principles of a Transformer
·
Basic Operation of a Transformer
·
Types
of Transformers
·
Importance
of Transformer
What is an electrical transformer?
An electrical transformer
is a static electrical machine that transfers electrical power from one circuit
to another circuit through electromagnetic induction.
A basic transformer
consists of two coils wound on a metallic core. These coils are coupled together
magnetically instead of any electrical contact and the core provides a path for
the magnetic field.
It is used to change the
voltage level of the electrical supply, either it increases or decreases the
voltage while the frequency and power remain the same.
Construction of a Transformer
Basically, a transformer can be divided into
four parts.
1. Input Terminals: The main electrical power which
has to be changed is connected to the input terminals of the transformer, It is
called the primary side of the transformer.
2. Primary winding: The input terminals are
connected to the primary winding. It consists of coils, generally made of
copper conductors to reduce the losses.
3. Core: It is a metallic structure basically made
up of steel sheets or layers. These sheets are in the shapes of I, E, and L. These
sheets are connected together to make a laminated structure. This core provides
a path for the magnetic flux.
4. Secondary winding: The secondary winding also
consists of coils made of copper. It is electrically separated from the primary
winding but magnetically linked with it.
5. Output Terminals: The load is connected to the
transformer through these terminals. These terminals take the transformed
energy of the transformer and supply it to the load.
Working Principles of a Transformer
It should be noted that the transformer does
not produce or generate electrical energy, it only transfers electrical energy
from one circuit to another circuit. For this purpose, a transformer first transfers electrical energy from the first circuit to magnetic energy, and then
the magnetic energy is converted to electrical energy. The voltage level can be
managed during the manufacturing process by the number of turns of the coils.
A transformer works on
the principles of electromagnetic induction stated by Faraday. According to this
phenomenon;
when alternating current passes through a
coil it sets a magnetic field around the coil and this magnetic field produces
another current in the coil which opposes the first current responsible for the
process, as the process takes place in the same coil so it is Self-Induction. When
another coil is placed near this coil, the magnetic flux links with the
other coil and the EMF (Electro Motive Force) is produced in the other coil and
results in the transfer of power from one coil or circuit to another coil or
circuit, as the process takes place in two coils so it is called mutual
induction. All the transformers work on the principle of mutual induction.
Basic Operation of a Transformer
The main important thing to note is that
a transformer works on an AC (Alternating Current) electrical supply. It doesn’t
operate on DC (Direct Current).
When the input terminals of a transformer
are connected to the AC supply, the power is sent to the primary winding by the
terminals. The primary winding performs its inductive action and generates a
magnetic field. Note that the magnetic field is also alternating.
The core facilitates the magnetic flux of
the primary winding and provides a controlled path for it. As the secondary
winding is located on the same core, the magnetic flux links with it.
The secondary winding induces an EMF (Electro
Motive Force) through mutual induction. This transformation of electrical
energy from the primary winding or circuit to the secondary winding or circuit
results in a change in electrical quantities i.e., voltage and current. During
this process, the frequency and the overall electrical power remain constant neglecting
the losses. The power with the required voltage level and current is delivered to
the load through the output terminals of the transformer.
Types of Transformers
There are a lot of different types of
transformers used in many fields. These types may be classified into many groups,
these are:
1.
Types of transformers based on voltage conversion
There are mainly two types of transformers
concerning voltage conversion i.e., voltage increasing or decreasing on
the output. These are,
·
Step Up Transformer
·
Step Down Transformer
2.
Types of transformers based on their core
There are basically three types of transformers based
on the type of core used in them. These are,
·
Shell Type Transformer
·
Core Type Transformer
·
Berry Type Transformer
3. Types of
transformers based on their functions
There are six types of transformers based on their functions. These are,
a.
Power Transformer
b. Distribution Transformer
c. Isolation Transformer
d. Instrument Transformers
e. Current Transformer
f. Potential Transformer
4.
Types of Transformers based on windings
There are two types of transformers based on windings. These are,
a. Two Winding Transformer
b.
Autotransformer
5.
Types of Transformers based on the insulation used
There are two types of transformers based on the insulation
used. These are,
a. Dry Type Transformer
b. Oil
Immersed Transformer
6.
Types of Transformers based on the number of phases
There are two types of transformers based on the number of phases. These are,
a. Single Phase Transformer
b. Three
Phase Transformer
Importance of Transformer
Transformers are widely used in small
electronic circuits to large power transmission and generating stations. The transformer has made it very easy to use electrical energy in our daily lives. Some
important uses and applications of transformers are;
·
The transformer allows it to transfer
electrical energy with high voltages to reduce the cost, line losses, and
heating of the wires.
·
The transformer allows us to transfer power
over a long distance from the load station to the generating station.
·
A series of transformers are used between
a generating station and a load center to utilize the power of the generating
station.
·
Transformers Are also used to convert the supply of the distribution line for small electronic circuits i.e., radio circuits,
mobile charging circuits, battery charging circuits, UPS circuits, etc.
·
Transformers are widely used to operate
electric trains on a high voltage line.
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