In a power plant, the main transformer is called Generator
transformer.The input given to the main transformer has
delta connection. The output taken out from the secondary
windings of the transformer has star connections.
A transformer is a device that transfers electrical energy
from one circuit to another through inductively coupled
conductors—the transformer's coils. A varying current in
the first or primary winding creates a varying magnetic
flux in the transformer's core, and thus a varying magnetic
field through the secondary winding. This varying magnetic
field induces a varying electromotive force (EMF)
or "voltage" in the secondary winding. This effect is
called mutual induction.
If a load is connected to the secondary, an electric
current will flow in the secondary winding and electrical
energy will be transferred from the primary circuit through
the transformer to the load. In an ideal transformer, the
induced voltage in the secondary winding (VS) is in
proportion to the primary voltage (VP), and is given by the
ratio of the number of turns in the secondary (NS) to the
number of turns in the primary (NP) as follows:
By appropriate selection of the ratio of turns, a
transformer thus allows an alternating current (AC) voltage
to be "stepped up" by making NS greater than NP,
or "stepped down" by making NS less than NP.
In the vast majority of transformers, the windings are
coils wound around a ferromagnetic core, air-core
transformers being a notable exception.
Transformers range in size from a thumbnail-sized coupling
transformer hidden inside a stage microphone to huge units
weighing hundreds of tons used to interconnect portions of
power grids. All operate with the same basic principles,
although the range of designs is wide. While new
technologies have eliminated the need for transformers in
some electronic circuits, transformers are still found in
nearly all electronic devices designed for household
("mains") voltage. Transformers are essential for high
voltage power transmission, which makes long distance
transmission economically practical.
A Device which tranform the electrical voltage form one
magnitude to another magnitude without changing the supplu
frequency is know as Transformer.
It does so by faraday`s Electromagnetic induction law.
A main x-mer is satuated at generating end the
output of Alternator is connected with this& then its
output is feeded for supply in Y-connection maaner.
If a load is connected to the secondary, an electric
current will flow in the secondary winding and electrical
energy will be transferred from the primary circuit through
the transformer to the load. In an ideal transformer, the
induced voltage in the secondary winding (VS) is in
proportion to the primary voltage (VP), and is given by the
ratio of the number of turns in the secondary (NS) to the
number of turns in the primary
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