IUgNsd8BY
New Member
- Последняя активность IUgNsd8BY:
- 27 янв 2022
- Загрузка...
- Загрузка...
-
О себе
What is a Transformer?
A transformer is defined as a passive electrical device that
transfers electrical energy from one circuit to another through the
process of electromagnetic induction. It is most commonly used to
increase (‘step up’) or decrease (‘step down’) voltage levels
between circuits.
Working Principle of Transformer
The working principle of a
Power
Transformer is very simple. Mutual induction between two or
more windings (also known as coils) allows for electrical energy to
be transferred between circuits. This principle is explained in
further detail below.
Transformer Theory
Say you have one winding (also known as a coil) which is supplied by
an alternating electrical source. The alternating current through the
winding produces a continually changing and alternating flux that
surrounds the winding.
If another winding is brought close to this winding, some portion of
this alternating flux will link with the second winding. As this flux
is continually changing in its amplitude and direction, there must be
a changing flux linkage in the second winding or coil.
According to Faraday’s law of electromagnetic induction, there will
be an EMF induced in the second winding. If the circuit of this
secondary winding is closed, then a current will flow through it.
This is the basic working principle of a
Distribution Transformer.
Let us use electrical symbols to help visualize this. The winding
which receives electrical power from the source is known as the
‘primary winding’. In the diagram below this is the ‘First Coil’.
The winding which gives the desired output voltage due to mutual
induction is commonly known as the ‘secondary winding’. This is the
‘Second Coil’ in the diagram above.
A transformer that increases voltage between the primary to secondary
windings is defined as a step-up transformer. Conversely, a
transformer that decreases voltage between the primary to secondary
windings is defined as a step-down transformer.
Whether the transformer increases or decreases the voltage level
depends on the relative number of turns between the primary and
secondary side of the Dry Type Transformer.
If there are more turns on the primary coil than the secondary coil
than the voltage will decrease (step down).
If there are less turns on the primary coil than the secondary coil
than the voltage will increase (step up).
While the diagram of the transformer above is theoretically possible
in an ideal transformer – it is not very practical. This is because
in the open air only a very tiny portion of the flux produced from
the first coil will link with the second coil. So the current that
flows through the closed circuit connected to the secondary winding
will be extremely small (and difficult to measure).
LV switchgear layout: Design & Size
Low voltage (LV) switchgear is a broad terminology that includes a
wide range of equipment like circuit breakers, switches, offload
isolators, MCCBs, etc. within the 1 kV rating required to protect the
LV system. The most common use of
HV And LV
Switchgear is in the LV distribution board which further
comprises multiple segments like the main incomer, sub-incomers,
feeders, etc. the size, configuration, and physical layout for
switchgear vary as per specific requirements and standards.
The switchgear is of different type based on the voltage level at
which it operates. HV switchgear operates at a voltage level of above
33 kV. MV switchgear operates at the voltage level of 33 kV and
below. Likewise, LV switchgear operates at the voltage level of 1.1
kV maximum.
Irrespective of particular voltage levels, switchgear are known for
their complete reliability, quick operation, and absolute isolation
compared to other similar devices.
Compact Secondary Substations (CSS)
Compact
Substations are used for energy transformation in secondary
distribution network from MV to LV or LV to MV. CSS is a type tested
and arc tested assembly comprising an enclosure containing medium
voltage (MV) switchgear, distribution transformers, low voltage (LV)
switchboards, connections and auxiliary equipment to supply low
voltage energy from medium voltage systems. These substations are
typically installed in locations accessible to the public and ensure
protection for all people according to specified service conditions.Взаимодействовать