Conductors are physical medium that carries electrical energy
from one place to another place. The slightest conductivity and tensile
strength are the most important factors for transmission and distribution
systems. Earlier, for energy transmission copper conductors were utilized, but
now, they have been replaced by the stranded hard drawn aluminium wires to
improve the tensile strength, conductivity, and efficiency. Aluminium
conductors are portable, economical in design, and also have a low cost. Different types of AI conductors are used
these days including AAC, ACSR, AAAC, and ACAR.
Definition: ACSR stands for Aluminium
Conductor Steel Reinforced. A strong stranded conductor consisting of one or
more layers of hard-driven aluminium wire with a galvanized coated steel core.
These conductors are primarily used in the distribution and transmission lines
due to their high tensile strength, economical design, lightweight with good
properties, and suitable voltage overhead lines. Also, the conductivity of this
type of conductor is higher than that of copper conductors.
ACSR CONDUCTOR TYPES
Earlier copper conductors were
utilized many years back for transmission of energy but at present, Aluminium
conductors have replaced these conductors due to some reasons like not being
costly as compared with copper, elevated diameter, etc. There are different
varieties of ACSR conductors available which include the following.
●
All Aluminimum Conductor (AAC)
AAC conductors have low
stability and extra sag per span length as compared with any classification.
So, it is utilized at the distribution level because the conductivity of this
conductor is better at the distribution level. The price for both the
conductors i.e. AAC and ACSR are the
same.
●
Aluminium Conductor Aluminium Reinforce (ACAR)
This conductor combines AI
alloy strands to furnish a transmission conductor with outstanding electrical
& mechanical proportioned properties. These aluminum lines are coated with aluminum alloy wires. The body of the
conductor includes the number of strands. The major objective of this conductor
is that all the layers in it are identical, thus allowing it to be designed
with adequate electrical & mechanical characteristics.
●
All Aluminium Alloy Conductors (AAAC)
These conductors are somewhat
similar to AAC excluding the alloy. The durability of this conductor is similar
to ACSR, however, its lightweight and strong tensile strength make it usable in
the distribution level that is a river crossing. AAAC is portable, and a
favorable element for transmission as well as sub-transmission wherever less
weight supporting configuration is needed like swamps, mountains, etc.
●
Aluminium Conductor Steel Reinforced (ACSR)
This conductor is compressed
with a steel substance inside. The high stability makes it applicable for
overhead earth wires, installations
relating to extra-long spans & river crossings. These are produced with
various tensile strengths. With the high diameter, a much higher radiance limit
can be attained.
ACSR CONDUCTOR PROPERTIES
The properties include the
following.
1. Skin effect
Due to skin effects, the current that flows through
the conductor reduces the cross-sectional area where the AC frequency also
increases. Most of the current flow between the surface and the skin depth
depends on the frequency, current, conductivity, and mechanical properties. The
reduction in the cross-sectional area leads to an increase in resistance and is
inversely proportional to the cross-sectional area of the conductor.
2.
Proximity effect
When high voltage is carried
by the conductor, the distribution level of the current becomes non-uniform on
the cross-sectional area of the conductor. This is known
as the proximity effect. This effect intensifies conductor resistance and also
due to the other conductors carrying current within the surrounding area. The
percentage of this effect can be determined by frequency, conductivity, and
geometry factors.
Well, ACSRs can reduce this effect. When the steel is set at the
core, the aluminium posture will be around the steel wire in the ACSR. Hence,
the conductive strength is expanded and the surface area is reduced. This leads
to the current flow only on the outward layer and no current flow in the center
of the conductor. This is how the proximity effect is reduced in these
conductors.
3.
Hysteresis loss
The main reason for hysteresis
loss in this conductor is the atomic dipole inside the steel core. This loss is
less attractive but can be lessened with the help of an aluminum layer that is
also inside the conductor. The Aluminum layers having the magnetization feature
are used for accurate calculation of AC resistance. The hysteresis loss in
steel is due to the associated core heating; the odd-layer will have a
low-capacity mark as compared to the same level.
ACSR
CONDUCTOR ADVANTAGES
The
advantages are as follows.
● ACSR conductor’s structure is plane
● The capacity of transmission is high
● These cables are characterized by outstanding
tensile power
● Excellent performance
● They have a long-lifespan
●
They
deliver a great deal of flexibility
This is all about the ACSR
definition, design, sizing, types, properties, and its great advantages. These
conductors are accessible in wide ranges for transmission and distribution
systems as overhead conductors.
Comments
Post a Comment