Types of Transmission Line Conductors

 Types of Transmission Line Conductors

In general the following conductors are mainly used for transmission lines, namely

1.      Solid conductors

2.      Stranded conductors

3.      Hollow conductors

4.      Bundle conductors

1. Solid conductors: The solid conductors. These are mainly available in two forms.

Namely:

(i) Solid copper

(ii) Copper clad steel conductors.

Features:

(i) Over weight as compared to other conductors.

(ii) These are very difficult to handle and for transport

(iii) Skin effect is more

(iv) These are used for smaller cross-section only.

(v) Solid Aluminum conductors are for transport.

2. Stranded conductors:

The stranded conductor. The stranded conductor. These conductors have greater flexibility and greater mechanical strength as compared to single conductor of same cross-sectional area.

Features:

(i)     Stranded conductors usually have a central wire surrounded by successive layers  of wires containing 6, 12, 18, 24,…wires.

(ii)     The number of stands in a stranded conductor can be determine by

                 N = 3n (n + 1)

Where     N – is the number of stranded conductor.

                  N – is the number of layers

(iii)     The total diameter of stranded conductor can be determined by

                               D = (2N + 1 ) D

Where                          D = is the total diameter of the stranded conductor.

                                      d – is the diameter of the each strand.

                                      n – is the number of layers.

(iv)       Because of more flexibility these conductors are easier to handle and transport.

(v)          Stranded conductors are mainly available in the following form

·        Hard drawn copper

·        A.C.S.R (Aluminium conductor steel Reinforced)

·        AAC (All Aluminium conductors)

·        AAAC (All Aluminium Alloy conductors).

·        ACAR (Aliminium conductor Alloy Reinforced).

Out of the above all conductors for transmission lines, ACSR Conductors are Used. These stranded conductors are identified by their code names assigned by the different manufacturers. Usually names of some animals, birds  (or) Flowers are used.

S.No.                       Type of Conductors                                                   Names Used    

 1.                AAC (All Aluminium conductor)           Rose, pansy, Ant, Aster, Iris, Gnat etc.

 2.             ACSR (Aluminium conductor)         Squirrel, Tiger, panther, Lion, wolf, Zebra, Moose                                                                                                       etc. steel Reinforced                

3. Hollow Conductors: Shows the hollow conductor.

Features:

(i)                 These conductors gives a larges a diameter.

(ii)               Corona loss is reduced due to large diameter of the conductors.

(iii)             Skin effects is less as compared to other conductors.

(iv)             Major portion of the conductor surface is exposed to atmosphere, causing.

·        More wind pressure on the conductor.

·        Too much ice formation on its surface.

4. Bundled conductors:

Generally there is no difference in construction between stranded conductor and bundled conductors but only difference is that these are mainly used in very large in number of strands as compared to stranded conductors.