Types of Conductor used in Overhead Transmission Lines

-
CONTENTS
> Properties of Good Conductor
> Types of conductors used in Overhead Transmision Lines


A Conductor is one of the most important component of overhead lines. Proper selection of coductor is as important as selection of size and voltage .  
 
Properties required for a good conductor :
a) HIgh electrical conductivity
b) High tensile strength 
c) Lower cost 
d) Corrosion resistive
e) Light in weight 


Types of Conductors used for Transmission Lines

Following are four common types of overhead conductors that are used for overhead transimission and distribution to carry generated power from generating stations to the end users.

1) AAC : All Aluminium Conductor
2) AAAC : All Aluminium Alloy Conductor
3) ACSR : Aluminium Conductor Steel Reinforced
4) ACAR : Aluminium Conductor Alloy
 Reinforced

AAC :- 
(a) All Aluminium Conductor is also called as Alumunuim Stranded Conductor.
 
(b) It has conductivity about 61% IACS( International Annealed Copper Stranded ). 

(c) AAC has limited use in transimission and distribution lines due to relatively poor strength despite of good conductivity.

AAAC :-
(a) All Aluminium Alloy Conductor are made from aluminium alloy which is a high strength aluminium magnesium-silicon alloy.

(b) This alloy conductor offer good electrical conductivity of about 52.5% IACS with better mechanical strength. 

(c) AAAC is used for distribution purposes not usually preferred for transimission because AAAC is lighter in weight as compared to ACSR of equal strength and current capacity. 

ACSR :-
(a) Aluminum Conductor Steel Reinforced consist of solid or stranded steel core with one or more layer of high purity aluminium wires wrapped in spiral. 

(b) The core wires may be zinc coated (galvanizisd ) steel or aluminium coated steel. Galvanization or aluminization coating are applied to protect the steel from corrosion. 

(c) The central steel core provides additional mechanical strength and produce less sag. 

(d) ACSR conductors are available in a wide range of steel content from 6% to 40%.

(e) ACSR conductors are very widely used for both transmission and distribution purposes.

ACAR :-
(a) Aluminium Conductor Alloy Reinforced conductor is formed by wrapping strands of high purity aluminium on high strength Aluminium-Magnesium-Silicon alloy core. 

(b) ACAR has better electrical as well as mechanical properties then equivalent ACSR conductors. 

(c) ACAR conductors may be used in overhead transmission as well as distribution lines. 




  

Comments

Post a Comment

Popular posts from this blog

Sag Template

-
Image
Sag Template  1) Sag template is used for allocating the position and height of the supports correctly on the profile.  2) The sag template is usually made up of transparent celluloid, perplex, or somtimes cardboard. 3) Sag template defines the limit of minimum clearance angle between the sag and the ground for safety purpose. Curves marked on the sag template are : 1 ) Hot template Curve or Hot Curve 2 ) Ground Clearance Curve 3 ) Support Foot or Tower Curve 4 ) Cold curve or Uplift Curve                                fig : 1 ( Note : Above image is enlarged in fig 2 )                                    fig : 2 Hot Curve :  The hot curve is obtained by plotting the sag at maximum temperature against span length. It shows where the supports must be located to maintain the prescribed ground clearance. Ground Clearance Curve : The clearance curve is below the hot curve. It is drawn parallel to the hot curve and at a vertical distance equal to the ground clearnc
Read more

Vibration in Overhead Conductors

-
Image
CONTENT > Vibrations in Overhead Conductors > Types of Vibrations >  Precautions Vibrations in Overhead Conductors Vibration is one of the serious cause of conductor failure (i.e. having cracks , breaking of conductor , or flash over ) in overhead conductors of transmission lines. So, vibration should be kept within limits for safe operation of the transmission lines.  Types of Vibrations  Vibration in Power Lines can be categorized into three types caused under the influence of wind :  i) Resonant or Aeolian Vibration  ii) Galloping  iii) Simple swinging i) Aeolian Vibration  1) These vibrations are caused by aerodynamic forces generated as the wind blows across the conductor.       fig : Damage due to Aeolian vibration 2) The frequency of the vibration may receive a positive feedback from the conductor's natural vibration frequency.  3) This self- exciting vibration can cause cracks on the conductors due to fatigue and can cause damage particular
Read more