The document outlines the key considerations in the design of transmission lines, focusing on electrical and mechanical aspects. It emphasizes the importance of low voltage drop, power loss reduction, and high conductivity in conductors, as well as mechanical strength to withstand various stresses. Different types of conductors, such as aluminum and steel-reinforced options, are discussed regarding their cost-effectiveness, strength, and efficiency in supporting transmission over longer spans.

1. CONDUCTORS OF
TRANSMISSION LINE

2. General Considerations
Electrical Considerations for T.L. Design:
• Low voltage drop
• Minimum power loss for high efficiency of
power transmission.
• The line should have sufficient
current carrying capacity so that the power
can be transmitted without excessive
voltage drop or overheating.

3. • Conductivity of Conductor:
R = p.L/A , or
R = L/6. A
Where:
L: Conductor length.
A: Conductor cross sectional
area.
p: resistivity
6: Conductivity 1/p)

4. • The conductor conductivity must be very high
to reduce Conductor resistance R and hence
reduce losses
I2 .R

5. Mechanical Considerations for T.L. Design:
• The conductors and line supports
should
have sufficient mechanical strength:
- towithstand conductor weight,
Conductor Tension and weather
conditions (wind, ice).
- The Spans between the towers can be long.
- Sag will be small.
- Reducing the number and height of
towers

6. • Heat expansion coefficient must be very
small.
Rd'
Ro•(!
o
•’)
a t is the heat expansion coefficient
at t.

7. Aluminum Conductors
(AAC)
lowest cost - low mechanical
strength Used for small span

10. Aluminum Conductor Steel
Reinforced (ACSR)
1 Steel strands
2 Aluminum strands
ACSR
(26/7)

14. Advantages of ACSR
• High mechanical strength can be
utilized by using spans of larger lengths.
• A reduction in the number of
supports also include reduction in
insulators and the risk of lines outage
due to flash over or faults is
reduced.
• losses are reduced due to larger
diameter of conductor.

15. 4-Aluminum Conductor Alloy
Reinforced (ACAR)