SUMBUL.H.Abidi

OVERHEAD CONDUCTOTS

Stranded Conductors

•Flexibility•Mechanical Strength increases•Central strand surrounded by successive layers•6,12,18,24

•n=no of layers•Total conductors=1+3n(1+n)

•Overall diameter of n layer stranded conductor D=(1+2n)d

AAC ( All-Aluminium Conductors ) Concentric lay stranded Aluminium Conductor ( AAC) is

made up of one or more strands of hard drawn 1350 aluminum alloy.

These conductors are used in low, medium and high voltage overhead lines.

AAC has seen extensive use in urban areas where spans are usually short but high conductivity us required.

Because its relatively poor strength to weight ratio, AAC had limited use in transmission lines and rural distribution because of long spans utilized.

The excellent corrosion resistance of aluminium has made AAC a conductor of choice in coastal areas. Because of its relatively poor strength to

AAAC ( All Aluminium Alloy Conductors )Concentric lay stranded Aluminium Alloy Conductors

(AAAC) are made out of high strength Aluminium-Magnesium-Silicon Alloy.

conductors are designed to get better strength to weight ratio and offer improved electrical properties, excellent sag-tension characteristics, and superior corrosion resistance when compared with ACSR.

As compared to a conventional ACSR conductor, the lighter weight, comparable strength & current carrying capacity, lower electrical losses and superior corrosion resistance have given AAAC a wide acceptance in the distribution and medium & high voltage transmission lines..

ACSR (Aluminium Conductor Steel Reinforced )

Aluminium Conductor Steel Reinforced (ACSR) is concentrically stranded conductor with one or more layers of hard drawn aluminium wire on galvanized steel wire core.

The core can be single wire or stranded depending on the size. Steel core wire is galvanized to protect for corrosion protection. Additional corrosion protection is available through the application of grease to the core or infusion of the completed conductor with grease.

The proportion of steel and aluminium in an ACSR conductor can be selected based on the mechanical strength and current carrying capacity demanded by each application.

ACSR ContdACSR conductors are recognized for their

record of economy, dependability and favourable strength / weight ratio.

ACSR conductors combine the light weight and good conductivity of aluminium with the high tensile strength and ruggedness of steel.

In line design, this can provide higher tensions, less sag, and longer span lengths than obtainable with most other types of overhead conductors.

ACSR

ACAR (Aluminium Conductor Alloy Reinforced )Aluminium Conductor Alloy Reinforced (ACAR) is formed by

concentrically stranded wires of Aluminium on high strength Aluminium -Magnesium -Silicon(AlMgSi) alloy core.

The number of wires of Aluminum & AlMgSi alloy depends on the cable design. Though the general design comprises a stranded core of AlMgSi alloy strand, in certain cable constructions , the wires of AlMgSi alloy strands can be distributed in layers throughout the Aluminium strands.ACAR has got a better mechanical and electrical properties as compared to an equivalent ACSR, AAC or AAAC.

A very good balance between the mechanical and electrical properties therefore makes ACAR the best choice where the ampacity, strength and light weight are the main consideration of the line design.

These conductors are extensively used in overhead transmission and distribution lines.

Smooth body ACSR conductor

• They are also called compacted ACSR• The conductors are pressed through dies to

flatten the aluminum strands into segmental shape.

• The interstrand space id filled and the diameter of the conductor is reduced without affecting electrical and mechanical properties.

• For the same aluminium area the steel core diameter is increased so mechanical strength is increased.

• Can be used for long span length.• ACSR/TWD is ideal for reconductoring: it offers

the same diameter for ice and wind but loading at higher ampacity than traditional ACSR designs.

Expanded ACSR Conductor

A plastic or fibrous material is introduced between the steel core and almunium strands to make diameter of the conductor large to reduce corona loss and radio interference

ACCC® (Aluminum Conductor Composite Core)

•The new Generation, highly energy efficient ACCC® (Aluminum Conductor Composite Core) is a concentrically stranded conductor with one or more layers of trapezoidal shaped hard drawn and annealed 1350-0 aluminum wires on a central core of light weight Carbon-Glass fiber composite. •The ACCC® Conductor uses a carbon fiber core that is 25% stronger and 60% lighter than a traditional steel core. This along with trapezoidal shaped aluminum strands help to increases the aluminum content in ACCC® by over 28% without increasing the conductor’s overall diameter or weight.

ACCC® contd

ACCC® is designed to operate continuously at elevated temperatures and has excellent sag characteristics through out the operating range.

ACCC® is the right choice if reconductoring of the existing lines are required to enhance the transmission capacity.

This conductor offers very low line losses and excellent self-damping properties. Because of it's high strength to weight ratio, ACCC® can be used with long spans which brings down the cost of structures in new lines