High Strength Aluminium Clad Invar Wire for Core Wire of Hstacir/Aw

High Temperature Low Sag Conductors (HTLS) can withstand operating temperatures of up to 210°C, thus carrying higher power compared to conventional conductors. These conductors can be applied when there is a need to use an existing OHL that has clearance problems (ampacity limitations) and restrictions to the use of new and higher towers. HTLS conductors will allow an increase of the ampacity without the need to modify most of the existing towers.

Technology Types

HTLS conductors can be one of four types [11]:

• Type 0: Conventional steel core reinforced aluminium conductors ACSR or ACSR/TW for operating temperatures <100°C
• Type 1: Conductors consisting of a strength member made of steel, coated steel or steel alloy, and an envelope for which the high temperature effects are mitigated by means of thermal-resistant aluminium alloys (TACIR, TACSR)
• Type 2: Conductors consisting of a strength member made of steel, coated steel or steel alloy, and an envelope for which the high temperature effects are mitigated by means of annealed aluminium (ACSS)
• Type 3: Conductors consisting of a metal-matrix composite (MMC) strength member, and an envelope for which the high temperature effects are mitigated by means of thermal-resistant aluminium alloys or annealed aluminium. (ACCR, ACMR)
• Type 4: Conductors consisting of a polymer-matrix composite (PMC) strength member, and an envelope for which the high temperature effects are mitigated by means of annealed aluminium or thermal- resistant aluminium alloys for HTLS applications (ACPR)

Aluminum clad invar is different from aluminum clad steel that it use invar rather than high-carbon steel wire as the steel core material,although invar is no match for high-carbon steel in the aspect of strength,ti is coefficient of thermal expansion is much lower than high-carbon steel. So the transmission capacity of the cable products which adopt invar material may increased by 50% than other cable  products with the same structure. As the characteristic of thermal expansion,the sag of aluminum clad invar products is much smaller than the sag of aluminum clad steel products at the same temperature,when the cable is being laid,the span between the towers can be increased and the height can be reduced, when it conveying the same capacity of electricity, its investment costs are lower than ordinary aluminum clad steel conductor.