ACCC conductor

ACCC (Aluminum Conductor Composite Core) is a registered trade mark for a type of "high-temperature low-sag" (HTLS) overhead power line conductor.

Description

CTC Global developed and commercialized the ACCC Conductor.

Advantages

It is able to carry approximately twice as much current as a traditional aluminium-conductor steel-reinforced cable (ACSR) cable of the same size and weight, ^[1]

Steel-reinforced ACSR and composite-core ACCC conductors

Its light weight and softness result in roughly 30% greater conductivity than an equivalent ACSR conductor, allowing 14% more current to be carried at equal temperature. For example, 1.107 in (28.1 mm) diameter ACCC "Drake" conductor at 75 °C has an AC resistance of 106 mΩ/mile, ^[2] while equivalent ACSR conductor has an AC resistance of 139 mΩ/mile, ^[3] 31% higher.

Sag Comparison Test Data: temperature vs. sag of various conductor types on a 215' test span.

Operation at high temperatures implies high line losses, which may be uneconomical, but the ability to carry such current contributes to the redundancy of the electric grid (the high overload capacity can stop a potential cascading failure) and thus can be valuable even when rarely used directly. Even at higher operating temperatures, the ACCC conductor's added aluminum content and lower electrical resistance offers reduced line losses compared to other conductors of the same diameter and weight.

Disadvantages

ACCC-specific conductor dead-end Assembly. This grips only the central strength member.

• The primary disadvantage is cost; ACCC costs 2.5–3 times as much as ACSR cable. ^[4]
• Although ACCC has significantly less thermal sag than even other HTLS conductor designs, it has a lower axial stiffness. ^[5] Therefore, it sags more than other designs under ice load, although an "ultra-low-sag" (higher modulus) version is available at a cost premium. ^[5] Also, other aluminium alloys with an increased strength at the expense of electrical conductivity can be used to improve ice load sag. Ice load can also lead to the loosening of outer layer strands because of plastic deformation by the attached weight.
• Annealed aluminum is extremely soft and makes the conductor prone to surface damage during installation if mishandled.
• The conductor has a larger minimum bend radius, requiring extra care during installation.
• The conductor requires special fittings and stringing equipment that are more expensive.

References

1. Wareing, B. (28 February 2011). Types and Uses of High Temperature Conductors (PDF). CIGRÉ (International Council on Large Electric Systems) Seminar. Bangkok: CIGRÉ Study Committee B2 Working group 11. Archived from the original (PDF) on 3 December 2013. Retrieved 2014-02-03.
2. Banerjee, Koustubh (January 2014). Making the Case for High Temperature Low Sag (HTLS) Overhead Transmission Line Conductors (PDF) (M.Sc.). Arizona State University. p. 70.
3. "Aluminum Conductor. Steel Reinforced. Bare". Southwire. Archived from the original on 2016-03-04. Retrieved 2016-01-08.
4. "Advanced Conductor Scan Report" (PDF). Idaho National Laboratory. Archived from the original (PDF) on 2024-03-18.
5. Qiao, Kun; Zhu, Anping; Wang, Baoming; Di, Chengrui; Yu, Junwei; Zhu, Bo (31 March 2020). "Characteristics of Heat Resistant Aluminum Alloy Composite Core Conductor Used in overhead Power Transmission Lines". Materials. 13 (7): 1592. Bibcode:2020Mate...13.1592Q. doi: 10.3390/ma13071592 . PMC   7178384 . PMID   32244389.