Types of Aluminum Conductors for Electricity Power Transmission

Types of Aluminum Conductors for Electricity Power Transmission

2017-03-08
There are 4 significant kinds of above conductors made use of for electric transmission as well as circulation.
  • AAC - All Light weight aluminum Conductor
  • AAAC - All Light weight aluminum Alloy Conductor
  • ACSR - Light weight aluminum Conductor Steel Reinforced
  • ACAR - Light weight aluminum Conductor Aluminum-Alloy Reinforced

The different mixes and also adjustments of these conductor kinds supply a wide range of feasible conductor layouts.

AAC - All Aluminum Conductor, sometimes referred to as ASC, Aluminum Stranded Conductor, is made up of one or more strands of 1350 Alloy Aluminum in the hard drawn H19 temper. 1350 Aluminum Alloy, previously known as EC grade or electrical conductor grade aluminum, has a minimum conductivity of 61.2% IACS.

ACSR - Aluminum Conductor Steel Reinforced, a standard of the electrical utility industry since the early 1900's, consists of a solid or stranded steel core surrounded by one or more layers of strands of 1350 aluminum.
Historically, the amount of steel used to obtain higher strength soon increased to a substantial portion of the cross-section of the ACSR, but more recently, as conductors have become larger, the trend has been to less steel content. The latter produces a conductor designated as ACSR/AW in which the aluminum cladding comprises 25% of the area of the wire, with a minimum coating thickness of 10% of the overall radius.

6201 "AAAC" - A high toughness Aluminum-Magnesium-Silicon Alloy Cable television was established to change the high stamina 6/1 ACSR conductors. Initially called AAAC, this alloy conductor supplies outstanding electric features with a conductivity of 52.5% IACS, exceptional sag-tension attributes as well as exceptional deterioration resistance to that of ACSR. The mood of 6201 is typically T-81 aluminum.

6201 aluminum alloy conductors are typically sold as O.D. (overall diameter) equivalents for 6/1 and 26/7 ACSR constructions. As with AAC conductors, the maximum short circuit temperature of 6201 must be kept below 340 ° C to prevent dangerous conductor annealing.

Compared with ACSR, AAAC's lighter weight, similar stamina as well as existing bring ability, reduced electric losses and also premium deterioration resistance have actually provided this conductor large approval as a circulation conductor. It has actually located restricted usage, nonetheless, as a transmission conductor.

The primary advantage of the ACAR conductor lies in the fact that all strands are interchangeable between EC and 6201, thereby permitting the design of a conductor with an optimum balance between mechanical and electrical characteristics. In effect, ACAR is a composite aluminum-aluminum alloy conductor which is designed for each application to optimize properties. Inverse ACAR conductors are also available with the harder 6201 aluminum alloy wires being on the outer surface of the conductor and the 1350 aluminum making up the heart of the conductor.

The high tensile strength of the 6201-T81 wires combined with the high strength of steel provides an exceptionally high strength conductor with good conductivity. AACSR conductors have approximately 40% to 60% more strength than comparable standard ACSR conductors of equivalent stranding, with only an 8-10% decrease in conductivity.

ACSS OR SSAC - (Aluminum Conductor Steel Supported) - SSAC conductor was designed for use as a replacement conductor in upgrading existing transmission and distribution power lines and grids with minimum capital outlay and expense.  The premise of design is higher conductor operating temperature without detrimental annealing of the aluminum in standard ACSR causing a loss of strength in the aluminum. ACSS conductor is an aluminum-steel composite conductor resembling standard ACSR in appearance, stranding and overall diameter.

ACSS has actually seen minimal usage in the USA. Despite the fact that ACSS has far better conductivity, a greater operating temperature level as well as enhanced damping features when as compared to traditional ACSR, it has a reduced breaking stamina, generally producing higher preliminary and also last droops. It is, nonetheless, a great conductor to think about for line upgrades if the determined existing well worth of electric losses reveals a cost savings over line conversion price.

Expanded ACSR - This conductor is designed to be used where large diameter single conductors are required to reduce the electrical stress gradient at the surface of the conductor to provide corona-free operation. Expanded ACSR is used when a single conductor rather than a conductor bundle is used at EHV voltage levels. Because of the precise fabrication techniques required to manufacture expanded conductors and a history of installation problems, these conductors have not been widely used.



Smooth Body Conductors (trapezoidal designed cable)

Some wires are created to generate a smooth external surface area and also decrease general size. This smaller sized size lowers the ice as well as wind packing run into throughout extreme climate, consequently minimizing the pole/tower loading or permitting longer style periods. Smooth body conductors are of 2 kinds - small conductors or trapezoidal designed cable small conductors, i.e., TW conductors.

Compact Conductors - Compact overhanging conductors are typically offered in both AAC as well as ACSR with size decreases varying from 8% to 11%. AAC conductors are offered in a dimension series of # 8 AWG via 1000 kcmil with conventional stranding as noted in ASTM. Small ACSR conductors are readily available just in dimensions # 6 AWG with 336.4 kcmil in buildings with a solitary steel core cord.

Portable conductors are produced by passing the stuck wire via effective condensing rolls or a condensing die. The hairs are flawed, to the level they loose their circularity, partly filling up the interstrand gaps as well as the external surface area of the conductor ends up being a fairly smooth cyndrical tube. The resulting decrease in total size not just decreases the ice and also wind loading attributes of the conductor however additionally decreases the tension slope at the conductor surface area.

150%/ 200% ACSR - The terms 150% and also 200% ACSR describe a household of solitary layer (6/1) building and constructions of ACSR that have 150% and also 200% of the toughness of the comparable building and construction basic ACSR while showing around the exact same total size. The 150% and also 200% smooth body ACSR was created to offer a conductor with a significant rise in best toughness as compared to conventional 6/1 ACSR buildings. This is completed by utilizing a bigger steel core cable as well as dramatically squashing the light weight aluminum hairs to produce a smooth round conductor surface area.

150% as well as 200% smooth body ACSR is produced by passing the composite stuck wire via a die or rolls so developed to squash the light weight aluminum hairs as well as fill up the interstices which exist in standard stuck ACSR. This causes a decrease in general wire size which suggests a reduced ice as well as wind tons as well as higher toughness to crammed weight proportion.

These conductors were mainly made for usage on country circulation lines. The minimized size and also added high toughness supply significant layout as well as functional benefits for the longer periods of a country circulation line offering sparcely inhabited locations based on serious winter problems.

Trapezoidal Shaped Conductors - Formed cord portable conductors made from trapezoidal (TW) designed cables is a fairly brand-new conductor layout. These conductors could be offered in AAC, AAAC as well as ACSR buildings and also are assigned as kinds AAC/TW, AAAC/TW as well as ACSR/TW.

Traditional conductor styles have actually generally made use of rounded cords. Using innovation to style as well as create trapezoidal cords (TW) gives conductor developers with a choice to standard round hair conductor layouts. Making use of trapezoidal cord layouts returns portable conductors with much less void location as well as a decreased outside size.

With conventional ACSR strandings, the number of aluminum and steel strands uniquely define the ratio of steel area to aluminum area. The designation of "type" has replaced the stranding designation to more accurately identify TW conductors. The aluminum area and steel area of both conductors are identical.

An alternate style principle is to define ACSR/TW conductors with comparable general sizes to standard ACSR buildings. In this case, the size is matched to that of the basic ACSR while keeping the very same ratio of steel to aluminum by location. Given that the aluminum location is increased, the steel location should be increased to preserve the correct location ratio.

If a decreased size TW building is chosen, the size is minimized by around 10% therefore decreasing the style ice and wind loading on the conductor. If an equivalent size TW building is chosen, the aluminum location is increased by around 20% - 25% supplying a decline in Air Conditioning resistance of 15% - 20% and increasing the present bring capability 8% to 10%.

Using trapezoidal wires supplies a more compact conductor style with mechanical homes a minimum of equivalent to that of standard ACSR. Given that ACSR/TW styles have the very same steel-to-aluminum ratios as their comparable ACSR building and constructions, stress-strain and sneak information established for traditional strandings of ACSR can be utilized to forecast droop and stress style information for ACSR/TW conductor buildings.

TW conductor setup needs no unique tools, devices or training just like the normal AAC OR ACSR conductors.