FEATURE NEWS:
More power and security for overhead high-voltage lines
In Europe, aerial power lines are becoming an increasingly important ecological and aesthetic issue, with some advocates urging their complete removal from the landscape. This is forcing power utilities to exploit their existing lines and pylons to the maximum rather than incur the expense and uncertainty of new rights-of-way. New technologies such as Nexans’ AERO-Z® allow for an equal diameter, a greater useful cross-sectional area, and therefore an increased transport capacity; or for a smaller diameter, almost the same transport capacity. The French company provides bare overhead conductors that offer low corrosion, various alloys adapted to each country's norms, high-transmission capacity for dense grids and various sizes according to customers' needs. AERO-Z® offers the ideal replacement for conventional conductors, since it allows energy providers to achieve significant increases in both the efficiency and security of their networks.
Nexans’ AERO-Z® conductors comprise specially profiled Z-formed wires, which fit neatly into each other, resulting in more metal within a given cross-section. This means lower electrical resistance and less joule loss, so that more energy can be carried along the same size of conductor. The interlocking of the Z-formed wires also avoids them to un-strand in case of damage on a wire, avoiding that the latter comes in contact with a narrow phase or structure. Since the AERO-Z® conductors have exactly the same diameter as traditional conductors, they can be installed without changing the type of fixation accessories, such as suspension and dead-end clamps. This makes them user-friendly and means that the energy providers do not have to carry a double inventory.
One of the key technical challenges that had to be resolved in developing and improving the new conductor was the “CX” factor, which is the effect that wind has on an object in terms of drag coefficient. This can exert terrific strain, not only on the conductor itself, but also on the support structure. Rigorous wind tunnel and field tests have shown that at certain wind speeds, AERO-Z® has a greatly reduced drag coefficient compared to traditional stranded conductors - as much as 40% lower. Similarly, the conductor “gallops” less, even at extremely high wind speeds, and this is an important security factor which lowers the strain on both the pylons and the conductor. Numerical simulations have also confirmed that the strains can be reduced by 30% on the hardware in case of turbulent winds thanks to the excellent self-damping of the AERO-Z® design, increasing the security and the life expectancy of the line. A further advantage of AERO-Z®’s compact design and structure is that it is less prone to internal corrosion and has improved shock absorption, while its smooth surface not only reduces noise, but also reduces frost and ice accretion.
AERO-Z® conductors are systematically used on all 1,500km of Belgium’s overhead power lines and the proven performance, savings and security has prompted France’s RTE to order over 900 tonnes since 2002 and to include the AERO-Z® in their yearly overhead frame agreement. “We proved to RTE that despite the higher cost of AERO-Z®, they would see a return on their investment within three years thanks to reduced Joule losses. In most of our study cases, the ROI is possible in less than five years”, commented According Mr Thierry Capelle, Nexans AERO-Z® sales manager. Peru’s ETECEN utility has also recently decided to install over 1,000km of AERO-Z® along its sandy and windy Pacific coastline.
Company: |
Nexans |
Country: |
France |
Fax: |
+33 1 56 69 84 84 |
Email: |
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Website: |
www.nexans.com |