Increase Efficiency in Power Transmission with ACCR

October 13, 2012 7:30 am

“Aluminium conductor composite reinforced (ACCR) can withstand temperatures as high as 240°C with no damage or loss of performance,” says Mohan Nair, General Manager – Electrical Market Division, 3M India
Mr. Nair, could you brief us on the power crisis situation in India?With the growing infrastructure need in the country, there is an increasing demand for efficient power. Power transmission & distribution plays a key role in ensuring electricity reaches homes, offices and industries.  In order to meet growing requirement, there needs to be a strong transmission system between generation complex and bulk consumption centres.
Failure in transmission lines is one of the key reasons for frequent power outages; could you suggest some solutions for increasing efficiency of transmission lines?Transmission tower upgrades, revamping of distribution systems in urban areas are the key discussion topics across public utilities in the country. Nowadays, public expectations can conflict with sound planning and engineering; and where efforts to ensure grid reliability are seen as blocking access and constraining the potential of the future. Power utilities are faced with a major challenge in keeping up with the exponential growth in the heavily populated urban areas. This situation often involves upgrading the existing transmission lines to carry more power. However, upgradations need larger towers on wider swathes of land in areas where land is at a premium. Also, distribution lines, railroads and buildings may be close to the line that an upgrade cannot be done without displacing them. This is where upgraded conductor is required. Tell us about the benefits of ACCR over the aluminium conductor steel reinforced (ACSR).The traditional overhead transmission conductors such as aluminium conductor steel reinforced (ACSR) are composed of a core made of steel wires stranded together and then covered with aluminium wires. The steel core carries the mechanical load of the conductor while the aluminium outer wires carry the electrical current. Modern transmission conductor such as the 3M aluminium conductor composite reinforced (ACCR) replaces the core steel wires with alumina fibre wires infused with high purity aluminium and the aluminium outer wires are a high temperature aluminium zirconium alloy, producing a lighter conductor than conventional ACSR conductors, but with the same strength. ACCR is an advanced high temperature low sag conductor which provides numerous benefits to utilities. Also, when energy flows through a conductor, it gets heated up and expands, causing the conductor to sag. But ACCR sags about half as much as standard ACSR and can withstand temperatures as high as 240°C with no damage or loss of performance. The combination of high strength, low weight and low sag; allows twice the current to flow through it even while maintaining clearance and performance at high temperatures and over long periods of time. So existing transmission lines can be upgraded using existing structures and minimise disruption to existing facilities.
How do you see the acceptance of ACCR in India in comparison with global market?Continuing its legacy of innovation, 3M has developed the advanced high temperature low sag conductor used in power transmission. The 3M ACCR (aluminium conductor composite reinforced) is one such product which provides numerous benefits to utilities across the globe. The ACCR conductor has been installed in many applications world over since 2001 including the hot deserts, fast-growing areas, densely populated and environmentally sensitive areas. This product is satisfying the specific need of reliable and superior high tension low sag (HTLS) conductor in India.
3M has provided solutions for Tata Power’s installation in Mumbai…In Mumbai, Tata Power needed to upgrade two transmission lines. The population density is approximately 27,000 people per sq km as a result of which the company needed to upgrade their 110kV Borivali-Malad and Salsette-Saki transmission lines. To further complicate the issue, two-storey residences had sprung up under the lines severely violating the sag levels.
Tata Power was looking for a solution that would survive Mumbai heat and heavy monsoons making the conductor’s reliability under harsh environmental and operating conditions essential. 3M ACCR was an automatic choice and the installation was completed using existing structures and without displacing people living nearby. The line capacity was increased from 900 to 1800 amps.