Prysmian & Siemens commission HV transmission link in Australia

"Basslink" high-voltage direct current transmission link (HVDCT) handed over to the customer, National Grid Australia.

Milan, Italy   -   06/02/2006

Prysmian Cables & Systems and Siemens Power Transmission and Distribution (PTD) handed over the "Basslink" high-voltage direct current transmission link (HVDCT) to the customer, National Grid Australia . The link, operating since April 2006 , after a successful trial period, allows the electricity's flow between the Australian mainland and Tasmania .

A rated power of 500 megawatts at a direct current voltage of 400 kilovolts and a rated current of 1250 amperes can now be transported via the long-distance high-voltage direct current transmission link from Georgetown in Tasmania over a distance of about 360 kilometers ( 220 miles ) to Loy Yang , Victoria , and in the reverse direction. The overload capacity of the transmission system is more than 630 megawatts for up to eight hours a day.

Prysmian delivered and installed the 295 kilometer ( 180 mile ) long submarine power cable , paper insulated mass impregnated type, 1500 sqmm copper conductor size, steel armoured, currently the longest in the world used for power transmission, the extruded MV cable for the return current of the whole system and the 12 fibre optic data transmission cable.

The cables were manufactured in the Italian plant of Arco Felice ( Naples ), the world's most advanced excellence centre for submarine applications within the Prysmian group. In addition, Prysmian installed 6.4 km of high voltage underground land cables on the Australian mainland and 1.7 km in Tasmania , to interconnect the submarine link to the nearest terminals.

Prysmian installed the submarine portion of the interconnection with its own cableship " Giulio Verne ". The vessel is capable of laying all types of submarine cables even under severe weather conditions thanks to its state-of-the-art Dynamic Positioning System, which allows the cable-ship to follow a predetermined route with extremely high accuracy. It is equipped with a turntable with a capacity of 7,000 tons of high voltage cables and with a capstan machine capable of operating with a pulling tension of 55 tons to lay cables at water depths in excess of 1,000 m. The installation was performed simultaneously for the three cables in "bundle" configuration and in three separate campaigns, given the long length of the link, with the execution of two sea jointing operations.

Siemens was responsible for the HVDC transmission technology, including the key components of power converter valves, converter transformers, smoothing reactors, high-voltage switching stations as well as the communications and control technology. It was also responsible for the construction work, including the valve halls and the operational building, as well as for the erection of the overhead power lines with a total length of about 70 kilometers (45 miles). The project also included the expansion of existing switching stations that were linked to the HVDCT system.

Prysmian Group 
Prysmian Group is world leader in the energy and telecom cables and systems industry. With sales of some €8 billion in 2011, about 22,000 employees across 50 countries and 97 plants, the Group is strongly positioned in high-tech markets and provides the widest range of products, services, technologies and know-how. In the Energy sector, Prysmian Group operates in the business of underground and submarine power transmission cables and systems, special cables for applications in many different industrial sectors and medium and low voltage cables for the construction and infrastructure industry. In the Telecom sector, the Group manufactures cables and accessories for the voice, video and data transmission industry, offering a complete range of optical fibres, optical and copper cables and connectivity systems. Prysmian is listed on the Milan Stock Exchange in the Blue Chip index.