wire 2012: Wire and secure electricity supplies
Modern wire materials facilitiating modernisation of power gridsWire, cable and cable-processing industries and the trade fair wire 2012
One of the outstanding features of the past century is that electricity consumption has gone up continuously. Whereas most people would not even have noticed a power cut at the beginning of the 20th century, it would paralyse social life in many parts of the world today. To carry the power required, which keeps growing, transmission grids must both be modernised and extended. To do so, wire shall be needed. Contemporary processing technologies will be presented at the wire trade fair to be held from 26 to 30 March 2012.
Electricity supplies
For a couple of decades public interest in power supply was mostly focused on the various ways to generate electricity and not on transmission systems. But professional associations like German Environmental Aid (DUH) have already pointed out for years that the power supply systems in Germany have reached the limits of their transmission capacities and stand in urgent need of modenisation and extension. This will be necessary to guarantee security of supplies for the future as well. This demand assumed additional and strong impact in the context of the disasters occurring in Japanese nuclear power stations in March 2011 because they led to debates in many places concentrating on a greater use of renewable energy.
Extending transmission networks
To guarantee that consumers in the European Union will be able to rely on safe power supplies, Mr Guenther Oettinger, the EU’s Energy Commissioner, calls for building new high-voltage transmission and power lines to criss-cross Europe over a length of at least 45,000 kilometres. In November 2010, the "VDI nachrichten" weekly carried a quote of Mr Oettinger: "Once we want to exploit wind energy mainly in the North Sea and exploitable sunlight hours in southern Europe, we shall be in need of intelligent networks to carry electricity to major urban areas like Paris, Hamburg, Lyon or Munich". The German Energy Agency (dena) found out that over 3,500 kilometres of new power lines will be needed in Germany alone until 2020. These are to guarantee that electricity generated in the offshore wind farms in the North Sea as well as electricity from other renewable sources shall reliably be conducted into the conurbations and industrial areas in western and southern Germany. The German Energy and Water Association (BDEW) pointed out, however, that attention cannot solely be devoted to major transmission lines but must also be given to the various levels of power supply grids. In keeping with plans for the use of renewable sources of energy, another 195,000 kilometres of cables and lines will be called for in Germany. Over and above matters of funding, acceptance by the population of such extension projects as well as the input required for licensing and approval represent major socio-political challenges.
Solutions on offer by wire and cable industries
Wire and cable making industries developed solutions which might be acceptable to all those involved and which also meet recommended objectives of specialised associations. Thus, a so-called plan N for the extension of German power networks worked out by the German Environmental Aid association and submitted to the public in late 2010, amongst other measures proposed bringing up transmission capacities of high-voltage lines by up to 50 per cent through introducing conductor strand monitoring. Following this study, existing transmission lines may be reinforced by high-temperature supraconduction transmission cables coping with higher voltages. This is known as "reconducturing" among experts. At present, transmission lines consisting of a steel wire and aluminium wires with round cross sections are wide-spread. These ACSR or aluminium conductor steel-reinforced lines may cope with operating temperatures of up to 100 degrees.
Alteratives are offered by ACCS-TW-HTLS conductors made from certain aluminium materials and produced in trapezoidal shapes. Conducting elements are concentrically-stranded around steel wire core cables and then compacted. Compared to conventional cables these new types may be manufactured with the same conducting cross sections or with the same diameters. The first version offers the same current carrying capacity and uses smaller diameters, the second version makes for higher current carrying capacities. ACCS-TW-HTLS conductors come with similarly high breaking strengths as standard ACSR conductors but almost twice their power transmission capacity. Also, they offer higher fatigue strength, very good self-attenuating properties and lower sag compared to conventional conductors and may operate continuously at temperatures reaching up to 250 degrees C. An even more recent type is available in the shape of ACCC-TW-HTLS conductors, where the supporting element is a glass-fibre tube filled with carbon filaments. Its maximum working temperature is 200 degrees C and its current carrying capacity of 1,610 A is the same as that of ACCS-TW conductors. On account of its unique conductor core of composite materials, its specific weight falls to 1,240 kilogrammes a kilometre. It also features higher tensile strength, resulting in extremely low sag. No matter whether complete lines or just parts thereof are involved, such as sections spanning wide motorways or rivers, these new conductors offer numerous advantageous chances to build modern overhead lines with optimal properties.
Aluminium-wire drawing for HTLS conductors
Manufacturing these new lines involves essential know-how because of their trapezoidal cross section. One way involves to produce a round wire with a diametre of 9.52 mm from the 1350 aluminium alloy containing 99.9 per cent of this metal in six consecutive profile drawing operations to bring about its final shape. A typical manufacturing unit was developed by the Niehoff company, working all over the world. This device, an electronically controlled MSM 85 rolled wire drawing machine comes with the RA 501 continuous annealing section. Machines like these are mainly meant to process copper or aluminium into wire materials, but they are also used for drawing supraconducting wires. The continuous annealing section is especially designed to take over inline annealing of aluminium materials. As each of the drawing dies is powered by its own AC motor, operation may proceed with minimum slip. Depending on the properties of materials and cross sections of wire shapes, drawing operations may be set to different wire lengthening.
Special cables for "intelligent energy networks"
Beyond the extension of power transmission systems, the efficient use of these systems is assuming ever greater importance. Thus, conductor strand monitoring assists transmission line operators to control transmission and in making optimum use of the grid. Many institutions, the Fraunhofer network "Intelligent energy networks" among them, work on developing "smart grids". These have as their specific feature that electricity flows may be most effectively controlled by jointly operating many information and communication technologies, and that electricity will be used more economically than until now. Again wire and products made from it, such as cables, are indispensable.
Wire and the wire 2012 trade fair
Whether they are needed for carrying electricity, electronic data or bearing mechanical force, wire and products made from it, such as cables, ropes, springs, screws, meshes, grids or electrical coils play major and indispensable parts in all spheres of our daily lives. wire, the leading global trade fair for the wire and cable industries, held for the 13th time in Düsseldorf in the spring of 2012, will offer information on future-oriented manufacturing and application concepts. In addition, synergies will be generated by the international tube and pipe trade fair, Tube 2012, to be held at the same time and in parallel with wire 2012. Both trade fairs will be held in Düsseldorf from 26 to 30 March 2012.
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ACSR – aluminium conductor steel reinforced (with galvanised steel core)
ACSS - aluminium conductor steel supported
ACCC – aluminium conductor composite core
TW – trapezoidal wire
HTLS – high temperature low sag conductors
Press Contact 2012:
Petra Hartmann-Bresgen
Kathrin Kleophas
( +49 (0)211/4560-541/-544
2 +49 (0)211/4560-87 541/-87 544
7 HartmannP@messe-duesseldorf.de
7 KleophasK@messe-duesseldorf.de