Smart Grid - energy distribution and network control

Transport double the amount of electricity without replacing the old power masts

ACCR conductor technology
In view of the upcoming reconstruction of the German energy infrastructure – it is being carried out in order to offer a full supply of renewable energy – and the related volatile feed-in, the expansion and upgrade of the German electricity grid is an extremely important task. With ACCR (Aluminium Conductor Composite Reinforced) technology, 3M has developed a conductor that can carry twice as much electricity as conventional aluminium-steel conductors. It therefore serves as a element in the accelerated realisation of the network expansion.

Suitable for all voltage levels, the high-temperature, low-sag 3M ACCR ensures significantly less sag than conventional aluminium-steel cables. Due to its material quality, it can operate at temperatures of up to 210 °C continuously *( and 240°C in an emergency situation). Thanks to these properties, twice the amount of electricity can be transferred simply by replacing the installed conductor with 3M ACCR. This can be achieved without having to interfere with the towers – elaborate foundation reinforcements or expensive tower heightening procedures need not be carried out. This is to say that the existing towers and insulator chains can still be used without having to alter them. The electricity losses are comparable to those of standard conductors at the same current. Even over very long distances, the voltage with high-temperature, low-sag systems is preserved as it would be with conventional cables if substations, consumers or power plants (phase shifters) stabilise the system.

Since it is about upgrading an existing line without changing the towers, just a new BlmSchV (Federal Immission Control Ordinance) approval must be obtained due to the fact that the magnetic field will change. Due to the size of these fields with modern lines, it is likely that even if the amount of power is doubled, the fields will remain within the prescribed limits.

The advantages for the turnaround in German energy policy are obvious. Strengthening the network with the 3M ACCR conductor is another element in the network expansion’s portfolio and, most importantly, it offers both a high level of supply security and stability when feeding in as well as the ability to transfer renewable energy. Limiting the amount of network expansion with planning approvals and new lines. A simple exchange of the conductor of existing lines can lead to an increased acceptance in society and thus accelerate the process of strengthening the network in a similar manner.

Projects with 3M ACCR cables in Germany and throughout the world
ACCR technology has been in use since 2001 in the US. Europe, South America, North America, Asia and Africa. In Germany, there are already a number of successful pilot projects that have been carried out with  ACCR conductors . Throughout the world, 3M has realised over 61 projects and installed a total of 1,600 km of ACCR cable. Since 2009, four projects have been successfully installed in Germany and are permanently in network operation. The partners involved include E.ON Netz, Amprion, EnBW and 50 Hertz – Tennet will undertake the fifth pilot project within 2013. The German projects have voltage levels of 110 kV, 220 kV and 400 kV.

A recent study at RWTH Aachen University has also confirmed that strengthening existing lines using high-temperature, low-sag cables (e.g. 3M ACCR) in selected scenarios can present an economical alternative to line replacement through conductors with larger cross sections.

Conclusion: High-temperature conductors  with low sag – such as 3M ACCR – support the rapid realisation of the turnaround in energy policy. 3M ACCR can make a particularly valuable contribution in addressing the challenges of integrating volatile and high amounts of electricity (from wind energy, for example) into the existing network infrastructure.

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contact details/company:
3M Deutschland GmbH
Electronics & Energy
Carl-Schurz-Str. 1
41453 Neuss

contact person:
Thomas Junck
+49 (0) 2131 143638