Cleaning up on the network

A custom-built power supply system that reduces environmental impact is to be fitted to the Channel Tunnel Rail Link.

The new transmission technology, developed by ABB, will enable the rail link to become the first in the UK to use a European high-speed electrification standard, which itself will reduce electromagnetic interference.

ABB will carry out the £16m project for London Electricity Services, owner of the electrical distribution infrastructure alongside the dedicated rail line that will link the Channel Tunnel with London.

The company will use power technology specifically developed for trackside applications, installing feeder substations or auto-transformer stations at seven points along the route into London St Pancras.

These will lower the voltage of power drawn from the national grid to that required by the rail link, which will use the +/-25kv distribution system widely used in con-tinental Europe.

This has become the standard for electrification projects that need high power or transmission over long distances. It is also used in Japan and on trans-continental freight lines in Australia.

The +/-25kv system allows for a transmission voltage of 50kv, of which the train uses half. The standard can support higher traction loads on the track and cuts down electromagnetic interference to communications and signalling equipment.

Conventional 25kv transmission systems require booster transformers, leading to more track feeding points and more connections to the distribution grid.Les Manning, transmission technology manager for ABB, claimed this is one of a number of areas where the system will offer environmental as well as technical advantages.

‘The units are compact, so from an environmental point of view the impact is not so great. That is an important extra consideration in this type of project,’ he said.

Work will begin later this year. The CTRL is due to be fully operational by 2007, allowing trains to run at maximum speed between the UK and Europe.

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