Optical sensor to provide early warning of power-line defects

It is hoped the technology will form the basis of an early-warning system to detect defects before they escalate and cause major failures — a problem known as ‘dewirement’.

In June this year the London-Norwich rail line made headlines for major train delays, reportedly resulting from the 30ºC+ temperatures causing powers lines to sag.

‘You can get all sorts of strange effects on power lines,’ said Prof Ken Grattan of City University who is leading the project. ‘You can get sagging in the winter with snow and you get it in the summer with heat, so it’s potentially problematic.’

Grattan and colleague Prof Tong Sun have received £102,000 in funding from the EPSRC collaboration fund to develop a prototype sensor system with industrial partners.

The team, which specialises in building sensors for industry, developed a novel fibre-optic sensor design for attachment to the pantographs — the ‘coat hanger-like’ structures that collect power for trains from overhead lines. The sensors will measure the critical strain and temperature parameters of the power lines as they run along the wires.