Experience with Distributed Temperature Sensing (DTS) on power cables

[ItAintMe]

Has anyone had some experience with using DTS systems to monitor power cables, particularly at higher voltages? I want to find some companies that supply the equipment, apart from SENSA/York in the UK. I have found a couple of others (Hitele, Optech) but I want to find out if there are other companies with units in the field already.

Also, what your experience has been to date. From what I've heard so far, cable temperatures seem to be coming back as quite a bit cooler than predicted by modelling?

Finally, what about location of the optical fibres for the temperature sensing. We've tried putting it in tubes laid up with the copper screen wires on 132kV single core cables, and it creates a lot of problems at the joints, so we are thinking about running them against the side of the power cable - either as a normal optical fibre tube, or in a larger tube into which the fibre is blown - permitting later replacement as the fibres age.

Any comments much appreciated.

 

[wilber]

The temperature that the fiber optic member is trying to measure should be compared to the rated temp of the cable. That rated temp is assumed to be the temp of the metal conductor. So the closer you get to the conductor, the better. However the manufacturing techniques of the cable manufacturer and the connection techniques of installing the cable, limit how close the fiber can betot he conductor. The best place, for both ease of manufacturing and protection of the fiber, while getting the fiber close to the conductor, is in the screen (shield or neutrals in the U.S.). Easier, but less accurate would be to place the fiber in a tube and lay it next to the cable. The temperature reading of the fiber would need to be corrected to get a calucated temperature of the hottest point next to the conductor. Ampacity calculatins based on Neher/McGrath would help with making the corrections.

 

[WillyTXD]

Sensa is now established in the U.S.A and has installed many fibers in high voltage cables in recent months. I head up the U.S.- based operation and would be happy to provide you with references or other appropriate material if you'd like.

Dennis Carr
DCarr@slb.com
(713) 253-0839

 

[panther721]

Halliburton also has a fiber optic monitoring unit they acquired. It was previously called Pruett industries.

 

[canyoncruz]

You might try going with an interferrometric system in which the demodulation scheme can measure at any point along the fiber thus alowing thermal gradient correction.

Try Optiphase in Van Nuys, CA

 

[jbartos]

Suggestion: Visit

http://www.olex.com.au/pdf/dts.pdf

http://www.engcom.com.au/publications/eea2000_dts.pdf

http://www.sensa.org/index.html

etc. for more info

 

[peterjs]

There have been lots of people taking measurements on power cables over the last few years in Australia. Some results were recently presented at Techcon in Sydney and follow the links at

http://www.engcom.com.au

to find out some of the active parties who will have had their own experiences with fiber installation to share.