Until recently, outages and phase-earth faults on medium-voltage power cables could not be detected using conventional equipment. Phase-earth faults reduce the lifespan of cables and create other weak spots in the grid if not detected and repaired.
Two major operators of Dutch power grids, Liander and Enexis, are all set to roll out 'Smart Cable Guard’, a revolutionary system that can predict power outages. Smart Cable Guard they claim can prevent disturbances by locating a dormant defect in an underground power cable. The system was designed and developed by DNV GL (formerly KEMA), Locamation, Liander and Enexis. Smart Cable Guard makes it possible to reduce the number of power failures by 25%.

The system employs measurement nodes installed on carefully selected points, probing the underground power grid. These nodes detect and record sparking and other disturbances on the cables and are capable of pinpointing the place to ‘start digging’ using propagation time measurement and an internet connected structure. Occasional sparking and discharges in medium-voltage (10-kV) power cables is acceptable but still a sign of trouble brewing. With the system the power grid operators have a powerful tool to locate and replace the suspect cable stretch a few weeks before a block, industrial area, or a whole city goes dark and cold for hours, possibly days.
 


The Netherlands have one of the most reliable electricity networks in the world, and many visitors to the country, especially those from the US marvel at not seeing electricity or telephone delivered by overhead cables to any home, even in rural areas. With Smart Cable Guard and fast-response crews the reliability of the underground part of the power grid is expected to get a further boost.