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ENERGIX-Stort program energi

Smart On-Line Health Assessment of Cable Terminations

Alternative title: Smart On-Line tilstandskontroll av høyspente kabeltermineringer

Awarded: NOK 6.1 mill.

Power transmission is today facilitated by underground cables and overhead lines. For long distances or high power transmission, extra high voltages are normally used. The highest voltage level in Norway is 420 000 volts which is almost 2000 times higher than the voltage level in the in-house sockets. Cables at this voltage level must be carefully terminated at the ends. For extra high voltage levels such components are critical. Statnett experience that monitoring systems are not included with these terminations despite their criticality. It is implicitly assumed that they are maintenance free. A monitoring system can in due time give warnings that "something is about to happen". In SmartACT a novel hardware will be developed based on sensors placed inside the termination. The signals from the sensors will be transferred wireless to a receiver placed outside the termination. The power supply of the sensor will also be wireless transferred from outside. The expected lifetime of the cable terminations at a system voltage of 420 000 V is very long, and therefore the installed hardware for monitoring should have a service life of similar length. The data management and interpretation will be taken care of by using AI. In the initial stage of this project focus has been to select the different type of sensors and define the measuring range that are critical for the terminations. Project success means that incipient failures will be detected for these crucial components during their lifetime. In the end, the extra high voltage system in Norway will be more reliable and robust in the future with SmartACT monitoring units.

Transmission grid failures can result in long outage periods with unacceptable societal impacts and negative economic consequences including significant loss of industry production and high not-delivered-energy costs (KILE). In the SmartACT project, an innovative and non-intrusive long-life sensor system for online condition assessment and monitoring will be developed and tested for installation inside 420 kV oil-filled cable terminations, which are the components most prone to failure. This novel sensor system will provide continuous feedback concerning the condition of the cable terminals, thus allowing for mitigation procedures to be enacted when necessary hence avoiding disruption of supply. The sensor system is expected to increase security of energy supply by assessing temperature, humidity, pressure, and partial discharges (PDs) combined with a new digitized machine-learning-assisted assessment methodology. SmartACT, therefore, addresses thematic priority area 3 in the ENERGIX work programme. Cooperation between the Norwegian TSO Statnett, Nexans Norway, SINTEF and NTNU is essential to meet the project goals.

Funding scheme:

ENERGIX-Stort program energi