The electrical current load of power cables is limited by the maximum allowed temperature of the boundary between the inner cable insulation and the conductor core. The present temperature of the conductor/insulation boundary does not only depend on cable design and current load but also on cable laying, filling material, soil moisture, previous load, crossing with other cables, and other heat sources. Cables may even be operated at a higher than the design load for a certain time because of their large thermal capacity.
Distributed temperature monitoring along a power cable using a controller enables safe cable operation at any location even at high loads. The optical fiber sensor cable may be incorporated into the shield of the power cable or attached externally. It is immune to electromagnetic interference.
In 2021, ITS., JSC successfully implemented the distributed temperature sensing solution for 02 underground power cables with the length of each cable is 4km. The cables connect 220kV Long Bien substation to 110kV Sai Dong 2 substation that has been energized since February 2021. This solution supplies maximum support for monitoring and locating faults for 02 underground power cables.