On-line dynamic cable rating for underground cables based on DTS and FEM

The development of surface temperature on-line monitoring techniques for 110kV and above XLPE power cable gives a strong support to power cable load dynamic adjustment. However, the problem is how to determine the conductor temperature from the surface temperature. A technique based on distributed temperature sensing (DTS) and finite element method (FEM) is presented to estimate the soil thermal properties by matching the computed thermal fields to that obtained from measurement and predict the real-time current carrying capacity by iterative method in order to prevent overheat of insulation. Compare with the thermal circuit model, the method based on DTS and FEM is more accuracy.