关键词: 分布式光纤测温系统（DTS）, 有限元法, 优化方法, 热参数, 载流量, 预测

Abstract: Numerous power utilities are installed with advanced distributed temperature sensing (DTS) systems to measure the temperature of underground cables. However, two problems needs to be solved for full application of the advanced DTS. The first is to calculate the conductor’s temperature according to the measured cable surface temperature by DTS; the second is to predict the maximum allowable load under the condition of emergency overloading. This paper presents a novel technique for solving the above two problems, the basic principle of which is based on the estimation of soil thermal parameters by matching the computed thermal field with the measured thermal field. Two methods, i.e., the finite-element method(FEM) and the gradient-based optimization method, needs to be used for the proposed technique. It is found through comparing the calculated results and measured results that the predicted values are consistent with the measured values, which verifies the technique’s effectiveness and can provide a basis for dynamic assessment of ampacity.

Key words: distributed temperature sensing, finite-element method, optimization method, thermal parameters, ampacity, estimation