基于温度场逆问题的电力电缆缺陷检测方法研究

Research on defect detection method of power cable based on inverse problem of temperature field

本文基于不同缺陷状态下电缆径向热导率的分布差异,提出一种电缆局部缺陷检测的温度场逆问题算法。本文首先利用有限元算法对典型缺陷下电缆的径向温度场分布进行了计算分析;其次建立了由电缆表面温度场求取电缆内部热导率分布的逆问题模型,并运用正则化牛顿迭代方法进行模型求解;最后通过仿真和模拟实验对电缆的水树枝典型缺陷进行了检测,结果表明:温度场逆问题求解得到的热导率分布图像能够反映电缆内部局部缺陷的位置和大小,验证了该方法的正确性。

Based on the distribution difference of radial thermal conductivity of cable under different defect states, an inverse problem algorithm of temperature field for cable local defect detection is proposed in this paper. In this paper, the finite element method is used to calculate and analyze the temperature field distribution of the cable under typical defects. In addition, the inverse problem model that calculates the thermal conductivity distribution inside the cable via the surface temperature field is established, and the regularized Newton iteration method is used to solve this model. Finally, the typical defects of the cable are detected by simulation and simulated laboratory experiments. The results show that the thermal conductivity distribution image obtained by solving the inverse problem of temperature field can reflect the size and contour of the local defects in the cable, which verifies the correctness of the method.