关键词: 110 kV电缆, 电缆温度场, 缆芯温度, 隧道敷设电缆模型, 数字孪生

Abstract: Temperature is one of the important physical quantities to determine the operating status of the cable, but usually only the temperature of the outer sheath can be monitored, while the temperature of the cable core cannot be directly obtained. In this study, a temperature field model of tunnel laying 110 kV cable is built, incorporating the real-time monitoring temperature of the cable outer sheath. The cable temperature distribution is thus obtained by optimizing and correcting the physical quantities such as material parameters of the cable to make the model more consistent with the real operation state. The influences of parameters such as dielectric loss factor, dielectric constant and thermal conductivity of XLPE on the physical model of cable temperature prediction are further discussed. The temperature distribution of low resistance grounding fault in cable is simulated. It was found that the difference between the fault phase cable core temperature and its outer sheath temperature was 47 ℃, and this cable core temperature can reach 250 ℃, and meanwhile, the temperature of the same circuit non-fault phase cable core also rose to more than 120 ℃, which was in severe overload state. The data-driven high voltage cable model in this paper can effectively calculate the cable core temperature, which helps to grasp the core data and working status of cable operation,so that it can lay the foundation for the final construction of the cable digital twin model.

Key words: 110 kV cable, cable temperature field, cable core temperature, tunnel laying cable model, digital twin