基于表面温度场的电缆线芯温度在线诊断研究

线芯温度是电缆的一个重要参数，当电缆过负荷时，其线芯温度高于允许温度，使电缆绝缘加速老化，甚至造成绝缘介质热击穿。文中提出了一种基于电缆表面温度场的对电缆线芯温度进行在线诊断的方法。该方法采用红外热象仪拍摄电缆的表面热图象，可根据电缆的表面温度、结构参数，物性参数和环境温度，通过建立传热数学模型，对电缆的线芯温度进行反演计算，并与其允许温度进行比较，实现了电习温度的非接触，在线诊断。

SURFACE TEMPERATURE FIELD BASED ONLINE DIAGNOSES STUDY FOR ELECTRIC CABLE'S CONDUCTOR TEMPERATURE

The conductor temperature is an important parameter of electric cable. Once the electric cable is overloaded, the conductor temperature will be higher than the allowed temperature, which will accelerate aging of cable's dielectric, and even cause thermal breakdown of dielectric. Online diagnoses method on conductor temperature of electric cable, based on surface temperature field of electric cable, is presented in this paper. Surface thermal image of electric cable is gained with infrared thermal video system and surface temperature is read out. By constructing heat transfer mathematical model, in which surface temperature, structure parameters, physical property parameters and environmental temperature are considered, the conductor temperature of cable could be reversibly calculated and be compared with the allowed temperature to realize online and non contact diagnoses of the electric cable's conductor temperature.