采用均热铜环实现由三芯电缆表面温度准确计算导体温度的方法分析

A Method for Correctly Calculating Conductor Temperature Based on Three-core Cable Surface Temperature by Using Soaking Copper Ring

运行电缆的表面温度是计算三芯电缆导体温度的重要参数。通过推导稳态下三芯电缆表面温度与导体温度的关系,分析表面温度对导体温度的灵敏度,并在不同电流下采用不同厚度的铜环进行测温实验,对比分析铜环测温的有效性。试验结果表明,铜环的厚度对测温精度影响不大,使用铜环测温方法,能减少三芯电缆表面温度的测温误差,使三芯电缆导体温度的计算更为准确,且在大电流运行状态下效果更显著。

Surface temperature of running cable is an important parameter for calculating three-core cable conductor temper- ature. By deducing relationship between surface temperature and conductor temperature of the three-core cable under steady state, this paper analyzes sensitivity of surface temperature to conductor temperature, and by means of temperature meas- urement experiment on copper rings with different thickness under different current, it compares and analyzes validity of temperature measurement for copper rings. Experimental results indicate that influence on precision of temperature meas- urement by thickness of the copper ring is not great and it is able to reduce error of temperature measurement for surface temperature of the three-core cable by using copper rings to measure temperature which means more correctness in calculat- ing conductor temperature, especially under the state of big current operation.