覆冰交流输电线路保线电流及其影响因素分析

Analysis on Anti-Icing Current and Its Impacting Factors for Ice-Coated AC Transmission Lines

建立了导线覆冰过程的热平衡方程,同时考虑绞线几何外形及集肤效应对传热过程的影响,提出了基于焦耳热效应的输电线路导线保线电流计算公式,并采用Runge-Kutta算法对水滴运动轨迹进行模拟,得到碰撞系数这一关键参量值。仿真结果表明,保线电流是导线外径、导线电阻、表面几何外形等导线自身参数以及环境温度、风速、水滴中值体积直径、空气中液态水含量等大气参数的函数;得到了不同绞线在典型覆冰类型下的保线电流,与人工气候室的试验结果相吻合。将该模型的预测结果与其他模型进行了比较,进一步证明该模型的准确性。

On the basis of analyzing the process of transmission line ice-coating, the thermal balance equation of this phenomenon is built, meanwhile the influences of geometric shape and skin-effect of steel-cored aluminum stranded wire on heat-transfer process are taken into account, and based on Joule heating effect the formula computing anti-icing current of transmission line is proposed. By use of Runge-Kutta algorithm the motion trajectory of water drop is simulated and the value of such a key parameter as collision coefficient is obtained. Simulation results show that the anti-icing current is a function of conductor its own parameters and meteorological parameters, the conductor diameter, conductor resistance and geometric shape of conductor surface belong to the former and the ambient temperature, wind speed, median volume diameter of water drop and liquid water content in the air belong to the latter. The anti-icing currents of different steel-cored aluminum stranded wires under typical ice-coating types are obtained and the obtained results coincide with test results in artificial climate chamber. Comparing the forecasted results by the proposed model with those by other models, it is proved further that the proposed model is accurate.