架空导线动态载流量的分析及改进算法

Analysis and improved method for overhead conductor dynamic ampacity

架空导线的输送容量在很大程度上受限于导线的温度,即架空导线存在一定的热稳定容量。本文基于IEEE Std 738和CIGRE架空导线载流量的计算方法,研究了导线热平衡方程中散热、发热的影响因素,分析关键因素对散、发热的影响程度。针对传统法将散、发热代入架空导线的稳态热平衡方程直接计算的动态载流量波动剧烈这一问题,提出在其基础上对一段时间的几个时刻所载电流单值加权求解架空导线动态载流量的改进算法。改进算法可极大地减小载流量的波动,导线温度的仿真分析表明导线温度在一个很小的范围内变化,增强了动态增容技术的实际应用性。

The ampacity of the overhead transmission line is largely limited by the temperature of conductors since there is a fixed range of overhead conductors ampacity of thermal stability. Based on IEEE Std 738 and CIGRE＇s method for calculating overhead conductor ampacity,this paper discussed related factors which have impact on the cooling and heating dynamic process of heat balance equation. Key factor＇s impact on ampacity was analyzed. For the issue of highly oscillatory of dynamic ampacity brought by the utilization of traditional method which directly substitute cooling and heating terms into the steady heat balance equation,this paper suggests a solution which uses weighted current value at several points in a period of time to solve conductors＇ dynamic ampacity based on the traditional method. This method can largely reduce the oscillatory of dynamic ampacity and the temperature of conductors varies in a tiny interval based on simulation analysis,which enhance practical application of dynamic capacityincrease technology.