考虑融冰因素的输电线路覆冰故障概率计算

根据导线覆冰表面热平衡方程分析内外部融冰因素对导线冰载荷的影响,计及地形对冰载荷的影响以及覆冰引起导线等效半径增大对风载荷的影响,通过气象实测的降雨量、风速、风向、温度等信息以及电网运行信息、当前监测覆冰厚度等信息建立输电线覆冰厚度增长预测模型。从输电线路覆冰过载机理出发,构建覆冰故障概率计算框架,从力学角度分析覆冰厚度及风速对输电线路的共同作用,采用反映金属承载极限特性的指数模型计算输电线路故障概率。以实际线路为例验证了该模型计算得到的线路覆冰故障概率变化趋势与实际故障情况相符,能够充分验证覆冰故障率与实际天气的相关性。

Fault probability calculation of transmission line considering ice melting factors

The impacts of internal and external ice melting factors on ice load are analyzed according to heat balance equation of ice surface, and then the landform factor and the increased equivalent radius of iced line are taken into account for ice load and wind load calculation. The measured meteorological data such as rainfall, wind speed, wind direction, temperature, the power grid operation information, and the monitoring ice thickness information are used to establish the icing-thickness growth forecasting model of transmission line. The framework of icing fault probability calculation is formed via the icing overload mechanism of transmission line. The combined influence of icing-thickness and wind speed on transmission lines is analyzed from the standpoint of mechanics, and the fault probability of transmission line is achieved using exponential model that reflects metal bearing limit characteristic. The actual example verifies that the calculated icing fault probability of transmission lines is consistent with the actual fault trend, and the model can fully verify the correlation between icing fault probability and the actual weather condition.