基于数值天气预报的输电线路风偏闪络预警方法

现有输电线路风偏预警一般是采用在线监测装置实现，且没有对风偏后空气间隙的闪络风险进行有效评估，导致工程上适用性不强、预警效果不理想等问题。利用传统的风偏研究成果，提出了一种基于数值天气预报的输电线路风偏闪络预警方法。首先，采用反距离加权的插值算法进行格点预报风速映射处理，并依据风向与线路走向的夹角完成垂直于线路风速分量的计算。然后，以典型的酒杯塔为例，运用刚体直棒法计算线路与杆塔的最小空气间隙。最后，对间隙击穿电压进行空气密度、湿度、降水量的修正，得到预报天气条件下的闪络电压值，并与系统运行电压进行对比完成风偏闪络预警。该方法可为安装在线装置困难而又处于强风区的重要输电线路提供一种可行、有效的风偏闪络风险管控手段，对电网防风减灾工作具有重要的实用意义。

Method for windage yaw flashover warning of transmission lines based on numerical weather prediction

Current windage yaw warning methods of transmission lines are generally implemented by on-line monitoring devices, and these methods rarely involve effective evaluation on flashover risk of the air gap between line and tower after windage yaw, which leads to weak applicability and unsatisfactory warning effect in engineering. This paper takes the traditional windage yaw research achievements into account, and proposes a method for windage yaw flashover warning of transmission lines based on numerical weather prediction. Firstly, wind speed predicted in grid is mapped into the tower by using inverse distance weighted interpolation algorithm. Wind speed vertical to line is calculated by using the angle between wind direction and line trend. Then, cup type tower is taken to solve the minimum air gap by rigid rod method as an example. Finally, the flashover voltage of the minimum air gap under standard atmospheric conditions is amended by air density, humidity and rainfall to obtain the flashover voltage under the forecast weather conditions, which is utilized to realize windage yaw flashover warning by compared with the system operating voltage. This method provides a viable and effective risk control measure for windage yaw flashover on transmission lines which are in strong wind area but the on-line monitoring devices are difficult to install on, and it has the vital practical significance on power grid disaster prevention and mitigation caused by windage yaw. This work is supported by Science and Technology Project of State Grid Corporation of China (Real-time Evaluation and Warning of Electrical Reliability for UHV Transmission Line Based on Meteorological Parameters).