输电线路雷电屏蔽性能的科学评估对线路防雷设计和施工建设具有重要参考价值.由于输电线路上行连接先导的发展对雷击线路过程影响较大,上行连接先导成为分析线路雷电屏蔽性能的关键因素之一,合理地描述上行连接先导发展速度有利于提高输电线路雷电屏蔽性能评估的准确性.本文基于先导放电理论,推导了计算单位长度流注转化为先导所需电荷量的计算公式,并结合人工引雷试验数据,提出了一种求解上行连接先导速度的计算模型.采用该速度模型对自然雷击高塔上行连接先导过程的模拟结果与观测结果较为一致,验证了该模型的有效性.另外,将提出的速度模型与以往先导速度模型对雷击水平导线的仿真结果进行了比较,得到的上行连接先导长度介于其他学者模型的仿真结果之间.%The evaluation of lightning shielding characteristic of transmission lines plays an important role in power transmission system design.Since the development process of upward connecting leader initiated from the transmission line has a great influence on the interception of lightning downward leader,it is necessary to study the upward connecting leader characteristics,and the proper description of the upward connecting leader velocity is beneficial for improving the accuracy of lightning shielding analysis.Based on the leader discharge theory,a method to calculate the charge per unit length necessary to achieve the transition from the streamer corona to a new leader segment is suggested,and then a formula to analyze the velocity of lightning upward connecting leader is proposed by combining with the experimental data of triggered lightning.The simulation results of upward connecting leader velocity based on the proposed model agree well with the observation data of the natural lightning interaction with a high tower,which shows the validity of this model.Moreover,the proposed model is compared with the existing leader velocity models,and the obtained upward connecting leader length is within the range of simulation results by the traditional models.
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