基于危险雷电流区间分布的输电线路雷击故障性质判断方法

Identification of Shielding Failure and Back Striking Based on Interval Distribution of Dangerous Lightning Current

雷电定位系统可获取雷电流幅值、定位等信息,用于线路雷击故障定位,但至今缺乏实用的方法将雷击信息与线路雷击跳闸信息合理整合,实现雷击故障性质判定。为此,对不同杆塔接地电阻下线路反击耐雷水平及不同地线保护角和地面倾角下线路绕击临界雷电流分布区间进行量化,得到线路直击雷危险雷电流幅值分布区间,再以雷电定位系统监测所得雷击电流幅值与反击、绕击危险雷电流区间作比对的机制,建立线路雷击故障性质判别概率算法模型,形成一套完整的雷击故障性质判断方法,并基于此开发了线路雷击故障性质判断软件。经典型雷击跳闸线路的雷击性质判断验证,该方法能实现输电线路雷击故障性质的快速判定,判断结论准确可靠。

Although the lightning stroke imformation obtained by lightning location system can be used in the field of fault location, it is lack of a practical method to intergrate lightning stroke imformation with lightning trip information, finally to achieve the goal of distinguishing back flashover from shielding failure. The variation trend of back flashover lightning withstand level under different grounding resistance is calculated so as the variation trend of critical lightning current under varying shielding angle and ground obliquity. Based on this, the dangerous lightning interval is obtained. By making proper contrast between lightning stroke current which provided by lightning location system and dangerous lightning interval, a complete set of lightning fault type judgement method is formed. A software for lightning trip types identification has been developed. The proposed judge method has been verified by the information from typical lightning tripping accidents. The line walking results shows that the method can distinguish back flashover from shielding failure flashover fast and with high accuracy.