直击雷故障类型下雷电流分流系数仿真研究

雷电参数反演研究对采取有效防雷措施具有十分重要的意义。不同雷击故障类型的输电线路雷电流分布情况相差较大,给雷电流幅值反演带来极大困难,有必要对直击雷下的雷电流分布进行研究。以110 k V输电线路典型直击雷故障电流波为研究对象,首先介绍基于微分环的输电线路雷电流在线监测系统监测原理以明确杆塔分流系数相关量;其次,结合某110 k V输电线路实际参数,建立ATP-EMTP电磁暂态仿真模型;最后,分析不同波形及幅值的雷电流源在直击雷故障下的雷电流分布情况以统计分流系数变化规律。ATP-EMTP结果表明,不同波形的雷电流源下绕击闪络分流系数及其随幅值变化的变化规律相近,而不同波形雷电流源下反击的分流系数相差较大,其随幅值变化的变化规律均较为平稳。因此,雷电流参数反演计算时可根据不同直击雷故障类型采用相应的选择方案。

Simulation and Analysis of Lightning Distribution Coefficient with Different Direct Lightning Fault Types

The Lightning parameters inversion research is importantly meaningful to take measures to protect electrical devices from lightning efficiently. The distribution with different lightning fault types are quite different. It is necessary to study on current distribution with direct lightning strike faults, which occurs more often. In this paper, 110kV transmission line is taken as the research object. Firstly, the novel contactless lightning current monitoring system based on differential-integral loop is briefly introduced, which is to state the aim to focus on lightning current on the phase wires. Secondly, combining with the field data of 110kV transmission line, the transmission line model built by EMTP-ATP software is established. Finally, the lightning current distribution coefficient variation trends are acquired by simulation models with different lightning sources under different direct lightning strike fault types. The results show that the distribution coefficient variation trends of shielding failure with flashover are almost the same, while they are quite different with back flashover type. Therefore, it needs to choose the appropriate distribution coefficient respecting to different fault types when doing lightning parameters inversion research.