大型悬浮电位导体对空气间隙操作冲击放电特性的影响机制及调控研究

The insulation reliability has en important influence on power grid safe operation reliability of insulated transmission lines, in the process of nsulation safety has an important impact on the reliability of the power grid, and the invasion of the suspended potential conductor into the air gap has a significant impact on the insulation strength. According to the scientific problem of coupling effect between the suspension conductor with different charging condition and streamer discharge as well as the effects on the switching impulse voltage discharge characteristics of air gaps, the floating conductor discharge test platform will be applied to explore the influence of floating conductors on the discharge characteristics of typical gap, to obtain discharge voltage of air gaps with suspension potential conductor , the discharge current waveform, the gap breakdown time, critical wave-front time, discharge path and the stricken rate of floating conductor through the test. The discharge current waveform, the discharge path and the stricken rate are used to calculate the charges on the floating conductor and to evaluate the charges generation, accumulation and dissipation process. The influence of charging condition and polarity of floating conductor on the air gap field distribution and the electric field magnitude and direction of streamer discharge head are calculated by the electromagnetic field simulation. Based on the discharge characteristic of air gaps with floating potential conductors and streamer discharge model the coupling theory between the floating conductor with different charging conditions (air gaps structure, shape, position and charging state) and streamer discharge are explored, and the control theory and method for floating conductor (charging state and shape) and the electric field distribution are put forward to improve the insulation performance of the air gap and to provide reference for the application of the project results to the countermeasures for bird related trips, suspension electrode design and minimum approach distances for live working .

电网外绝缘安全对电网的运行可靠性具有重要影响，大型悬浮电位导体侵入空气间隙会对绝缘强度产生明显影响。针对大型悬浮电位导体与流注之间的耦合及对间隙放电特性影响的问题，本项目对含有大型悬浮导体的典型间隙的操作冲击电压放电特性进行研究，通过测试放电电压、放电电流波形、击穿时间、临界波头时间、放电路径和悬浮电位导体的击中率，获取大型悬浮电位导体对放电发展的关键参数。基于悬浮电位导体上的放电电流波形、放电路径和击中率，分析悬浮电位导体上的电荷的产生、积累与消散过程，采用电磁场仿真计算获得悬浮电位导体荷电量的大小、极性对空气间隙的电场分布和流注放电的捕获或排斥的影响，探讨间隙结构、悬浮电位导体的形状、位置和荷电状态与流注放电耦合的理论依据分析悬浮电位导体（电荷的生成）与流注放电的耦合关系及对放电电压和最低放电区的影响，为大型悬浮电位导体触发放电、带电作业、悬浮电极的优化设计和应用提供依据。

随着我国经济的发展，确保远距离大容量输电线路的运行可靠性具有重要意义。电网外绝缘安全对电网的运行可靠性具有重要影响，大型悬浮电位导体侵入空气间隙会对绝缘强度产生明显影响。针对大型悬浮电位导体与流注之间的耦合及对间隙放电特性影响的问题，本项目对含有大型悬浮导体的典型间隙的操作冲击电压放电特性进行研究，主要开展了如下的研究工作：（1）开展了含有大型悬浮电位导体的典型间隙的放电特性，发现悬浮电位导体的击中率在距导线外侧1m的区域存在一个放电电压明显降低的区域，并在作业人员距离导线0.4 m处放电电压最低；当人与导线距离超过1 m后，放电电压逐步饱和并趋于一个较高值。（2）采用电场分析了典型悬浮电位导体人体在距离高压导体不同距离下的体表电场的分布的影响；（3）建立含有大型悬浮电位导体的放电模型，分析了间隙结构、悬浮电位导体的形状、位置对放电电压和击中率的影响；（4）基于不同进入等电位路径下的放电电压，分析了大型悬浮电位导体进入等电位的路径，为大型悬浮电位导体触发放电、带电作业、悬浮电极的优化设计和应用提供依据。