35kV架空输电线路间隙灭弧的研究

为解决35 kV架空输电线路的雷击问题,研制了在35 kV架空输电线路上的防雷保护间隙喷射气流灭弧装置。该装置运用了"瞬时疏导"的防雷理念,能够在线路发生雷击闪络时有效地保护绝缘子串免受工频电弧的灼烧,在疏导雷电能量后能够迅速切断工频续流电弧,实现既可以限制绝缘子的外部过电压又可以避免断路器频繁跳闸的功能。笔者在链式电弧模型的基础上结合激波理论研究喷射气流条件下电弧的运动,对电弧的熄灭过程进行了讨论。在高压试验中借助高速摄像机和数字示波器,获取了在高速气流作用下电弧被迅速熄灭的过程图像和数据。

Jet Stream Interrupter Gap Lightning Protection Device for 35 kV Overhead Transmission Lines

To address the problem of lightning stroke on 35 kV overhead transmission lines,a jet stream interrupter gap lightning protection device(JSGLPD) for 35 kV overhead transmission lines was developed.When a lightning stroke on the transmission line causes AC flashover on insulator strings,the device is able to quickly cut off the power frequency freewheeling arc to effectively protect the insulator strings against ablation of the power frequency arc.The JSGLPD can achieve the function of limiting the external over-voltage on insulators and avoiding frequent tripping of circuit breaker.Moreover,the movement characteristics of electric arc in jet stream were investigated on the basis of an arc model,in which the arc is assumed to be a chain of small rigid cylindrical current elements,and the arc quenching process was discussed.In addition,a high speed camera system and an oscillograph were used to observe the changes in the current of arc,and the result shows that the arc can be cut off instantly by the high-speed air jet stream.