10 kV线路防雷用反冲多间隙结构灭弧装置理论与试验研究

Theoretical and Experimental Study on Arc Extinguishing Device with Multi-gap Structure against Lightning for 10 kV Line

摘要:

针对配电网线路易受雷击引起绝缘子闪络造成线路停电的难题，文中研究了一种基于“疏导-灭弧式”思想的反冲多间隙结构灭弧装置。该装置利用绝缘配合先于绝缘子击穿闪络泄放雷电流入地，同时利用其反冲结构和多断口结构迅速熄灭电弧。首先，对装置的结构和灭弧原理进行了介绍；然后，对反冲结构和多断口结构的灭弧过程用数学模型进行了描述；接着，探讨了影响电弧熄灭的主要因素，得出提高气流速度是提高灭弧效率和缩短灭弧时间的有效方式；最后，通过工频大电流灭弧试验论证了该装置具有良好的灭弧效果，能够在4 ms内将幅值为2 kA的电弧熄灭，并且该装置在4片绝缘伞裙下也能控制电弧进入其内部。

Abstract:

Aiming at the difficult problem that the lines of distribution network are subject to lightning stroke which causes insulator flashover resulting in power failure, a device called arc extinguishing device with multi-gap structure is studied based on the idea of "dredging-arc extinguishing".The device uses insulation coordination to discharge lightning current into the ground before insulator breakdown, and at the same time, uses its recoil structure and multi-fracture structure to extinguish the arc rapidly. Firstly, the structure and arc extinguishing principle of the device are introduced. And then the arc extinguishing process of recoil structure and multi-fracture structure are described by mathematical model. And next, the main factors that affect the arc extinction are discussed, and it is concluded that increasing gas velocity is an effective way to improve the arc extinction efficiency and shorten the arc extinction time. Finally, the arc extinguishing test with high power frequency current proves that the proposed device has good arc extinguishing effect, and can extinguish the arc with 2 kA in 4 ms, and under four pieces of insulator shed, this device can also control the arc to get into its interior.