高速铁路牵引供电接触网雷电防护

Lightning Protection of Traction Power Supply Catenary of High-speed Railway

中国高速铁路多采用高架桥敷设方式,牵引供电接触网的导线对地高度较大,雷击跳闸率较高,必须采取有效措施加以解决。建立了接触网的雷电过电压计算模型,并基于矢量匹配技术和网络综合理论提取了高架桥冲击阻抗的等值电路;计算分析了接触网雷击跳闸的概率和特点。结果表明:接触网F线的雷击跳闸率很高,而受到F线屏蔽的T线雷击跳闸率较低;提出了将PW线兼做避雷线使用以及在F线绝缘子上安装带串联间隙避雷器的防护方案,同时,建议加强高架桥非预应力结构钢筋与接地钢筋的可靠等电位连接,以提高防护方案的效果。

Because viaducts are widely adopted in china high-speed railway system, the conductors of traction power supply catenary are high, which makes the catenary suffer from lightning frequently. The paper gives a solution to the problem. Firstly, lightning overvoltage calculation models of the catenary were built, where the impulse grounding impedance equivalent circuit of the viaduct was extracted based on the Vector Fitting Method and Electric Network Theory. Secondly, the probability and characteristics of lightning outage of the catenary were analyzed, and the result shows that the probability of lightning outage of F wire is higher than T wire because T wire is shielded by F wire. Thirdly, two protection measures were proposed, One measure is to use PW wire as lightning shield wire and the other one is to install surge arresters with series gap on the insulators of F wire. Finally, it is also suggested that the equipotential connection of non-prestressed and grounding steels of the viaduct should be encouraged for getting better protection effect.