±800 kV云广特高压直流线路雷电防护特性

雷击是造成输电线路闪络的主要原因之一.为了解决±800kV云广特高压直流线路的雷电防护问题,通过分析该线路的参数和调研线路沿线的雷电活动特点,以先导发展法为基础建立特高压线路雷击计算方法,对线路的反击和绕击防雷性能进行分析.首先调研了沿线各区域的雷电活动情况,给出了各区域境内的雷电日取值.然后,对云广特高压直流线路的雷击闪络特性进行了分析,给出了不同地形条件下地面倾角、绝缘强度、跨谷深度对雷击绕击特性的影响,以及杆塔高度、接地电阻等对雷击反击特性的影响.考虑地形对雷击故障的影响,通过地形加权和分段分析的方法求得线路各段的雷击闪络率.最后,就降低接地电阻、减小保护角等防雷措施进行了研究.

The Lightning Protection Characteristics of ±800 kV Yunnan – Guangdong UHVDC Transmission Line

Lightning is one of the main causes of transmission lines trip-outs. Aiming to solve the lightning protection problem of ±800 kV Yunnan–Guangdong HVDC transmission line, this paper calculates and analyzes the lightning protection charac-teristics of the line by analyzing the parameters of the line, investigating the lightning activity along the line and building a cal-culation method based on the advanced leader progression model. Firstly, the lightning activities in the passing areas are inves-tigated as to have the proper corresponding lightning day values. Then, the influences of ground slope, insulation strength and cross-valley depth on the shielding failure characteristic, the impacts of tower height and grounding resistance on the lightning direct striking characteristic are analyzed, and the lightning trip-out rates of each segment of the line are achieved by consider-ing the impact of topography. Finally, some proper lightning protection measures such as for reducing grounding resistance and decreasing the protection angle are discussed.