UHVAC输电线路大跨越段的防雷保护

Lightning Protection on River Crossing of AC 1000kV Transmission Line

为确保特高压输电线路的耐雷可靠性,对晋东南-南阳-荆门UHV输电线路的黄河大跨越段和汉江大跨越段的雷电性能进行了研究并介绍了UHV输电线路大跨越段雷电性能评估的计算方法,同时根据我国输电线路大跨越段的运行情况,参考俄罗斯标准,以大跨越段在雷电过电压下的雷击无故障时间(耐雷指标)来确定防雷保护方案,还计算了UHV输电线路大跨越段的年绕击跳闸次数和年反击跳闸次数及雷击避雷线跨越档距中央的反击跳闸次数,提出了按雷电过电压要求的跨越塔塔头间隙。研究表明,我国特高压输电线路大跨越段的耐雷指标不宜<50 a。

The lightning performance on the Yellow River crossing section and the Han River crossing section in the 1000kV UHVAC test and demonstration project, which transmit power from southeastern Shanxi province via Nanyang in Henan province to Jingmen in Hubei province of China, was estimated. The estimative method of lightning performance on river crossing line was introduced. Combining with the operation experiences of other large crossing transmission lines in China, and referring to the relavant overvoltage protection standard of Russian, the auhors estimated and confirmed appropriate lightning protections according to the statistical interval time of lightning failure of river crossing transmission lines. And the authors advise the interval time of lightning failure of UHVAC river crossing transmission lines in China should be larger than fifty years. This paper gives the results of lightning shielding failure outage number and the backflashover outage number per year of the two river crossing lines, calculates the flashover outage number per year while lightning stroke on the grounding wire in the middle of the span, and also gives the requirement values of the river crossing towers clearance decided by lightning overvoltage.