±800kV特高压直流开关场内避雷线的参数选择  

Parameter Selection of Overhead Shield Wires for ±800 kV Ultra-high Voltage DC Yard

作　　者：胡军[1] 李伟[1] 何金良[1] 刘泽洪[2] 余军[2] 高理迎[2] 俞正[3] 

机构地区：[1]清华大学电机系电力系统国家重点实验室,北京100084 [2]国家电网公司特高压部,北京100031 [3]华东电力设计院,上海200063

出　　处：《高电压技术》2010年第1期136-143,共8页High Voltage Engineering

基　　金：国家自然科学基金重点项目(50737001);国家重点基础研究发展计划(973计划)(2009CB724504)~~

摘　　要：直流换流站不同于交流变电站,主回路有很多电子设备,即使很小的直击雷传入阀厅也会造成换流阀的破坏。采用避雷针难以达到直流换流站的防雷要求,而采用密集布置的避雷线更为合适,但需对相关参数进行具体分析。为此,采用数值计算方法分析了±800 kV特高压直流开关场内的避雷线参数,参数选择不仅要考虑绝缘安全距离要求,而且要避免避雷线表面场强过大发生电晕放电。分析结果表明,避雷线直径越粗、高度越高,其表面场强越小,而采用双分裂避雷线可以更有效降低表面场强,并减少雷击断线的危害,比单根避雷线更有优势。据此提出了双避雷线在母线及设备上方架设时的合理直径及高度,相关结果已用于向家坝-上海及锦屏-苏南±800 kV特高压直流开关场的设计方案。The lightning protection in the DC yard is a key problem of the --±800 kV UHVDC power transmission systems. Since the lightning rods in the DC yard can not meet the demands of lightning protection, the densely packed shield wires are proposed, showing a better effect than the lightning rods. The numerical method is applied to analyze the parameters of the shied wires. The safety clearance between the shield wire and the bus or apparatus is considered for the parameter selection of the shield wire. In addition, the surface electric field of the shield wire should also be small enough to avoid the corona discharge. As a conclusion, the duplex shield wires surpass the single shield wire due to the relatively low surface electric field and the robustness against the wire breaking. Finally, the diameter and the height of the shield wire above the bus or apparatus are provided, which had been adopted in the shield wire designs of Xiangjiaba-Shanghai and Jinping-Sunan ±800 kV UHVDC yards.

关 键 词：特高压直流 换流站 换流阀 避雷线 安全距离 电晕放电 

分 类 号：TM862[电气工程—高电压与绝缘技术]