特高压交流输电线路耐雷水平相关因素研究  

The Effect Correlative Factors on Lightning Withstand Level of UHV A.C. Transmission Line

作　　者：李瑞芳[1] 吴广宁[1] 马御棠[1] 樊春雷[1] 

机构地区：[1]西南交通大学电气工程学院,成都610031

出　　处：《电瓷避雷器》2009年第3期14-17,21,共5页Insulators and Surge Arresters

摘　　要：随着输电电压等级的提高,雷击跳闸占跳闸总数的比例也在提高,而我国特高压交流输电线路的防雷研究尚属于起步阶段。通过改变线路耐雷水平参数,即:杆塔接地电阻、绝缘子片数、线路档距、避雷线架设方式、杆塔高度及雷击时输电线路的相位,建立了相应的PSCAD模型,仿真分析了雷击不同部位时各种因素对特高压架空输电线路耐雷水平的影响。结果表明:雷击塔顶时,"IVI"水平排列的耐雷水平最高;雷击档距中央时,"VVV"三角排列的耐雷水平最高,雷击档距中央比雷击塔顶时线路的耐雷水平高出很多。在雷击塔顶,档距小于360 m时,耐雷水平随档距增加而快速增加;大于360 m后,随档距增加其耐雷水平基本不变;雷击避雷线档距中央时,耐雷水平与档距的关系呈"U"形分布,在档距大于400 m以后,耐雷水平随档距的增加而提高。耐雷水平随绝缘子片数增加呈线性增加。无论哪种雷击形式,1.2/50μs雷电流波形下的耐雷水平明显比2.6/50μs雷电流波形下的高。The ratio of lightning strike tripping to the total tripping number increases along with the enhancement of transmission line voltage. So far research work on the anti-lightning performance of UHV transmission line is only at initiating stage. Relevant PSCAD model was built with varied lightning withstand capability of the transmission line such as tower grounding resistance, string insulator unit number, line span, shield line arrangement, tower height and voltage phase at lightning striking ere, and effect of these factors on lightning withstand performance of transmission line while lightning strikes onto different spots was simulated. The result shows： the horizontal ＂IVI＂ insulator string arrangement has the highest lightning withstand level when lightning strikes on the tower top and the ＂VVV＂ triangular arrangement has even higher level when lightning strikes onto the mid span. lightning withstand level enhances very fast with increases of span length when it is less than 360 m and the lightning strikes onto the span mid, the withstand level is steady as the span length more than 360 m and than enhances again at the span length more than 400 m, a U-shaped dependence is obtained. The withstand level enhances linearly with increases of string insulator units number, the lightning withstand is always higher at lightning wave of 1.2/50 μs than at wave of 2.6/50 μs at any strike mode.

关 键 词：特高压交流输电 PSCAD仿真 耐雷水平 

分 类 号：TM862[电气工程—高电压与绝缘技术]