基于改进EGM的±800 kV输电雷电屏蔽性能优化配置研究

Optimal Configuration Simulation of Influencing Factors of Lightning Shielding Performance on ± 800 kV Transmission Lines

特高压直流输电线路沿途地形复杂、雷电活动差异大,雷电绕击已成为其安全运行的首要威胁。建立了一种综合考虑导线工作电压、风速、杆塔高度、地面倾斜角、地线保护角等因素的改进电气几何模型,开展了杆塔地面倾斜角与输电线路雷电屏蔽影响因素间优化配置关系的研究,仿真计算了±800 k V直流输电线路雷电屏蔽失效率及绕击闪络率。计算结果表明:不同地面倾斜角下导线电压极性、杆塔高度、风速、避雷线保护角对线路雷电屏蔽性能的影响存在差异,对于保护角,倾斜角不大于15°、保护角不大于10°或者倾斜角范围在15°~30°、保护角不大于-5°时,可满足地闪密度为6. 85次/km^2·a时±800 kV直流输电线路绕击闪络率不超过0. 197次/100 km·a的要求。

The terrain along the UHVDC transmission lines is complex and lightning activityvaries greatly. Lightning strikes become the primary threat to the safe operation of UHVDC power transmission lines. Based on the improved electrical geometry method,this paper studies the optimal configuration relationship between the tower ground inclination angle and the factors affecting the lightning protection of the transmission line. The lightning shielding failure rate and the flashover ratio of the ± 800 kV DC transmission line are simulated and calculated. The calculation results show that the effects of voltage polarity,tower height,wind speed,and lightning protection angle on the lightning shielding performance of the line are different under different ground inclination angles. For the protection angle,the inclination angle is not greater than 15° and the protection angle is not greater than 10°. When the tilt angle is in the range of 15° to 30° and the protection angle is less than-5°,the flash lightning density of the ± 800 kV DC transmission line does not exceed 0. 197 times/100 km·a when the ground flash density is 6. 85 times/km^2·a.