【作者】 索春梅；

【导师】 鲁志伟；

【作者基本信息】 东北电力大学 ， 电力系统及其自动化， 2007， 硕士

【摘要】 为了适应我国经济高速发展对电力负荷增长的需要,电网建设不断往超高压、大容量的方向发展,不仅500kV电网已经成为我国的骨干网架,而且为了减少超高压输电线路走廊占地,采用同杆架设多回输电线路已成为超高压主干网架发展的必然趋势。因此,研究500kV同杆并架多回线路的耐雷性能,具有重要的科学意义和工程应用价值。本文针对500kV同杆双回并架输电线路的防雷保护问题,采用Bergeron特征线法,建立适合双回同杆并架线路的防雷计算模型。此模型可以真实地反映雷电流在杆塔上的传播过程。通过编程对同杆双回交流500kV输电线路的反击耐雷性能进行了详细的计算和分析。考虑了感应过电压、工频电压等因素的影响,并针对雷击塔顶时,导线运行电压相位角的随机性,本文假定雷击出现于交流一周期的任一角度区间内的概率相等,利用统计法计算同杆双回线路的反击跳闸率。把计算结果与EMTP(电磁暂态计算程序)以及清华大学的计算数据进行比较,以确定其正确性和可行性。本文并对500kV同杆四回路进行了计算,通过分析得出了降低反击跳闸率及其危害的措施。本文利用该程序,系统地研究了采用不平衡绝缘、改变相序和降低冲击接地电阻对提高线路防雷能力的影响。最后提出了合理的防雷保护措施,本文研究结果将为同类型的线路设计提供参考。更多还原

【Abstract】 To adapt the need of power load for the quick development of economy, the development of power system is turning for the higher voltage and larger capacity direction. Using multiple -circuit transmission line is the developing tide for 500kV main configuration to reduce line holding ground. So it is important significance and applied value for 500kV multiple-circuit transmission line on same tower lightning protection performance designing.The paper presents studies of the lightning performance of 500kV double-circuit. A numerical method has been developed to predict Back Flashover Rate based on Bergeron traveling wave method. It can truly reflect the spreading course of lightning current on the tower. This paper calculates and analyses the lightning protection performance of back striking for AC 500kV double-circuit transmission line by program in detail. Furthermore, considering the randomness of working voltage phase when lightning strokes the top tower and supposing the equal probability of lightning appearing arbitrary phase in a cycle of AC, this paper adopts the statistical method to calculate the rate of back stroking on double circuit line. Compared with the result of that of Qinghua University and EMTP (Electro-Magnetic Transient Program), the validity of the calculation program is approved. The paper presents the measures to reduce the rate of back stroking and their harm by the calculation program for the lightning protection performance of back striking for AC 500kV four-circuit transmission line on one tower.With the calculation program, the effect of differential insulation and the phase arrangement of conduct and grounding resistance is discussed as measure to reduce double-circuit trip out rate in details. Finally, a proper lightning resisting measure is presented. These results will propose reference for the same type of transmission line.Research on the Lightning Protection Performance of Back Striking for 500kV Multiple -circuit Transmission Line更多还原