基于组合赋权法分析后续回击对线路反击跳闸影响研究*

为探究后续回击对500kV输电线路反击跳闸率的影响,本文统计出后续回击的次数及雷电流幅值的分布规律。随后,通过组合赋权法分析了不含后续回击的首次回击、含后续回击的首次回击及后续回击的次数和雷电流幅值对线路反击跳闸的影响。根据后续回击次数与雷电流幅值在反击跳闸的影响比重,确定后续回击次数是线路反击跳闸的主要影响因素。根据组合赋权法分析结果,本文提出了一种考虑后续回击的反击闪络模型,通过ATP-EMTP模型分析后续回击对反击耐雷水平的影响。仿真结果可知：首次回击未跳闸时,考虑后续回击线路的反击耐雷水平会降低,降低程度与导线工频电压周期有关,平均降低原反击耐雷水平的36.4%。仿真结果和理论分析结果一致,可为输电线路运维和防雷设计提供有效地理论支撑。

Research on influence of subsequent return stroke on line counterattack trip based on combination weighting method

In order to explore the impact of subsequent return stroke(SRS) on the counterattack trip rate of 500kV transmission line, this paper calculates the number of SRS and the distribution of lightning current amplitude. Then, the influence of the first return stroke with and without SRS, and the number of SRS and lightning current amplitude on the line counterattack trip are analyzed by combination weighting method. According to the influence proportion of these factors, it is determined that the number of SRS is the main influencing factor of line counterattack tripping. According to the analysis results of combination weighting method, this paper proposes a counterattack flashover model considering SRS, and analyzes the impact of SRS on the level of lightning resistance of counterattack through ATP-EMTP model. The simulation results show that: when the line does not trip under the first return stroke, the lightning withstand level of the line considering SRS will be reduced. The reduction degree is related to the power frequency voltage period of the conductor, and the average lightning withstand level of the original counterattack is reduced by 36.4%. The simulation results are consistent with the theoretical analysis results, which can provide effective theoretical support for transmission line operation and lightning protection design.