强台风环境下考虑微地形因素的输电通道结构安全概率评估方法

Safety probability assessment method considering micro-topography for transmission grid under strong typhoon environment

提出一种强台风环境下考虑微地形因素的输电通道结构安全概率评估方法。首先,基于地面自动气象站信息,提出了一种适用于输电塔结构安全分析的台风近地面风场模型;其次,针对真实台风环境中受破坏输电塔主要集中在峡谷地貌区域的灾损现象,分别提出了平地与峡谷地貌的2种输电塔失效计算方法;然后,对峡谷地貌进行了微地形建模,给出了峡谷吹出风速、漩涡气流风速与漩涡区范围经验计算公式以用于输电塔结构安全分析。指出峡谷区域气流的狭管效应在台风环境下对输电塔结构性破坏有重要作用,并建立了良态风环境与漩涡气流环境下的2种输电塔失效概率曲线。最后,综合评估台风环境下电网总体结构安全水平。基于2016年台风莫兰蒂对F省的输电通道结构安全进行分析评估,结果验证了所提方法的有效性和工程实用性,评估结果可为电网运维部门安全校核及物资调配提供重要依据。

A method considering micro-topography for evaluating the safety probability of the transmission grid under strong typhoon environment is proposed.According to the data from surface automatic meteorological stations,a typhoon near-surface wind field model for structural security assessment of transmission towers is proposed.Considering that the damaged power transmission towers are mainly concentrated on the valley area,the calculation methods of damage mechanism respectively for transmission towers in flat and valley areas are proposed.By modeling the micro-topography of valley,the empirical formulas of wind speed in the exit of the valley,the turbulence wind speed and the radius of the turbulent area are obtained to analyze the structural safety of the power transmission towers.It is pointed out that funneling effect of the valley is of key importance to the structural damage of the power transmission channels during typhoon.Thus failure probability curves respectively in the normal climate condition and the turbulence condition are computed.The level of power system’s structural safety under typhoon environment is evaluated.The structural safety of power transmission channels in F province under the influence of Typhoon Meranti in 2016 is evaluated,the results verify that the proposed method is effective and can be used pragmatically in an actual system operation.The evaluation results can provide an important basis for the safety check and material allocation of the grid operation and maintenance department.