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

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 du-ring typhoon. Thus failure probability curves respectively in the normal climate condition and the turbu-lence 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.