【摘要】 明确了风压不均匀系数的概念,并从导线风荷载的角度揭示了风压不均匀系数和档距折减系数的本质差异。根据风荷载等效原则建立了基于中国输电线路设计规范的等效档距折减系数表达式,并与不同国家输电线路设计规范的档距折减系数取值进行了比较,发现中国现行输电线路设计规范的等效档距折减系数小于其他各国规范。针对发生风偏闪络事故的某1 000 k V特高压线路,采用GLE(阵风荷载包络线)方法确定了线路的风荷载调整系数,进一步采用有限元非线性方法计算风偏角,建立了风偏角与风压不均匀系数的关系,根据风偏闪络事故的风偏角推算出风压不均匀系数。结果表明,在广袤的平坦地貌中,对于季节强风或台风等大尺度风场而言,风压不均匀系数接近1.0。更多还原

【Abstract】 This paper defines the concept of non-uniformity coefficient of wind pressure and clarifies the qualitative difference between non-uniformity coefficient of wind pressure and span reduction coefficient in terms of wind load of conductors. Based on the equivalence principle of wind load, the formula of equivalent span reduction coefficient based on transmission line design code of China is established and compared with the values of span reduction coefficients of codes from different countries. It is found that the value of the equivalent span reduction coefficient of China is smaller than those of other countries. Based on a wind-induced flashover accident of a 1 000 kV UHV line, GLE method is employed to calculate the wind load adjustment coefficient.On this basis, nonlinear FEM method for wind-induced flashover accidents is employed to calculate wind deflection angle; then the relationship between wind deflection angle and non-uniformity coefficient of wind pressure is established and the non-uniformity coefficient of wind pressure is inferred according to the wind deflection angle in the accidents. Results show that for flat terrain and large scale wind fields such as strong monsoon and typhoon, the value of the non-uniformity coefficient of wind pressure is approximately up to 1.0.更多还原