±500kV同塔双回线路杆塔空气间隙操作冲击放电特性试验研究

摘要

The characteristics of switching impulse flashover at air gaps on the tower with ±500 kV double-circuit lines were experimentally studied at the altitudes of 2 100 m and 50 m.The curves of 50％ flashover voltage over the upper and lower air gaps were gained, and it was verified that the lower arm of the tower gives a negligible influence on the flashover characteristics at the upper air gap.By comparing the experimental results at these altitudes, an altitude correction method and a series of correction coefficients were brought forward.Furthermore, the minimum air clearances in the upper and lower air gaps at the different altitudes were presented when the switching overvoltage was 1.6 p.u..These results have been used to guide the external insulation design for Xiluodu Right-Bank Station to Guangdong DC transmission project with ±500 kV double-circuit lines.%在海拔2 100m和50m地区对±500 kV同塔双回线路杆塔空气间隙的操作冲击放电特性进行试验研究,在实验条件下,获得了上、下层间隙的50%放电电压曲线,验证了下横担的存在对上层空气间隙的操作冲击放电特性无明显影响.基于两种海拔高度试验结果对比,提出了海拔2100m及以下地区的海拔校正方法和校正系数,进而给出了当操作过电压标幺值取1.6时,不同海拔高度下所要求的杆塔上、下层空气间隙的最小允许距离.成果已用于指导溪洛渡右岸电站送电广东±500 kV同塔双回直流输电工程的外绝缘设计.