采用差绝缘方式降低110kV同塔双回线同跳几率

同塔双回输电线路若发生雷击,由于两回线路耐雷水平相当,较易发生同时闪络跳闸事故。为减少输电线路同时跳闸的概率,以某条110 kV输电线路为例,提出采用差绝缘的方法,降低输电线路双回跳闸率,同时考察了不同因素对雷击跳闸率的影响。结果表明：采用一回绝缘强度不变,另一回增加3片绝缘子的差绝缘方式,可将双回跳闸率降低至总跳闸率的12%以下。同时,减小地面倾斜角和避雷线保护角、采取合理的相序排列、减小接地电阻值都可以在一定程度上减小雷击跳闸率。

Reduction of Simultaneous Trip Probability for 110 kV Double Circuit Transmission Lines on Same Tower by Unbalanced Insulation

When the double circuit transmission line on the same tower is hit by lightning strike,flashover trip accident might occur at the same time as the lightning withstanding levels of the two lines are equal.Taking a 110 kV transmission lines as an example,this paper presents an unbalanced insulation method to reduce the rate of simultaneous trip of double circuit transmission lines while considering the effects of different factors on the trip rate.The simulation results show that after using the method of adding three insulators to one line while another remains unchanged,the double circuit trip rate can be lowered to 12% and below of the total trip rate.Meanwhile,the lightning trip rate can be decreased to some extent by reducing the ground inclination angle and the protection angle of ground wire,using reasonable phase sequence arrangement and reducing the grounding resistance.