高海拔沙尘环境对典型长间隙操作冲击放电特性的影响

Influence of Sand and Dust Environment in High Altitude Area on Impulse Discharge Characteristics of Typical Long Gap Operation

沙尘条件下输电线路容易发生闪络和跳闸事故。为了研究不同沙尘环境参数对输电线路外绝缘性能的影响,设计了能够调节沙尘天气强度、风沙流风速、沙尘含盐比、粒径和沙尘荷电量的沙尘环境模拟系统,利用额定电压为2400 kV的冲击电压发生器产生标准正极性操作冲击电压波,在青海塔拉地区(海拔3000 m)对1、2、3 m间隙距离的棒-棒、棒-板长空气间隙进行正极性放电特性研究。试验结果表明:风和沙尘混合作用下,间隙的50%操作冲击放电电压随着风速的增大而降低,且下降幅度随着间隙距离的增大而增大;沙尘环境对间隙的操作冲击放电特性既有促进作用也有抑制作用。

Transmission lines are prone to flashover and tripping accidents under sand and dust conditions.To study the influence of different sand-dust environmental parameters on the external insulation performance of transmission lines,a sand-dust environment simulation system that can adjust the intensity of sand-dust weather,wind speed,sand to dust salt ratio,particle size,and sand-dust charge was used to create a dusty environment.An impulse voltage generator with a rated voltage of 2400 kV was used to generate a standard positive polarity operating impulse voltage wave,and the positive polarity discharge of rod-rod and rod-plate long air gaps of 1 m,2 m,and 3 m was studied in the Tala area(3000 m above sea level)Qinghai,NW China.Results show that under the mixed action of wind and dust,the 50%operating impulse discharge voltage of the gap decrease with the increase of wind speed,and the decreasing amplitude increase with the increase of the gap distance.It is concluded that sand-dust environment could either promote or inhibit the operating impact discharge of the gap.