Analysis of the Effect of Sand and Dust on Long Air Gap Discharge Characteristics in High-altitude Area

There are a large number of AC/DC power transmission and transformation projects in China that pass through desert. Therefore, it is of great significance to study the effect of sand and dust on the external insulation characteristics of transmission lines for the safe and reliable operation of the power grid. This paper investigates the wind-sand weather in the high altitude areas of northwest China, samples and analyzes the sand dust in the field, determines the key parameters of the experiment, and develops a wind-sand simulation device that can flexibly adjust the wind speed, sand and dust concentration, and different charge levels. The DC discharge experiment of rod-to-plate and rod-to-rod long air gaps under sand and dust conditions was conducted at an altitude of 3000 m. The results show that within the range of 1 to 3 m, under the condition of the wind speed, particle size, salt content and dust charge, sand dust have no significant effect on the DC breakdown voltage of the long air gap of the rod-plate and rod-rod. The research results in this paper provide technical reference for the design of transmission and transformation engineering and later operation and maintenance.