Numerical Simulation of Influence of Dust on Electric Field Distribution of Insulators in Northwest China

Abstract

UHV DC transmission lines have large transmission capacity and have networking functions. Large-scale use of insulators in DC UHV lines is an significant part of ensuring the safe and stable operation of transmission lines. Once a pollution flashover occurs, the losses will be huge. The northwestern region has the characteristics of frequent sand and dust weather and high wind speed. In the sand and dust weather, pollution flashovers and other accidents may occur, causing large-scale blackouts and train delays. In response to the above problems, with the sand and dust environment in Xinjiang Uygur Autonomous Region and Qinghai province as the background, the impact of sand and dust on the electric field distribution of insulators under DC field was studied, and a numerical simulation model of insulator operating characteristics under wind and sand environment was established to analyze wind speed, particle size and concentration of sand dust. The influence of peripheral flow field on the pressure and electric field distribution of composite insulators. The study found that wind and sand have a significant impact on the electric field and potential distribution along the insulator. In a dusty environment, the electric field along the shed at both ends of the insulator is still the largest, and the particle charging makes the electric field at both ends increase, and the field strength distortion intensity near the middle shed Compared with the same position in a clean environment, the field strength value becomes lower; the arc is prone to occur at the high voltage end during sandstorm, and the increase of dust particles can directly distort the field strength along the surface; the effect of wind speed on the surface pressure of the insulator is obvious. With the increase of particle size and concentration, its effect on surface pressure tends to be stable. Severe electric field distortion may cause the insulation performance of insulators to fail. Therefore, it is necessary to pay attention to the influence of wind and sand on the electric field changes of insulators during power grid operation to prevent pollution flashover caused by this.