The Influence of Charged Sand Particles on the External Insulation Performance of Composite Insulators in Sandstorm Condition

In sandstorm condition, sand particles with different size collide with each other, resulting in electrification of sand particles and a strong electric field will form. When the charged sand particles move to the neighborhood of line insulators, they will impact the external insulation performance of line insulators. In this paper, electric field distribution of composite insulators with the existence of charged sand particles is calculated by means of finite element method. The result indicates that charged sand particles distort the electric field distribution around insulators obviously; the degree of aberration varies with the amount of charge that the sand particles take; when charged sand particles suspend on the surface of sheds or sheaths, these parts will bear very high field stress; when the charge-to-mass ratio of charged sand particles reaches a certain extent, corona discharge will happen in the ambient air, this will accelerate the ageing of composite insulators