Influence of surface contamination on electric field distribution of insulators

Atmospheric particle adsorption on insulator surfaces, coupled with humid environments, significantly affects contamination flashover, necessitating a clear understanding of the electric field distribution on insulator surfaces with adsorbed particles. This is crucial for accurately assessing insulator safety and informing critical decision-making. Although previous research has demonstrated that particle arrangement significantly influences the electric field distribution around transmission lines, an in-depth analysis of its effects on insulator surfaces remains lacking. To address this gap, this study establishes a composite insulator model to examine how three types of spherical contamination layers affect the electric field distribution on insulator surfaces under varying environmental conditions. The results reveal that in dry environments, the electric field strength at the apex of single-particle contamination layers increases with the particle size and relative permittivity. For the double-particle contamination layers, the electric field intensity on the insulator surface decreases as the particle spacing increases, and larger particles are more likely to attract smaller charged particles. For triple-particle contamination layers arranged in a triangular pattern, the maximum surface field strength is nearly double that of the chain-arranged particles. Furthermore, within the chain-arranged triple-particle contamination layers, a large–small–large size arrangement has a more pronounced impact on the surface electric field than a small–large–small size arrangement. In humid environments, the surface electric field strength of insulators decreases with increasing contamination levels. These findings are of significant theoretical and practical importance for ensuring the safe operation of power systems.