Molecular Dynamics Simulations of the Conductivity of Aqueous NaCl in the presence of Sucrose and Electric Fields

摘要

Various natural contamination components distributed on the surface of high-voltage insulators play important roles on the flashover hazard. Under the low humidity condition, the flashover voltage could be affected considerably by the sucrose contaminations. Molecular dynamics simulations have been carried out in order to reveal the microscopic mechanisms for the sucrose-involved flashover uptake. It is found that the diffusion of ions decreases significantly and thus the conductivity of aqueous medium is lowered apparently. In the presence of sucrose, the contact ion pairs formed between Na~+ and Cl~- ions are enhanced because both ions are less coordinated to water molecules. The influence of the external electric fields on the diffusion and conductivity were investigated as well. It is suggested that the sucrose contamination might lead to the uneven electric fields on the insulator surface.