Study on the Effect of External DC Electric Field on the Distribution of Ions in Solution

Abstract

Corrosion of insulators is widespread in UHV DC transmission lines, which seriously affects the safe operation of transmission lines. In fact, the surface of the insulator's hardware will absorb water droplets, the electrochemical corrosion caused by this situation is the main reason for the corrosion of the insulator hardware. However, there are many different degrees of influencing factors in the corrosion process. The principle of DC electric field acceleration of hardware corrosion is not very clear. Therefore, this paper focuses on the effect of the applied DC electric field on the ions adsorbed on the surface of the hardware, and measures the migration of different types of ions in the solution under the action of the applied DC electric field at the same time. To this end, a simulation model of the adsorption of water droplets on the surface of the carbon steel under the action of a DC electric field and an experimental model of ion migration within the solution were established. Through the coupling of multiple physical fields, different levels of voltage gradients were established, and the influence of the DC electric field on the received voltage was established Thus, the influence of the applied DC electric field on the local concentration of the ionic solution and the influence of the applied DC electric field on the electrolyte current density are obtained. The simulation results show that there is a change in ion migration under the DC electric field. As the field strength increases, the change also increases. The applied DC electric field will increase the electrolyte current density, but as the voltage increases, the electrolyte current density remains the same. The change of the electrode surface dynamic parameters with the change of the applied DC electric field is not an important factor.