Surface Charge Inversion Method on Cylindrical Insulators Based on Surface Potentials Measured Online

In this paper, a model of the Kelvin probe is established in COMSOL Multiphysics based on electrostatic field theory, and it is verified by measuring the surface potentials. The influence of the probe is also investigated. An improved charge inversion method based on surface potentials measured online is proposed. The surface charge density is directly obtained by the Gauss's theorem to avoid the calculation of the inversion matrix. The improved method is verified by comparing the surface charge density calculated by the analytical method. When considering the effect of the probe, the maximum difference in surface charge density is 0.3 μC/m
²
comparing to that when ignoring its effect, and the percentage of the difference is as high as 41%. The results indicate that the effects of the voltage of the probe under online measurement conditions must be considered.