A single-electron tunneling model: a theoretical analysis of a metal nanoparticle-doped epoxy resin to suppress surface charge accumulation on insulators subjected to DC voltages

In high-voltage direct current transmission systems, charges accumulate at the gas-solid interface, distorting the local field strength, causing a reduction in the flashover voltage, and threatening the safe and reliable operation of the power system. The latest research has found that doping metal nanoparticles into an epoxy resin effectively suppresses the surface charge accumulation on insulators and improves their flashover voltage. This paper further analyzes the microscopic mechanism of this phenomenon, establishes a single-electron tunneling mode, and draws two conclusions: when there is no agglomeration of the doped nanoparticles, a higher doping concentration can be achieved, which provides a better insulative performance. The optimal metal nanoparticle radius is several to tens of nanometers. This work provides theoretical guidance for the future improvement of insulating materials through metal nanoparticle doping and has good prospects in engineering applications.