Epoxy resin insulator surface charge dissipation characteristics coating with different TiO2 content

Summary

Charge accumulation and dissipation on the epoxy resin insulator surface directly affects its creepage flashover voltage under the DC high voltage. It is one of the key issues to be solved urgently in the DC high voltage gas insulated transmission line design and manufacture. As a modification method, epoxy resin with nano particles composite coating can regulate the surface state and change the dynamic characteristic of surface charge. In this paper, with epoxy resin as matrix material, and 10nm TiO2/EP composite coating as substrate surface modification technology, charge dissipation characteristics of epoxy resin coating with different TiO2 nano particles concentration had been studied by the isothermal surface potential decay method. Results show that, comparing to the matrix material without coating, the charge dissipation rate was slower when TiO2 particles concentration in the coating was 0.2~1wt%. However, when TiO2 concentration was between 2wt% and 4wt%, the charge dissipation rate had been increased by 23.13% to 68.29% than the matrix material. When the TiO2 concentration reached 5wt% and 7wt%, the charge dissipation rate was only 58.54% and 61.35% of the matrix material. And with the analysis of material trap characteristics, it had been found that, the surface trap parameters of samples were closely related to the TiO2 concentration in the coating. When the TiO2 concentration was between 2wt% and 4wt%, shallow traps were more than the matrix material by the nano coating, and deep traps were less. Compared with other TiO2 concentration, when the TiO2 concentration was 3wt% and 4wt%, the deep traps charge decay time constant was smaller. It can be concluded that, the specific concentration of TiO2 nano coating method can effectively improve the dissipation rate of insulator surface charge. The results in this paper can provide theoretical reference on the dc high voltage gas insulated transmission line insulator design and improvement.

Additional informations

Authors

PASSON, SCHIERDING, KATO, STIGLIANO, KOZAKO

Keywords

Charge accumulation and dissipation, epoxy resin insulator, creepage flashover, TiO2 coating