Electric Field Simulation of Permittivity and Conductivity Graded Materials (e/s-FGM) for HVDC GIS Spacers

This paper discusses the application of the novel technology - functionally graded material (FGM), which combines both spatial permittivity (epsilon) and conductivity (sigma) distributions with the aim to control the electric field around DC-GIS spacer. Some distribution types of epsilon and/or sigma in the spacer bulk, such as U-type and graded to higher conductivity (GHC) are investigated through electric field simulation, in comparison to the uniform spacer with constant epsilon and sigma distributions. The electric field relaxation effect of each distribution type of epsilon/sigma-FGM under DC steady state, DC polarity reversal, DC-on, and lightning impulse voltage superimposed on DC steady state condition are obtained. The results show that epsilon/sigma-FGM with U-type permittivity and GHC-type conductivity distribution of which low s is applied near the high voltage side of the DC-GIS spacer is the most effective in reducing the maximum electric field under all stated conditions.

Automated summary

This paper discusses the application of functionally graded materials in controlling electric fields, and finds that FGM with U-type permittivity and GHC-type conductivity distribution is the most effective in reducing maximum electric field strength.