@article{oai:nagoya.repo.nii.ac.jp:02001695,
 author = {Rachmawati and Kojima, Hiroki and Hayakawa, Naoki and Kato, Katsumi and Zebouchi, Nabila},
 issue = {2},
 journal = {IEEE Transactions on Dielectrics and Electrical Insulation},
 month = {Apr},
 note = {This paper discusses the application of the novel technology - functionally graded material (FGM), which combines both spatial permittivity (ε) and conductivity (σ) distributions with the aim to control the electric field around DC-GIS spacer. Some distribution types of ε and/or σ 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 ε and σ distributions. The electric field relaxation effect of each distribution type of ε/σ-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 ε/σ-FGM with U-type permittivity and GHC-type conductivity distribution of which low σ 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.},
 pages = {736--744},
 title = {Electric Field Simulation of Permittivity and Conductivity Graded Materials (ε/σ-FGM) for HVDC GIS Spacers},
 volume = {28},
 year = {2021}
}