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.

中文翻译：

---

HVDC GIS间隔物的介电常数和电导率梯度材料（ε/σ-FGM）的电场模拟

本文讨论了新技术的应用-功能梯度材料（FGM），该技术结合了空间介电常数（ε）和电导率（σ）分布，旨在控制DC-GIS垫片周围的电场。与具有恒定ε和σ分布的均匀垫片相比，通过电场模拟研究了垫片主体中ε和/或σ的一些分布类型，例如U型和分级为较高电导率（GHC）。在直流稳态，直流极性反转，直流导通和雷电冲击电压叠加在直流稳态条件下，获得了每种分布类型的ε/σ-FGM的电场缓和效果。